Refactor a bit.

prod/taskqueue.go

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package prod
-
-import (
-        "fmt"
-        "reflect"
-
-        "github.com/luci/gae"
-        "golang.org/x/net/context"
-        "google.golang.org/appengine/taskqueue"
-)
-
-// useTQ adds a gae.TaskQueue implementation to context, accessible
-// by gae.GetTQ(c)
-func useTQ(c context.Context) context.Context {
-        return gae.SetTQFactory(c, func(ci context.Context) gae.TaskQueue {
-                return tqImpl{ci}
-        })
-}
-
-type tqImpl struct {
-        context.Context
-}
-
-func init() {
-        const TASK_EXPECTED_FIELDS = 9
-        // Runtime-assert that the number of fields in the Task structs is 9, to
-        // avoid missing additional fields if they're added later.
-        // all other type assertions are statically enforced by o2n() and tqF2R()
-
-        oldType := reflect.TypeOf((*taskqueue.Task)(nil))
-        newType := reflect.TypeOf((*gae.TQTask)(nil))
-
-        if oldType.NumField() != newType.NumField() ||
-                oldType.NumField() != TASK_EXPECTED_FIELDS {
-                panic(fmt.Errorf(
-                        "prod/taskqueue:init() field count differs: %v, %v",
-                        oldType, newType))
-        }
-}
-
-// tqR2FErr (TQ real-to-fake w/ error) converts a *taskqueue.Task to a
-// *gae.TQTask, and passes through an error.
-func tqR2FErr(o *taskqueue.Task, err error) (*gae.TQTask, error) {
-        if err != nil {
-                return nil, err
-        }
-        n := gae.TQTask{}
-        n.Path = o.Path
-        n.Payload = o.Payload
-        n.Header = o.Header
-        n.Method = o.Method
-        n.Name = o.Name
-        n.Delay = o.Delay
-        n.ETA = o.ETA
-        n.RetryCount = o.RetryCount
-        n.RetryOptions = (*gae.TQRetryOptions)(o.RetryOptions)
-        return &n, nil
-}
-
-// tqF2R (TQ fake-to-real) converts a *gae.TQTask to a *taskqueue.Task.
-func tqF2R(n *gae.TQTask) *taskqueue.Task {
-        o := taskqueue.Task{}
-        o.Path = n.Path
-        o.Payload = n.Payload
-        o.Header = n.Header
-        o.Method = n.Method
-        o.Name = n.Name
-        o.Delay = n.Delay
-        o.ETA = n.ETA
-        o.RetryCount = n.RetryCount
-        o.RetryOptions = (*taskqueue.RetryOptions)(n.RetryOptions)
-        return &o
-}
-
-// tqMR2FErr (TQ multi-real-to-fake w/ error) converts a slice of
-// *taskqueue.Task to a slice of *gae.TQTask
-func tqMR2FErr(os []*taskqueue.Task, err error) ([]*gae.TQTask, error) {
-        if err != nil {
-                return nil, gae.FixError(err)
-        }
-        ret := make([]*gae.TQTask, len(os))
-        for i, t := range os {
-                ret[i], _ = tqR2FErr(t, nil)
-        }
-        return ret, nil
-}
-
-// tqMF2R (TQ multi-fake-to-real) converts []*gae.TQTask to []*taskqueue.Task.
-func tqMF2R(ns []*gae.TQTask) []*taskqueue.Task {
-        ret := make([]*taskqueue.Task, len(ns))
-        for i, t := range ns {
-                ret[i] = tqF2R(t)
-        }
-        return ret
-}
-
-//////// TQSingleReadWriter
-
-func (t tqImpl) Add(task *gae.TQTask, queueName string) (*gae.TQTask, error) {
-        return tqR2FErr(taskqueue.Add(t.Context, tqF2R(task), queueName))
-}
-func (t tqImpl) Delete(task *gae.TQTask, queueName string) error {
-        return taskqueue.Delete(t.Context, tqF2R(task), queueName)
-}
-
-//////// TQMultiReadWriter
-
-func (t tqImpl) AddMulti(tasks []*gae.TQTask, queueName string) ([]*gae.TQTask, error) {
-        return tqMR2FErr(taskqueue.AddMulti(t.Context, tqMF2R(tasks), queueName))
-}
-func (t tqImpl) DeleteMulti(tasks []*gae.TQTask, queueName string) error {
-        return gae.FixError(taskqueue.DeleteMulti(t.Context, tqMF2R(tasks), queueName))
-}
-
-//////// TQLeaser
-
-func (t tqImpl) Lease(maxTasks int, queueName string, leaseTime int) ([]*gae.TQTask, error) {
-        return tqMR2FErr(taskqueue.Lease(t.Context, maxTasks, queueName, leaseTime))
-}
-func (t tqImpl) LeaseByTag(maxTasks int, queueName string, leaseTime int, tag string) ([]*gae.TQTask, error) {
-        return tqMR2FErr(taskqueue.LeaseByTag(t.Context, maxTasks, queueName, leaseTime, tag))
-}
-func (t tqImpl) ModifyLease(task *gae.TQTask, queueName string, leaseTime int) error {
-        return taskqueue.ModifyLease(t.Context, tqF2R(task), queueName, leaseTime)
-}
-
-//////// TQPurger
-
-func (t tqImpl) Purge(queueName string) error {
-        return taskqueue.Purge(t.Context, queueName)
-}
-
-//////// TQStatter
-
-func (t tqImpl) QueueStats(queueNames []string) ([]gae.TQStatistics, error) {
-        stats, err := taskqueue.QueueStats(t.Context, queueNames)
-        if err != nil {
-                return nil, err
-        }
-        ret := make([]gae.TQStatistics, len(stats))
-        for i, s := range stats {
-                ret[i] = gae.TQStatistics(s)
-        }
-        return ret, nil
-}