Optional backoff

README.md

@@ -19,7 +19,7 @@ Queue That is built primarily to queue XHR requests for reporting.
 
 - When more than one tab is open, only one active queue will process tasks.
 - If `options.process` calls back with an error, the tasks will be passed to `options.process`
-  again after a second. This backoff time doubles for each sequential error. The backoff timer is
+  again after a second. This backoff time doubles for each sequential error, up to `options.maxBackoff` (5 minutes by default). The backoff timer is
   stored in localStorage and so will not reset when Queue That is reinitialised.
 - There is a **2 second** timeout for the process function, after which the queue will back off and retry later, ignoring any success/error callback from the first `options.process` call.
 - The batch array passed to `options.process` contains a `containsRepeatedItems` property, useful for deduplicating requests sent to a server.

lib/queue-that.js

@@ -7,6 +7,7 @@ var BACKOFF_TIME = 1000
 var QUEUE_GROUP_TIME = 100
 var PROCESS_TIMEOUT = 2000
 var DEFAULT_BATCH_SIZE = 20
+var DEFAULT_MAX_BACKOFF = 5 * 60 * 1000
 var ACTIVE_QUEUE_TIMEOUT = 2500
 
 module.exports = createQueueThat
@@ -20,6 +21,7 @@ function createQueueThat (options) {
   options.trim = options.trim || identity
   options.queueGroupTime = options.queueGroupTime || QUEUE_GROUP_TIME
   options.backoffTime = options.backoffTime || BACKOFF_TIME
+  options.maxBackoff = options.maxBackoff || DEFAULT_MAX_BACKOFF
   options.processTimeout = options.processTimeout || PROCESS_TIMEOUT
   options.activeQueueTimeout = options.activeQueueTimeout || ACTIVE_QUEUE_TIMEOUT
 
@@ -166,7 +168,13 @@ function createQueueThat (options) {
     log.error('Process error, backing off (' + err.message + ')')
     var errorCount = storageAdapter.getErrorCount() + 1
     storageAdapter.setErrorCount(errorCount)
-    storageAdapter.setBackoffTime(now() + options.backoffTime * Math.pow(2, errorCount - 1))
+    storageAdapter.setBackoffTime(
+      now() +
+      Math.min(
+        options.maxBackoff,
+        options.backoffTime * Math.pow(2, errorCount - 1)
+      )
+    )
     log.warn('backoff time ' + (storageAdapter.getBackoffTime() - now()) + 'ms')
   }