Add and test GetNumProjects

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

@@ -10,6 +10,7 @@ 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.SwapJobConfig;
 import uk.ac.ic.wlgitbridge.bridge.swap.SwapJobImpl;
 import uk.ac.ic.wlgitbridge.bridge.swap.SwapStore;
 import uk.ac.ic.wlgitbridge.data.CandidateSnapshot;
@@ -43,18 +44,19 @@ 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,
+            SwapJobConfig swapJobConfig
     ) {
         ProjectLock lock = new ProjectLockImpl((int threads) ->
                 Log.info("Waiting for " + threads + " projects...")
@@ -64,14 +66,15 @@ public class Bridge {
                 repoStore,
                 dbStore,
                 swapStore,
-                new NetSnapshotAPI(),
-                new UrlResourceCache(dbStore),
                 new SwapJobImpl(
+                        swapJobConfig,
                         lock,
                         repoStore,
                         dbStore,
                         swapStore
-                )
+                ),
+                new NetSnapshotAPI(),
+                new UrlResourceCache(dbStore)
         );
     }
 
@@ -80,9 +83,9 @@ 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;

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

@@ -8,6 +8,8 @@ import java.util.List;
  */
 public interface DBStore {
 
+    int getNumProjects();
+
     List<String> getProjectNames();
 
     void setLatestVersionForProject(String project, int versionID);

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

@@ -2,10 +2,7 @@ package uk.ac.ic.wlgitbridge.bridge.db.sqlite;
 
 import uk.ac.ic.wlgitbridge.bridge.db.DBInitException;
 import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
-import uk.ac.ic.wlgitbridge.bridge.db.sqlite.query.GetLatestVersionForProjectSQLQuery;
-import uk.ac.ic.wlgitbridge.bridge.db.sqlite.query.GetOldestProjectName;
-import uk.ac.ic.wlgitbridge.bridge.db.sqlite.query.GetPathForURLInProjectSQLQuery;
-import uk.ac.ic.wlgitbridge.bridge.db.sqlite.query.GetProjectNamesSQLQuery;
+import uk.ac.ic.wlgitbridge.bridge.db.sqlite.query.*;
 import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.create.*;
 import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.delete.DeleteFilesForProjectSQLUpdate;
 import uk.ac.ic.wlgitbridge.bridge.db.sqlite.update.insert.AddURLIndexSQLUpdate;
@@ -34,6 +31,11 @@ public class SqliteDBStore implements DBStore {
         }
     }
 
+    @Override
+    public int getNumProjects() {
+        return query(new GetNumProjects());
+    }
+
     @Override
     public List<String> getProjectNames() {
         return query(new GetProjectNamesSQLQuery());

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/update/create/CreateProjectsTableSQLUpdate.java

@@ -9,8 +9,8 @@ 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" +
+            "  `name` VARCHAR NOT NULL DEFAULT '',\n" +
+            "  `version_id` INT NOT NULL DEFAULT 0,\n" +
             "  PRIMARY KEY (`name`)\n" +
             ")";
     @Override

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

@@ -0,0 +1,33 @@
+package uk.ac.ic.wlgitbridge.bridge.swap;
+
+/**
+ * Created by winston on 23/08/2016.
+ */
+public class SwapJobConfig {
+
+    public static final SwapJobConfig DEFAULT =
+            new SwapJobConfig(1, 1, 2);
+
+    private final int minProjects;
+    private final long lowGiB;
+    private final long highGiB;
+
+    public SwapJobConfig(int minProjects, long lowGiB, long highGiB) {
+        this.minProjects = minProjects;
+        this.lowGiB = lowGiB;
+        this.highGiB = highGiB;
+    }
+
+    public int getMinProjects() {
+        return minProjects;
+    }
+
+    public long getLowGiB() {
+        return lowGiB;
+    }
+
+    public long getHighGiB() {
+        return highGiB;
+    }
+
+}

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

@@ -14,6 +14,10 @@ import java.util.concurrent.atomic.AtomicInteger;
  */
 public class SwapJobImpl implements SwapJob {
 
+    private final int minProjects;
+    private final long lowGiB;
+    private final long highGiB;
+
     private final ProjectLock lock;
     private final RepoStore repoStore;
     private final SwapStore swapStore;
@@ -24,12 +28,15 @@ public class SwapJobImpl implements SwapJob {
     final AtomicInteger swaps;
 
     public SwapJobImpl(
+            SwapJobConfig cfg,
             ProjectLock lock,
             RepoStore repoStore,
             DBStore dbStore,
             SwapStore swapStore
     ) {
-
+        minProjects = cfg.getMinProjects();
+        lowGiB = cfg.getLowGiB();
+        highGiB = cfg.getHighGiB();
         this.lock = lock;
         this.repoStore = repoStore;
         this.swapStore = swapStore;
@@ -54,7 +61,13 @@ public class SwapJobImpl implements SwapJob {
 
     private void doSwap() {
         Log.info("Running {}th swap", swaps.getAndIncrement());
+        while (repoStore.totalSize() > lowGiB) {
+            doEvict();
+        }
+    }
 
+    private void doEvict() {
+        dbStore.getOldestUnswappedProject();
     }
 
 }

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

@@ -13,6 +13,7 @@ import uk.ac.ic.wlgitbridge.bridge.db.DBStore;
 import uk.ac.ic.wlgitbridge.bridge.db.sqlite.SqliteDBStore;
 import uk.ac.ic.wlgitbridge.bridge.repo.FSRepoStore;
 import uk.ac.ic.wlgitbridge.bridge.repo.RepoStore;
+import uk.ac.ic.wlgitbridge.bridge.swap.SwapJobConfig;
 import uk.ac.ic.wlgitbridge.bridge.swap.SwapStore;
 import uk.ac.ic.wlgitbridge.git.exception.InvalidRootDirectoryPathException;
 import uk.ac.ic.wlgitbridge.git.servlet.WLGitServlet;
@@ -75,7 +76,8 @@ public class GitBridgeServer {
         bridgeAPI = Bridge.make(
                 repoStore,
                 dbStore,
-                swapStore
+                swapStore,
+                SwapJobConfig.DEFAULT
         );
         jettyServer = new Server(port);
         configureJettyServer(config);

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

@@ -44,9 +44,9 @@ public class BridgeTest {
                 repoStore,
                 dbStore,
                 swapStore,
+                swapJob,
                 snapshotAPI,
-                resourceCache,
-                swapJob
+                resourceCache
         );
     }
 

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

@@ -26,6 +26,17 @@ public class SqliteDBStoreTest {
         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());

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

@@ -31,6 +31,7 @@ public class SwapJobImplTest {
         dbStore = mock(DBStore.class);
         swapStore = mock(SwapStore.class);
         swapJob = new SwapJobImpl(
+                SwapJobConfig.DEFAULT,
                 lock,
                 repoStore,
                 dbStore,