Refactor keys and queries in datastore service and implementation.

impl/memory/datastore_index.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"
         "sort"
@@ skipping 18 matching lines @@
                 for _, v := range pvals {
                         if v.IndexSetting() == ds.ShouldIndex {
                                 needsIndex = true
                                 break
                         }
                 }
                 if !needsIndex {
                         continue
                 }
                 ret = append(ret, &ds.IndexDefinition{Kind: kind, SortBy: []ds.IndexColumn{{Property: name}}})
-                ret = append(ret, &ds.IndexDefinition{Kind: kind, SortBy: []ds.IndexColumn{{Property: name, Direction: ds.DESCENDING}}})
+                ret = append(ret, &ds.IndexDefinition{Kind: kind, SortBy: []ds.IndexColumn{{Property: name, Descending: true}}})
         }
         if serializationDeterministic {
                 sort.Sort(ret)
         }
         return ret
 }
 
-func indexEntriesWithBuiltins(k ds.Key, pm ds.PropertyMap, complexIdxs []*ds.IndexDefinition) *memStore {
+func indexEntriesWithBuiltins(k *ds.Key, pm ds.PropertyMap, complexIdxs []*ds.IndexDefinition) *memStore {
         sip := partiallySerialize(k, pm)
-        return sip.indexEntries(k.Namespace(), append(defaultIndexes(k.Kind(), pm), complexIdxs...))
+        return sip.indexEntries(k.Namespace(), append(defaultIndexes(k.Last().Kind, pm), complexIdxs...))
 }
 
 // serializedPvals is all of the serialized DSProperty values in qASC order.
 type serializedPvals [][]byte
 
 func (s serializedPvals) Len() int           { return len(s) }
 func (s serializedPvals) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
 func (s serializedPvals) Less(i, j int) bool { return bytes.Compare(s[i], s[j]) < 0 }
 
 // prop name -> [<serialized DSProperty>, ...]
@@ skipping 11 matching lines @@
                 data := serialize.ToBytes(v.ForIndex())
                 dataS := string(data)
                 if !dups.Add(dataS) {
                         continue
                 }
                 ret = append(ret, data)
         }
         return ret
 }
 
-func partiallySerialize(k ds.Key, pm ds.PropertyMap) (ret serializedIndexablePmap) {
+func partiallySerialize(k *ds.Key, pm ds.PropertyMap) (ret serializedIndexablePmap) {
         ret = make(serializedIndexablePmap, len(pm)+2)
         if k == nil {
                 impossible(fmt.Errorf("key to partiallySerialize is nil"))
         }
         ret["__key__"] = [][]byte{serialize.ToBytes(ds.MkProperty(k))}
         for k != nil {
                 ret["__ancestor__"] = append(ret["__ancestor__"], serialize.ToBytes(ds.MkProperty(k)))
                 k = k.Parent()
         }
         for k, vals := range pm {
                 newVals := serializeRow(vals)
                 if len(newVals) > 0 {
                         ret[k] = newVals
                 }
         }
         return
 }
 
 // indexRowGen contains enough information to generate all of the index rows which
 // correspond with a propertyList and a ds.IndexDefinition.
 type indexRowGen struct {
-        propVec []serializedPvals
-        orders  []ds.IndexDirection
+        propVec   []serializedPvals
+        decending []bool
 }
 
 // permute calls cb for each index row, in the sorted order of the rows.
 func (s indexRowGen) permute(collSetFn func(k, v []byte)) {
         iVec := make([]int, len(s.propVec))
         iVecLim := make([]int, len(s.propVec))
 
         incPos := func() bool {
                 for i := len(iVec) - 1; i >= 0; i-- {
                         var done bool
                         var newVal int
-                        if s.orders[i] == ds.ASCENDING {
+                        if !s.decending[i] {
                                 newVal = (iVec[i] + 1) % iVecLim[i]
                                 done = newVal != 0
                         } else {
                                 newVal = (iVec[i] - 1)
                                 if newVal < 0 {
                                         newVal = iVecLim[i] - 1
                                 } else {
                                         done = true
                                 }
                         }
                         iVec[i] = newVal
                         if done {
                                 return true
                         }
                 }
                 return false
         }
 
         for i, sps := range s.propVec {
                 iVecLim[i] = len(sps)
         }
 
         for i := range iVec {
-                if s.orders[i] == ds.DESCENDING {
+                if s.decending[i] {
                         iVec[i] = iVecLim[i] - 1
                 }
         }
 
         for {
                 bufsiz := 0
                 for pvalSliceIdx, pvalIdx := range iVec {
                         bufsiz += len(s.propVec[pvalSliceIdx][pvalIdx])
                 }
                 buf := serialize.Invertible(bytes.NewBuffer(make([]byte, 0, bufsiz)))
                 for pvalSliceIdx, pvalIdx := range iVec {
                         data := s.propVec[pvalSliceIdx][pvalIdx]
-                        buf.SetInvert(s.orders[pvalSliceIdx] == ds.DESCENDING)
-                        buf.Write(data)
+                        buf.SetInvert(s.decending[pvalSliceIdx])
+                        _, _ = buf.Write(data)
                 }
                 collSetFn(buf.Bytes(), []byte{})
                 if !incPos() {
                         break
                 }
         }
 }
 
 type matcher struct {
         buf indexRowGen
 }
 
 // matcher.match checks to see if the mapped, serialized property values
 // match the index. If they do, it returns a indexRowGen. Do not write or modify
 // the data in the indexRowGen.
 func (m *matcher) match(sortBy []ds.IndexColumn, sip serializedIndexablePmap) (indexRowGen, bool) {
         m.buf.propVec = m.buf.propVec[:0]
-        m.buf.orders = m.buf.orders[:0]
+        m.buf.decending = m.buf.decending[:0]
         for _, sb := range sortBy {
                 if pv, ok := sip[sb.Property]; ok {
                         m.buf.propVec = append(m.buf.propVec, pv)
-                        m.buf.orders = append(m.buf.orders, sb.Direction)
+                        m.buf.decending = append(m.buf.decending, sb.Descending)
                 } else {
                         return indexRowGen{}, false
                 }
         }
         return m.buf, true
 }
 
 func (sip serializedIndexablePmap) indexEntries(ns string, idxs []*ds.IndexDefinition) *memStore {
         ret := newMemStore()
         idxColl := ret.SetCollection("idx", nil)
@@ skipping 95 matching lines @@
         }
 
         if allEnts := store.GetCollection("ents:" + ns); allEnts != nil {
                 allEnts.VisitItemsAscend(nil, true, func(i *gkvlite.Item) bool {
                         pm, err := rpmWoCtx(i.Val, ns)
                         memoryCorruption(err)
 
                         prop, err := serialize.ReadProperty(bytes.NewBuffer(i.Key), serialize.WithoutContext, globalAppID, ns)
                         memoryCorruption(err)
 
-                        k := prop.Value().(ds.Key)
+                        k := prop.Value().(*ds.Key)
 
                         sip := partiallySerialize(k, pm)
 
                         mergeIndexes(ns, store,
                                 newMemStore(),
                                 sip.indexEntries(ns, normalized))
                         return true
                 })
         }
 }
 
-func updateIndexes(store *memStore, key ds.Key, oldEnt, newEnt ds.PropertyMap) {
+func updateIndexes(store *memStore, key *ds.Key, oldEnt, newEnt ds.PropertyMap) {
         // load all current complex query index definitions.
         compIdx := []*ds.IndexDefinition{}
         walkCompIdxs(store, nil, func(i *ds.IndexDefinition) bool {
                 compIdx = append(compIdx, i)
                 return true
         })
 
         mergeIndexes(key.Namespace(), store,
                 indexEntriesWithBuiltins(key, oldEnt, compIdx),
                 indexEntriesWithBuiltins(key, newEnt, compIdx))
 }