impl/memory: Implement Queries

impl/memory/gkvlite_iter_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 memory
 
 import (
         "bytes"
-        "fmt"
         "testing"
 
         "github.com/luci/gkvlite"
         "github.com/luci/luci-go/common/cmpbin"
         . "github.com/smartystreets/goconvey/convey"
 )
 
 func mkNum(n int64) []byte {
         buf := &bytes.Buffer{}
         _, err := cmpbin.WriteInt(buf, n)
-        if err != nil {
-                panic(fmt.Errorf("your RAM is busted: %s", err))
-        }
+        memoryCorruption(err)
+
         return buf.Bytes()
 }
 
 func readNum(data []byte) int64 {
         ret, _, err := cmpbin.ReadInt(bytes.NewBuffer(data))
-        if err != nil {
-                panic(fmt.Errorf("your RAM is (probably) busted: %s", err))
-        }
+        memoryCorruption(err)
+
         return ret
 }
 
 func TestIterator(t *testing.T) {
         t.Parallel()
 
         s := newMemStore()
         c := s.SetCollection("zup", nil)
         prev := []byte{}
         for i := 5; i < 100; i++ {
                 data := mkNum(int64(i))
                 c.Set(data, prev)
                 prev = data
         }
 
-        get := func(c C, t *iterator) int64 {
-                ret := int64(0)
+        get := func(c C, t *iterator) interface{} {
+                ret := interface{}(nil)
                 t.next(nil, func(i *gkvlite.Item) {
-                        c.So(i, ShouldNotBeNil)
-                        ret = readNum(i.Key)
+                        if i != nil {
+                                ret = readNum(i.Key)
+                        }
                 })
                 return ret
         }
 
-        skipGet := func(c C, t *iterator, skipTo int64) int64 {
-                ret := int64(0)
+        skipGet := func(c C, t *iterator, skipTo int64) interface{} {
+                ret := interface{}(nil)
                 t.next(mkNum(skipTo), func(i *gkvlite.Item) {
-                        c.So(i, ShouldNotBeNil)
-                        ret = readNum(i.Key)
+                        if i != nil {
+                                ret = readNum(i.Key)
+                        }
                 })
                 return ret
         }
 
         Convey("Test iterator", t, func() {
                 Convey("start at nil", func(ctx C) {
-                        t := newIterator(c, nil, nil)
+                        t := newIterator(&iterDefinition{c: c})
                         defer t.stop()
                         So(get(ctx, t), ShouldEqual, 5)
                         So(get(ctx, t), ShouldEqual, 6)
                         So(get(ctx, t), ShouldEqual, 7)
 
-                        Convey("And can skip", func() {
+                        Convey("And can skip", func(ctx C) {
                                 So(skipGet(ctx, t, 10), ShouldEqual, 10)
                                 So(get(ctx, t), ShouldEqual, 11)
 
-                                Convey("But not forever", func(c C) {
+                                Convey("But not forever", func(ctx C) {
                                         t.next(mkNum(200), func(i *gkvlite.Item) {
-                                                c.So(i, ShouldBeNil)
+                                                ctx.So(i, ShouldBeNil)
                                         })
                                         t.next(nil, func(i *gkvlite.Item) {
-                                                c.So(i, ShouldBeNil)
+                                                ctx.So(i, ShouldBeNil)
                                         })
                                 })
                         })
 
-                        Convey("Can iterate explicitly", func() {
+                        Convey("Can iterate explicitly", func(ctx C) {
                                 So(skipGet(ctx, t, 7), ShouldEqual, 8)
                                 So(skipGet(ctx, t, 8), ShouldEqual, 9)
 
                                 // Giving the immediately next key doesn't cause an internal reset.
                                 So(skipGet(ctx, t, 10), ShouldEqual, 10)
                         })
 
-                        Convey("Can stop", func(c C) {
+                        Convey("Can stop", func(ctx C) {
                                 t.stop()
                                 t.next(mkNum(200), func(i *gkvlite.Item) {
-                                        c.So(i, ShouldBeNil)
+                                        ctx.So(i, ShouldBeNil)
                                 })
                                 t.next(nil, func(i *gkvlite.Item) {
-                                        c.So(i, ShouldBeNil)
+                                        ctx.So(i, ShouldBeNil)
                                 })
                                 So(t.stop, ShouldNotPanic)
                         })
 
-                        Convey("Going backwards is ignored", func(c C) {
+                        Convey("Going backwards is ignored", func(ctx C) {
                                 So(skipGet(ctx, t, 3), ShouldEqual, 8)
                                 So(get(ctx, t), ShouldEqual, 9)
                                 So(skipGet(ctx, t, 20), ShouldEqual, 20)
                                 So(get(ctx, t), ShouldEqual, 21)
                         })
+
+                        Convey("will stop at the end of the list", func(ctx C) {
+                                So(skipGet(ctx, t, 95), ShouldEqual, 95)
+                                So(get(ctx, t), ShouldEqual, 96)
+                                So(get(ctx, t), ShouldEqual, 97)
+                                So(get(ctx, t), ShouldEqual, 98)
+                                So(get(ctx, t), ShouldEqual, 99)
+                                So(get(ctx, t), ShouldBeNil)
+                                So(get(ctx, t), ShouldBeNil)
+                        })
                 })
 
                 Convey("can have caps on both sides", func(ctx C) {
-                        t := newIterator(c, mkNum(20), mkNum(25))
+                        t := newIterator(&iterDefinition{c: c, start: mkNum(20), end: mkNum(25)})
                         So(get(ctx, t), ShouldEqual, 20)
                         So(get(ctx, t), ShouldEqual, 21)
                         So(get(ctx, t), ShouldEqual, 22)
                         So(get(ctx, t), ShouldEqual, 23)
                         So(get(ctx, t), ShouldEqual, 24)
                         t.next(nil, func(i *gkvlite.Item) {
                                 ctx.So(i, ShouldBeNil)
                         })
                 })
 
                 Convey("can skip over starting cap", func(ctx C) {
-                        t := newIterator(c, mkNum(20), mkNum(25))
+                        t := newIterator(&iterDefinition{c: c, start: mkNum(20), end: mkNum(25)})
                         So(skipGet(ctx, t, 22), ShouldEqual, 22)
                         So(get(ctx, t), ShouldEqual, 23)
                         So(get(ctx, t), ShouldEqual, 24)
                         t.next(nil, func(i *gkvlite.Item) {
                                 ctx.So(i, ShouldBeNil)
                         })
                 })
 
         })
 }
 
 func TestMultiIteratorSimple(t *testing.T) {
         t.Parallel()
 
         // Simulate an index with 2 columns (int and int).
         vals := [][]int64{
                 {1, 0},
                 {1, 2},
                 {1, 4},
                 {1, 7},
                 {1, 9},
                 {3, 10},
                 {3, 11},
         }
 
         valBytes := make([][]byte, len(vals))
         for i, nms := range vals {
                 numbs := make([][]byte, len(nms))
-                for i, n := range nms {
-                        numbs[i] = mkNum(n)
+                for j, n := range nms {
+                        numbs[j] = mkNum(n)
                 }
                 valBytes[i] = bjoin(numbs...)
         }
 
         otherVals := [][]int64{
                 {3, 0},
                 {4, 10},
                 {19, 7},
                 {20, 2},
                 {20, 3},
@@ skipping 20 matching lines @@
                 c2 := s.SetCollection("zup2", nil)
                 for _, row := range otherValBytes {
                         c2.Set(row, []byte{})
                 }
 
                 Convey("can join the same collection twice", func() {
                         // get just the (1, *)
                         // starting at (1, 2) (i.e. >= 2)
                         // ending at (1, 4) (i.e. < 7)
                         defs := []*iterDefinition{
-                                {c, mkNum(1), mkNum(2), mkNum(7)},
-                                {c, mkNum(1), mkNum(2), mkNum(7)},
+                                {c: c, prefix: mkNum(1), prefixLen: len(mkNum(1)), start: mkNum(2), end: mkNum(7)},
+                                {c: c, prefix: mkNum(1), prefixLen: len(mkNum(1)), start: mkNum(2), end: mkNum(7)},
                         }
 
                         i := 1
                         multiIterate(defs, func(suffix []byte) bool {
                                 So(readNum(suffix), ShouldEqual, vals[i][1])
                                 i++
                                 return true
                         })
 
                         So(i, ShouldEqual, 3)
                 })
 
                 Convey("can make empty iteration", func() {
                         // get just the (20, *) (doesn't exist)
                         defs := []*iterDefinition{
-                                {c, mkNum(20), nil, nil},
-                                {c, mkNum(20), nil, nil},
+                                {c: c, prefix: mkNum(20)},
+                                {c: c, prefix: mkNum(20)},
                         }
 
                         i := 0
                         multiIterate(defs, func(suffix []byte) bool {
                                 panic("never")
                         })
 
                         So(i, ShouldEqual, 0)
                 })
 
                 Convey("can join (other, val, val)", func() {
                         // 'other' must start with 20, 'vals' must start with 1
                         // no range constraints
                         defs := []*iterDefinition{
-                                {c2, mkNum(20), nil, nil},
-                                {c, mkNum(1), nil, nil},
-                                {c, mkNum(1), nil, nil},
+                                {c: c2, prefix: mkNum(20)},
+                                {c: c, prefix: mkNum(1)},
+                                {c: c, prefix: mkNum(1)},
                         }
 
                         expect := []int64{2, 4}
                         i := 0
                         multiIterate(defs, func(suffix []byte) bool {
                                 So(readNum(suffix), ShouldEqual, expect[i])
                                 i++
                                 return true
                         })
                 })
 
                 Convey("Can stop early", func() {
                         defs := []*iterDefinition{
-                                {c, mkNum(1), nil, nil},
-                                {c, mkNum(1), nil, nil},
+                                {c: c, prefix: mkNum(1), prefixLen: len(mkNum(1))},
+                                {c: c, prefix: mkNum(1), prefixLen: len(mkNum(1))},
                         }
 
                         i := 0
                         multiIterate(defs, func(suffix []byte) bool {
                                 So(readNum(suffix), ShouldEqual, vals[i][1])
                                 i++
                                 return true
                         })
                         So(i, ShouldEqual, 5)
 
                         i = 0
                         multiIterate(defs, func(suffix []byte) bool {
                                 So(readNum(suffix), ShouldEqual, vals[i][1])
                                 i++
                                 return false
                         })
                         So(i, ShouldEqual, 1)
                 })
 
         })
 
 }