coppied the lock manager over from doc updater

services/web/app/coffee/infrastructure/LockManager.coffee

@@ -0,0 +1,54 @@
+metrics = require('./Metrics')
+Settings = require('settings-sharelatex')
+redis = require("redis-sharelatex")
+rclient = redis.createClient(Settings.redis.web)
+logger = require "logger-sharelatex"
+
+module.exports = LockManager =
+	LOCK_TEST_INTERVAL: 50 # 50ms between each test of the lock
+	MAX_LOCK_WAIT_TIME: 10000 # 10s maximum time to spend trying to get the lock
+	REDIS_LOCK_EXPIRY: 30 # seconds. Time until lock auto expires in redis.
+
+	_blockingKey : (key)-> "Blocking:"+key
+
+	tryLock : (key, callback = (err, isFree)->)->
+		rclient.set LockManager._blockingKey(key), "locked", "EX", LockManager.REDIS_LOCK_EXPIRY, "NX", (err, gotLock)->
+			return callback(err) if err?
+			if gotLock == "OK"
+				metrics.inc "doc-not-blocking"
+				callback err, true
+			else
+				metrics.inc "doc-blocking"
+				logger.log key: key, redis_response: gotLock, "doc is locked"
+				callback err, false
+
+	getLock: (key, callback = (error) ->) ->
+		startTime = Date.now()
+		do attempt = () ->
+			if Date.now() - startTime > LockManager.MAX_LOCK_WAIT_TIME
+				return callback(new Error("Timeout"))
+
+			LockManager.tryLock key, (error, gotLock) ->
+				return callback(error) if error?
+				if gotLock
+					callback(null)
+				else
+					setTimeout attempt, LockManager.LOCK_TEST_INTERVAL
+
+	checkLock: (key, callback = (err, isFree)->)->
+		multi = rclient.multi()
+		multi.exists LockManager._blockingKey(key)
+		multi.exec (err, replys)->
+			return callback(err) if err?
+			exists = parseInt replys[0]
+			if exists == 1
+				metrics.inc "doc-blocking"
+				callback err, false
+			else
+				metrics.inc "doc-not-blocking"
+				callback err, true
+
+	releaseLock: (key, callback)->
+		rclient.del LockManager._blockingKey(key), callback
+
+	

services/web/test/UnitTests/coffee/infrastructure/LockManager/CheckingTheLock.coffee

@@ -0,0 +1,49 @@
+require('coffee-script')
+sinon = require('sinon')
+assert = require('assert')
+path = require('path')
+modulePath = path.join __dirname, '../../../../../app/js/infrastructure/LockManager.js'
+project_id = 1234
+doc_id     = 5678
+blockingKey = "Blocking:#{doc_id}"
+SandboxedModule = require('sandboxed-module')
+
+describe 'Lock Manager - checking the lock', ()->
+
+	existsStub = sinon.stub()
+	setStub = sinon.stub()
+	exireStub = sinon.stub()
+	execStub = sinon.stub()
+	
+	mocks =
+		"logger-sharelatex": log:->
+
+		"redis-sharelatex":
+			createClient : ()->
+				auth:->
+				multi: ->
+					exists: existsStub
+					expire: exireStub
+					set: setStub
+					exec: execStub
+	LockManager = SandboxedModule.require(modulePath, requires: mocks)
+
+	it 'should check if lock exists but not set or expire', (done)->
+		execStub.callsArgWith(0, null, ["1"])
+		LockManager.checkLock doc_id, (err, docIsLocked)->
+			existsStub.calledWith(blockingKey).should.equal true
+			setStub.called.should.equal false
+			exireStub.called.should.equal false
+			done()
+
+	it 'should return true if the key does not exists', (done)->
+		execStub.callsArgWith(0, null, "0")
+		LockManager.checkLock doc_id, (err, free)->
+			free.should.equal true
+			done()
+
+	it 'should return false if the key does exists', (done)->
+		execStub.callsArgWith(0, null, "1")
+		LockManager.checkLock doc_id, (err, free)->
+			free.should.equal false
+			done()

services/web/test/UnitTests/coffee/infrastructure/LockManager/ReleasingTheLock.coffee

@@ -0,0 +1,27 @@
+require('coffee-script')
+sinon = require('sinon')
+assert = require('assert')
+path = require('path')
+modulePath = path.join __dirname, '../../../../../app/js/infrastructure/LockManager.js'
+project_id = 1234
+doc_id     = 5678
+SandboxedModule = require('sandboxed-module')
+
+describe 'LockManager - releasing the lock', ()->
+
+	deleteStub = sinon.stub().callsArgWith(1)
+	mocks =
+		"logger-sharelatex": log:->
+
+		"redis-sharelatex":
+			createClient : ()->
+				auth:->
+				del:deleteStub
+	
+	LockManager = SandboxedModule.require(modulePath, requires: mocks)
+
+	it 'should put a all data into memory', (done)->
+		LockManager.releaseLock doc_id, ->
+			deleteStub.calledWith("Blocking:#{doc_id}").should.equal true
+			done()
+

services/web/test/UnitTests/coffee/infrastructure/LockManager/getLockTests.coffee

@@ -0,0 +1,70 @@
+sinon = require('sinon')
+chai = require('chai')
+should = chai.should()
+path = require('path')
+modulePath = path.join __dirname, '../../../../../app/js/infrastructure/LockManager.js'
+SandboxedModule = require('sandboxed-module')
+
+describe 'LockManager - getting the lock', ->
+	beforeEach ->
+		@LockManager = SandboxedModule.require modulePath, requires:
+			"logger-sharelatex": log:->
+			"redis-sharelatex":
+				createClient : () =>
+					auth:->
+		@callback = sinon.stub()
+		@doc_id = "doc-id-123"
+	
+	describe "when the lock is not set", ->
+		beforeEach (done) ->
+			@LockManager.tryLock = sinon.stub().callsArgWith(1, null, true)
+			@LockManager.getLock @doc_id, (args...) =>
+				@callback(args...)
+				done()
+
+		it "should try to get the lock", ->
+			@LockManager.tryLock
+				.calledWith(@doc_id)
+				.should.equal true
+
+		it "should only need to try once", ->
+			@LockManager.tryLock.callCount.should.equal 1
+
+		it "should return the callback", ->
+			@callback.calledWith(null).should.equal true
+
+	describe "when the lock is initially set", ->
+		beforeEach (done) ->
+			startTime = Date.now()
+			@LockManager.LOCK_TEST_INTERVAL = 5
+			@LockManager.tryLock = (doc_id, callback = (error, isFree) ->) ->
+				if Date.now() - startTime < 20
+					callback null, false
+				else
+					callback null, true
+			sinon.spy @LockManager, "tryLock"
+
+			@LockManager.getLock @doc_id, (args...) =>
+				@callback(args...)
+				done()
+
+		it "should call tryLock multiple times until free", ->
+			(@LockManager.tryLock.callCount > 1).should.equal true
+
+		it "should return the callback", ->
+			@callback.calledWith(null).should.equal true
+
+	describe "when the lock times out", ->
+		beforeEach (done) ->
+			time = Date.now()
+			@LockManager.MAX_LOCK_WAIT_TIME = 5
+			@LockManager.tryLock = sinon.stub().callsArgWith(1, null, false)
+			@LockManager.getLock @doc_id, (args...) =>
+				@callback(args...)
+				done()
+
+		it "should return the callback with an error", ->
+			@callback.calledWith(new Error("timeout")).should.equal true
+		
+
+

services/web/test/UnitTests/coffee/infrastructure/LockManager/tryLockTests.coffee

@@ -0,0 +1,38 @@
+sinon = require('sinon')
+chai = require('chai')
+should = chai.should()
+path = require('path')
+modulePath = path.join __dirname, '../../../../../app/js/infrastructure/LockManager.js'
+SandboxedModule = require('sandboxed-module')
+
+describe 'LockManager - trying the lock', ->
+	beforeEach ->
+		@LockManager = SandboxedModule.require modulePath, requires:
+			"logger-sharelatex": log:->
+			"redis-sharelatex":
+				createClient : () =>
+					auth:->
+					set: @set = sinon.stub()
+		@callback = sinon.stub()
+		@doc_id = "doc-id-123"
+	
+	describe "when the lock is not set", ->
+		beforeEach ->
+			@set.callsArgWith(5, null, "OK")
+			@LockManager.tryLock @doc_id, @callback
+
+		it "should set the lock key with an expiry if it is not set", ->
+			@set.calledWith("Blocking:#{@doc_id}", "locked", "EX", 30, "NX")
+				.should.equal true
+
+		it "should return the callback with true", ->
+			@callback.calledWith(null, true).should.equal true
+
+	describe "when the lock is already set", ->
+		beforeEach ->
+			@set.callsArgWith(5, null, null)
+			@LockManager.tryLock @doc_id, @callback
+
+		it "should return the callback with false", ->
+			@callback.calledWith(null, false).should.equal true
+