Refactor keys and queries in datastore service and implementation.

filter/dscache/dscache_test.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 dscache
 
 import (
         "bytes"
         "encoding/binary"
         "errors"
@@ skipping 48 matching lines @@
 
         Convey("Test dscache", t, func() {
                 c := mathrand.Set(context.Background(), rand.New(rand.NewSource(1)))
                 clk := testclock.New(zeroTime)
                 c = clock.Set(c, clk)
                 c = memory.Use(c)
 
                 dsUnder := datastore.Get(c)
                 mc := memcache.Get(c)
 
-                itmFor := func(i int, k datastore.Key) memcache.Item {
+                itmFor := func(i int, k *datastore.Key) memcache.Item {
                         return mc.NewItem(MakeMemcacheKey(i, k))
                 }
 
-                shardsForKey := func(k datastore.Key) int {
-                        if k.Kind() == "shardObj" {
-                                return int(k.IntID())
+                shardsForKey := func(k *datastore.Key) int {
+                        last := k.Last()

[iannucci, 2015/09/18 04:31:52]

Key changed a bit. Now instead of k.Kind(), you get the last token with Last(),
and then that has Kind, StringID and IntID. You can also get the full list of
all the tokens in the key. Or you can recurse down it with Parent, but I wanted
to make that usecase a bit more awkward, because it involves a lot of extra
(avoidable) allocations

+                        if last.Kind == "shardObj" {
+                                return int(last.IntID)
                         }
-                        if k.Kind() == "noCacheObj" {
+                        if last.Kind == "noCacheObj" {
                                 return 0
                         }
                         return DefaultShards
                 }
 
                 numMemcacheItems := func() uint64 {
                         stats, err := mc.Stats()
                         So(err, ShouldBeNil)
                         return stats.Items
                 }
@@ skipping 359 matching lines @@
                 InstanceEnabledStatic = false
                 defer func() {
                         InstanceEnabledStatic = true
                 }()
 
                 c := context.Background()
                 newC := FilterRDS(c, nil)
                 So(newC, ShouldEqual, c)
         })
 }