Handle inavailability of cache gracefully. No longer crashes when memcache is not available.

acs.coffee

@@ -98,7 +98,7 @@ runTask = (task, reqParams) ->
   updateDevice(currentRequest.deviceId, actions)
 
   if Object.keys(resParams).length > 0
-    db.memcached.set(String(task._id), task, config.CACHE_DURATION, (err, result) ->
+    db.updateTask(task, (err) ->
       res = tr069.response(currentRequest.sessionId, resParams, {task : String(task._id)})
       writeResponse res
     )
@@ -106,7 +106,7 @@ runTask = (task, reqParams) ->
 
   # Task finished
   db.memcached.del(String(task._id))
-  db.tasksCollection.remove({'_id' : db.mongo.ObjectID(task._id)}, {safe: true}, (err, removed) ->
+  db.tasksCollection.remove({'_id' : db.mongo.ObjectID(String(task._id))}, {safe: true}, (err, removed) ->
     util.log("#{currentRequest.deviceId}: completed task #{task.name}(#{task._id})")
     cookies = {task : null}
     nextTask(cookies)
@@ -246,8 +246,7 @@ else
       if not taskId
         nextTask(cookies)
       else
-        db.memcached.get(taskId, (err, task) ->
-          # TODO if not found in memcached, fetch from mongo
+        db.getTask(taskId, (task) ->
           runTask(task, reqParams)
         )
 

db.coffee

@@ -2,27 +2,60 @@ config = require './config'
 mongo = require 'mongodb'
 Memcached = require 'memcached'
 Memcached.config.maxExpiration = 86400
+Memcached.config.timeout = 1000
+Memcached.config.retries = 0
+Memcached.config.reconnect = 1000
 memcached = new Memcached(config.MEMCACHED_SOCKET)
 
+tasksCollection = null
+devicesCollection = null
+presetsCollection = null
 
 dbserver = new mongo.Server(config.MONGODB_SOCKET, 0, {auto_reconnect: true})
 db = new mongo.Db(config.DATABASE_NAME, dbserver, {native_parser:true, safe:true})
 
 db.open( (err, db) ->
   db.collection('tasks', (err, collection) ->
-    exports.tasksCollection = collection
+    exports.tasksCollection = tasksCollection = collection
     collection.ensureIndex({device: 1, timestamp: 1}, (err) ->
     )
   )
 
   db.collection('devices', (err, collection) ->
-    exports.devicesCollection = collection
+    exports.devicesCollection  = devicesCollection = collection
   )
 
   db.collection('presets', (err, collection) ->
-    exports.presetsCollection = collection
+    exports.presetsCollection = presetsCollection = collection
   )
 )
 
+getTask = (taskId, callback) ->
+  memcached.get(taskId, (err, task) ->
+    if not task?
+      tasksCollection.findOne({_id : mongo.ObjectID(String(taskId))}, (err, task) ->
+        callback(task)
+      )
+    else
+      callback(task)
+  )
+
+
+updateTask = (task, callback) ->
+  id = String(task._id)
+
+  memcached.set(id, task, config.CACHE_DURATION, (err, res) ->
+    if res
+      callback()
+    else
+      task._id = mongo.ObjectID(id)
+      tasksCollection.save(task, (err) ->
+        callback(err)
+      )
+  )
+
+
 exports.mongo = mongo
 exports.memcached = memcached
+exports.getTask = getTask
+exports.updateTask = updateTask

presets.coffee

@@ -6,8 +6,6 @@ mongoQuery = require './mongo-query'
 
 getPresets = (callback) ->
   db.memcached.get('presets', (err, res) ->
-    throw new Error(err) if err
-
     if res
       callback(res)
       return