Merge pull request #17 from overleaf/swapstore

v0.5: Upgrade deps, huge refactor, swap store

services/git-bridge/.gitignore

@@ -1,6 +1,11 @@
 # Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
 # Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
 
+# Let's not share anything because we're using Maven.
+
+.idea
+*.iml
+
 # User-specific stuff:
 .idea/workspace.xml
 .idea/tasks.xml

services/git-bridge/.idea/compiler.xml

@@ -1,32 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="CompilerConfiguration">
-    <resourceExtensions />
-    <wildcardResourcePatterns>
-      <entry name="!?*.java" />
-      <entry name="!?*.form" />
-      <entry name="!?*.class" />
-      <entry name="!?*.groovy" />
-      <entry name="!?*.scala" />
-      <entry name="!?*.flex" />
-      <entry name="!?*.kt" />
-      <entry name="!?*.clj" />
-      <entry name="!?*.aj" />
-    </wildcardResourcePatterns>
-    <annotationProcessing>
-      <profile default="true" name="Default" enabled="false">
-        <processorPath useClasspath="true" />
-      </profile>
-      <profile default="false" name="Maven default annotation processors profile" enabled="true">
-        <sourceOutputDir name="target/generated-sources/annotations" />
-        <sourceTestOutputDir name="target/generated-test-sources/test-annotations" />
-        <outputRelativeToContentRoot value="true" />
-        <processorPath useClasspath="true" />
-        <module name="writelatex-git-bridge" />
-      </profile>
-    </annotationProcessing>
-    <bytecodeTargetLevel>
-      <module name="writelatex-git-bridge" target="1.8" />
-    </bytecodeTargetLevel>
-  </component>
-</project>

services/git-bridge/.idea/copyright/profiles_settings.xml

@@ -1,3 +0,0 @@
-<component name="CopyrightManager">
-  <settings default="" />
-</component>

services/git-bridge/.idea/encodings.xml

@@ -1,7 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="Encoding">
-    <file url="file://$PROJECT_DIR$" charset="UTF-8" />
-    <file url="PROJECT" charset="UTF-8" />
-  </component>
-</project>

services/git-bridge/.idea/misc.xml

@@ -1,42 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="EntryPointsManager">
-    <entry_points version="2.0" />
-  </component>
-  <component name="MavenProjectsManager">
-    <option name="originalFiles">
-      <list>
-        <option value="$PROJECT_DIR$/pom.xml" />
-      </list>
-    </option>
-  </component>
-  <component name="ProjectLevelVcsManager" settingsEditedManually="false">
-    <OptionsSetting value="true" id="Add" />
-    <OptionsSetting value="true" id="Remove" />
-    <OptionsSetting value="true" id="Checkout" />
-    <OptionsSetting value="true" id="Update" />
-    <OptionsSetting value="true" id="Status" />
-    <OptionsSetting value="true" id="Edit" />
-    <ConfirmationsSetting value="0" id="Add" />
-    <ConfirmationsSetting value="0" id="Remove" />
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
-    <output url="file://$PROJECT_DIR$/out" />
-  </component>
-  <component name="masterDetails">
-    <states>
-      <state key="ProjectJDKs.UI">
-        <settings>
-          <last-edited>1.8</last-edited>
-          <splitter-proportions>
-            <option name="proportions">
-              <list>
-                <option value="0.2" />
-              </list>
-            </option>
-          </splitter-proportions>
-        </settings>
-      </state>
-    </states>
-  </component>
-</project>

services/git-bridge/.idea/modules.xml

@@ -1,8 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="ProjectModuleManager">
-    <modules>
-      <module fileurl="file://$PROJECT_DIR$/writelatex-git-bridge.iml" filepath="$PROJECT_DIR$/writelatex-git-bridge.iml" />
-    </modules>
-  </component>
-</project>

services/git-bridge/README.md

@@ -3,9 +3,23 @@ writelatex-git-bridge
 
 Required
 --------
-  * `maven` (for building)
+  * `maven` (for building, running tests and packaging)
   * `jdk-8` (for compiling and running)
 
+Commands
+--------
+
+To be run from the base directory:
+
+**Build jar**:
+`mvn package`
+
+**Run tests**:
+`mvn test`
+
+**Clean**:
+`mvn clean`
+
 Installation
 ------------
 
@@ -32,16 +46,46 @@ The configuration file is in `.json` format.
 
     {
         "port" (int): the port number,
-        "rootGitDirectory" (string): the directory in which to store git repos and the db/atts,
+        "rootGitDirectory" (string): the directory in which to store
+                                     git repos and the db/atts,
         "apiBaseUrl" (string): base url for the snapshot api,
         "username" (string, optional): username for http basic auth,
         "password" (string, optional): password for http basic auth,
         "postbackBaseUrl" (string): the postback url,
-        "serviceName" (string): current name of writeLaTeX in case it ever changes
-        "oauth2" (object): { /* null or missing if oauth2 shouldn't be used */
-            "oauth2ClientID" (string): oauth2 client ID
-            "oauth2ClientSecret" (string): oauth2 client secret
-            "oauth2Server" (string): oauth2 server, with protocol and without trailing slash
+        "serviceName" (string): current name of writeLaTeX
+                                in case it ever changes,
+        "oauth2" (object): { null or missing if oauth2 shouldn't be used
+            "oauth2ClientID" (string): oauth2 client ID,
+            "oauth2ClientSecret" (string): oauth2 client secret,
+            "oauth2Server" (string): oauth2 server,
+                                     with protocol and
+                                     without trailing slash
+        },
+        "swapStore" (object, optional): { the place to swap projects to.
+                                          if null, type defaults to
+                                          "noop"
+            "type" (string): "s3", "memory", "noop" (not recommended),
+            "awsAccessKey" (string, optional): only for s3,
+            "awsSecret" (string, optional): only for s3,
+            "s3BucketName" (string, optional): only for s3
+        },
+        "swapJob" (object, optional): { configure the project
+                                        swapping job.
+                                        if null, defaults to no-op
+            "minProjects" (int64): lower bound on number of projects
+                                   present. The swap job will never go
+                                   below this, regardless of what the
+                                   watermark shows. Regardless, if
+                                   minProjects prevents an eviction,
+                                   the swap job will WARN,
+            "lowGiB" (int32): the low watermark for swapping,
+                              i.e. swap until disk usage is below this,
+            "highGiB" (int32): the high watermark for swapping,
+                               i.e. start swapping when
+                               disk usage becomes this,
+            "intervalMillis" (int64): amount of time in between running
+                                      swap job and checking watermarks.
+                                      3600000 is 1 hour
         }
     }
 

services/git-bridge/conf/example_config.json

@@ -0,0 +1,26 @@
+{
+    "port": 8080,
+    "rootGitDirectory": "/tmp/wlgb",
+    "apiBaseUrl": "https://localhost/api/v0",
+    "username": "user",
+    "password": "pass",
+    "postbackBaseUrl": "https://localhost",
+    "serviceName": "Overleaf",
+    "oauth2": {
+        "oauth2ClientID": "asdf",
+        "oauth2ClientSecret": "asdf",
+        "oauth2Server": "https://localhost"
+    },
+    "swapStore": {
+        "type": "s3",
+        "awsAccessKey": "asdf",
+        "awsSecret": "asdf",
+        "s3BucketName": "com.overleaf.testbucket"
+    },
+    "swapJob": {
+        "minProjects": 50,
+        "lowGiB": 128,
+        "highGiB": 256,
+        "intervalMillis": 3600000
+    }
+}

services/git-bridge/newrelic.yml

@@ -0,0 +1,300 @@
+# This file configures the New Relic Agent.  New Relic monitors
+# Java applications with deep visibility and low overhead.  For more details and additional
+# configuration options visit https://docs.newrelic.com/docs/java/java-agent-configuration.
+#
+# This configuration file is custom generated for Winston
+#
+# This section is for settings common to all environments.
+# Do not add anything above this next line.
+common: &default_settings
+
+  # ============================== LICENSE KEY ===============================
+  # You must specify the license key associated with your New Relic
+  # account. For example, if your license key is 12345 use this:
+  # license_key: '12345'
+  # The key binds your Agent's data to your account in the New Relic service.
+  license_key: '<LICENSE KEY>'
+
+  # Agent Enabled
+  # Use this setting to disable the agent instead of removing it from the startup command.
+  # Default is true.
+  agent_enabled: true
+
+  # Set the name of your application as you'd like it show up in New Relic.
+  # If enable_auto_app_naming is false, the agent reports all data to this application.
+  # Otherwise, the agent reports only background tasks (transactions for non-web applications)
+  # to this application. To report data to more than one application 
+  # (useful for rollup reporting), separate the application names with ";".
+  # For example, to report data to "My Application" and "My Application 2" use this:
+  # app_name: My Application;My Application 2
+  # This setting is required. Up to 3 different application names can be specified.
+  # The first application name must be unique.
+  app_name: Git Bridge
+
+  # To enable high security, set this property to true. When in high
+  # security mode, the agent will use SSL and obfuscated SQL. Additionally,
+  # request parameters and message parameters will not be sent to New Relic.
+  high_security: false
+
+  # Set to true to enable support for auto app naming.
+  # The name of each web app is detected automatically
+  # and the agent reports data separately for each one.
+  # This provides a finer-grained performance breakdown for
+  # web apps in New Relic.
+  # Default is false.
+  enable_auto_app_naming: false
+
+  # Set to true to enable component-based transaction naming.
+  # Set to false to use the URI of a web request as the name of the transaction.
+  # Default is true.
+  enable_auto_transaction_naming: true
+
+  # The agent uses its own log file to keep its logging
+  # separate from that of your application.  Specify the log level here.
+  # This setting is dynamic, so changes do not require restarting your application.
+  # The levels in increasing order of verboseness are:
+  #   off, severe, warning, info, fine, finer, finest
+  # Default is info.
+  log_level: info
+
+  # Log all data sent to and from New Relic in plain text.
+  # This setting is dynamic, so changes do not require restarting your application.
+  # Default is false.
+  audit_mode: false
+
+  # The number of backup log files to save.
+  # Default is 1.
+  log_file_count: 1
+
+  # The maximum number of kbytes to write to any one log file.
+  # The log_file_count must be set greater than 1.
+  # Default is 0 (no limit).
+  log_limit_in_kbytes: 0
+
+  # Override other log rolling configuration and roll the logs daily.
+  # Default is false.
+  log_daily: false
+
+  # The name of the log file.
+  # Default is newrelic_agent.log.
+  log_file_name: newrelic_agent.log
+
+  # The log file directory.
+  # Default is the logs directory in the newrelic.jar parent directory.
+  #log_file_path:
+
+  # The agent communicates with New Relic via https by
+  # default.  If you want to communicate with newrelic via http,
+  # then turn off SSL by setting this value to false.
+  # This work is done asynchronously to the threads that process your
+  # application code, so response times will not be directly affected
+  # by this change.
+  # Default is true.
+  ssl: true
+
+  # Proxy settings for connecting to the New Relic server:
+  # If a proxy is used, the host setting is required.  Other settings
+  # are optional.  Default port is 8080.  The username and password
+  # settings will be used to authenticate to Basic Auth challenges
+  # from a proxy server.
+  #proxy_host: hostname
+  #proxy_port: 8080
+  #proxy_user: username
+  #proxy_password: password
+
+  # Limits the number of lines to capture for each stack trace. 
+  # Default is 30
+  max_stack_trace_lines: 30
+
+  # Provides the ability to configure the attributes sent to New Relic. These
+  # attributes can be found in transaction traces, traced errors, Insight's 
+  # transaction events, and Insight's page views.
+  attributes:
+  
+    # When true, attributes will be sent to New Relic. The default is true.
+    enabled: true
+    
+    #A comma separated list of attribute keys whose values should 
+    # be sent to New Relic.
+    #include:
+    
+    # A comma separated list of attribute keys whose values should 
+    # not be sent to New Relic.
+    #exclude:
+    
+
+  # Transaction tracer captures deep information about slow
+  # transactions and sends this to the New Relic service once a
+  # minute. Included in the transaction is the exact call sequence of
+  # the transactions including any SQL statements issued.
+  transaction_tracer:
+
+    # Transaction tracer is enabled by default. Set this to false to turn it off.
+    # This feature is not available to Lite accounts and is automatically disabled.
+    # Default is true.
+    enabled: true
+
+    # Threshold in seconds for when to collect a transaction
+    # trace. When the response time of a controller action exceeds
+    # this threshold, a transaction trace will be recorded and sent to
+    # New Relic. Valid values are any float value, or (default) "apdex_f",
+    # which will use the threshold for the "Frustrated" Apdex level
+    # (greater than four times the apdex_t value).
+    # Default is apdex_f.
+    transaction_threshold: apdex_f
+
+    # When transaction tracer is on, SQL statements can optionally be
+    # recorded. The recorder has three modes, "off" which sends no
+    # SQL, "raw" which sends the SQL statement in its original form,
+    # and "obfuscated", which strips out numeric and string literals.
+    # Default is obfuscated.
+    record_sql: obfuscated
+
+    # Set this to true to log SQL statements instead of recording them.
+    # SQL is logged using the record_sql mode.
+    # Default is false.
+    log_sql: false
+
+    # Threshold in seconds for when to collect stack trace for a SQL
+    # call. In other words, when SQL statements exceed this threshold,
+    # then capture and send to New Relic the current stack trace. This is
+    # helpful for pinpointing where long SQL calls originate from.
+    # Default is 0.5 seconds.
+    stack_trace_threshold: 0.5
+
+    # Determines whether the agent will capture query plans for slow
+    # SQL queries. Only supported for MySQL and PostgreSQL.
+    # Default is true.
+    explain_enabled: true
+
+    # Threshold for query execution time below which query plans will not 
+    # not be captured.  Relevant only when `explain_enabled` is true.
+    # Default is 0.5 seconds.
+    explain_threshold: 0.5
+
+    # Use this setting to control the variety of transaction traces.
+    # The higher the setting, the greater the variety.
+    # Set this to 0 to always report the slowest transaction trace.
+    # Default is 20.
+    top_n: 20
+
+  # Error collector captures information about uncaught exceptions and
+  # sends them to New Relic for viewing.
+  error_collector:
+
+    # This property enables the collection of errors. If the property is not
+    # set or the property is set to false, then errors will not be collected.
+    # Default is true.
+    enabled: true
+
+    # Use this property to exclude specific exceptions from being reported as errors
+    # by providing a comma separated list of full class names.
+    # The default is to exclude akka.actor.ActorKilledException. If you want to override
+    # this, you must provide any new value as an empty list is ignored.
+    ignore_errors: akka.actor.ActorKilledException
+
+    # Use this property to exclude specific http status codes from being reported as errors
+    # by providing a comma separated list of status codes.
+    # The default is to exclude 404s. If you want to override
+    # this, you must provide any new value as an empty list is ignored.
+    ignore_status_codes: 404
+
+  # Transaction Events are used for Histograms and Percentiles. Unaggregated data is collected
+  # for each web transaction and sent to the server on harvest. 
+  transaction_events:
+
+    # Set to false to disable transaction events.
+    # Default is true.
+    enabled: true
+
+    # Events are collected up to the configured amount. Afterwards, events are sampled to
+    # maintain an even distribution across the harvest cycle.
+    # Default is 2000.  Setting to 0 will disable.
+    max_samples_stored: 2000
+
+  # Cross Application Tracing adds request and response headers to
+  # external calls using supported HTTP libraries to provide better
+  # performance data when calling applications monitored by other New Relic Agents.
+  cross_application_tracer:
+
+    # Set to false to disable cross application tracing.
+    # Default is true.
+    enabled: true
+
+  # Thread profiler measures wall clock time, CPU time, and method call counts
+  # in your application's threads as they run.
+  # This feature is not available to Lite accounts and is automatically disabled.
+  thread_profiler:
+
+    # Set to false to disable the thread profiler.
+    # Default is true.
+    enabled: true
+
+  # New Relic Real User Monitoring gives you insight into the performance real users are
+  # experiencing with your website. This is accomplished by measuring the time it takes for
+  # your users' browsers to download and render your web pages by injecting a small amount
+  # of JavaScript code into the header and footer of each page. 
+  browser_monitoring:
+
+    # By default the agent automatically inserts API calls in compiled JSPs to
+    # inject the monitoring JavaScript into web pages. Not all rendering engines are supported.
+    # See https://docs.newrelic.com/docs/java/real-user-monitoring-in-java#manual_instrumentation
+    # for instructions to add these manually to your pages.
+    # Set this attribute to false to turn off this behavior.
+    auto_instrument: true
+
+  class_transformer:
+    # This instrumentation reports the name of the user principal returned from 
+    # HttpServletRequest.getUserPrincipal() when servlets and filters are invoked.
+    com.newrelic.instrumentation.servlet-user:
+      enabled: false
+
+    com.newrelic.instrumentation.spring-aop-2:
+      enabled: false
+
+    # Classes loaded by classloaders in this list will not be instrumented.
+    # This is a useful optimization for runtimes which use classloaders to
+    # load dynamic classes which the agent would not instrument.
+    classloader_excludes:
+      groovy.lang.GroovyClassLoader$InnerLoader,
+      org.codehaus.groovy.runtime.callsite.CallSiteClassLoader,
+      com.collaxa.cube.engine.deployment.BPELClassLoader,
+      org.springframework.data.convert.ClassGeneratingEntityInstantiator$ObjectInstantiatorClassGenerator,
+      org.mvel2.optimizers.impl.asm.ASMAccessorOptimizer$ContextClassLoader,
+      gw.internal.gosu.compiler.SingleServingGosuClassLoader,
+
+  # User-configurable custom labels for this agent.  Labels are name-value pairs.
+  # There is a maximum of 64 labels per agent.  Names and values are limited to 255 characters.
+  # Names and values may not contain colons (:) or semicolons (;).
+  labels:
+
+    # An example label
+    #label_name: label_value
+
+
+# Application Environments
+# ------------------------------------------
+# Environment specific settings are in this section.
+# You can use the environment to override the default settings.
+# For example, to change the app_name setting.
+# Use -Dnewrelic.environment=<environment> on the Java startup command line
+# to set the environment.
+# The default environment is production.
+
+# NOTE if your application has other named environments, you should
+# provide configuration settings for these environments here.
+
+development:
+  <<: *default_settings
+  app_name: Git Bridge (Development)
+
+test:
+  <<: *default_settings
+  app_name: Git Bridge (Test)
+
+production:
+  <<: *default_settings
+
+staging:
+  <<: *default_settings
+  app_name: Git Bridge (Staging)

services/git-bridge/pom.xml

@@ -140,5 +140,29 @@
             <artifactId>mockito-core</artifactId>
             <version>1.10.19</version>
         </dependency>
+        <!-- https://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk -->
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-java-sdk</artifactId>
+            <version>1.11.28</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+            <version>4.5.2</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/commons-io/commons-io -->
+        <dependency>
+            <groupId>commons-io</groupId>
+            <artifactId>commons-io</artifactId>
+            <version>2.5</version>
+        </dependency>
+        <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-compress -->
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-compress</artifactId>
+            <version>1.12</version>
+        </dependency>
     </dependencies>
 </project>

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/application/GitBridgeApp.java

@@ -22,10 +22,10 @@ public class GitBridgeApp implements Runnable {
 
     public static final int EXIT_CODE_FAILED = 1;
     private static final String USAGE_MESSAGE =
-            "usage: writelatex-git-bridge config_file";
+            "usage: writelatex-git-bridge [config_file]";
 
     private String configFilePath;
-    private Config config;
+    Config config;
     private GitBridgeServer server;
 
     /**

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/application/config/Config.java

@@ -4,12 +4,16 @@ import com.google.gson.Gson;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import uk.ac.ic.wlgitbridge.application.exception.ConfigFileException;
+import uk.ac.ic.wlgitbridge.bridge.swap.job.SwapJobConfig;
+import uk.ac.ic.wlgitbridge.bridge.swap.store.SwapStoreConfig;
 import uk.ac.ic.wlgitbridge.snapshot.base.JSONSource;
 import uk.ac.ic.wlgitbridge.util.Instance;
 
+import javax.annotation.Nullable;
 import java.io.FileReader;
 import java.io.IOException;
 import java.io.Reader;
+import java.util.Optional;
 
 /**
  * Created by Winston on 05/12/14.
@@ -25,7 +29,9 @@ public class Config implements JSONSource {
                 config.apiBaseURL,
                 config.postbackURL,
                 config.serviceName,
-                Oauth2.asSanitised(config.oauth2)
+                Oauth2.asSanitised(config.oauth2),
+                SwapStoreConfig.sanitisedCopy(config.swapStore),
+                config.swapJob
         );
     }
 
@@ -36,7 +42,12 @@ public class Config implements JSONSource {
     private String apiBaseURL;
     private String postbackURL;
     private String serviceName;
+    @Nullable
     private Oauth2 oauth2;
+    @Nullable
+    private SwapStoreConfig swapStore;
+    @Nullable
+    private SwapJobConfig swapJob;
 
     public Config(String configFilePath) throws ConfigFileException,
                                                 IOException {
@@ -47,14 +58,18 @@ public class Config implements JSONSource {
         fromJSON(new Gson().fromJson(reader, JsonElement.class));
     }
 
-    public Config(int port,
-                  String rootGitDirectory,
-                  String username,
-                  String password,
-                  String apiBaseURL,
-                  String postbackURL,
-                  String serviceName,
-                  Oauth2 oauth2) {
+    public Config(
+            int port,
+            String rootGitDirectory,
+            String username,
+            String password,
+            String apiBaseURL,
+            String postbackURL,
+            String serviceName,
+            Oauth2 oauth2,
+            SwapStoreConfig swapStore,
+            SwapJobConfig swapJob
+    ) {
         this.port = port;
         this.rootGitDirectory = rootGitDirectory;
         this.username = username;
@@ -63,6 +78,8 @@ public class Config implements JSONSource {
         this.postbackURL = postbackURL;
         this.serviceName = serviceName;
         this.oauth2 = oauth2;
+        this.swapStore = swapStore;
+        this.swapJob = swapJob;
     }
 
     @Override
@@ -89,6 +106,14 @@ public class Config implements JSONSource {
             postbackURL += "/";
         }
         oauth2 = new Gson().fromJson(configObject.get("oauth2"), Oauth2.class);
+        swapStore = new Gson().fromJson(
+                configObject.get("swapStore"),
+                SwapStoreConfig.class
+        );
+        swapJob = new Gson().fromJson(
+                configObject.get("swapJob"),
+                SwapJobConfig.class
+        );
     }
 
     public String getSanitisedString() {
@@ -134,6 +159,14 @@ public class Config implements JSONSource {
         return oauth2;
     }
 
+    public Optional<SwapStoreConfig> getSwapStore() {
+        return Optional.ofNullable(swapStore);
+    }
+
+    public Optional<SwapJobConfig> getSwapJob() {
+        return Optional.ofNullable(swapJob);
+    }
+
     private JsonElement getElement(JsonObject configObject, String name) {
         JsonElement element = configObject.get(name);
         if (element == null) {

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/Bridge.java

@@ -3,15 +3,17 @@ package uk.ac.ic.wlgitbridge.bridge;
 import com.google.api.client.auth.oauth2.Credential;
 import org.eclipse.jgit.transport.ServiceMayNotContinueException;
 import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
+import uk.ac.ic.wlgitbridge.bridge.db.ProjectState;
+import uk.ac.ic.wlgitbridge.bridge.lock.LockGuard;
 import uk.ac.ic.wlgitbridge.bridge.lock.ProjectLock;
 import uk.ac.ic.wlgitbridge.bridge.repo.RepoStore;
 import uk.ac.ic.wlgitbridge.bridge.resource.ResourceCache;
 import uk.ac.ic.wlgitbridge.bridge.resource.UrlResourceCache;
 import uk.ac.ic.wlgitbridge.bridge.snapshot.NetSnapshotAPI;
 import uk.ac.ic.wlgitbridge.bridge.snapshot.SnapshotAPI;
-import uk.ac.ic.wlgitbridge.bridge.swap.SwapJob;
-import uk.ac.ic.wlgitbridge.bridge.swap.SwapJobImpl;
-import uk.ac.ic.wlgitbridge.bridge.swap.SwapStore;
+import uk.ac.ic.wlgitbridge.bridge.swap.job.SwapJob;
+import uk.ac.ic.wlgitbridge.bridge.swap.job.SwapJobConfig;
+import uk.ac.ic.wlgitbridge.bridge.swap.store.SwapStore;
 import uk.ac.ic.wlgitbridge.data.CandidateSnapshot;
 import uk.ac.ic.wlgitbridge.data.ProjectLockImpl;
 import uk.ac.ic.wlgitbridge.data.filestore.GitDirectoryContents;
@@ -29,7 +31,10 @@ import uk.ac.ic.wlgitbridge.snapshot.push.PushResult;
 import uk.ac.ic.wlgitbridge.snapshot.push.exception.*;
 import uk.ac.ic.wlgitbridge.util.Log;
 
+import java.io.File;
 import java.io.IOException;
+import java.sql.Timestamp;
+import java.time.LocalDateTime;
 import java.util.*;
 
 /**
@@ -42,18 +47,19 @@ public class Bridge {
     private final RepoStore repoStore;
     private final DBStore dbStore;
     private final SwapStore swapStore;
+    private final SwapJob swapJob;
 
     private final SnapshotAPI snapshotAPI;
     private final ResourceCache resourceCache;
 
-    private final SwapJob swapJob;
 
     private final PostbackManager postbackManager;
 
     public static Bridge make(
             RepoStore repoStore,
             DBStore dbStore,
-            SwapStore swapStore
+            SwapStore swapStore,
+            Optional<SwapJobConfig> swapJobConfig
     ) {
         ProjectLock lock = new ProjectLockImpl((int threads) ->
                 Log.info("Waiting for " + threads + " projects...")
@@ -63,14 +69,15 @@ public class Bridge {
                 repoStore,
                 dbStore,
                 swapStore,
-                new NetSnapshotAPI(),
-                new UrlResourceCache(dbStore),
-                new SwapJobImpl(
+                SwapJob.fromConfig(
+                        swapJobConfig,
                         lock,
                         repoStore,
                         dbStore,
                         swapStore
-                )
+                ),
+                new NetSnapshotAPI(),
+                new UrlResourceCache(dbStore)
         );
     }
 
@@ -79,9 +86,9 @@ public class Bridge {
             RepoStore repoStore,
             DBStore dbStore,
             SwapStore swapStore,
+            SwapJob swapJob,
             SnapshotAPI snapshotAPI,
-            ResourceCache resourceCache,
-            SwapJob swapJob
+            ResourceCache resourceCache
     ) {
         this.lock = lock;
         this.repoStore = repoStore;
@@ -104,66 +111,140 @@ public class Bridge {
         Log.info("Bye");
     }
 
-    public void startSwapJob(int intervalMillis) {
-        swapJob.start(intervalMillis);
+    public void startSwapJob() {
+        swapJob.start();
     }
 
-    /* TODO: Remove these when WLBridged is moved into RepoStore */
-    public void lockForProject(String projectName) {
-        lock.lockForProject(projectName);
-    }
-
-    public void unlockForProject(String projectName) {
-        lock.unlockForProject(projectName);
+    public void checkDB() {
+        Log.info("Checking DB");
+        File rootDir = repoStore.getRootDirectory();
+        for (File f : rootDir.listFiles()) {
+            if (f.getName().equals(".wlgb")) {
+                continue;
+            }
+            String projName = f.getName();
+            try (LockGuard __ = lock.lockGuard(projName)) {
+                File dotGit = new File(f, ".git");
+                if (!dotGit.exists()) {
+                    Log.warn("Project: {} has no .git", projName);
+                    continue;
+                }
+                ProjectState state = dbStore.getProjectState(projName);
+                if (state != ProjectState.NOT_PRESENT) {
+                    continue;
+                }
+                Log.warn("Project: {} not in swap_store, adding", projName);
+                dbStore.setLastAccessedTime(
+                        projName,
+                        new Timestamp(dotGit.lastModified())
+                );
+            }
+        }
     }
 
-    public boolean repositoryExists(Credential oauth2, String projectName)
-            throws ServiceMayNotContinueException, GitUserException {
-        lockForProject(projectName);
-        GetDocRequest getDocRequest = new GetDocRequest(oauth2, projectName);
-        getDocRequest.request();
-        try {
+    public boolean projectExists(
+            Credential oauth2,
+            String projectName
+    ) throws ServiceMayNotContinueException,
+             GitUserException {
+        try (LockGuard __ = lock.lockGuard(projectName)) {
+            GetDocRequest getDocRequest = new GetDocRequest(
+                    oauth2,
+                    projectName
+            );
+            getDocRequest.request();
             getDocRequest.getResult().getVersionID();
+            return true;
         } catch (InvalidProjectException e) {
             return false;
-        } finally {
-            unlockForProject(projectName);
         }
-        return true;
     }
 
-    public void getWritableRepositories(
+    public void updateRepository(
             Credential oauth2,
             ProjectRepo repo
-    ) throws IOException,
-             GitUserException {
-        Log.info("[{}] Fetching", repo.getProjectName());
-        updateProjectWithName(oauth2, repo);
+    ) throws IOException, GitUserException {
+        String projectName = repo.getProjectName();
+        try (LockGuard __ = lock.lockGuard(projectName)) {
+            Log.info("[{}] Updating", projectName);
+            updateRepositoryCritical(oauth2, repo);
+        }
     }
 
-    public void
-    putDirectoryContentsToProjectWithName(Credential oauth2,
-                                          String projectName,
-                                          RawDirectory directoryContents,
-                                          RawDirectory oldDirectoryContents,
-                                          String hostname)
-            throws SnapshotPostException, IOException, ForbiddenException {
-        lock.lockForProject(projectName);
-        CandidateSnapshot candidate = null;
-        try {
-            Log.info("[{}] Pushing", projectName);
-            String postbackKey = postbackManager.makeKeyForProject(projectName);
-            Log.info(
-                    "[{}] Created postback key: {}",
+    private void updateRepositoryCritical(
+            Credential oauth2,
+            ProjectRepo repo
+    ) throws IOException, GitUserException {
+        String projectName = repo.getProjectName();
+        ProjectState state = dbStore.getProjectState(projectName);
+        switch (state) {
+        case NOT_PRESENT:
+            repo.initRepo(repoStore);
+            break;
+        case SWAPPED:
+            swapJob.restore(projectName);
+            /* Fallthrough */
+        default:
+            repo.useExistingRepository(repoStore);
+        }
+        updateProject(oauth2, repo);
+        dbStore.setLastAccessedTime(
+                projectName,
+                Timestamp.valueOf(LocalDateTime.now())
+        );
+    }
+
+    public void putDirectoryContentsToProjectWithName(
+            Credential oauth2,
+            String projectName,
+            RawDirectory directoryContents,
+            RawDirectory oldDirectoryContents,
+            String hostname
+    ) throws SnapshotPostException, IOException, ForbiddenException {
+        try (LockGuard __ = lock.lockGuard(projectName)) {
+            pushToProjectCritical(
+                    oauth2,
                     projectName,
-                    postbackKey
+                    directoryContents,
+                    oldDirectoryContents
+            );
+        } catch (SevereSnapshotPostException e) {
+            Log.warn("[" + projectName + "] Failed to put to Overleaf", e);
+            throw e;
+        } catch (SnapshotPostException e) {
+            /* Stack trace should be printed further up */
+            Log.warn(
+                    "[{}] Exception when waiting for postback: {}",
+                    projectName,
+                    e.getClass().getSimpleName()
             );
-            candidate =
-                    createCandidateSnapshot(
-                            projectName,
-                            directoryContents,
-                            oldDirectoryContents
-                    );
+            throw e;
+        } catch (IOException e) {
+            Log.warn("[{}] IOException on put", projectName);
+            throw e;
+        }
+    }
+
+    private void pushToProjectCritical(
+            Credential oauth2,
+            String projectName,
+            RawDirectory directoryContents,
+            RawDirectory oldDirectoryContents
+    ) throws IOException, ForbiddenException, SnapshotPostException {
+        Log.info("[{}] Pushing", projectName);
+        String postbackKey = postbackManager.makeKeyForProject(projectName);
+        Log.info(
+                "[{}] Created postback key: {}",
+                projectName,
+                postbackKey
+        );
+        try (
+                CandidateSnapshot candidate = createCandidateSnapshot(
+                                projectName,
+                                directoryContents,
+                                oldDirectoryContents
+                );
+        ) {
             Log.info(
                     "[{}] Candindate snapshot created: {}",
                     projectName,
@@ -195,6 +276,10 @@ public class Bridge {
                         projectName,
                         versionID
                 );
+                dbStore.setLastAccessedTime(
+                        projectName,
+                        Timestamp.valueOf(LocalDateTime.now())
+                );
             } else {
                 Log.warn(
                         "[{}] Went out of date while waiting for push",
@@ -202,31 +287,6 @@ public class Bridge {
                 );
                 throw new OutOfDateException();
             }
-        } catch (SevereSnapshotPostException e) {
-            Log.warn("[" + projectName + "] Failed to put to Overleaf", e);
-            throw e;
-        } catch (SnapshotPostException e) {
-            /* Stack trace should be printed further up */
-            Log.warn(
-                    "[{}] Exception when waiting for postback: {}",
-                    projectName,
-                    e.getClass().getSimpleName()
-            );
-            throw e;
-        } catch (IOException e) {
-            Log.warn("[{}] IOException on put", projectName);
-            throw e;
-        } finally {
-            if (candidate != null) {
-                candidate.deleteServletFiles();
-            } else {
-                Log.error(
-                        "[{}] Candidate snapshot was null: " +
-                                "this should never happen.",
-                        projectName
-                );
-            }
-            lock.unlockForProject(projectName);
         }
     }
 
@@ -266,7 +326,7 @@ public class Bridge {
 
     /* PRIVATE */
 
-    private void updateProjectWithName(
+    private void updateProject(
             Credential oauth2,
             ProjectRepo repo
     ) throws IOException, GitUserException {

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/GitProjectRepo.java

@@ -1,33 +1,36 @@
 package uk.ac.ic.wlgitbridge.bridge;
 
+import com.google.common.base.Preconditions;
 import org.eclipse.jgit.api.Git;
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.storage.file.FileRepositoryBuilder;
+import uk.ac.ic.wlgitbridge.bridge.repo.RepoStore;
 import uk.ac.ic.wlgitbridge.data.filestore.GitDirectoryContents;
 import uk.ac.ic.wlgitbridge.data.filestore.RawFile;
 import uk.ac.ic.wlgitbridge.git.exception.GitUserException;
 import uk.ac.ic.wlgitbridge.git.util.RepositoryObjectTreeWalker;
 import uk.ac.ic.wlgitbridge.util.Log;
+import uk.ac.ic.wlgitbridge.util.Project;
 import uk.ac.ic.wlgitbridge.util.Util;
 
+import java.io.File;
 import java.io.IOException;
-import java.util.Collection;
-import java.util.Map;
-import java.util.Set;
-import java.util.TimeZone;
+import java.util.*;
 
 /**
  * Created by winston on 20/08/2016.
  */
 public class GitProjectRepo implements ProjectRepo {
 
-    private final Repository repository;
     private final String projectName;
+    private Optional<Repository> repository;
 
-    public GitProjectRepo(Repository repository, String projectName) {
-        this.repository = repository;
+    public GitProjectRepo(String projectName) {
+        Preconditions.checkArgument(Project.isValidProjectName(projectName));
         this.projectName = projectName;
+        repository = Optional.empty();
     }
 
     @Override
@@ -35,11 +38,34 @@ public class GitProjectRepo implements ProjectRepo {
         return projectName;
     }
 
+    @Override
+    public void initRepo(
+            RepoStore repoStore
+    ) throws IOException {
+        initRepositoryField(repoStore);
+        Preconditions.checkState(repository.isPresent());
+        Repository repo = this.repository.get();
+        Preconditions.checkState(!repo.getObjectDatabase().exists());
+        repo.create();
+    }
+
+    @Override
+    public void useExistingRepository(
+            RepoStore repoStore
+    ) throws IOException {
+        initRepositoryField(repoStore);
+        Preconditions.checkState(repository.isPresent());
+        Preconditions.checkState(
+                repository.get().getObjectDatabase().exists()
+        );
+    }
+
     @Override
     public Map<String, RawFile> getFiles()
             throws IOException, GitUserException {
+        Preconditions.checkState(repository.isPresent());
         return new RepositoryObjectTreeWalker(
-                repository
+                repository.get()
         ).getDirectoryContents().getFileTable();
     }
 
@@ -54,13 +80,33 @@ public class GitProjectRepo implements ProjectRepo {
         }
     }
 
+    public Repository getJGitRepository() {
+        return repository.get();
+    }
+
+    private void initRepositoryField(RepoStore repoStore) throws IOException {
+        Preconditions.checkNotNull(repoStore);
+        Preconditions.checkArgument(Project.isValidProjectName(projectName));
+        Preconditions.checkState(!repository.isPresent());
+        repository = Optional.of(createJGitRepository(repoStore, projectName));
+    }
+
+    private Repository createJGitRepository(
+            RepoStore repoStore,
+            String projName
+    ) throws IOException {
+        File repoDir = new File(repoStore.getRootDirectory(), projName);
+        return new FileRepositoryBuilder().setWorkTree(repoDir).build();
+    }
+
     private Collection<String> doCommitAndGetMissing(
             GitDirectoryContents contents
     ) throws IOException, GitAPIException {
+        Preconditions.checkState(repository.isPresent());
         String name = getProjectName();
         Log.info("[{}] Writing commit", name);
         contents.write();
-        Git git = new Git(repository);
+        Git git = new Git(repository.get());
         Log.info("[{}] Getting missing files", name);
         Set<String> missingFiles = git.status().call().getMissing();
         for (String missing : missingFiles) {

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/ProjectRepo.java

@@ -1,5 +1,6 @@
 package uk.ac.ic.wlgitbridge.bridge;
 
+import uk.ac.ic.wlgitbridge.bridge.repo.RepoStore;
 import uk.ac.ic.wlgitbridge.data.filestore.GitDirectoryContents;
 import uk.ac.ic.wlgitbridge.data.filestore.RawFile;
 import uk.ac.ic.wlgitbridge.git.exception.GitUserException;
@@ -15,6 +16,14 @@ public interface ProjectRepo {
 
     String getProjectName();
 
+    void initRepo(
+            RepoStore repoStore
+    ) throws IOException;
+
+    void useExistingRepository(
+            RepoStore repoStore
+    ) throws IOException;
+
     Map<String, RawFile> getFiles() throws IOException, GitUserException;
 
     Collection<String> commitAndGetMissing(

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/WLBridgedProject.java

@@ -1,73 +0,0 @@
-package uk.ac.ic.wlgitbridge.bridge;
-
-import com.google.api.client.auth.oauth2.Credential;
-import org.eclipse.jgit.errors.RepositoryNotFoundException;
-import org.eclipse.jgit.lib.Repository;
-import org.eclipse.jgit.transport.ServiceMayNotContinueException;
-import uk.ac.ic.wlgitbridge.git.exception.GitUserException;
-import uk.ac.ic.wlgitbridge.snapshot.getdoc.exception.InvalidProjectException;
-
-import java.io.IOException;
-
-/**
- * Created by Winston on 05/11/14.
- */
-public class WLBridgedProject {
-
-    private final Repository repository;
-    private final String name;
-    private final Bridge bridgeAPI;
-
-    public WLBridgedProject(Repository repository, String name, Bridge bridgeAPI) {
-        this.repository = repository;
-        this.name = name;
-        this.bridgeAPI = bridgeAPI;
-    }
-
-    public void buildRepository(Credential oauth2) throws RepositoryNotFoundException, ServiceMayNotContinueException, GitUserException {
-        bridgeAPI.lockForProject(name);
-        try {
-            if (repository.getObjectDatabase().exists()) {
-                updateRepositoryFromSnapshots(oauth2, repository);
-            } else {
-                buildRepositoryFromScratch(oauth2, repository);
-            }
-        } catch (RuntimeException e) {
-            e.printStackTrace();
-            throw new ServiceMayNotContinueException(e);
-        } finally {
-            bridgeAPI.unlockForProject(name);
-        }
-    }
-
-    private void updateRepositoryFromSnapshots(
-            Credential oauth2,
-            Repository repository
-    ) throws RepositoryNotFoundException,
-             ServiceMayNotContinueException,
-             GitUserException {
-        try {
-            bridgeAPI.getWritableRepositories(
-                    oauth2,
-                    new GitProjectRepo(repository, name)
-            );
-        } catch (InvalidProjectException e) {
-            throw new RepositoryNotFoundException(name);
-        } catch (IOException e) {
-            throw new ServiceMayNotContinueException(e);
-        }
-    }
-
-    private void buildRepositoryFromScratch(Credential oauth2, Repository repository) throws RepositoryNotFoundException, ServiceMayNotContinueException, GitUserException {
-        if (!bridgeAPI.repositoryExists(oauth2, name)) {
-            throw new RepositoryNotFoundException(name);
-        }
-        try {
-            repository.create();
-        } catch (IOException e) {
-            throw new ServiceMayNotContinueException(e);
-        }
-        updateRepositoryFromSnapshots(oauth2, repository);
-    }
-
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/DBInitException.java

@@ -0,0 +1,20 @@
+package uk.ac.ic.wlgitbridge.bridge.db;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class DBInitException extends RuntimeException {
+
+    public DBInitException(String message) {
+        super(message);
+    }
+
+    public DBInitException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public DBInitException(Throwable cause) {
+        super(cause);
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/DBStore.java

@@ -1,5 +1,6 @@
 package uk.ac.ic.wlgitbridge.bridge.db;
 
+import java.sql.Timestamp;
 import java.util.List;
 
 /**
@@ -7,6 +8,8 @@ import java.util.List;
  */
 public interface DBStore {
 
+    int getNumProjects();
+
     List<String> getProjectNames();
 
     void setLatestVersionForProject(String project, int versionID);
@@ -19,4 +22,17 @@ public interface DBStore {
 
     String getPathForURLInProject(String projectName, String url);
 
+    String getOldestUnswappedProject();
+
+    int getNumUnswappedProjects();
+
+    ProjectState getProjectState(String projectName);
+
+    /**
+     * Sets the last accessed time for the given project name.
+     * @param projectName the project's name
+     * @param time the time, or null if the project is to be swapped
+     */
+    void setLastAccessedTime(String projectName, Timestamp time);
+
 }

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/ProjectState.java

@@ -0,0 +1,12 @@
+package uk.ac.ic.wlgitbridge.bridge.db;
+
+/**
+ * Created by winston on 24/08/2016.
+ */
+public enum ProjectState {
+
+    NOT_PRESENT,
+    PRESENT,
+    SWAPPED
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/SqliteDBStore.java

@@ -1,87 +0,0 @@
-package uk.ac.ic.wlgitbridge.bridge.db;
-
-import uk.ac.ic.wlgitbridge.data.model.db.sql.SQLiteWLDatabase;
-import uk.ac.ic.wlgitbridge.util.Log;
-
-import java.io.File;
-import java.sql.SQLException;
-import java.util.Arrays;
-import java.util.List;
-
-/**
- * Created by winston on 20/08/2016.
- */
-public class SqliteDBStore implements DBStore {
-
-    private final SQLiteWLDatabase database;
-
-    public SqliteDBStore(File rootDirectory) {
-        try {
-            database = new SQLiteWLDatabase(rootDirectory);
-        } catch (SQLException e) {
-            throw new RuntimeException(e);
-        } catch (ClassNotFoundException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    @Override
-    public List<String> getProjectNames() {
-        try {
-            return database.getProjectNames();
-        } catch (SQLException e) {
-            throw new RuntimeException(e);
-        }
-    }
-    @Override
-    public void setLatestVersionForProject(String project, int versionID) {
-        try {
-            database.setVersionIDForProject(project, versionID);
-            Log.info("[{}] Wrote latest versionId: {}", project, versionID);
-        } catch (SQLException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    @Override
-    public int getLatestVersionForProject(String project) {
-        try {
-            return database.getVersionIDForProjectName(project);
-        } catch (SQLException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    @Override
-    public void addURLIndexForProject(String projectName, String url, String path) {
-        try {
-            database.addURLIndex(projectName, url, path);
-            Log.info("[{}] Wrote url index: {} -> {}", projectName, url, path);
-        } catch (SQLException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-    @Override
-    public void deleteFilesForProject(String project, String... files) {
-        try {
-            database.deleteFilesForProject(project, files);
-            Log.info(
-                    "[{}] Deleting from url index: {}",
-                    project,
-                    Arrays.toString(files)
-            );
-        } catch (SQLException e) {
-            throw new RuntimeException(e);
-        }
-    }
-    @Override
-    public String getPathForURLInProject(String projectName, String url) {
-        try {
-            return database.getPathForURLInProject(projectName, url);
-        } catch (SQLException e) {
-            throw new RuntimeException(e);
-        }
-    }
-
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/SQLQuery.java → services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/SQLQuery.java

@@ -1,4 +1,4 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql;
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/SQLUpdate.java

@@ -0,0 +1,18 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite;
+
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+
+/**
+ * Created by Winston on 20/11/14.
+ */
+public interface SQLUpdate {
+
+    String getSQL();
+    default void addParametersToStatement(
+            PreparedStatement statement
+    ) throws SQLException {
+
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/SqliteDBStore.java

@@ -0,0 +1,204 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite;
+
+import com.google.common.base.Preconditions;
+import uk.ac.ic.wlgitbridge.bridge.db.DBInitException;
+import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
+import uk.ac.ic.wlgitbridge.bridge.db.ProjectState;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.query.*;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.alter.ProjectsAddLastAccessed;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.create.CreateIndexURLIndexStore;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.create.CreateProjectsIndexLastAccessed;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.create.CreateProjectsTableSQLUpdate;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.create.CreateURLIndexStoreSQLUpdate;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.delete.DeleteFilesForProjectSQLUpdate;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.insert.AddURLIndexSQLUpdate;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.insert.SetProjectLastAccessedTime;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.insert.SetProjectSQLUpdate;
+
+import java.io.File;
+import java.sql.*;
+import java.util.List;
+import java.util.stream.Stream;
+
+/**
+ * Created by Winston on 17/11/14.
+ */
+public class SqliteDBStore implements DBStore {
+
+    private final Connection connection;
+
+    public SqliteDBStore(File dbFile) {
+        try {
+            connection = openConnectionTo(dbFile);
+            createTables();
+        } catch (Throwable t) {
+            throw new DBInitException(t);
+        }
+    }
+
+    @Override
+    public int getNumProjects() {
+        return query(new GetNumProjects());
+    }
+
+    @Override
+    public List<String> getProjectNames() {
+        return query(new GetProjectNamesSQLQuery());
+    }
+
+    @Override
+    public void setLatestVersionForProject(
+            String projectName,
+            int versionID
+    ) {
+        update(new SetProjectSQLUpdate(projectName, versionID));
+    }
+
+    @Override
+    public int getLatestVersionForProject(
+            String projectName
+    ) {
+        return query(new GetLatestVersionForProjectSQLQuery(projectName));
+    }
+
+    @Override
+    public void addURLIndexForProject(
+            String projectName,
+            String url,
+            String path
+    ) {
+        update(new AddURLIndexSQLUpdate(projectName, url, path));
+    }
+
+    @Override
+    public void deleteFilesForProject(
+            String projectName,
+            String... paths
+    ) {
+        update(new DeleteFilesForProjectSQLUpdate(projectName, paths));
+    }
+
+    @Override
+    public String getPathForURLInProject(
+            String projectName,
+            String url
+    ) {
+        return query(new GetPathForURLInProjectSQLQuery(projectName, url));
+    }
+
+    @Override
+    public String getOldestUnswappedProject() {
+        return query(new GetOldestProjectName());
+    }
+
+    @Override
+    public int getNumUnswappedProjects() {
+        return query(new GetNumUnswappedProjects());
+    }
+
+    @Override
+    public ProjectState getProjectState(String projectName) {
+        return query(new GetProjectState(projectName));
+    }
+
+    @Override
+    public void setLastAccessedTime(
+            String projectName,
+            Timestamp lastAccessed
+    ) {
+        update(new SetProjectLastAccessedTime(projectName, lastAccessed));
+    }
+
+    private Connection openConnectionTo(File dbFile) {
+        File parentDir = dbFile.getParentFile();
+        if (!parentDir.exists() && !parentDir.mkdirs()) {
+            throw new DBInitException(
+                    parentDir.getAbsolutePath() + " directory didn't exist, " +
+                            "and unable to create. Check your permissions."
+            );
+        }
+        try {
+            Class.forName("org.sqlite.JDBC");
+        } catch (ClassNotFoundException e) {
+            throw new DBInitException(e);
+        }
+        try {
+            return DriverManager.getConnection(
+                    "jdbc:sqlite:" + dbFile.getAbsolutePath()
+            );
+        } catch (SQLException e) {
+            throw new DBInitException("Unable to connect to DB", e);
+        }
+    }
+
+    private void createTables() {
+        try {
+            doUpdate(new ProjectsAddLastAccessed());
+        } catch (SQLException ignore) {
+            /* We need to eat exceptions from here */
+        }
+        Stream.of(
+                new CreateProjectsTableSQLUpdate(),
+                new CreateProjectsIndexLastAccessed(),
+                new CreateURLIndexStoreSQLUpdate(),
+                new CreateIndexURLIndexStore()
+        ).forEach(this::update);
+        /* In the case of needing to change the schema, we need to check that
+           ProjectsAddLastAccessed didn't just fail */
+        Preconditions.checkState(query(new LastAccessedColumnExists()));
+    }
+
+    private void update(SQLUpdate update) {
+        try {
+            doUpdate(update);
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private <T> T query(SQLQuery<T> query) {
+        try {
+            return doQuery(query);
+        } catch (SQLException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private void doUpdate(SQLUpdate update) throws SQLException {
+        PreparedStatement statement = null;
+        try {
+            statement = connection.prepareStatement(update.getSQL());
+            update.addParametersToStatement(statement);
+            statement.executeUpdate();
+        } catch (SQLException e) {
+            throw e;
+        } finally {
+            try {
+                statement.close();
+            } catch (Throwable t) {
+                throw new SQLException(t);
+            }
+        }
+    }
+
+    private <T> T doQuery(SQLQuery<T> query) throws SQLException {
+        PreparedStatement statement = null;
+        ResultSet results = null;
+        try {
+            statement = connection.prepareStatement(query.getSQL());
+            query.addParametersToStatement(statement);
+            results = statement.executeQuery();
+            return query.processResultSet(results);
+        } catch (SQLException e) {
+            throw e;
+        } finally {
+            if (statement != null) {
+                statement.close();
+            }
+            if (results != null) {
+                results.close();
+            }
+        }
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/query/GetLatestVersionForProjectSQLQuery.java → services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/query/GetLatestVersionForProjectSQLQuery.java

@@ -1,6 +1,6 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql.query;
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.query;
 
-import uk.ac.ic.wlgitbridge.data.model.db.sql.SQLQuery;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLQuery;
 
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/query/GetNumProjects.java

@@ -0,0 +1,30 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.query;
+
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLQuery;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+/**
+ * Created by winston on 24/08/2016.
+ */
+public class GetNumProjects implements SQLQuery<Integer> {
+
+    private static final String GET_NUM_PROJECTS =
+            "SELECT COUNT(*)\n" +
+            "    FROM `projects`";
+
+    @Override
+    public String getSQL() {
+        return GET_NUM_PROJECTS;
+    }
+
+    @Override
+    public Integer processResultSet(ResultSet resultSet) throws SQLException {
+        while (resultSet.next()) {
+            return resultSet.getInt("COUNT(*)");
+        }
+        throw new IllegalStateException("Count always returns results");
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/query/GetNumUnswappedProjects.java

@@ -0,0 +1,31 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.query;
+
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLQuery;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+/**
+ * Created by winston on 24/08/2016.
+ */
+public class GetNumUnswappedProjects implements SQLQuery<Integer> {
+
+    private static final String GET_NUM_UNSWAPPED_PROJECTS =
+            "SELECT COUNT(*)\n" +
+            "    FROM `projects`\n" +
+            "    WHERE `last_accessed` IS NOT NULL";
+
+    @Override
+    public String getSQL() {
+        return GET_NUM_UNSWAPPED_PROJECTS;
+    }
+
+    @Override
+    public Integer processResultSet(ResultSet resultSet) throws SQLException {
+        while (resultSet.next()) {
+            return resultSet.getInt("COUNT(*)");
+        }
+        throw new IllegalStateException("Count always returns results");
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/query/GetOldestProjectName.java

@@ -0,0 +1,30 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.query;
+
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLQuery;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class GetOldestProjectName implements SQLQuery<String> {
+
+    private static final String GET_OLDEST_PROJECT_NAME =
+            "SELECT `name`, MIN(`last_accessed`)\n" +
+            "    FROM `projects`";
+
+    @Override
+    public String getSQL() {
+        return GET_OLDEST_PROJECT_NAME;
+    }
+
+    @Override
+    public String processResultSet(ResultSet resultSet) throws SQLException {
+        while (resultSet.next()) {
+            return resultSet.getString("name");
+        }
+        return null;
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/query/GetPathForURLInProjectSQLQuery.java → services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/query/GetPathForURLInProjectSQLQuery.java

@@ -1,6 +1,6 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql.query;
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.query;
 
-import uk.ac.ic.wlgitbridge.data.model.db.sql.SQLQuery;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLQuery;
 
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/query/GetProjectNamesSQLQuery.java → services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/query/GetProjectNamesSQLQuery.java

@@ -1,8 +1,7 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql.query;
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.query;
 
-import uk.ac.ic.wlgitbridge.data.model.db.sql.SQLQuery;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLQuery;
 
-import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.LinkedList;
@@ -30,9 +29,4 @@ public class GetProjectNamesSQLQuery implements SQLQuery<List<String>> {
         return GET_URL_INDEXES_FOR_PROJECT_NAME;
     }
 
-    @Override
-    public void addParametersToStatement(PreparedStatement statement) throws SQLException {
-
-    }
-
 }

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/query/GetProjectState.java

@@ -0,0 +1,47 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.query;
+
+import uk.ac.ic.wlgitbridge.bridge.db.ProjectState;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLQuery;
+
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+/**
+ * Created by winston on 24/08/2016.
+ */
+public class GetProjectState implements SQLQuery<ProjectState> {
+
+    private static final String GET_PROJECT_STATE =
+            "SELECT `last_accessed`\n" +
+            "    FROM `projects`\n" +
+            "    WHERE `name` = ?";
+
+    private final String projectName;
+
+    public GetProjectState(String projectName) {
+        this.projectName = projectName;
+    }
+
+    @Override
+    public String getSQL() {
+        return GET_PROJECT_STATE;
+    }
+
+    @Override
+    public ProjectState processResultSet(ResultSet resultSet) throws SQLException {
+        while (resultSet.next()) {
+            if (resultSet.getTimestamp("last_accessed") == null) {
+                return ProjectState.SWAPPED;
+            }
+            return ProjectState.PRESENT;
+        }
+        return ProjectState.NOT_PRESENT;
+    }
+
+    @Override
+    public void addParametersToStatement(PreparedStatement statement) throws SQLException {
+        statement.setString(1, projectName);
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/query/LastAccessedColumnExists.java

@@ -0,0 +1,31 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.query;
+
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLQuery;
+
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+/**
+ * Created by winston on 04/09/2016.
+ */
+public class LastAccessedColumnExists implements SQLQuery<Boolean> {
+
+    private static final String LAST_ACCESSED_COLUMN_EXISTS =
+            "PRAGMA table_info(`projects`)";
+
+    @Override
+    public String getSQL() {
+        return LAST_ACCESSED_COLUMN_EXISTS;
+    }
+
+    @Override
+    public Boolean processResultSet(ResultSet resultSet) throws SQLException {
+        while (resultSet.next()) {
+            if (resultSet.getString(2).equals("last_accessed")) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/update/alter/ProjectsAddLastAccessed.java

@@ -0,0 +1,19 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.alter;
+
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLUpdate;
+
+/**
+ * Created by winston on 03/09/2016.
+ */
+public class ProjectsAddLastAccessed implements SQLUpdate {
+
+    private static final String PROJECTS_ADD_LAST_ACCESSED =
+            "ALTER TABLE `projects`\n" +
+            "ADD COLUMN `last_accessed` DATETIME NULL DEFAULT 0";
+
+    @Override
+    public String getSQL() {
+        return PROJECTS_ADD_LAST_ACCESSED;
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/update/create/CreateIndexURLIndexStore.java

@@ -0,0 +1,19 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.create;
+
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLUpdate;
+
+/**
+ * Created by Winston on 21/02/15.
+ */
+public class CreateIndexURLIndexStore implements SQLUpdate {
+
+    public static final String CREATE_INDEX_URL_INDEX_STORE =
+            "CREATE UNIQUE INDEX IF NOT EXISTS `project_path_index` " +
+            "ON `url_index_store`(`project_name`, `path`);\n";
+
+    @Override
+    public String getSQL() {
+        return CREATE_INDEX_URL_INDEX_STORE;
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/update/create/CreateProjectsIndexLastAccessed.java

@@ -0,0 +1,19 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.create;
+
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLUpdate;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class CreateProjectsIndexLastAccessed implements SQLUpdate {
+
+    private static final String CREATE_PROJECTS_INDEX_LAST_ACCESSED =
+            "CREATE INDEX IF NOT EXISTS `projects_index_last_accessed`\n" +
+            "    ON `projects`(`last_accessed`)";
+
+    @Override
+    public String getSQL() {
+        return CREATE_PROJECTS_INDEX_LAST_ACCESSED;
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/update/create/CreateProjectsTableSQLUpdate.java

@@ -0,0 +1,23 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.create;
+
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLUpdate;
+
+/**
+ * Created by Winston on 20/11/14.
+ */
+public class CreateProjectsTableSQLUpdate implements SQLUpdate {
+
+    private static final String CREATE_PROJECTS_TABLE =
+            "CREATE TABLE IF NOT EXISTS `projects` (\n" +
+            "    `name` VARCHAR NOT NULL DEFAULT '',\n" +
+            "    `version_id` INT NOT NULL DEFAULT 0,\n" +
+            "    `last_accessed` DATETIME NULL DEFAULT 0,\n" +
+            "    PRIMARY KEY (`name`)\n" +
+            ")";
+
+    @Override
+    public String getSQL() {
+        return CREATE_PROJECTS_TABLE;
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/update/create/CreateURLIndexStoreSQLUpdate.java → services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/update/create/CreateURLIndexStoreSQLUpdate.java

@@ -1,9 +1,6 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql.update.create;
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.create;
 
-import uk.ac.ic.wlgitbridge.data.model.db.sql.SQLUpdate;
-
-import java.sql.PreparedStatement;
-import java.sql.SQLException;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLUpdate;
 
 /**
  * Created by Winston on 20/11/14.
@@ -16,7 +13,11 @@ public class CreateURLIndexStoreSQLUpdate implements SQLUpdate {
             "  `url` text NOT NULL,\n"+
             "  `path` text NOT NULL,\n"+
             "  PRIMARY KEY (`project_name`,`url`),\n"+
-            "  CONSTRAINT `url_index_store_ibfk_1` FOREIGN KEY (`project_name`) REFERENCES `projects` (`name`) ON DELETE CASCADE ON UPDATE CASCADE\n"+
+            "  CONSTRAINT `url_index_store_ibfk_1` " +
+                    "FOREIGN KEY (`project_name`) " +
+                    "REFERENCES `projects` (`name`) " +
+                    "ON DELETE CASCADE " +
+                    "ON UPDATE CASCADE\n"+
             ");\n";
 
     @Override
@@ -24,9 +25,4 @@ public class CreateURLIndexStoreSQLUpdate implements SQLUpdate {
         return CREATE_URL_INDEX_STORE;
     }
 
-    @Override
-    public void addParametersToStatement(PreparedStatement statement) throws SQLException {
-
-    }
-
 }

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/update/delete/DeleteFilesForProjectSQLUpdate.java → services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/update/delete/DeleteFilesForProjectSQLUpdate.java

@@ -1,6 +1,6 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql.update.delete;
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.delete;
 
-import uk.ac.ic.wlgitbridge.data.model.db.sql.SQLUpdate;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLUpdate;
 
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
@@ -11,7 +11,8 @@ import java.sql.SQLException;
 public class DeleteFilesForProjectSQLUpdate implements SQLUpdate {
 
     private static final String DELETE_URL_INDEXES_FOR_PROJECT_NAME =
-            "DELETE FROM `url_index_store` WHERE `project_name` = ? AND path IN (";
+            "DELETE FROM `url_index_store` " +
+                    "WHERE `project_name` = ? AND path IN (";
 
     private final String projectName;
     private final String[] paths;
@@ -23,7 +24,9 @@ public class DeleteFilesForProjectSQLUpdate implements SQLUpdate {
 
     @Override
     public String getSQL() {
-        StringBuilder sb = new StringBuilder(DELETE_URL_INDEXES_FOR_PROJECT_NAME);
+        StringBuilder sb = new StringBuilder(
+                DELETE_URL_INDEXES_FOR_PROJECT_NAME
+        );
         for (int i = 0; i < paths.length; i++) {
             sb.append("?");
             if (i < paths.length - 1) {
@@ -35,7 +38,9 @@ public class DeleteFilesForProjectSQLUpdate implements SQLUpdate {
     }
 
     @Override
-    public void addParametersToStatement(PreparedStatement statement) throws SQLException {
+    public void addParametersToStatement(
+            PreparedStatement statement
+    ) throws SQLException {
         statement.setString(1, projectName);
         for (int i = 0; i < paths.length; i++) {
             statement.setString(i + 2, paths[i]);

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/update/insert/AddURLIndexSQLUpdate.java → services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/update/insert/AddURLIndexSQLUpdate.java

@@ -1,6 +1,6 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql.update.insert;
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.insert;
 
-import uk.ac.ic.wlgitbridge.data.model.db.sql.SQLUpdate;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLUpdate;
 
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
@@ -11,7 +11,12 @@ import java.sql.SQLException;
 public class AddURLIndexSQLUpdate implements SQLUpdate {
 
     private static final String ADD_URL_INDEX =
-            "INSERT OR REPLACE INTO `url_index_store` (`project_name`, `url`, `path`) VALUES (?, ?, ?);\n";
+            "INSERT OR REPLACE INTO `url_index_store`(" +
+                    "`project_name`, " +
+                    "`url`, " +
+                    "`path`" +
+            ") VALUES " +
+            "(?, ?, ?)\n";
 
     private final String projectName;
     private final String url;
@@ -29,7 +34,9 @@ public class AddURLIndexSQLUpdate implements SQLUpdate {
     }
 
     @Override
-    public void addParametersToStatement(PreparedStatement statement) throws SQLException {
+    public void addParametersToStatement(
+            PreparedStatement statement
+    ) throws SQLException {
         statement.setString(1, projectName);
         statement.setString(2, url);
         statement.setString(3, path);

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/update/insert/SetProjectLastAccessedTime.java

@@ -0,0 +1,43 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.insert;
+
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLUpdate;
+
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.sql.Timestamp;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class SetProjectLastAccessedTime implements SQLUpdate {
+
+    private static final String SET_PROJECT_LAST_ACCESSED_TIME =
+            "UPDATE `projects`\n" +
+            "SET `last_accessed` = ?\n" +
+            "WHERE `name` = ?";
+
+    private final String projectName;
+    private final Timestamp lastAccessed;
+
+    public SetProjectLastAccessedTime(
+            String projectName,
+            Timestamp lastAccessed
+    ) {
+        this.projectName = projectName;
+        this.lastAccessed = lastAccessed;
+    }
+
+    @Override
+    public String getSQL() {
+        return SET_PROJECT_LAST_ACCESSED_TIME;
+    }
+
+    @Override
+    public void addParametersToStatement(
+            PreparedStatement statement
+    ) throws SQLException {
+        statement.setTimestamp(1, lastAccessed);
+        statement.setString(2, projectName);
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/update/insert/SetProjectSQLUpdate.java → services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/update/insert/SetProjectSQLUpdate.java

@@ -1,6 +1,6 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql.update.insert;
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.insert;
 
-import uk.ac.ic.wlgitbridge.data.model.db.sql.SQLUpdate;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SQLUpdate;
 
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
@@ -11,7 +11,8 @@ import java.sql.SQLException;
 public class SetProjectSQLUpdate implements SQLUpdate {
 
     private static final String SET_PROJECT =
-            "INSERT OR REPLACE INTO `projects`(`name`, `version_id`) VALUES (?, ?);\n";
+            "INSERT OR REPLACE INTO `projects`(`name`, `version_id`, `last_accessed`) " +
+            "VALUES (?, ?, DATETIME('now'));\n";
 
     private final String projectName;
     private final int versionID;

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/lock/LockGuard.java

@@ -0,0 +1,10 @@
+package uk.ac.ic.wlgitbridge.bridge.lock;
+
+/**
+ * Created by winston on 24/08/2016.
+ */
+public interface LockGuard extends AutoCloseable {
+
+    void close();
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/lock/ProjectLock.java

@@ -4,9 +4,17 @@ package uk.ac.ic.wlgitbridge.bridge.lock;
  * Created by winston on 20/08/2016.
  */
 public interface ProjectLock {
+
     void lockAll();
 
     void lockForProject(String projectName);
 
     void unlockForProject(String projectName);
+
+    /* RAII hahaha */
+    default LockGuard lockGuard(String projectName) {
+        lockForProject(projectName);
+        return () -> unlockForProject(projectName);
+    }
+
 }

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/repo/FSGitRepoStore.java

@@ -0,0 +1,112 @@
+package uk.ac.ic.wlgitbridge.bridge.repo;
+
+import com.google.api.client.repackaged.com.google.common.base.Preconditions;
+import org.apache.commons.io.FileUtils;
+import uk.ac.ic.wlgitbridge.util.Project;
+import uk.ac.ic.wlgitbridge.util.Tar;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import static uk.ac.ic.wlgitbridge.util.Util.deleteInDirectoryApartFrom;
+
+/**
+ * Created by winston on 20/08/2016.
+ */
+public class FSGitRepoStore implements RepoStore {
+
+    private final String repoStorePath;
+    private final File rootDirectory;
+
+    public FSGitRepoStore(String repoStorePath) {
+        this.repoStorePath = repoStorePath;
+        rootDirectory = initRootGitDirectory(repoStorePath);
+    }
+
+    @Override
+    public String getRepoStorePath() {
+        return repoStorePath;
+    }
+
+    @Override
+    public File getRootDirectory() {
+        return rootDirectory;
+    }
+
+    /* TODO: Perhaps we should just delete bad directories on the fly. */
+    @Override
+    public void purgeNonexistentProjects(
+            Collection<String> existingProjectNames
+    ) {
+        List<String> excludedFromDeletion =
+                new ArrayList<>(existingProjectNames);
+        excludedFromDeletion.add(".wlgb");
+        deleteInDirectoryApartFrom(
+                rootDirectory,
+                excludedFromDeletion.toArray(new String[] {})
+        );
+    }
+
+    @Override
+    public long totalSize() {
+        return FileUtils.sizeOfDirectory(rootDirectory);
+    }
+
+    @Override
+    public InputStream bzip2Project(
+            String projectName,
+            long[] sizePtr
+    ) throws IOException {
+        Preconditions.checkArgument(Project.isValidProjectName(projectName));
+        return Tar.bz2.zip(getDotGitForProject(projectName), sizePtr);
+    }
+
+    @Override
+    public void remove(String projectName) throws IOException {
+        Preconditions.checkArgument(Project.isValidProjectName(projectName));
+        FileUtils.deleteDirectory(new File(rootDirectory, projectName));
+    }
+
+    @Override
+    public void unbzip2Project(
+            String projectName,
+            InputStream dataStream
+    ) throws IOException {
+        Preconditions.checkArgument(Project.isValidProjectName(projectName));
+        Preconditions.checkState(getDirForProject(projectName).mkdirs());
+        Tar.bz2.unzip(dataStream, getDirForProject(projectName));
+    }
+
+    private File getDirForProject(String projectName) {
+        Preconditions.checkArgument(Project.isValidProjectName(projectName));
+        return Paths.get(
+                rootDirectory.getAbsolutePath()
+        ).resolve(
+                projectName
+        ).toFile();
+    }
+
+    private File getDotGitForProject(String projectName) {
+        Preconditions.checkArgument(Project.isValidProjectName(projectName));
+        return Paths.get(
+                rootDirectory.getAbsolutePath()
+        ).resolve(
+                projectName
+        ).resolve(
+                ".git"
+        ).toFile();
+    }
+
+    private File initRootGitDirectory(String rootGitDirectoryPath) {
+        File rootGitDirectory = new File(rootGitDirectoryPath);
+        rootGitDirectory.mkdirs();
+        Preconditions.checkArgument(rootGitDirectory.isDirectory());
+        return rootGitDirectory;
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/repo/FSRepoStore.java

@@ -1,52 +0,0 @@
-package uk.ac.ic.wlgitbridge.bridge.repo;
-
-import uk.ac.ic.wlgitbridge.util.Util;
-
-import java.io.File;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-
-/**
- * Created by winston on 20/08/2016.
- */
-public class FSRepoStore implements RepoStore {
-
-    private final String repoStorePath;
-    private final File rootDirectory;
-
-    public FSRepoStore(String repoStorePath) {
-        this.repoStorePath = repoStorePath;
-        rootDirectory = initRootGitDirectory(repoStorePath);
-    }
-
-    @Override
-    public String getRepoStorePath() {
-        return repoStorePath;
-    }
-
-    @Override
-    public File getRootDirectory() {
-        return rootDirectory;
-    }
-
-    @Override
-    public void purgeNonexistentProjects(
-            Collection<String> existingProjectNames
-    ) {
-        List<String> excludedFromDeletion =
-                new ArrayList<>(existingProjectNames);
-        excludedFromDeletion.add(".wlgb");
-        Util.deleteInDirectoryApartFrom(
-                rootDirectory,
-                excludedFromDeletion.toArray(new String[] {})
-        );
-    }
-
-    private File initRootGitDirectory(String rootGitDirectoryPath) {
-        File rootGitDirectory = new File(rootGitDirectoryPath);
-        rootGitDirectory.mkdirs();
-        return rootGitDirectory;
-    }
-
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/repo/RepoStore.java

@@ -1,8 +1,8 @@
 package uk.ac.ic.wlgitbridge.bridge.repo;
 
-import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
-
 import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
 import java.util.Collection;
 
 /**
@@ -10,13 +10,47 @@ import java.util.Collection;
  */
 public interface RepoStore {
 
+    /* Still need to get rid of these two methods.
+       Main dependency: GitRepoStore needs a Repository which needs a directory.
+       Instead, use a visitor or something. */
     String getRepoStorePath();
 
     File getRootDirectory();
 
-
     void purgeNonexistentProjects(
             Collection<String> existingProjectNames
     );
 
+    long totalSize();
+
+    /**
+     * Tars and bzip2s the .git directory of the given project. Throws an
+     * IOException if the project doesn't exist. The returned stream is a copy
+     * of the original .git directory, which must be deleted using remove().
+     */
+    InputStream bzip2Project(
+            String projectName,
+            long[] sizePtr
+    ) throws IOException;
+
+    default InputStream bzip2Project(
+            String projectName
+    ) throws IOException {
+        return bzip2Project(projectName, null);
+    }
+
+    void remove(String projectName) throws IOException;
+
+    /**
+     * Unbzip2s the given data stream into a .git directory for projectName.
+     * Creates the project directory.
+     * If projectName already exists, throws an IOException.
+     * @param projectName the name of the project, e.g. abc123
+     * @param dataStream the data stream containing the bzipped contents.
+     */
+    void unbzip2Project(
+            String projectName,
+            InputStream dataStream
+    ) throws IOException;
+
 }

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/SwapJob.java

@@ -1,12 +0,0 @@
-package uk.ac.ic.wlgitbridge.bridge.swap;
-
-/**
- * Created by winston on 20/08/2016.
- */
-public interface SwapJob {
-
-    void start(int intervalMillis);
-
-    void stop();
-
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/SwapJobImpl.java

@@ -1,53 +0,0 @@
-package uk.ac.ic.wlgitbridge.bridge.swap;
-
-import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
-import uk.ac.ic.wlgitbridge.bridge.lock.ProjectLock;
-import uk.ac.ic.wlgitbridge.bridge.repo.RepoStore;
-import uk.ac.ic.wlgitbridge.util.Util;
-
-import java.util.Timer;
-
-/**
- * Created by winston on 20/08/2016.
- */
-public class SwapJobImpl implements SwapJob {
-
-    private final ProjectLock lock;
-    private final RepoStore repoStore;
-    private final SwapStore swapStore;
-    private final DBStore dbStore;
-
-    private final Timer timer;
-
-    public SwapJobImpl(
-            ProjectLock lock,
-            RepoStore repoStore,
-            DBStore dbStore, SwapStore swapStore
-    ) {
-
-        this.lock = lock;
-        this.repoStore = repoStore;
-        this.swapStore = swapStore;
-        this.dbStore = dbStore;
-        timer = new Timer();
-    }
-
-    @Override
-    public void start(int intervalMillis) {
-        timer.scheduleAtFixedRate(
-                Util.makeTimerTask(this::doSwap),
-                0,
-                intervalMillis
-        );
-    }
-
-    @Override
-    public void stop() {
-        timer.cancel();
-    }
-
-    private void doSwap() {
-        throw new UnsupportedOperationException();
-    }
-
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/SwapStore.java

@@ -1,7 +0,0 @@
-package uk.ac.ic.wlgitbridge.bridge.swap;
-
-/**
- * Created by winston on 20/08/2016.
- */
-public interface SwapStore {
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/job/NoopSwapJob.java

@@ -0,0 +1,30 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.job;
+
+import java.io.IOException;
+
+/**
+ * Created by winston on 24/08/2016.
+ */
+public class NoopSwapJob implements SwapJob {
+
+    @Override
+    public void start() {
+
+    }
+
+    @Override
+    public void stop() {
+
+    }
+
+    @Override
+    public void evict(String projName) throws IOException {
+
+    }
+
+    @Override
+    public void restore(String projName) throws IOException {
+
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/job/SwapJob.java

@@ -0,0 +1,42 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.job;
+
+import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
+import uk.ac.ic.wlgitbridge.bridge.lock.ProjectLock;
+import uk.ac.ic.wlgitbridge.bridge.repo.RepoStore;
+import uk.ac.ic.wlgitbridge.bridge.swap.store.SwapStore;
+
+import java.io.IOException;
+import java.util.Optional;
+
+/**
+ * Created by winston on 20/08/2016.
+ */
+public interface SwapJob {
+
+    static SwapJob fromConfig(
+            Optional<SwapJobConfig> cfg,
+            ProjectLock lock,
+            RepoStore repoStore,
+            DBStore dbStore,
+            SwapStore swapStore
+    ) {
+        if (cfg.isPresent()) {
+            return new SwapJobImpl(
+                    cfg.get(),
+                    lock,
+                    repoStore,
+                    dbStore,
+                    swapStore
+            );
+        }
+        return new NoopSwapJob();
+    }
+
+    void start();
+
+    void stop();
+
+    void evict(String projName) throws IOException;
+
+    void restore(String projName) throws IOException;
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/job/SwapJobConfig.java

@@ -0,0 +1,41 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.job;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class SwapJobConfig {
+
+    private final int minProjects;
+    private final int lowGiB;
+    private final int highGiB;
+    private final long intervalMillis;
+
+    public SwapJobConfig(
+            int minProjects,
+            int lowGiB,
+            int highGiB,
+            long intervalMillis
+    ) {
+        this.minProjects = minProjects;
+        this.lowGiB = lowGiB;
+        this.highGiB = highGiB;
+        this.intervalMillis = intervalMillis;
+    }
+
+    public int getMinProjects() {
+        return minProjects;
+    }
+
+    public int getLowGiB() {
+        return lowGiB;
+    }
+
+    public int getHighGiB() {
+        return highGiB;
+    }
+
+    public long getIntervalMillis() {
+        return intervalMillis;
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/job/SwapJobImpl.java

@@ -0,0 +1,175 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.job;
+
+import com.google.api.client.repackaged.com.google.common.base.Preconditions;
+import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
+import uk.ac.ic.wlgitbridge.bridge.lock.LockGuard;
+import uk.ac.ic.wlgitbridge.bridge.lock.ProjectLock;
+import uk.ac.ic.wlgitbridge.bridge.repo.RepoStore;
+import uk.ac.ic.wlgitbridge.bridge.swap.store.SwapStore;
+import uk.ac.ic.wlgitbridge.util.Log;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.sql.Timestamp;
+import java.time.Duration;
+import java.time.LocalDateTime;
+import java.util.Timer;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Created by winston on 20/08/2016.
+ */
+public class SwapJobImpl implements SwapJob {
+
+    private static final long GiB = (1l << 30);
+
+    int minProjects;
+    long lowWatermarkBytes;
+    long highWatermarkBytes;
+    Duration interval;
+
+    private final ProjectLock lock;
+    private final RepoStore repoStore;
+    private final DBStore dbStore;
+    private final SwapStore swapStore;
+
+    private final Timer timer;
+
+    final AtomicInteger swaps;
+
+    public SwapJobImpl(
+            SwapJobConfig cfg,
+            ProjectLock lock,
+            RepoStore repoStore,
+            DBStore dbStore,
+            SwapStore swapStore
+    ) {
+        this(
+                cfg.getMinProjects(),
+                GiB * cfg.getLowGiB(),
+                GiB * cfg.getHighGiB(),
+                Duration.ofMillis(cfg.getIntervalMillis()),
+                lock,
+                repoStore,
+                dbStore,
+                swapStore
+        );
+    }
+
+    SwapJobImpl(
+            int minProjects,
+            long lowWatermarkBytes,
+            long highWatermarkBytes,
+            Duration interval,
+            ProjectLock lock,
+            RepoStore repoStore,
+            DBStore dbStore,
+            SwapStore swapStore
+    ) {
+        this.minProjects = minProjects;
+        this.lowWatermarkBytes = lowWatermarkBytes;
+        this.highWatermarkBytes = highWatermarkBytes;
+        this.interval = interval;
+        this.lock = lock;
+        this.repoStore = repoStore;
+        this.dbStore = dbStore;
+        this.swapStore = swapStore;
+        timer = new Timer();
+        swaps = new AtomicInteger(0);
+    }
+
+    @Override
+    public void start() {
+        timer.schedule(
+                uk.ac.ic.wlgitbridge.util.Timer.makeTimerTask(this::doSwap),
+                0
+        );
+    }
+
+    @Override
+    public void stop() {
+        timer.cancel();
+    }
+
+    private void doSwap() {
+        try {
+            doSwap_();
+        } catch (Throwable t) {
+            Log.warn("Exception thrown during swap job", t);
+        }
+        timer.schedule(
+                uk.ac.ic.wlgitbridge.util.Timer.makeTimerTask(this::doSwap),
+                interval.toMillis()
+        );
+    }
+
+    private void doSwap_() {
+        Log.info("Running swap number {}", swaps.get() + 1);
+        long totalSize = repoStore.totalSize();
+        Log.info("Size is {}/{} (high)", totalSize, highWatermarkBytes);
+        if (totalSize < highWatermarkBytes) {
+            Log.info("No need to swap.");
+            swaps.incrementAndGet();
+            return;
+        }
+        int numProjects = dbStore.getNumProjects();
+        while (
+                (totalSize = repoStore.totalSize()) > lowWatermarkBytes &&
+                (numProjects = dbStore.getNumUnswappedProjects()) > minProjects
+        ) {
+            try {
+                evict(dbStore.getOldestUnswappedProject());
+            } catch (IOException e) {
+                Log.warn("Exception while swapping, giving up", e);
+            }
+        }
+        if (totalSize > lowWatermarkBytes) {
+            Log.warn(
+                    "Finished swapping, but total size is still too high."
+            );
+        }
+        Log.info(
+                "Size: {}/{} (low), " +
+                        "{} (high), " +
+                        "projects on disk: {}/{}, " +
+                        "min projects on disk: {}",
+                totalSize,
+                lowWatermarkBytes,
+                highWatermarkBytes,
+                numProjects,
+                dbStore.getNumProjects(),
+                minProjects
+        );
+        swaps.incrementAndGet();
+    }
+
+    @Override
+    public void evict(String projName) throws IOException {
+        Preconditions.checkNotNull(projName);
+        Log.info("Evicting project: {}", projName);
+        try (LockGuard __ = lock.lockGuard(projName)) {
+            long[] sizePtr = new long[1];
+            InputStream bzipped = repoStore.bzip2Project(projName, sizePtr);
+            swapStore.upload(projName, bzipped, sizePtr[0]);
+            dbStore.setLastAccessedTime(projName, null);
+            repoStore.remove(projName);
+        }
+        Log.info("Evicted project: {}", projName);
+    }
+
+    @Override
+    public void restore(String projName) throws IOException {
+        try (LockGuard __ = lock.lockGuard(projName)) {
+            repoStore.unbzip2Project(
+                    projName,
+                    swapStore.openDownloadStream(projName)
+            );
+            swapStore.remove(projName);
+            dbStore.setLastAccessedTime(
+                    projName,
+                    Timestamp.valueOf(LocalDateTime.now())
+            );
+        }
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/store/InMemorySwapStore.java

@@ -0,0 +1,54 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.store;
+
+import org.apache.commons.io.IOUtils;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class InMemorySwapStore implements SwapStore {
+
+    private final Map<String, byte[]> store;
+
+    public InMemorySwapStore() {
+        store = new HashMap<>();
+    }
+
+    public InMemorySwapStore(SwapStoreConfig __) {
+        this();
+    }
+
+    @Override
+    public void upload(
+            String projectName,
+            InputStream uploadStream,
+            long contentLength
+    ) throws IOException {
+        store.put(
+                projectName,
+                IOUtils.toByteArray(uploadStream, contentLength)
+        );
+    }
+
+    @Override
+    public InputStream openDownloadStream(String projectName) {
+        byte[] buf = store.get(projectName);
+        if (buf == null) {
+            throw new IllegalArgumentException(
+                    "no such project in swap store: " + projectName
+            );
+        }
+        return new ByteArrayInputStream(buf);
+    }
+
+    @Override
+    public void remove(String projectName) {
+        store.remove(projectName);
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/store/NoopSwapStore.java

@@ -0,0 +1,35 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.store;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Created by winston on 24/08/2016.
+ */
+public class NoopSwapStore implements SwapStore {
+
+    public NoopSwapStore(SwapStoreConfig config) {
+
+    }
+
+    @Override
+    public void upload(
+            String projectName,
+            InputStream uploadStream,
+            long contentLength
+    ) throws IOException {
+
+    }
+
+    @Override
+    public InputStream openDownloadStream(String projectName) {
+        return new ByteArrayInputStream(new byte[0]);
+    }
+
+    @Override
+    public void remove(String projectName) {
+
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/store/S3SwapStore.java

@@ -0,0 +1,72 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.store;
+
+import com.amazonaws.auth.BasicAWSCredentials;
+import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.AmazonS3Client;
+import com.amazonaws.services.s3.model.*;
+
+import java.io.InputStream;
+
+/**
+ * Created by winston on 21/08/2016.
+ */
+public class S3SwapStore implements SwapStore {
+
+    private final AmazonS3 s3;
+
+    private final String bucketName;
+
+    public S3SwapStore(SwapStoreConfig cfg) {
+        this(
+                cfg.getAwsAccessKey(),
+                cfg.getAwsSecret(),
+                cfg.getS3BucketName()
+        );
+    }
+
+    S3SwapStore(
+            String accessKey,
+            String secret,
+            String bucketName
+    ) {
+        s3 = new AmazonS3Client(new BasicAWSCredentials(accessKey, secret));
+        this.bucketName = bucketName;
+    }
+
+    @Override
+    public void upload(
+            String projectName,
+            InputStream uploadStream,
+            long contentLength
+    ) {
+        ObjectMetadata metadata = new ObjectMetadata();
+        metadata.setContentLength(contentLength);
+        PutObjectRequest put = new PutObjectRequest(
+                bucketName,
+                projectName,
+                uploadStream,
+                metadata
+        );
+        PutObjectResult res = s3.putObject(put);
+    }
+
+    @Override
+    public InputStream openDownloadStream(String projectName) {
+        GetObjectRequest get = new GetObjectRequest(
+                bucketName,
+                projectName
+        );
+        S3Object res = s3.getObject(get);
+        return res.getObjectContent();
+    }
+
+    @Override
+    public void remove(String projectName) {
+        DeleteObjectRequest del = new DeleteObjectRequest(
+                bucketName,
+                projectName
+        );
+        s3.deleteObject(del);
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/store/SwapStore.java

@@ -0,0 +1,44 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.store;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.function.Function;
+
+/**
+ * Created by winston on 20/08/2016.
+ */
+public interface SwapStore {
+
+    Map<String, Function<SwapStoreConfig, SwapStore>> swapStores =
+            new HashMap<String, Function<SwapStoreConfig, SwapStore>>() {
+
+                {
+                    put("noop", NoopSwapStore::new);
+                    put("memory", InMemorySwapStore::new);
+                    put("s3", S3SwapStore::new);
+                }
+
+            };
+
+    static SwapStore fromConfig(
+            Optional<SwapStoreConfig> cfg
+    ) {
+        SwapStoreConfig cfg_ = cfg.orElse(SwapStoreConfig.NOOP);
+        String type = cfg_.getType();
+        return swapStores.get(type).apply(cfg_);
+    }
+
+    void upload(
+            String projectName,
+            InputStream uploadStream,
+            long contentLength
+    ) throws IOException;
+
+    InputStream openDownloadStream(String projectName);
+
+    void remove(String projectName);
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/bridge/swap/store/SwapStoreConfig.java

@@ -0,0 +1,76 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.store;
+
+/**
+ * Created by winston on 24/08/2016.
+ */
+public class SwapStoreConfig {
+
+    public static final SwapStoreConfig NOOP = new SwapStoreConfig(
+            "noop",
+            null,
+            null,
+            null
+    );
+
+    private String type;
+    private String awsAccessKey;
+    private String awsSecret;
+    private String s3BucketName;
+
+    public SwapStoreConfig() {}
+
+    public SwapStoreConfig(
+            String awsAccessKey,
+            String awsSecret,
+            String s3BucketName
+    ) {
+        this(
+                "s3",
+                awsAccessKey,
+                awsSecret,
+                s3BucketName
+        );
+    }
+
+    SwapStoreConfig(
+            String type,
+            String awsAccessKey,
+            String awsSecret,
+            String s3BucketName
+    ) {
+        this.type = type;
+        this.awsAccessKey = awsAccessKey;
+        this.awsSecret = awsSecret;
+        this.s3BucketName = s3BucketName;
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    public String getAwsAccessKey() {
+        return awsAccessKey;
+    }
+
+    public String getAwsSecret() {
+        return awsSecret;
+    }
+
+    public String getS3BucketName() {
+        return s3BucketName;
+    }
+
+    public SwapStoreConfig sanitisedCopy() {
+        return new SwapStoreConfig(
+                type,
+                awsAccessKey == null ? null : "<awsAccessKey>",
+                awsSecret == null ? null : "<awsSecret>",
+                s3BucketName
+        );
+    }
+
+    public static SwapStoreConfig sanitisedCopy(SwapStoreConfig swapStore) {
+        return swapStore == null ? null : swapStore.sanitisedCopy();
+    }
+    
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/CandidateSnapshot.java

@@ -17,7 +17,7 @@ import java.util.Map.Entry;
 /**
  * Created by Winston on 16/11/14.
  */
-public class CandidateSnapshot {
+public class CandidateSnapshot implements AutoCloseable {
 
     private final String projectName;
     private final int currentVersion;
@@ -25,14 +25,22 @@ public class CandidateSnapshot {
     private final List<String> deleted;
     private File attsDirectory;
 
-    public CandidateSnapshot(String projectName, int currentVersion, RawDirectory directoryContents, RawDirectory oldDirectoryContents) {
+    public CandidateSnapshot(
+            String projectName,
+            int currentVersion,
+            RawDirectory directoryContents,
+            RawDirectory oldDirectoryContents
+    ) {
         this.projectName = projectName;
         this.currentVersion = currentVersion;
         files = diff(directoryContents, oldDirectoryContents);
         deleted = deleted(directoryContents, oldDirectoryContents);
     }
 
-    private List<ServletFile> diff(RawDirectory directoryContents, RawDirectory oldDirectoryContents) {
+    private List<ServletFile> diff(
+            RawDirectory directoryContents,
+            RawDirectory oldDirectoryContents
+    ) {
         List<ServletFile> files = new LinkedList<ServletFile>();
         Map<String, RawFile> fileTable = directoryContents.getFileTable();
         Map<String, RawFile> oldFileTable = oldDirectoryContents.getFileTable();
@@ -43,10 +51,16 @@ public class CandidateSnapshot {
         return files;
     }
 
-    private List<String> deleted(RawDirectory directoryContents, RawDirectory oldDirectoryContents) {
+    private List<String> deleted(
+            RawDirectory directoryContents,
+            RawDirectory oldDirectoryContents
+    ) {
         List<String> deleted = new LinkedList<String>();
         Map<String, RawFile> fileTable = directoryContents.getFileTable();
-        for (Entry<String, RawFile> entry : oldDirectoryContents.getFileTable().entrySet()) {
+        for (
+                Entry<String, RawFile> entry :
+                oldDirectoryContents.getFileTable().entrySet()
+        ) {
             String path = entry.getKey();
             RawFile newFile = fileTable.get(path);
             if (newFile == null) {
@@ -57,7 +71,10 @@ public class CandidateSnapshot {
     }
 
     public void writeServletFiles(File rootGitDirectory) throws IOException {
-        attsDirectory = new File(rootGitDirectory, ".wlgb/atts/" + projectName);
+        attsDirectory = new File(
+                rootGitDirectory,
+                ".wlgb/atts/" + projectName
+        );
         for (ServletFile file : files) {
             if (file.isChanged()) {
                 file.writeToDisk(attsDirectory);
@@ -90,11 +107,18 @@ public class CandidateSnapshot {
         return filesArray;
     }
 
-    private JsonObject getFileAsJson(ServletFile file, String projectURL, String postbackKey) {
+    private JsonObject getFileAsJson(
+            ServletFile file,
+            String projectURL,
+            String postbackKey
+    ) {
         JsonObject jsonFile = new JsonObject();
         jsonFile.addProperty("name", file.getPath());
         if (file.isChanged()) {
-            jsonFile.addProperty("url", projectURL + "/" + file.getPath() + "?key=" + postbackKey);
+            jsonFile.addProperty(
+                    "url",
+                    projectURL + "/" + file.getPath() + "?key=" + postbackKey
+            );
         }
         return jsonFile;
     }
@@ -119,4 +143,9 @@ public class CandidateSnapshot {
         return sb.toString();
     }
 
+    @Override
+    public void close() throws IOException {
+        deleteServletFiles();
+    }
+
 }

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/ProjectLockImpl.java

@@ -33,11 +33,13 @@ public class ProjectLockImpl implements ProjectLock {
         setWaiter(waiter);
     }
 
+    @Override
     public void lockForProject(String projectName) {
         getLockForProjectName(projectName).lock();
         rlock.lock();
     }
 
+    @Override
     public void unlockForProject(String projectName) {
         getLockForProjectName(projectName).unlock();
         rlock.unlock();

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/SnapshotRepositoryBuilder.java

@@ -1,53 +0,0 @@
-package uk.ac.ic.wlgitbridge.data;
-
-import com.google.api.client.auth.oauth2.Credential;
-import org.eclipse.jgit.errors.RepositoryNotFoundException;
-import org.eclipse.jgit.lib.Repository;
-import org.eclipse.jgit.storage.file.FileRepositoryBuilder;
-import org.eclipse.jgit.transport.ServiceMayNotContinueException;
-import uk.ac.ic.wlgitbridge.bridge.Bridge;
-import uk.ac.ic.wlgitbridge.bridge.WLBridgedProject;
-import uk.ac.ic.wlgitbridge.git.exception.GitUserException;
-import uk.ac.ic.wlgitbridge.snapshot.push.exception.InternalErrorException;
-import uk.ac.ic.wlgitbridge.util.Log;
-
-import java.io.File;
-import java.io.IOException;
-
-/**
- * Created by Winston on 03/11/14.
- */
-public class SnapshotRepositoryBuilder {
-
-    private final Bridge bridgeAPI;
-
-    public SnapshotRepositoryBuilder(Bridge bridgeAPI) {
-        this.bridgeAPI = bridgeAPI;
-    }
-
-    public Repository getRepositoryWithNameAtRootDirectory(String name, File rootDirectory, Credential oauth2) throws RepositoryNotFoundException, ServiceMayNotContinueException, GitUserException {
-        if (!bridgeAPI.repositoryExists(oauth2, name)) {
-            throw new RepositoryNotFoundException(name);
-        }
-        File repositoryDirectory = new File(rootDirectory, name);
-
-        Repository repository = null;
-        try {
-            repository = new FileRepositoryBuilder().setWorkTree(repositoryDirectory).build();
-            new WLBridgedProject(repository, name, bridgeAPI).buildRepository(oauth2);
-        } catch (IOException e) {
-            Log.warn(
-                    "IOException when trying to get repo: " +
-                            name +
-                            ", at: "
-                            + rootDirectory.getAbsolutePath(),
-                    e
-            );
-            throw new ServiceMayNotContinueException(
-                    new InternalErrorException().getDescriptionLines().get(0)
-            );
-        }
-        return repository;
-    }
-
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/PersistentStore.java

@@ -1,20 +0,0 @@
-package uk.ac.ic.wlgitbridge.data.model.db;
-
-import java.util.List;
-
-/**
- * Created by m on 20/11/15.
- */
-public interface PersistentStore {
-    List<String> getProjectNames();
-
-    void setLatestVersionForProject(String project, int versionID);
-
-    int getLatestVersionForProject(String project);
-
-    void addURLIndexForProject(String projectName, String url, String path);
-
-    void deleteFilesForProject(String project, String... files);
-
-    String getPathForURLInProject(String projectName, String url);
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/SQLUpdate.java

@@ -1,14 +0,0 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql;
-
-import java.sql.PreparedStatement;
-import java.sql.SQLException;
-
-/**
- * Created by Winston on 20/11/14.
- */
-public interface SQLUpdate {
-
-    public String getSQL();
-    public void addParametersToStatement(PreparedStatement statement) throws SQLException;
-
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/SQLiteWLDatabase.java

@@ -1,107 +0,0 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql;
-
-import uk.ac.ic.wlgitbridge.data.model.db.sql.query.GetLatestVersionForProjectSQLQuery;
-import uk.ac.ic.wlgitbridge.data.model.db.sql.query.GetPathForURLInProjectSQLQuery;
-import uk.ac.ic.wlgitbridge.data.model.db.sql.query.GetProjectNamesSQLQuery;
-import uk.ac.ic.wlgitbridge.data.model.db.sql.update.create.CreateIndexURLIndexStore;
-import uk.ac.ic.wlgitbridge.data.model.db.sql.update.create.CreateProjectsTableSQLUpdate;
-import uk.ac.ic.wlgitbridge.data.model.db.sql.update.create.CreateURLIndexStoreSQLUpdate;
-import uk.ac.ic.wlgitbridge.data.model.db.sql.update.delete.DeleteFilesForProjectSQLUpdate;
-import uk.ac.ic.wlgitbridge.data.model.db.sql.update.insert.AddURLIndexSQLUpdate;
-import uk.ac.ic.wlgitbridge.data.model.db.sql.update.insert.SetProjectSQLUpdate;
-import uk.ac.ic.wlgitbridge.util.Log;
-
-import java.io.File;
-import java.sql.*;
-import java.util.List;
-
-/**
- * Created by Winston on 17/11/14.
- */
-public class SQLiteWLDatabase {
-
-    private final Connection connection;
-
-    public SQLiteWLDatabase(File rootGitDirectory) throws SQLException, ClassNotFoundException {
-        File databaseFile = new File(rootGitDirectory, "/.wlgb/wlgb.db");
-        File dotWlgbDir = databaseFile.getParentFile();
-        if (!dotWlgbDir.exists()) {
-            if (!dotWlgbDir.mkdirs()) {
-                Log.error("{} directory didn't exist, and unable to create. Check your permissions", dotWlgbDir.getAbsolutePath());
-            }
-        }
-        Class.forName("org.sqlite.JDBC");
-        connection = DriverManager.getConnection("jdbc:sqlite:" + databaseFile.getAbsolutePath());
-        createTables();
-    }
-
-    public void setVersionIDForProject(String projectName, int versionID) throws SQLException {
-        update(new SetProjectSQLUpdate(projectName, versionID));
-    }
-
-    public void addURLIndex(String projectName, String url, String path) throws SQLException {
-        update(new AddURLIndexSQLUpdate(projectName, url, path));
-    }
-
-    public void deleteFilesForProject(String projectName, String... paths) throws SQLException {
-        update(new DeleteFilesForProjectSQLUpdate(projectName, paths));
-    }
-
-    public int getVersionIDForProjectName(String projectName) throws SQLException {
-        return query(new GetLatestVersionForProjectSQLQuery(projectName));
-    }
-
-    public String getPathForURLInProject(String projectName, String url) throws SQLException {
-        return query(new GetPathForURLInProjectSQLQuery(projectName, url));
-    }
-
-    public List<String> getProjectNames() throws SQLException {
-        return query(new GetProjectNamesSQLQuery());
-    }
-
-    private void createTables() throws SQLException {
-        final SQLUpdate[] createTableUpdates = {
-                new CreateProjectsTableSQLUpdate(),
-                new CreateURLIndexStoreSQLUpdate(),
-                new CreateIndexURLIndexStore()
-        };
-
-        for (SQLUpdate update : createTableUpdates) {
-            update(update);
-        }
-    }
-
-    private void update(SQLUpdate update) throws SQLException {
-        PreparedStatement statement = null;
-        try {
-            statement = connection.prepareStatement(update.getSQL());
-            update.addParametersToStatement(statement);
-            statement.executeUpdate();
-        } catch (SQLException e) {
-            throw e;
-        } finally {
-            statement.close();
-        }
-    }
-
-    private <T> T query(SQLQuery<T> query) throws SQLException {
-        PreparedStatement statement = null;
-        ResultSet results = null;
-        try {
-            statement = connection.prepareStatement(query.getSQL());
-            query.addParametersToStatement(statement);
-            results = statement.executeQuery();
-            return query.processResultSet(results);
-        } catch (SQLException e) {
-            throw e;
-        } finally {
-            if (statement != null) {
-                statement.close();
-            }
-            if (results != null) {
-                results.close();
-            }
-        }
-    }
-
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/update/create/CreateIndexURLIndexStore.java

@@ -1,26 +0,0 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql.update.create;
-
-import uk.ac.ic.wlgitbridge.data.model.db.sql.SQLUpdate;
-
-import java.sql.PreparedStatement;
-import java.sql.SQLException;
-
-/**
- * Created by Winston on 21/02/15.
- */
-public class CreateIndexURLIndexStore implements SQLUpdate {
-
-    public static final String CREATE_INDEX_URL_INDEX_STORE =
-            "CREATE UNIQUE INDEX IF NOT EXISTS `project_path_index` ON `url_index_store`(`project_name`, `path`);\n";
-
-    @Override
-    public String getSQL() {
-        return CREATE_INDEX_URL_INDEX_STORE;
-    }
-
-    @Override
-    public void addParametersToStatement(PreparedStatement statement) throws SQLException {
-
-    }
-
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/data/model/db/sql/update/create/CreateProjectsTableSQLUpdate.java

@@ -1,29 +0,0 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql.update.create;
-
-import uk.ac.ic.wlgitbridge.data.model.db.sql.SQLUpdate;
-
-import java.sql.PreparedStatement;
-import java.sql.SQLException;
-
-/**
- * Created by Winston on 20/11/14.
- */
-public class CreateProjectsTableSQLUpdate implements SQLUpdate {
-
-    private static final String CREATE_PROJECTS_TABLE =
-            "CREATE TABLE IF NOT EXISTS `projects` (\n" +
-            "  `name` varchar(10) NOT NULL DEFAULT '',\n" +
-            "  `version_id` int(11) NOT NULL DEFAULT 0,\n" +
-            "  PRIMARY KEY (`name`)\n" +
-            ")";
-    @Override
-    public String getSQL() {
-        return CREATE_PROJECTS_TABLE;
-    }
-
-    @Override
-    public void addParametersToStatement(PreparedStatement statement) throws SQLException {
-
-    }
-
-}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/git/handler/WLReceivePackFactory.java

@@ -19,10 +19,10 @@ import javax.servlet.http.HttpServletRequest;
 /* */
 public class WLReceivePackFactory implements ReceivePackFactory<HttpServletRequest> {
 
-    private final Bridge bridgeAPI;
+    private final Bridge bridge;
 
-    public WLReceivePackFactory(Bridge bridgeAPI) {
-        this.bridgeAPI = bridgeAPI;
+    public WLReceivePackFactory(Bridge bridge) {
+        this.bridge = bridge;
     }
 
     @Override
@@ -33,7 +33,7 @@ public class WLReceivePackFactory implements ReceivePackFactory<HttpServletReque
         if (hostname == null) {
             hostname = httpServletRequest.getLocalName();
         }
-        receivePack.setPreReceiveHook(new WriteLatexPutHook(bridgeAPI, hostname, oauth2));
+        receivePack.setPreReceiveHook(new WriteLatexPutHook(bridge, hostname, oauth2));
         return receivePack;
     }
 

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/git/handler/WLRepositoryResolver.java

@@ -7,35 +7,48 @@ import org.eclipse.jgit.transport.ServiceMayNotContinueException;
 import org.eclipse.jgit.transport.resolver.RepositoryResolver;
 import org.eclipse.jgit.transport.resolver.ServiceNotAuthorizedException;
 import org.eclipse.jgit.transport.resolver.ServiceNotEnabledException;
-import uk.ac.ic.wlgitbridge.data.SnapshotRepositoryBuilder;
+import uk.ac.ic.wlgitbridge.bridge.Bridge;
+import uk.ac.ic.wlgitbridge.bridge.GitProjectRepo;
 import uk.ac.ic.wlgitbridge.git.exception.GitUserException;
-import uk.ac.ic.wlgitbridge.git.exception.InvalidRootDirectoryPathException;
 import uk.ac.ic.wlgitbridge.server.Oauth2Filter;
 import uk.ac.ic.wlgitbridge.snapshot.base.ForbiddenException;
 import uk.ac.ic.wlgitbridge.util.Log;
 import uk.ac.ic.wlgitbridge.util.Util;
 
 import javax.servlet.http.HttpServletRequest;
-import java.io.File;
+import java.io.IOException;
 
 /**
  * Created by Winston on 02/11/14.
  */
-public class WLRepositoryResolver implements RepositoryResolver<HttpServletRequest> {
+public class WLRepositoryResolver
+        implements RepositoryResolver<HttpServletRequest> {
 
-    private File rootGitDirectory;
-    private SnapshotRepositoryBuilder snapshotRepositoryBuilder;
+    private final Bridge bridge;
 
-    public WLRepositoryResolver(String rootGitDirectoryPath, SnapshotRepositoryBuilder repositorySource) throws InvalidRootDirectoryPathException {
-        this.snapshotRepositoryBuilder = repositorySource;
-        initRootGitDirectory(rootGitDirectoryPath);
+    public WLRepositoryResolver(Bridge bridge) {
+        this.bridge = bridge;
     }
 
     @Override
-    public Repository open(HttpServletRequest httpServletRequest, String name) throws RepositoryNotFoundException, ServiceNotAuthorizedException, ServiceNotEnabledException, ServiceMayNotContinueException {
-        Credential oauth2 = (Credential) httpServletRequest.getAttribute(Oauth2Filter.ATTRIBUTE_KEY);
+    public Repository open(
+            HttpServletRequest httpServletRequest,
+            String name
+    ) throws RepositoryNotFoundException,
+             ServiceNotAuthorizedException,
+             ServiceNotEnabledException,
+             ServiceMayNotContinueException {
+        Credential oauth2 = (Credential) httpServletRequest.getAttribute(
+                Oauth2Filter.ATTRIBUTE_KEY
+        );
+        String projName = Util.removeAllSuffixes(name, "/", ".git");
         try {
-            return snapshotRepositoryBuilder.getRepositoryWithNameAtRootDirectory(Util.removeAllSuffixes(name, "/", ".git"), rootGitDirectory, oauth2);
+            if (!bridge.projectExists(oauth2, projName)) {
+                throw new RepositoryNotFoundException(projName);
+            }
+            GitProjectRepo repo = new GitProjectRepo(projName);
+            bridge.updateRepository(oauth2, repo);
+            return repo.getJGitRepository();
         } catch (RepositoryNotFoundException e) {
             Log.info("Repository not found: " + name);
             throw e;
@@ -45,25 +58,25 @@ public class WLRepositoryResolver implements RepositoryResolver<HttpServletReque
         } catch (ServiceNotEnabledException e) {
             cannot occur
             */
-        } catch (ServiceMayNotContinueException e) { /* Such as FailedConnectionException */
+        } catch (ServiceMayNotContinueException e) {
+            /* Such as FailedConnectionException */
             throw e;
         } catch (RuntimeException e) {
-            Log.warn("Runtime exception when trying to open repo", e);
+            Log.warn(
+                    "Runtime exception when trying to open repo: " + projName,
+                    e
+            );
             throw new ServiceMayNotContinueException(e);
         } catch (ForbiddenException e) {
             throw new ServiceNotAuthorizedException();
         } catch (GitUserException e) {
             throw new ServiceMayNotContinueException(e.getMessage(), e);
-        }
-    }
-
-    private void initRootGitDirectory(String rootGitDirectoryPath) throws InvalidRootDirectoryPathException {
-        rootGitDirectory = new File(rootGitDirectoryPath);
-        /* throws SecurityException */
-        rootGitDirectory.mkdirs();
-        rootGitDirectory.getAbsolutePath();
-        if (!rootGitDirectory.isDirectory()) {
-            throw new InvalidRootDirectoryPathException();
+        } catch (IOException e) {
+            Log.warn(
+                    "IOException when trying to open repo: " + projName,
+                    e
+            );
+            throw new ServiceMayNotContinueException("Internal server error.");
         }
     }
 

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/git/handler/hook/WriteLatexPutHook.java

@@ -26,12 +26,12 @@ import java.util.Iterator;
  */
 public class WriteLatexPutHook implements PreReceiveHook {
 
-    private final Bridge bridgeAPI;
+    private final Bridge bridge;
     private final String hostname;
     private final Credential oauth2;
 
-    public WriteLatexPutHook(Bridge bridgeAPI, String hostname, Credential oauth2) {
-        this.bridgeAPI = bridgeAPI;
+    public WriteLatexPutHook(Bridge bridge, String hostname, Credential oauth2) {
+        this.bridge = bridge;
         this.hostname = hostname;
         this.oauth2 = oauth2;
     }
@@ -75,7 +75,7 @@ public class WriteLatexPutHook implements PreReceiveHook {
     private void handleReceiveCommand(Credential oauth2, Repository repository, ReceiveCommand receiveCommand) throws IOException, GitUserException {
         checkBranch(receiveCommand);
         checkForcedPush(receiveCommand);
-        bridgeAPI.putDirectoryContentsToProjectWithName(
+        bridge.putDirectoryContentsToProjectWithName(
                 oauth2,
                 repository.getWorkTree().getName(),
                 getPushedDirectoryContents(repository,

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/git/servlet/WLGitServlet.java

@@ -2,12 +2,11 @@ package uk.ac.ic.wlgitbridge.git.servlet;
 
 import org.eclipse.jetty.servlet.ServletContextHandler;
 import org.eclipse.jgit.http.server.GitServlet;
+import uk.ac.ic.wlgitbridge.bridge.Bridge;
 import uk.ac.ic.wlgitbridge.git.exception.InvalidRootDirectoryPathException;
 import uk.ac.ic.wlgitbridge.git.handler.WLReceivePackFactory;
 import uk.ac.ic.wlgitbridge.git.handler.WLRepositoryResolver;
 import uk.ac.ic.wlgitbridge.git.handler.WLUploadPackFactory;
-import uk.ac.ic.wlgitbridge.data.SnapshotRepositoryBuilder;
-import uk.ac.ic.wlgitbridge.bridge.Bridge;
 
 import javax.servlet.ServletException;
 
@@ -16,11 +15,14 @@ import javax.servlet.ServletException;
  */
 public class WLGitServlet extends GitServlet {
 
-    public WLGitServlet(ServletContextHandler servletContextHandler, Bridge bridgeAPI, String rootGitDirectoryPath) throws ServletException, InvalidRootDirectoryPathException {
-        setRepositoryResolver(new WLRepositoryResolver(rootGitDirectoryPath, new SnapshotRepositoryBuilder(bridgeAPI)));
-        setReceivePackFactory(new WLReceivePackFactory(bridgeAPI));
+    public WLGitServlet(
+            ServletContextHandler ctxHandler,
+            Bridge bridge
+    ) throws ServletException, InvalidRootDirectoryPathException {
+        setRepositoryResolver(new WLRepositoryResolver(bridge));
+        setReceivePackFactory(new WLReceivePackFactory(bridge));
         setUploadPackFactory(new WLUploadPackFactory());
-        init(new WLGitServletConfig(servletContextHandler));
+        init(new WLGitServletConfig(ctxHandler));
     }
 
 }

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/git/servlet/WLGitServletConfig.java

@@ -15,8 +15,8 @@ public class WLGitServletConfig implements ServletConfig {
 
     private ServletContext servletContext;
 
-    public WLGitServletConfig(ServletContextHandler servletContextHandler) {
-        servletContext = servletContextHandler.getServletContext();
+    public WLGitServletConfig(ServletContextHandler ctxHandler) {
+        servletContext = ctxHandler.getServletContext();
     }
 
     @Override

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/server/GitBridgeServer.java

@@ -10,10 +10,10 @@ import uk.ac.ic.wlgitbridge.application.config.Config;
 import uk.ac.ic.wlgitbridge.application.jetty.NullLogger;
 import uk.ac.ic.wlgitbridge.bridge.Bridge;
 import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
-import uk.ac.ic.wlgitbridge.bridge.db.SqliteDBStore;
-import uk.ac.ic.wlgitbridge.bridge.repo.FSRepoStore;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SqliteDBStore;
+import uk.ac.ic.wlgitbridge.bridge.repo.FSGitRepoStore;
 import uk.ac.ic.wlgitbridge.bridge.repo.RepoStore;
-import uk.ac.ic.wlgitbridge.bridge.swap.SwapStore;
+import uk.ac.ic.wlgitbridge.bridge.swap.store.SwapStore;
 import uk.ac.ic.wlgitbridge.git.exception.InvalidRootDirectoryPathException;
 import uk.ac.ic.wlgitbridge.git.servlet.WLGitServlet;
 import uk.ac.ic.wlgitbridge.snapshot.base.SnapshotAPIRequest;
@@ -25,6 +25,7 @@ import javax.servlet.Filter;
 import javax.servlet.ServletException;
 import java.io.File;
 import java.net.BindException;
+import java.nio.file.Paths;
 import java.util.EnumSet;
 
 /**
@@ -36,7 +37,7 @@ import java.util.EnumSet;
  */
 public class GitBridgeServer {
 
-    private final Bridge bridgeAPI;
+    private final Bridge bridge;
 
     private final Server jettyServer;
 
@@ -44,21 +45,31 @@ public class GitBridgeServer {
     private String rootGitDirectoryPath;
     private String apiBaseURL;
 
-    public GitBridgeServer(Config config) throws ServletException, InvalidRootDirectoryPathException {
+    public GitBridgeServer(
+            Config config
+    ) throws ServletException, InvalidRootDirectoryPathException {
         org.eclipse.jetty.util.log.Log.setLog(new NullLogger());
         this.port = config.getPort();
         this.rootGitDirectoryPath = config.getRootGitDirectory();
-        RepoStore repoStore = new FSRepoStore(rootGitDirectoryPath);
-        DBStore dbStore = new SqliteDBStore(repoStore.getRootDirectory());
-        SwapStore swapStore = new SwapStore() {};
-        bridgeAPI = Bridge.make(
+        RepoStore repoStore = new FSGitRepoStore(rootGitDirectoryPath);
+        DBStore dbStore = new SqliteDBStore(
+                Paths.get(
+                        repoStore.getRootDirectory().getAbsolutePath()
+                ).resolve(".wlgb").resolve("wlgb.db").toFile()
+        );
+        SwapStore swapStore = SwapStore.fromConfig(config.getSwapStore());
+        bridge = Bridge.make(
                 repoStore,
                 dbStore,
-                swapStore
+                swapStore,
+                config.getSwapJob()
         );
         jettyServer = new Server(port);
         configureJettyServer(config);
-        SnapshotAPIRequest.setBasicAuth(config.getUsername(), config.getPassword());
+        SnapshotAPIRequest.setBasicAuth(
+                config.getUsername(),
+                config.getPassword()
+        );
         apiBaseURL = config.getAPIBaseURL();
         SnapshotAPIRequest.setBaseURL(apiBaseURL);
         Util.setServiceName(config.getServiceName());
@@ -71,7 +82,9 @@ public class GitBridgeServer {
      */
     public void start() {
         try {
+            bridge.checkDB();
             jettyServer.start();
+            bridge.startSwapJob();
             Log.info(Util.getServiceName() + "-Git Bridge server started");
             Log.info("Listening on port: " + port);
             Log.info("Bridged to: " + apiBaseURL);
@@ -92,7 +105,9 @@ public class GitBridgeServer {
         }
     }
 
-    private void configureJettyServer(Config config) throws ServletException, InvalidRootDirectoryPathException {
+    private void configureJettyServer(
+            Config config
+    ) throws ServletException, InvalidRootDirectoryPathException {
         HandlerCollection handlers = new HandlerList();
         handlers.addHandler(initApiHandler());
         handlers.addHandler(initGitHandler(config));
@@ -105,31 +120,44 @@ public class GitBridgeServer {
 
         HandlerCollection handlers = new HandlerList();
         handlers.addHandler(initResourceHandler());
-        handlers.addHandler(new PostbackHandler(bridgeAPI));
+        handlers.addHandler(new PostbackHandler(bridge));
         handlers.addHandler(new DefaultHandler());
 
         api.setHandler(handlers);
         return api;
     }
 
-    private Handler initGitHandler(Config config) throws ServletException, InvalidRootDirectoryPathException {
-        final ServletContextHandler servletContextHandler = new ServletContextHandler(ServletContextHandler.SESSIONS);
+    private Handler initGitHandler(
+            Config config
+    ) throws ServletException, InvalidRootDirectoryPathException {
+        final ServletContextHandler servletContextHandler =
+                new ServletContextHandler(ServletContextHandler.SESSIONS);
         if (config.isUsingOauth2()) {
             Filter filter = new Oauth2Filter(config.getOauth2());
-            servletContextHandler.addFilter(new FilterHolder(filter), "/*", EnumSet.of(DispatcherType.REQUEST));
+            servletContextHandler.addFilter(
+                    new FilterHolder(filter),
+                    "/*",
+                    EnumSet.of(DispatcherType.REQUEST)
+            );
         }
         servletContextHandler.setContextPath("/");
         servletContextHandler.addServlet(
                 new ServletHolder(
-                        new WLGitServlet(servletContextHandler, bridgeAPI, rootGitDirectoryPath)),
+                        new WLGitServlet(
+                                servletContextHandler,
+                                bridge
+                        )
+                ),
                 "/*"
         );
         return servletContextHandler;
     }
 
     private Handler initResourceHandler() {
-        ResourceHandler resourceHandler = new FileHandler(bridgeAPI);
-        resourceHandler.setResourceBase(new File(rootGitDirectoryPath, ".wlgb/atts").getAbsolutePath());
+        ResourceHandler resourceHandler = new FileHandler(bridge);
+        resourceHandler.setResourceBase(
+                new File(rootGitDirectoryPath, ".wlgb/atts").getAbsolutePath()
+        );
         return resourceHandler;
     }
 }

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/server/PostbackContents.java

@@ -17,7 +17,7 @@ public class PostbackContents implements JSONSource {
 
     private static final String CODE_SUCCESS = "upToDate";
 
-    private final Bridge bridgeAPI;
+    private final Bridge bridge;
     private final String projectName;
     private final String postbackKey;
 
@@ -26,8 +26,8 @@ public class PostbackContents implements JSONSource {
     private int versionID;
     private SnapshotPostException exception;
 
-    public PostbackContents(Bridge bridgeAPI, String projectName, String postbackKey, String contents) {
-        this.bridgeAPI = bridgeAPI;
+    public PostbackContents(Bridge bridge, String projectName, String postbackKey, String contents) {
+        this.bridge = bridge;
         this.projectName = projectName;
         this.postbackKey = postbackKey;
         snapshotPostExceptionBuilder = new SnapshotPostExceptionBuilder();
@@ -43,9 +43,9 @@ public class PostbackContents implements JSONSource {
 
     public void processPostback() throws UnexpectedPostbackException {
         if (exception == null) {
-            bridgeAPI.postbackReceivedSuccessfully(projectName, postbackKey, versionID);
+            bridge.postbackReceivedSuccessfully(projectName, postbackKey, versionID);
         } else {
-            bridgeAPI.postbackReceivedWithException(projectName, postbackKey, exception);
+            bridge.postbackReceivedWithException(projectName, postbackKey, exception);
         }
     }
 

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/server/PostbackHandler.java

@@ -19,10 +19,10 @@ import java.io.IOException;
  */
 public class PostbackHandler extends AbstractHandler {
 
-    private final Bridge bridgeAPI;
+    private final Bridge bridge;
 
-    public PostbackHandler(Bridge bridgeAPI) {
-        this.bridgeAPI = bridgeAPI;
+    public PostbackHandler(Bridge bridge) {
+        this.bridge = bridge;
     }
 
     @Override
@@ -39,7 +39,7 @@ public class PostbackHandler extends AbstractHandler {
                 String projectName = parts[1];
                 String postbackKey = parts[2];
                 Log.info(baseRequest.getMethod() + " <- " + baseRequest.getHttpURI());
-                PostbackContents postbackContents = new PostbackContents(bridgeAPI, projectName, postbackKey, contents);
+                PostbackContents postbackContents = new PostbackContents(bridge, projectName, postbackKey, contents);
                 JsonObject body = new JsonObject();
 
                 try {

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/util/Files.java

@@ -0,0 +1,127 @@
+package uk.ac.ic.wlgitbridge.util;
+
+import com.google.api.client.repackaged.com.google.common.base.Preconditions;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.filefilter.TrueFileFilter;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class Files {
+
+    private Files() {}
+
+    public static boolean contentsAreEqual(
+            File f0,
+            File f1
+    ) throws IOException {
+        try {
+            return uncheckedContentsAreEqual(f0, f1);
+        } catch (UncheckedIOException e) {
+            throw e.getCause();
+        }
+    }
+
+    public static void renameAll(
+            File fileOrDir,
+            String from,
+            String to
+    ) {
+        if (fileOrDir.isDirectory()) {
+            File f = doRename(fileOrDir, from, to);
+            for (File c : f.listFiles()) {
+                renameAll(c, from, to);
+            }
+        } else if (fileOrDir.isFile()) {
+            doRename(fileOrDir, from, to);
+        } else {
+            throw new IllegalArgumentException(
+                    "not a file or dir: " + fileOrDir
+            );
+        }
+    }
+
+    private static File doRename(File fileOrDir, String from, String to) {
+        if (!fileOrDir.getName().equals(from)) {
+            return fileOrDir;
+        }
+        File renamed = new File(fileOrDir.getParent(), to);
+        Preconditions.checkState(fileOrDir.renameTo(renamed));
+        return renamed;
+    }
+
+    private static boolean uncheckedContentsAreEqual(File f0, File f1) throws IOException {
+        if (f0.equals(f1)) {
+            return true;
+        }
+        if (!f0.isDirectory() || !f1.isDirectory()) {
+            return !f0.isDirectory() && !f1.isDirectory() &&
+                    Arrays.equals(
+                            FileUtils.readFileToByteArray(f0),
+                            FileUtils.readFileToByteArray(f1)
+                    );
+        }
+        Path f0Base = Paths.get(f0.getAbsolutePath());
+        Path f1Base = Paths.get(f1.getAbsolutePath());
+        Set<Path> children0 = getChildren(f0, f0Base);
+        Set<Path> children1 = getChildren(f1, f1Base);
+        if (children0.size() != children1.size()) {
+            return false;
+        }
+        return children0.stream(
+        ).allMatch(c0 ->
+                children1.contains(c0) && childEquals(c0, f0Base, f1Base)
+        );
+    }
+
+    private static Set<Path> getChildren(File f0, Path f0Base) {
+        return FileUtils.listFilesAndDirs(
+                f0,
+                TrueFileFilter.TRUE,
+                TrueFileFilter.TRUE
+        ).stream(
+        ).map(
+                File::getAbsolutePath
+        ).map(
+                Paths::get
+        ).map(p ->
+                f0Base.relativize(p)
+        ).filter(p ->
+                !p.toString().isEmpty()
+        ).collect(
+                Collectors.toSet()
+        );
+    }
+
+    private static boolean childEquals(
+            Path child,
+            Path f0Base,
+            Path f1Base
+    ) throws UncheckedIOException {
+        File c0 = f0Base.resolve(child).toFile();
+        File c1 = f1Base.resolve(child).toFile();
+        boolean c0IsDir = c0.isDirectory();
+        boolean c1IsDir = c1.isDirectory();
+        if (c0IsDir || c1IsDir) {
+            return c0IsDir && c1IsDir;
+        }
+        try {
+            return c0.isFile() && c1.isFile() && Arrays.equals(
+                    FileUtils.readFileToByteArray(c0),
+                    FileUtils.readFileToByteArray(c1)
+            );
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/util/Project.java

@@ -0,0 +1,13 @@
+package uk.ac.ic.wlgitbridge.util;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class Project {
+
+    public static boolean isValidProjectName(String projectName) {
+        return projectName != null && !projectName.isEmpty()
+                && !projectName.startsWith(".");
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/util/Tar.java

@@ -0,0 +1,151 @@
+package uk.ac.ic.wlgitbridge.util;
+
+import com.google.api.client.repackaged.com.google.common.base.Preconditions;
+import org.apache.commons.compress.archivers.ArchiveEntry;
+import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
+import org.apache.commons.compress.archivers.tar.TarArchiveOutputStream;
+import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream;
+import org.apache.commons.compress.compressors.bzip2.BZip2CompressorOutputStream;
+import org.apache.commons.compress.utils.IOUtils;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.output.ByteArrayOutputStream;
+
+import java.io.*;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class Tar {
+
+    public static class bz2 {
+
+        public static InputStream zip(
+                File fileOrDir
+        ) throws IOException {
+            return zip(fileOrDir, null);
+        }
+
+        public static InputStream zip(
+                File fileOrDir,
+                long[] sizePtr
+        ) throws IOException {
+            ByteArrayOutputStream target = new ByteArrayOutputStream();
+            try (OutputStream bzip2 = new BZip2CompressorOutputStream(target)) {
+                tarTo(fileOrDir, bzip2);
+            }
+            if (sizePtr != null) {
+                sizePtr[0] = target.size();
+            }
+            return target.toInputStream();
+        }
+
+        public static void unzip(
+                InputStream tarbz2,
+                File parentDir
+        ) throws IOException {
+            try (InputStream tar = new BZip2CompressorInputStream(tarbz2)) {
+                untar(tar, parentDir);
+            }
+        }
+
+    }
+
+    private Tar() {}
+
+    public static InputStream tar(File fileOrDir) throws IOException {
+        ByteArrayOutputStream target = new ByteArrayOutputStream();
+        tarTo(fileOrDir, target);
+        return target.toInputStream();
+    }
+
+    public static void tarTo(
+            File fileOrDir,
+            OutputStream target
+    ) throws IOException {
+        try (TarArchiveOutputStream tout = new TarArchiveOutputStream(target)) {
+            addTarEntry(
+                    tout,
+                    Paths.get(fileOrDir.getParentFile().getAbsolutePath()),
+                    fileOrDir
+            );
+        }
+    }
+
+    public static void untar(
+            InputStream tar,
+            File parentDir
+    ) throws IOException {
+        TarArchiveInputStream tin = new TarArchiveInputStream(tar);
+        ArchiveEntry e;
+        while ((e = tin.getNextEntry()) != null) {
+            File f = new File(parentDir, e.getName());
+            f.setLastModified(e.getLastModifiedDate().getTime());
+            f.getParentFile().mkdirs();
+            if (e.isDirectory()) {
+                f.mkdir();
+                continue;
+            }
+            long size = e.getSize();
+            Preconditions.checkArgument(
+                    size > 0 && size < Integer.MAX_VALUE,
+                    "file too big: tarTo should have thrown an IOException"
+            );
+            try (OutputStream out = new FileOutputStream(f)) {
+                /* TarInputStream pretends each
+                   entry's EOF is the stream's EOF */
+                IOUtils.copy(tin, out);
+            }
+        }
+    }
+
+    private static void addTarEntry(
+            TarArchiveOutputStream tout,
+            Path base,
+            File fileOrDir
+    ) throws IOException {
+        if (fileOrDir.isDirectory()) {
+            addTarDir(tout, base, fileOrDir);
+        } else if (fileOrDir.isFile()) {
+            addTarFile(tout, base, fileOrDir);
+        } else {
+            throw new IllegalArgumentException(
+                    "invalid file or dir: " + fileOrDir
+            );
+        }
+    }
+
+    private static void addTarDir(
+            TarArchiveOutputStream tout,
+            Path base,
+            File dir
+    ) throws IOException {
+        Preconditions.checkArgument(dir.isDirectory());
+        String name = base.relativize(
+                Paths.get(dir.getAbsolutePath())
+        ).toString();
+        ArchiveEntry entry = tout.createArchiveEntry(dir, name);
+        tout.putArchiveEntry(entry);
+        tout.closeArchiveEntry();
+        for (File f : dir.listFiles()) {
+            addTarEntry(tout, base, f);
+        }
+    }
+
+    private static void addTarFile(
+            TarArchiveOutputStream tout,
+            Path base,
+            File file
+    ) throws IOException {
+        Preconditions.checkArgument(file.isFile());
+        String name = base.relativize(
+                Paths.get(file.getAbsolutePath())
+        ).toString();
+        ArchiveEntry entry = tout.createArchiveEntry(file, name);
+        tout.putArchiveEntry(entry);
+        tout.write(FileUtils.readFileToByteArray(file));
+        tout.closeArchiveEntry();
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/util/Timer.java

@@ -0,0 +1,19 @@
+package uk.ac.ic.wlgitbridge.util;
+
+import java.util.TimerTask;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class Timer {
+
+    public static TimerTask makeTimerTask(Runnable lamb) {
+        return new TimerTask() {
+            @Override
+            public void run() {
+                lamb.run();
+            }
+        };
+    }
+
+}

services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/util/Util.java

@@ -19,15 +19,6 @@ public class Util {
     private static String POSTBACK_URL;
     private static final DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS");
 
-    public static TimerTask makeTimerTask(Runnable lamb) {
-        return new TimerTask() {
-            @Override
-            public void run() {
-                lamb.run();
-            }
-        };
-    }
-
     public static String entries(int entries) {
         if (entries == 1) {
             return "entry";

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/WLGitBridgeIntegrationTest.java → services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/application/WLGitBridgeIntegrationTest.java

@@ -1,13 +1,14 @@
-package uk.ac.ic.wlgitbridge;
+package uk.ac.ic.wlgitbridge.application;
 
 import com.ning.http.client.AsyncHttpClient;
 import com.ning.http.client.Response;
+import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.IOUtils;
 import org.eclipse.jgit.api.errors.GitAPIException;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
-import uk.ac.ic.wlgitbridge.application.GitBridgeApp;
+import uk.ac.ic.wlgitbridge.bridge.swap.job.SwapJobConfig;
 import uk.ac.ic.wlgitbridge.snapshot.servermock.server.MockSnapshotServer;
 import uk.ac.ic.wlgitbridge.snapshot.servermock.state.SnapshotAPIState;
 import uk.ac.ic.wlgitbridge.snapshot.servermock.state.SnapshotAPIStateBuilder;
@@ -15,6 +16,7 @@ import uk.ac.ic.wlgitbridge.snapshot.servermock.util.FileUtil;
 import uk.ac.ic.wlgitbridge.util.Util;
 
 import java.io.*;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.Arrays;
@@ -102,6 +104,9 @@ public class WLGitBridgeIntegrationTest {
         put("canServePushedFiles", new HashMap<String, SnapshotAPIState>() {{
             put("state", new SnapshotAPIStateBuilder(getResourceAsStream("/canServePushedFiles/state/state.json")).build());
         }});
+        put("wlgbCanSwapProjects", new HashMap<String, SnapshotAPIState>() {{
+            put("state", new SnapshotAPIStateBuilder(getResourceAsStream("/wlgbCanSwapProjects/state/state.json")).build());
+        }});
     }};
 
     @Rule
@@ -587,14 +592,56 @@ public class WLGitBridgeIntegrationTest {
         wlgb.stop();
     }
 
+    @Test
+    public void wlgbCanSwapProjects(
+    ) throws IOException, GitAPIException, InterruptedException {
+        MockSnapshotServer server = new MockSnapshotServer(
+                3874,
+                getResource("/wlgbCanSwapProjects").toFile()
+        );
+        server.start();
+        server.setState(states.get("wlgbCanSwapProjects").get("state"));
+        GitBridgeApp wlgb = new GitBridgeApp(new String[] {
+                makeConfigFile(33874, 3874, new SwapJobConfig(1, 0, 0, 250))
+        });
+        wlgb.run();
+        File dir = folder.newFolder();
+        File rootGitDir = new File(wlgb.config.getRootGitDirectory());
+        File testProj1ServerDir = new File(rootGitDir, "testproj1");
+        File testProj2ServerDir = new File(rootGitDir, "testproj2");
+        File testProj1Dir = cloneRepository("testproj1", 33874, dir);
+        assertTrue(testProj1ServerDir.exists());
+        assertFalse(testProj2ServerDir.exists());
+        cloneRepository("testproj2", 33874, dir);
+        while (testProj1ServerDir.exists());
+        assertFalse(testProj1ServerDir.exists());
+        assertTrue(testProj2ServerDir.exists());
+        FileUtils.deleteDirectory(testProj1Dir);
+        cloneRepository("testproj1", 33874, dir);
+        while (testProj2ServerDir.exists());
+        assertTrue(testProj1ServerDir.exists());
+        assertFalse(testProj2ServerDir.exists());
+        wlgb.stop();
+    }
+
     private File cloneRepository(String repositoryName, int port, File dir) throws IOException, InterruptedException {
         String repo = "git clone http://127.0.0.1:" + port + "/" + repositoryName + ".git";
         Process gitProcess = runtime.exec(repo, null, dir);
         int exitCode = gitProcess.waitFor();
         if (exitCode != 0) {
             System.err.println("git clone failed. Dumping stderr and stdout.");
-            System.err.println(IOUtils.toString(gitProcess.getErrorStream()));
-            System.err.println(IOUtils.toString(gitProcess.getInputStream()));
+            System.err.println(
+                    IOUtils.toString(
+                            gitProcess.getErrorStream(),
+                            StandardCharsets.UTF_8
+                    )
+            );
+            System.err.println(
+                    IOUtils.toString(
+                            gitProcess.getInputStream(),
+                            StandardCharsets.UTF_8
+                    )
+            );
             fail("git clone failed");
         }
         File repositoryDir = new File(dir, repositoryName);
@@ -606,30 +653,75 @@ public class WLGitBridgeIntegrationTest {
         return repositoryDir;
     }
 
-    private String makeConfigFile(int port, int apiPort) throws IOException {
+    private String makeConfigFile(
+            int port,
+            int apiPort
+    ) throws IOException {
+        return makeConfigFile(port, apiPort, null);
+    }
+
+    private String makeConfigFile(
+            int port,
+            int apiPort,
+            SwapJobConfig swapCfg
+    ) throws IOException {
         File wlgb = folder.newFolder();
         File config = folder.newFile();
         PrintWriter writer = new PrintWriter(config);
-        writer.println("{\n" +
-            "\t\"port\": " + port + ",\n" +
-            "\t\"rootGitDirectory\": \"" + wlgb.getAbsolutePath() + "\",\n" +
-            "\t\"apiBaseUrl\": \"http://127.0.0.1:" + apiPort + "/api/v0\",\n" +
-            "\t\"username\": \"\",\n" +
-            "\t\"password\": \"\",\n" +
-            "\t\"postbackBaseUrl\": \"http://127.0.0.1:" + port + "\",\n" +
-            "\t\"serviceName\": \"Overleaf\"\n," +
-            "    \"oauth2\": {\n" +
-            "        \"oauth2ClientID\": \"clientID\",\n" +
-            "        \"oauth2ClientSecret\": \"oauth2 client secret\",\n" +
-            "        \"oauth2Server\": \"https://www.overleaf.com\"\n" +
-            "    }\n" +
-            "}\n");
+        String cfgStr =
+                "{\n" +
+                "    \"port\": " + port + ",\n" +
+                "    \"rootGitDirectory\": \"" +
+                        wlgb.getAbsolutePath() +
+                        "\",\n" +
+                "    \"apiBaseUrl\": \"http://127.0.0.1:" +
+                        apiPort +
+                        "/api/v0\",\n" +
+                "    \"username\": \"\",\n" +
+                "    \"password\": \"\",\n" +
+                "    \"postbackBaseUrl\": \"http://127.0.0.1:" +
+                        port +
+                        "\",\n" +
+                "    \"serviceName\": \"Overleaf\",\n" +
+                "    \"oauth2\": {\n" +
+                "        \"oauth2ClientID\": \"clientID\",\n" +
+                "        \"oauth2ClientSecret\": \"oauth2 client secret\",\n" +
+                "        \"oauth2Server\": \"https://www.overleaf.com\"\n" +
+                "    }";
+        if (swapCfg != null) {
+            cfgStr += ",\n" +
+                    "    \"swapStore\": {\n" +
+                    "        \"type\": \"memory\",\n" +
+                    "        \"awsAccessKey\": null,\n" +
+                    "        \"awsSecret\": null,\n" +
+                    "        \"s3BucketName\": \"com.overleaf.testbucket\"\n" +
+                    "    },\n" +
+                    "    \"swapJob\": {\n" +
+                    "        \"minProjects\": " +
+                    swapCfg.getMinProjects() +
+                    ",\n" +
+                    "        \"lowGiB\": " +
+                    swapCfg.getLowGiB() +
+                    ",\n" +
+                    "        \"highGiB\": " +
+                    swapCfg.getHighGiB() +
+                    ",\n" +
+                    "        \"intervalMillis\": " +
+                    swapCfg.getIntervalMillis() +
+                    "\n" +
+                    "    }\n";
+        }
+        cfgStr += "}\n";
+        writer.print(cfgStr);
         writer.close();
         return config.getAbsolutePath();
     }
 
     private Path getResource(String path) {
-        return Paths.get("src/test/resources/uk/ac/ic/wlgitbridge/WLGitBridgeIntegrationTest" + path);
+        return Paths.get(
+                "src/test/resources/" +
+                "uk/ac/ic/wlgitbridge/WLGitBridgeIntegrationTest" + path
+        );
     }
 
     private InputStream getResourceAsStream(String path) {

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/BridgeTest.java

@@ -3,15 +3,25 @@ package uk.ac.ic.wlgitbridge.bridge;
 import org.junit.Before;
 import org.junit.Test;
 import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
+import uk.ac.ic.wlgitbridge.bridge.db.ProjectState;
 import uk.ac.ic.wlgitbridge.bridge.lock.ProjectLock;
 import uk.ac.ic.wlgitbridge.bridge.repo.RepoStore;
 import uk.ac.ic.wlgitbridge.bridge.resource.ResourceCache;
 import uk.ac.ic.wlgitbridge.bridge.snapshot.SnapshotAPI;
-import uk.ac.ic.wlgitbridge.bridge.swap.SwapJob;
-import uk.ac.ic.wlgitbridge.bridge.swap.SwapStore;
+import uk.ac.ic.wlgitbridge.bridge.swap.job.SwapJob;
+import uk.ac.ic.wlgitbridge.bridge.swap.store.SwapStore;
+import uk.ac.ic.wlgitbridge.data.model.Snapshot;
+import uk.ac.ic.wlgitbridge.git.exception.GitUserException;
 
+import java.io.IOException;
+import java.util.ArrayDeque;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyInt;
+import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 /**
  * Created by winston on 20/08/2016.
@@ -35,24 +45,42 @@ public class BridgeTest {
         dbStore = mock(DBStore.class);
         swapStore = mock(SwapStore.class);
         snapshotAPI = mock(SnapshotAPI.class);
+        resourceCache = mock(ResourceCache.class);
         swapJob = mock(SwapJob.class);
         bridge = new Bridge(
                 lock,
                 repoStore,
                 dbStore,
                 swapStore,
+                swapJob,
                 snapshotAPI,
-                resourceCache,
-                swapJob
+                resourceCache
         );
     }
 
     @Test
     public void shutdownStopsSwapJob() {
-        bridge.startSwapJob(1000);
+        bridge.startSwapJob();
         bridge.doShutdown();
-        verify(swapJob).start(1000);
+        verify(swapJob).start();
         verify(swapJob).stop();
     }
 
+    @Test
+    public void updatingRepositorySetsLastAccessedTime(
+    ) throws IOException, GitUserException {
+        ProjectRepo repo = mock(ProjectRepo.class);
+        when(repo.getProjectName()).thenReturn("asdf");
+        when(dbStore.getProjectState("asdf")).thenReturn(ProjectState.PRESENT);
+        when(
+                snapshotAPI.getSnapshotsForProjectAfterVersion(
+                        any(),
+                        any(),
+                        anyInt()
+                )
+        ).thenReturn(new ArrayDeque<Snapshot>());
+        bridge.updateRepository(null, repo);
+        verify(dbStore).setLastAccessedTime(eq("asdf"), any());
+    }
+
 }

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/SqliteDBStoreTest.java

@@ -0,0 +1,150 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import uk.ac.ic.wlgitbridge.bridge.db.ProjectState;
+
+import java.io.IOException;
+import java.sql.Timestamp;
+import java.time.LocalDateTime;
+import java.time.temporal.ChronoUnit;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class SqliteDBStoreTest {
+
+    private SqliteDBStore dbStore;
+
+    @Before
+    public void setup() throws IOException {
+        TemporaryFolder tmpFolder = new TemporaryFolder();
+        tmpFolder.create();
+        dbStore = new SqliteDBStore(tmpFolder.newFile("dbStore.db"));
+    }
+
+    @Test
+    public void testGetNumProjects() {
+        assertEquals(0, dbStore.getNumProjects());
+        dbStore.setLatestVersionForProject("asdf", 1);
+        assertEquals(1, dbStore.getNumProjects());
+        dbStore.setLatestVersionForProject("asdf1", 2);
+        assertEquals(2, dbStore.getNumProjects());
+        dbStore.setLatestVersionForProject("asdf1", 3);
+        assertEquals(2, dbStore.getNumProjects());
+    }
+
+    @Test
+    public void swapTableStartsOutEmpty() {
+        assertNull(dbStore.getOldestUnswappedProject());
+    }
+
+    @Test
+    public void testGetOldestUnswappedProject() {
+        dbStore.setLatestVersionForProject("older", 3);
+        dbStore.setLastAccessedTime(
+                "older",
+                Timestamp.valueOf(
+                        LocalDateTime.now().minus(5, ChronoUnit.SECONDS)
+                )
+        );
+        dbStore.setLatestVersionForProject("asdf", 1);
+        dbStore.setLastAccessedTime(
+                "asdf",
+                Timestamp.valueOf(
+                        LocalDateTime.now().minus(1, ChronoUnit.SECONDS)
+                )
+        );
+        assertEquals("older", dbStore.getOldestUnswappedProject());
+        dbStore.setLastAccessedTime(
+                "older",
+                Timestamp.valueOf(
+                        LocalDateTime.now()
+                )
+        );
+        assertEquals("asdf", dbStore.getOldestUnswappedProject());
+    }
+
+    @Test
+    public void noOldestProjectIfAllEvicted() {
+        dbStore.setLatestVersionForProject("older", 3);
+        dbStore.setLastAccessedTime("older", null);
+        assertNull(dbStore.getOldestUnswappedProject());
+    }
+
+    @Test
+    public void nullLastAccessedTimesDoNotCount() {
+        dbStore.setLatestVersionForProject("older", 2);
+        dbStore.setLastAccessedTime(
+                "older",
+                Timestamp.valueOf(
+                        LocalDateTime.now().minus(5, ChronoUnit.SECONDS)
+                )
+        );
+        dbStore.setLatestVersionForProject("newer", 3);
+        dbStore.setLastAccessedTime(
+                "newer",
+                Timestamp.valueOf(
+                        LocalDateTime.now()
+                )
+        );
+        assertEquals("older", dbStore.getOldestUnswappedProject());
+        dbStore.setLastAccessedTime("older", null);
+        assertEquals("newer", dbStore.getOldestUnswappedProject());
+    }
+
+    @Test
+    public void missingProjectLastAccessedTimeCanBeSet() {
+        dbStore.setLatestVersionForProject("asdf", 1);
+        dbStore.setLastAccessedTime(
+                "asdf",
+                Timestamp.valueOf(LocalDateTime.now())
+        );
+        assertEquals("asdf", dbStore.getOldestUnswappedProject());
+    }
+
+    @Test
+    public void testGetNumUnswappedProjects() {
+        dbStore.setLatestVersionForProject("asdf", 1);
+        dbStore.setLastAccessedTime(
+                "asdf",
+                Timestamp.valueOf(LocalDateTime.now())
+        );
+        assertEquals(1, dbStore.getNumUnswappedProjects());
+        dbStore.setLastAccessedTime(
+                "asdf",
+                null
+        );
+        assertEquals(0, dbStore.getNumUnswappedProjects());
+    }
+
+    @Test
+    public void projectStateIsNotPresentIfNotInDBAtAll() {
+        assertEquals(
+                ProjectState.NOT_PRESENT,
+                dbStore.getProjectState("asdf")
+        );
+    }
+
+    @Test
+    public void projectStateIsPresentIfProjectHasLastAccessed() {
+        dbStore.setLatestVersionForProject("asdf", 1);
+        dbStore.setLastAccessedTime(
+                "asdf",
+                Timestamp.valueOf(LocalDateTime.now())
+        );
+        assertEquals(ProjectState.PRESENT, dbStore.getProjectState("asdf"));
+    }
+
+    @Test
+    public void projectStateIsSwappedIfLastAccessedIsNull() {
+        dbStore.setLatestVersionForProject("asdf", 1);
+        dbStore.setLastAccessedTime("asdf", null);
+        assertEquals(ProjectState.SWAPPED, dbStore.getProjectState("asdf"));
+    }
+
+}

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/db/sqlite/update/delete/DeleteFilesForProjectSQLUpdateTest.java

@@ -0,0 +1,24 @@
+package uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.delete;
+
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class DeleteFilesForProjectSQLUpdateTest {
+
+    @Test
+    public void testGetSQL() {
+        DeleteFilesForProjectSQLUpdate update =
+                new DeleteFilesForProjectSQLUpdate(
+                        "projname",
+                        "path1",
+                        "path2"
+                );
+        assertEquals(
+                "DELETE FROM `url_index_store` " +
+                        "WHERE `project_name` = ? " +
+                        "AND path IN (?, ?);\n",
+                update.getSQL()
+        );
+    }
+
+}

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/repo/FSGitRepoStoreTest.java

@@ -0,0 +1,83 @@
+package uk.ac.ic.wlgitbridge.bridge.repo;
+
+import org.apache.commons.io.FileUtils;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import uk.ac.ic.wlgitbridge.util.Files;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class FSGitRepoStoreTest {
+
+    public static File makeTempRepoDir(
+            TemporaryFolder tmpFolder,
+            String name
+    ) throws IOException {
+        File tmp = tmpFolder.newFolder(name);
+        Path rootdir = Paths.get(
+                "src/test/resources/uk/ac/ic/wlgitbridge/"
+                        + "bridge/repo/FSGitRepoStoreTest/rootdir"
+        );
+        FileUtils.copyDirectory(rootdir.toFile(), tmp);
+        Files.renameAll(tmp, "DOTgit", ".git");
+        return tmp;
+    }
+
+    private FSGitRepoStore repoStore;
+    private File original;
+
+    @Before
+    public void setup() throws IOException {
+        TemporaryFolder tmpFolder = new TemporaryFolder();
+        tmpFolder.create();
+        File tmp = makeTempRepoDir(tmpFolder, "rootdir");
+        original = tmpFolder.newFolder("original");
+        FileUtils.copyDirectory(tmp, original);
+        repoStore = new FSGitRepoStore(tmp.getAbsolutePath());
+    }
+
+    @Test
+    public void testPurgeNonexistentProjects() {
+        File toDelete = new File(repoStore.getRootDirectory(), "idontexist");
+        File wlgb = new File(repoStore.getRootDirectory(), ".wlgb");
+        Assert.assertTrue(toDelete.exists());
+        Assert.assertTrue(wlgb.exists());
+        repoStore.purgeNonexistentProjects(Arrays.asList("proj1", "proj2"));
+        Assert.assertFalse(toDelete.exists());
+        Assert.assertTrue(wlgb.exists());
+    }
+
+    @Test
+    public void testTotalSize() {
+        assertEquals(31860, repoStore.totalSize());
+    }
+
+    @Test
+    public void zipAndUnzipShouldBeTheSame() throws IOException {
+        long beforeSize = repoStore.totalSize();
+        InputStream zipped = repoStore.bzip2Project("proj1");
+        repoStore.remove("proj1");
+        Assert.assertTrue(beforeSize > repoStore.totalSize());
+        repoStore.unbzip2Project("proj1", zipped);
+        Assert.assertEquals(beforeSize, repoStore.totalSize());
+        Assert.assertTrue(
+                Files.contentsAreEqual(
+                        original,
+                        repoStore.getRootDirectory()
+                )
+        );
+    }
+
+}

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/swap/job/SwapJobImplTest.java

@@ -0,0 +1,119 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.job;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SqliteDBStore;
+import uk.ac.ic.wlgitbridge.bridge.lock.ProjectLock;
+import uk.ac.ic.wlgitbridge.bridge.repo.FSGitRepoStore;
+import uk.ac.ic.wlgitbridge.bridge.repo.FSGitRepoStoreTest;
+import uk.ac.ic.wlgitbridge.bridge.repo.RepoStore;
+import uk.ac.ic.wlgitbridge.bridge.swap.store.InMemorySwapStore;
+import uk.ac.ic.wlgitbridge.bridge.swap.store.SwapStore;
+import uk.ac.ic.wlgitbridge.data.ProjectLockImpl;
+
+import java.io.IOException;
+import java.sql.Timestamp;
+import java.time.Duration;
+import java.time.LocalDateTime;
+import java.time.temporal.ChronoUnit;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Created by winston on 20/08/2016.
+ */
+public class SwapJobImplTest {
+
+    private SwapJobImpl swapJob;
+
+    private ProjectLock lock;
+    private RepoStore repoStore;
+    private DBStore dbStore;
+    private SwapStore swapStore;
+
+    @Before
+    public void setup() throws IOException {
+        TemporaryFolder tmpFolder = new TemporaryFolder();
+        tmpFolder.create();
+        lock = new ProjectLockImpl();
+        repoStore = new FSGitRepoStore(
+                FSGitRepoStoreTest.makeTempRepoDir(
+                        tmpFolder,
+                        "repostore"
+                ).getAbsolutePath()
+        );
+        dbStore = new SqliteDBStore(tmpFolder.newFile());
+        dbStore.setLatestVersionForProject("proj1", 0);
+        dbStore.setLatestVersionForProject("proj2", 0);
+        dbStore.setLastAccessedTime(
+                "proj1",
+                Timestamp.valueOf(LocalDateTime.now())
+        );
+        dbStore.setLastAccessedTime(
+                "proj2",
+                Timestamp.valueOf(
+                        LocalDateTime.now().minus(1, ChronoUnit.SECONDS)
+                )
+        );
+        swapStore = new InMemorySwapStore();
+        swapJob = new SwapJobImpl(
+                1,
+                15000,
+                30000,
+                Duration.ofMillis(100),
+                lock,
+                repoStore,
+                dbStore,
+                swapStore
+        );
+    }
+
+    @Test
+    public void startingTimerAlwaysCausesASwap() {
+        swapJob.lowWatermarkBytes = 16384;
+        swapJob.interval = Duration.ofHours(1);
+        assertEquals(0, swapJob.swaps.get());
+        swapJob.start();
+        while (swapJob.swaps.get() <= 0);
+        assertTrue(swapJob.swaps.get() > 0);
+    }
+
+    @Test
+    public void swapsHappenEveryInterval() {
+        swapJob.lowWatermarkBytes = 16384;
+        assertEquals(0, swapJob.swaps.get());
+        swapJob.start();
+        while (swapJob.swaps.get() <= 1);
+        assertTrue(swapJob.swaps.get() > 1);
+    }
+
+    @Test
+    public void noProjectsGetSwappedWhenUnderHighWatermark() {
+        swapJob.highWatermarkBytes = 65536;
+        assertEquals(2, dbStore.getNumUnswappedProjects());
+        swapJob.start();
+        while (swapJob.swaps.get() < 1);
+        assertEquals(2, dbStore.getNumUnswappedProjects());
+    }
+
+    @Test
+    public void correctProjGetSwappedWhenOverHighWatermark(
+    ) throws IOException {
+        swapJob.lowWatermarkBytes = 16384;
+        assertEquals(2, dbStore.getNumUnswappedProjects());
+        assertEquals("proj2", dbStore.getOldestUnswappedProject());
+        swapJob.start();
+        while (swapJob.swaps.get() < 1);
+        assertEquals(1, dbStore.getNumUnswappedProjects());
+        assertEquals("proj1", dbStore.getOldestUnswappedProject());
+        swapJob.restore("proj2");
+        int numSwaps = swapJob.swaps.get();
+        while (swapJob.swaps.get() <= numSwaps);
+        assertEquals(1, dbStore.getNumUnswappedProjects());
+        assertEquals("proj2", dbStore.getOldestUnswappedProject());
+    }
+
+}

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/swap/store/InMemorySwapStoreTest.java

@@ -0,0 +1,96 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.store;
+
+import org.apache.commons.io.IOUtils;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import uk.ac.ic.wlgitbridge.bridge.swap.store.InMemorySwapStore;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+
+import static org.junit.Assert.assertArrayEquals;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class InMemorySwapStoreTest {
+
+    private final InMemorySwapStore swapStore = new InMemorySwapStore();
+
+    @Rule
+    public final ExpectedException exception = ExpectedException.none();
+
+    @Test
+    public void downloadingNonExistentFileThrows() {
+        exception.expect(IllegalArgumentException.class);
+        swapStore.openDownloadStream("asdf");
+    }
+
+    @Test
+    public void canDownloadUploadedFiles() throws IOException {
+        byte[] proj1Contents = "helloproj1".getBytes();
+        byte[] proj2Contents = "asdfproj2".getBytes();
+        swapStore.upload(
+                "proj1",
+                new ByteArrayInputStream(proj1Contents),
+                proj1Contents.length
+        );
+        swapStore.upload(
+                "proj2",
+                new ByteArrayInputStream(proj2Contents),
+                proj2Contents.length
+        );
+        assertArrayEquals(
+                proj1Contents,
+                IOUtils.toByteArray(swapStore.openDownloadStream("proj1"))
+        );
+        assertArrayEquals(
+                proj2Contents,
+                IOUtils.toByteArray(swapStore.openDownloadStream("proj2"))
+        );
+    }
+
+    @Test
+    public void uploadingForTheSameProjectOverwritesTheFile(
+    ) throws IOException {
+        byte[] proj1Contents = "helloproj1".getBytes();
+        byte[] proj1NewContents = "goodbyeproj1".getBytes();
+        swapStore.upload(
+                "proj1",
+                new ByteArrayInputStream(proj1Contents),
+                proj1Contents.length
+        );
+        assertArrayEquals(
+                proj1Contents,
+                IOUtils.toByteArray(swapStore.openDownloadStream("proj1"))
+        );
+        swapStore.upload(
+                "proj1",
+                new ByteArrayInputStream(proj1NewContents),
+                proj1NewContents.length
+        );
+        assertArrayEquals(
+                proj1NewContents,
+                IOUtils.toByteArray(swapStore.openDownloadStream("proj1"))
+        );
+    }
+
+    @Test
+    public void canRemoveFiles() throws IOException {
+        byte[] projContents = "total garbage".getBytes();
+        swapStore.upload(
+                "proj",
+                new ByteArrayInputStream(projContents),
+                projContents.length
+        );
+        assertArrayEquals(
+                projContents,
+                IOUtils.toByteArray(swapStore.openDownloadStream("proj"))
+        );
+        swapStore.remove("proj");
+        exception.expect(IllegalArgumentException.class);
+        swapStore.openDownloadStream("proj");
+    }
+
+}

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/swap/store/S3SwapStoreTest.java

@@ -0,0 +1,41 @@
+package uk.ac.ic.wlgitbridge.bridge.swap.store;
+
+import org.junit.Before;
+
+/**
+ * Created by winston on 21/08/2016.
+ */
+public class S3SwapStoreTest {
+
+    private static final String accessKey = null;
+    private static final String secret = null;
+    private static final String bucketName = "com.overleaf.testbucket";
+
+    private S3SwapStore s3;
+
+    @Before
+    public void setup() {
+        if (accessKey == null || secret == null) {
+            s3 = null;
+            return;
+        }
+        s3 = new S3SwapStore(accessKey, secret, bucketName);
+    }
+
+//    @Ignore
+//    @Test
+//    public void testUploadDownloadDelete() throws Exception {
+//        assumeNotNull(s3);
+//        String projName = "abc123";
+//        byte[] contents = "hello".getBytes();
+//        s3.upload(
+//                projName,
+//                new ByteArrayInputStream(contents),
+//                contents.length
+//        );
+//        InputStream down = s3.openDownloadStream(projName);
+//        s3.remove(projName);
+//        assertArrayEquals(contents, IOUtils.toByteArray(down));
+//    }
+
+}

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/data/model/db/sql/update/delete/DeleteFilesForProjectSQLUpdateTest.java

@@ -1,14 +0,0 @@
-package uk.ac.ic.wlgitbridge.data.model.db.sql.update.delete;
-
-import org.junit.Test;
-import static org.junit.Assert.*;
-
-public class DeleteFilesForProjectSQLUpdateTest {
-
-    @Test
-    public void testGetSQL() {
-        DeleteFilesForProjectSQLUpdate update = new DeleteFilesForProjectSQLUpdate("projname", "path1", "path2");
-        assertEquals("DELETE FROM `url_index_store` WHERE `project_name` = ? AND path IN (?, ?);\n", update.getSQL());
-    }
-
-}

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/util/ProjectTest.java

@@ -0,0 +1,18 @@
+package uk.ac.ic.wlgitbridge.util;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class ProjectTest {
+
+    @Test
+    public void testValidProjectNames() {
+        Assert.assertFalse(Project.isValidProjectName(null));
+        Assert.assertFalse(Project.isValidProjectName(""));
+        Assert.assertFalse(Project.isValidProjectName(".wlgb"));
+    }
+
+}

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/util/TarTest.java

@@ -0,0 +1,52 @@
+package uk.ac.ic.wlgitbridge.util;
+
+import org.apache.commons.io.FileUtils;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class TarTest {
+
+    private File testDir;
+    private File tmpDir;
+
+    @Before
+    public void setup() throws IOException {
+        TemporaryFolder tmpFolder = new TemporaryFolder();
+        tmpFolder.create();
+        testDir = tmpFolder.newFolder("testdir");
+        Path resdir = Paths.get(
+                "src/test/resources/uk/ac/ic/wlgitbridge/util/TarTest/testdir"
+        );
+        FileUtils.copyDirectory(resdir.toFile(), testDir);
+        tmpDir = tmpFolder.newFolder();
+    }
+
+    @Test
+    public void tarAndUntarProducesTheSameResult() throws IOException {
+        InputStream tar = Tar.tar(testDir);
+        Tar.untar(tar, tmpDir);
+        File untarred = new File(tmpDir, "testdir");
+        assertTrue(Files.contentsAreEqual(testDir, untarred));
+    }
+
+    @Test
+    public void tarbz2AndUntarbz2ProducesTheSameResult() throws IOException {
+        InputStream tarbz2 = Tar.bz2.zip(testDir);
+        Tar.bz2.unzip(tarbz2, tmpDir);
+        File unzipped = new File(tmpDir, "testdir");
+        assertTrue(Files.contentsAreEqual(testDir, unzipped));
+    }
+
+}

services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/util/TimerTest.java

@@ -0,0 +1,19 @@
+package uk.ac.ic.wlgitbridge.util;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class TimerTest {
+
+    @Test
+    public void testMakeTimerTask() {
+        int[] iPtr = new int[] { 3 };
+        Timer.makeTimerTask(() -> iPtr[0] = 5).run();
+        assertEquals(5, iPtr[0]);
+    }
+
+}

services/git-bridge/src/test/resources/logback-test.xml

@@ -1,7 +1,7 @@
 <configuration>
     <!-- Log everything (subject to logger and root levels set below) to stdout. -->
-    <appender name="tempfile" class="ch.qos.logback.core.FileAppender">
-        <file>${java.io.tmpdir}/git-bridge-test.log</file>
+    <appender name="stderr" class="ch.qos.logback.core.ConsoleAppender">
+        <target>System.err</target>
         <encoder>
             <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} %-5level [%thread] %logger{0}: %msg%n</pattern>
         </encoder>
@@ -12,6 +12,6 @@
 
     <!-- The root log level determines how much our dependencies put in the logs. -->
     <root level="WARN">
-        <appender-ref ref="tempfile" />
+        <appender-ref ref="stderr" />
     </root>
 </configuration>

services/git-bridge/src/test/resources/uk/ac/ic/wlgitbridge/WLGitBridgeIntegrationTest/wlgbCanSwapProjects/state/state.json

@@ -0,0 +1,90 @@
+[
+	{
+		"project": "testproj1",
+		"getDoc": {
+			"versionID": 1,
+			"createdAt": "2014-11-30T18:40:58.123Z",
+			"email": "jdleesmiller+1@gmail.com",
+			"name": "John+1"
+		},
+		"getSavedVers": [
+        	{
+        		"versionID": 1,
+        		"comment": "added more info on doc GET and error details",
+        		"email": "jdleesmiller+1@gmail.com",
+        		"name": "John+1",
+        		"createdAt": "2014-11-30T18:47:01.456Z"
+        	}
+		],
+		"getForVers": [
+			{
+				"versionID": 1,
+				"srcs": [
+                    {
+                    	"content": "content\n",
+                    	"path": "main.tex"
+                    },
+                    {
+                    	"content": "This text is from another file.",
+                    	"path": "foo/bar/test.tex"
+                    }
+	            ],
+	            "atts": [
+	            	{
+	            		"url": "http://127.0.0.1:3874/state/testproj1/overleaf-white-410.png",
+	            		"path": "overleaf-white-410.png"
+	            	}
+	            ]
+	        }
+		],
+		"push": "success",
+		"postback": {
+			"type": "success",
+			"versionID": 2
+		}
+	},
+	{
+        "project": "testproj2",
+        "getDoc": {
+            "versionID": 1,
+            "createdAt": "2014-11-30T18:40:58.123Z",
+            "email": "jdleesmiller+1@gmail.com",
+            "name": "John+1"
+        },
+        "getSavedVers": [
+            {
+                "versionID": 1,
+                "comment": "added more info on doc GET and error details",
+                "email": "jdleesmiller+1@gmail.com",
+                "name": "John+1",
+                "createdAt": "2014-11-30T18:47:01.456Z"
+            }
+        ],
+        "getForVers": [
+            {
+                "versionID": 1,
+                "srcs": [
+                    {
+                        "content": "different content\n",
+                        "path": "main.tex"
+                    },
+                    {
+                        "content": "a different one",
+                        "path": "foo/bar/test.tex"
+                    }
+                ],
+                "atts": [
+                    {
+                        "url": "http://127.0.0.1:3874/state/testproj2/editor-versions-a7e4de19d015c3e7477e3f7eaa6c418e.png",
+                        "path": "editor-versions-a7e4de19d015c3e7477e3f7eaa6c418e.png"
+                    }
+                ]
+            }
+        ],
+        "push": "success",
+        "postback": {
+            "type": "success",
+            "versionID": 2
+        }
+    }
+]

services/git-bridge/src/test/resources/uk/ac/ic/wlgitbridge/WLGitBridgeIntegrationTest/wlgbCanSwapProjects/state/testproj1/foo/bar/test.tex

@@ -0,0 +1 @@
+This text is from another file.

services/git-bridge/src/test/resources/uk/ac/ic/wlgitbridge/WLGitBridgeIntegrationTest/wlgbCanSwapProjects/state/testproj1/main.tex

@@ -0,0 +1 @@
+content

services/git-bridge/src/test/resources/uk/ac/ic/wlgitbridge/WLGitBridgeIntegrationTest/wlgbCanSwapProjects/state/testproj2/foo/bar/test.tex

@@ -0,0 +1 @@
+a different one

services/git-bridge/src/test/resources/uk/ac/ic/wlgitbridge/WLGitBridgeIntegrationTest/wlgbCanSwapProjects/state/testproj2/main.tex

@@ -0,0 +1 @@
+different content