add check for dangling updates

services/track-changes/app.coffee

@@ -51,6 +51,7 @@ app.post  '/project/:project_id/doc/:doc_id/push', HttpController.pushDocHistory
 app.post  '/project/:project_id/doc/:doc_id/pull', HttpController.pullDocHistory
 
 app.post '/flush/all', HttpController.flushAll
+app.post '/check/dangling', HttpController.checkDanglingUpdates
 
 packWorker = null # use a single packing worker
 

services/track-changes/app/coffee/HttpController.coffee

@@ -34,6 +34,16 @@ module.exports = HttpController =
 			else
 				res.status(200).send "#{status}\nflushed all #{succeeded.length} projects\n"
 
+	checkDanglingUpdates: (req, res, next = (error) ->) ->
+		logger.log "checking dangling updates"
+		UpdatesManager.getDanglingUpdates (error, result) ->
+			return next(error) if error?
+			if result.length > 0
+				logger.log {dangling: result}, "found dangling updates"
+				res.status(500).send "dangling updates:\n#{result.join('\n')}\n"
+			else
+				res.status(200).send "no dangling updates found\n"
+
 	checkDoc: (req, res, next = (error) ->) ->
 		doc_id = req.params.doc_id
 		project_id = req.params.project_id

services/track-changes/app/coffee/RedisManager.coffee

@@ -33,11 +33,23 @@ module.exports = RedisManager =
 	getDocIdsWithHistoryOps: (project_id, callback = (error, doc_ids) ->) ->
 		rclient.smembers docsWithHistoryOpsKey(project_id), callback
 
+	# extract ids from keys like DocsWithHistoryOps:57fd0b1f53a8396d22b2c24b
+	_extractIds: (keyList) ->
+		ids = (key.split(":")[1] for key in keyList)
+		return ids
+
 	# this will only work on single node redis, not redis cluster
 	getProjectIdsWithHistoryOps: (callback = (error, project_ids) ->) ->
 		rclient.keys docsWithHistoryOpsKey("*"), (error, project_keys) ->
 			return callback(error) if error?
-			project_ids = for key in project_keys
-				[prefix, project_id] = key.split(":")
-				project_id
+			project_ids = RedisManager._extractIds project_keys
 			callback(error, project_ids)
+
+	# this will only work on single node redis, not redis cluster
+	getAllDocIdsWithHistoryOps: (callback = (error, doc_ids) ->) ->
+		# return all the docids, to find dangling history entries after
+		# everything is flushed.
+		rclient.keys rawUpdatesKey("*"), (error, doc_keys) ->
+			return callback(error) if error?
+			doc_ids = RedisManager._extractIds doc_keys
+			callback(error, doc_ids)

services/track-changes/app/coffee/UpdatesManager.coffee

@@ -159,8 +159,22 @@ module.exports = UpdatesManager =
 				return callback(error) if error?
 				failedProjects = (x.project_id for x in result when x.failed)
 				succeededProjects = (x.project_id for x in result when not x.failed)
+				RedisManager.getAllDocIdsWithHistoryOps (error, doc_ids) ->
 				callback(null, {failed: failedProjects, succeeded: succeededProjects})
 
+	getDanglingUpdates: (callback = (error, doc_ids) ->) ->
+		RedisManager.getAllDocIdsWithHistoryOps (error, all_doc_ids) ->
+			return callback(error) if error?
+			RedisManager.getProjectIdsWithHistoryOps (error, all_project_ids) ->
+				return callback(error) if error?
+				# function to get doc_ids for each project
+				task = (cb) -> async.concatSeries all_project_ids, RedisManager.getDocIdsWithHistoryOps, cb
+				# find the dangling doc ids
+				task (error, project_doc_ids) ->
+					dangling_doc_ids = _.difference(all_doc_ids, project_doc_ids)
+					logger.log {all_doc_ids: all_doc_ids, all_project_ids: all_project_ids, project_doc_ids: project_doc_ids, dangling_doc_ids: dangling_doc_ids}, "checking for dangling doc ids"
+					callback(null, dangling_doc_ids)
+
 	getDocUpdates: (project_id, doc_id, options = {}, callback = (error, updates) ->) ->
 		UpdatesManager.processUncompressedUpdatesWithLock project_id, doc_id, (error) ->
 			return callback(error) if error?