impl/memory: Use random int as auto generated task name in Task Queues.

impl/memory/taskqueue_data.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package memory
 
 import (
         "container/heap"
         "errors"
         "fmt"
@@ skipping 45 matching lines @@
                 isPullQueue:  isPullQueue,
                 tasks:        map[string]*tq.Task{},
                 archived:     map[string]*tq.Task{},
                 sortedPerTag: map[string]*taskIndex{},
         }
 }
 
 // All sortedQueue methods are assumed to be called under taskQueueData lock.
 
 func (q *sortedQueue) genTaskName(c context.Context) string {
-        const validTaskChars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_"
         for {
-                buf := [500]byte{}
-                for i := 0; i < 500; i++ {
-                        buf[i] = validTaskChars[mathrand.Intn(c, len(validTaskChars))]
-                }
-                name := string(buf[:])
+                // Real Task Queue service seems to be using random ints too.
+                name := fmt.Sprintf("%d", mathrand.Int63(c))
                 _, ok1 := q.tasks[name]
                 _, ok2 := q.archived[name]
                 if !ok1 && !ok2 {
                         return name
                 }
         }
 }
 
 func (q *sortedQueue) addTask(task *tq.Task) error {
         switch {
@@ skipping 447 matching lines @@
         return t.parent.GetScheduledTasks()
 }
 
 func (t *txnTaskQueueData) CreateQueue(queueName string) {
         t.parent.CreateQueue(queueName)
 }
 
 func (t *txnTaskQueueData) CreatePullQueue(queueName string) {
         t.parent.CreatePullQueue(queueName)
 }