Refactor: Rename some files.

impl/memory/plist.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"
-
-        ds "github.com/luci/gae/service/datastore"
-        "github.com/luci/gkvlite"
-)
-
-var indexCreationDeterministic = false
-
-type qIndexSlice []*qIndex
-
-func (s qIndexSlice) Len() int           { return len(s) }
-func (s qIndexSlice) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
-func (s qIndexSlice) Less(i, j int) bool { return s[i].Less(s[j]) }
-
-func defaultIndicies(kind string, pmap ds.PropertyMap) []*qIndex {
-        ret := make(qIndexSlice, 0, 2*len(pmap)+1)
-        ret = append(ret, &qIndex{kind, false, nil})
-        for name, pvals := range pmap {
-                needsIndex := false
-                for _, v := range pvals {
-                        if v.IndexSetting() == ds.ShouldIndex {
-                                needsIndex = true
-                                break
-                        }
-                }
-                if !needsIndex {
-                        continue
-                }
-                ret = append(ret, &qIndex{kind, false, []qSortBy{{name, qASC}}})
-                ret = append(ret, &qIndex{kind, false, []qSortBy{{name, qDEC}}})
-        }
-        if indexCreationDeterministic {
-                sort.Sort(ret)
-        }
-        return ret
-}
-
-func indexEntriesWithBuiltins(k ds.Key, pm ds.PropertyMap, complexIdxs []*qIndex) *memStore {
-        sip := partiallySerialize(pm)
-        return sip.indexEntries(k, append(defaultIndicies(k.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>, ...]
-type serializedIndexablePmap map[string]serializedPvals
-
-func partiallySerialize(pm ds.PropertyMap) (ret serializedIndexablePmap) {
-        if len(pm) == 0 {
-                return
-        }
-
-        buf := &bytes.Buffer{}
-        ret = make(serializedIndexablePmap, len(pm))
-        for k, vals := range pm {
-                newVals := make(serializedPvals, 0, len(vals))
-                for _, v := range vals {
-                        if v.IndexSetting() == ds.NoIndex {
-                                continue
-                        }
-                        buf.Reset()
-                        v.Write(buf, ds.WithoutContext)
-                        newVal := make([]byte, buf.Len())
-                        copy(newVal, buf.Bytes())
-                        newVals = append(newVals, newVal)
-                }
-                if len(newVals) > 0 {
-                        sort.Sort(newVals)
-                        ret[k] = newVals
-                }
-        }
-        return
-}
-
-// indexRowGen contains enough information to generate all of the index rows which
-// correspond with a propertyList and a qIndex.
-type indexRowGen struct {
-        propVec []serializedPvals
-        orders  []qDirection
-}
-
-// permute calls cb for each index row, in the sorted order of the rows.
-func (s indexRowGen) permute(cb func([]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] == qASC {
-                                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] == qDEC {
-                        iVec[i] = iVecLim[i] - 1
-                }
-        }
-
-        for {
-                bufsiz := 0
-                for pvalSliceIdx, pvalIdx := range iVec {
-                        bufsiz += len(s.propVec[pvalSliceIdx][pvalIdx])
-                }
-                buf := bytes.NewBuffer(make([]byte, 0, bufsiz))
-                for pvalSliceIdx, pvalIdx := range iVec {
-                        data := s.propVec[pvalSliceIdx][pvalIdx]
-                        if s.orders[pvalSliceIdx] == qASC {
-                                buf.Write(data)
-                        } else {
-                                for _, b := range data {
-                                        buf.WriteByte(b ^ 0xFF)
-                                }
-                        }
-                }
-                cb(buf.Bytes())
-                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(idx *qIndex, sip serializedIndexablePmap) (indexRowGen, bool) {
-        m.buf.propVec = m.buf.propVec[:0]
-        m.buf.orders = m.buf.orders[:0]
-        for _, sb := range idx.sortby {
-                if pv, ok := sip[sb.prop]; ok {
-                        m.buf.propVec = append(m.buf.propVec, pv)
-                        m.buf.orders = append(m.buf.orders, sb.dir)
-                } else {
-                        return indexRowGen{}, false
-                }
-        }
-        return m.buf, true
-}
-
-func (sip serializedIndexablePmap) indexEntries(k ds.Key, idxs []*qIndex) *memStore {
-        ret := newMemStore()
-        idxColl := ret.SetCollection("idx", nil)
-        // getIdxEnts retrieves an index collection or adds it if it's not there.
-        getIdxEnts := func(qi *qIndex) *memCollection {
-                buf := &bytes.Buffer{}
-                qi.WriteBinary(buf)
-                b := buf.Bytes()
-                idxColl.Set(b, []byte{})
-                return ret.SetCollection(fmt.Sprintf("idx:%s:%s", k.Namespace(), b), nil)
-        }
-
-        buf := &bytes.Buffer{}
-        ds.WriteKey(buf, ds.WithoutContext, k)
-        keyData := buf.Bytes()
-
-        walkPermutations := func(prefix []byte, irg indexRowGen, ents *memCollection) {
-                prev := []byte{} // intentionally make a non-nil slice, gkvlite hates nil.
-                irg.permute(func(data []byte) {
-                        buf := bytes.NewBuffer(make([]byte, 0, len(prefix)+len(data)+len(keyData)))
-                        buf.Write(prefix)
-                        buf.Write(data)
-                        buf.Write(keyData)
-                        ents.Set(buf.Bytes(), prev)
-                        prev = data
-                })
-        }
-
-        mtch := matcher{}
-        for _, idx := range idxs {
-                if irg, ok := mtch.match(idx, sip); ok {
-                        idxEnts := getIdxEnts(idx)
-                        if len(irg.propVec) == 0 {
-                                idxEnts.Set(keyData, []byte{}) // propless index, e.g. kind -> key = nil
-                        } else if idx.ancestor {
-                                for ancKey := k; ancKey != nil; ancKey = ancKey.Parent() {
-                                        buf := &bytes.Buffer{}
-                                        ds.WriteKey(buf, ds.WithoutContext, ancKey)
-                                        walkPermutations(buf.Bytes(), irg, idxEnts)
-                                }
-                        } else {
-                                walkPermutations(nil, irg, idxEnts)
-                        }
-                }
-        }
-
-        return ret
-}
-
-func updateIndicies(store *memStore, key ds.Key, oldEnt, newEnt ds.PropertyMap) {
-        idxColl := store.GetCollection("idx")
-        if idxColl == nil {
-                idxColl = store.SetCollection("idx", nil)
-        }
-
-        // load all current complex query index definitions.
-        compIdx := []*qIndex{}
-        idxColl.VisitItemsAscend(complexQueryPrefix, false, func(i *gkvlite.Item) bool {
-                if !bytes.HasPrefix(i.Key, complexQueryPrefix) {
-                        return false
-                }
-                qi := &qIndex{}
-                if err := qi.ReadBinary(bytes.NewBuffer(i.Key)); err != nil {
-                        panic(err) // memory corruption
-                }
-                compIdx = append(compIdx, qi)
-                return true
-        })
-
-        oldIdx := indexEntriesWithBuiltins(key, oldEnt, compIdx)
-
-        newIdx := indexEntriesWithBuiltins(key, newEnt, compIdx)
-
-        prefix := "idx:" + key.Namespace() + ":"
-
-        gkvCollide(oldIdx.GetCollection("idx"), newIdx.GetCollection("idx"), func(k, ov, nv []byte) {
-                ks := prefix + string(k)
-                idxColl.Set(k, []byte{})
-
-                coll := store.GetCollection(ks)
-                if coll == nil {
-                        coll = store.SetCollection(ks, nil)
-                }
-                oldColl := oldIdx.GetCollection(ks)
-                newColl := newIdx.GetCollection(ks)
-
-                switch {
-                case ov == nil && nv != nil: // all additions
-                        newColl.VisitItemsAscend(nil, false, func(i *gkvlite.Item) bool {
-                                coll.Set(i.Key, i.Val)
-                                return true
-                        })
-                case ov != nil && nv == nil: // all deletions
-                        oldColl.VisitItemsAscend(nil, false, func(i *gkvlite.Item) bool {
-                                coll.Delete(i.Key)
-                                return true
-                        })
-                case ov != nil && nv != nil: // merge
-                        gkvCollide(oldColl, newColl, func(k, ov, nv []byte) {
-                                if nv == nil {
-                                        coll.Delete(k)
-                                } else {
-                                        coll.Set(k, nv)
-                                }
-                        })
-                default:
-                        panic("impossible")
-                }
-                // TODO(riannucci): remove entries from idxColl and remove index collections
-                // when there are no index entries for that index any more.
-        })
-}