.

wcfs/internal/xbtree/xbtree.go

+// Copyright (C) 2021  Nexedi SA and Contributors.
+//                     Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Free Software licenses or any of the Open Source
+// Initiative approved licenses and Convey the resulting work. Corresponding
+// source of such a combination shall include the source code for all other
+// software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+// See https://www.nexedi.com/licensing for rationale and options.
+
 // Package xbtree complements package lab.nexedi.com/kirr/neo/go/zodb/btree.
 //
 // It provides the following amendments:

wcfs/internal/xbtree/δbtail.go

@@ -20,6 +20,8 @@
 package xbtree
 // ΔBtail
 
+// XXX ΔBtail organization
+
 import (
 	"context"
 	"fmt"
@@ -56,7 +58,7 @@ const debugΔBtail = false
 //
 // ΔBtail provides the following operations:
 //
-//   .Track(path)		- start tracking tree nodes and keys; root=path[0], keys=path[-1].(lo,hi]
+//   .Track(path)	- start tracking tree nodes and keys; root=path[0], keys=path[-1].(lo,hi]
 //
 //   .Update(δZ) -> δB				- update BTree δ tail given raw ZODB changes
 //   .ForgetPast(revCut)			- forget changes past revCut
@@ -109,8 +111,8 @@ type _ΔTtail struct {
 	trackNew blib.PPTreeSubSet
 	// XXX + trackNewKeys RangedKeySet
 
-	// index for LastRevOf queries
-	lastRevOf map[Key]zodb.Tid // {} key -> last
+	// index for GetAt queries
+	lastRevOf map[Key]zodb.Tid // {} key -> last revision
 }
 
 // _ΔBroots represents roots-only part of ΔB.
@@ -130,7 +132,7 @@ type ΔB struct {
 // ΔTree describes changes to one BTree in one revision.
 type ΔTree struct {
 	Rev  zodb.Tid
-	ΔKV  map[Key]ΔValue	// XXX -> KV ?
+	KV  map[Key]ΔValue
 }
 
 
@@ -211,10 +213,10 @@ func vδTClone(orig []ΔTree) []ΔTree {
 	for _, origδT := range orig {
 		klonδT := ΔTree{
 			Rev: origδT.Rev,
-			ΔKV: make(map[Key]ΔValue, len(origδT.ΔKV)),
+			KV:  make(map[Key]ΔValue, len(origδT.KV)),
 		}
-		for k, δv := range origδT.ΔKV {
-			klonδT.ΔKV[k] = δv
+		for k, δv := range origδT.KV {
+			klonδT.KV[k] = δv
 		}
 		klon = append(klon, klonδT)
 	}
@@ -525,7 +527,7 @@ func (δTtail *_ΔTtail) rebuild1(atPrev zodb.Tid, δZ zodb.ΔRevEntry, trackNew
 	})
 	if j == l || δTtail.vδT[j].Rev != δZ.Rev {
 		newRevEntry = true
-		δTcurr := ΔTree{Rev: δZ.Rev, ΔKV: map[Key]ΔValue{}}
+		δTcurr := ΔTree{Rev: δZ.Rev, KV: map[Key]ΔValue{}}
 		// insert(@j, δTcurr)
 		δTtail.vδT = append(δTtail.vδT[:j],
 				    append([]ΔTree{δTcurr},
@@ -537,13 +539,13 @@ func (δTtail *_ΔTtail) rebuild1(atPrev zodb.Tid, δZ zodb.ΔRevEntry, trackNew
 		// the diff was backward; δTtail entries are with diff forward
 		δv.New, δv.Old = δv.Old, δv.New
 
-		δv_, already := δTcurr.ΔKV[k]
+		δv_, already := δTcurr.KV[k]
 		if already {
 			if δv != δv_ {
 				panicf("[%v] inconsistent δv:\nδTcurr: %v\nδT:  %v", k, δTcurr, δT)
 			}
 		} else {
-			δTcurr.ΔKV[k] = δv
+			δTcurr.KV[k] = δv
 		}
 	}
 
@@ -597,7 +599,7 @@ func (δBtail *ΔBtail) Update(δZ *zodb.EventCommit) (_ ΔB, err error) {
 		if l > 0 {
 			δT := δTtail.vδT[l-1] // δT head
 			if δT.Rev == δZ.Tid {
-				δB.ByRoot[root] = δT.ΔKV
+				δB.ByRoot[root] = δT.KV
 			}
 		}
 
@@ -677,7 +679,7 @@ func (δBtail *ΔBtail) _Update1(δZ *zodb.EventCommit) (δB1 _ΔBUpdate1, err e
 		// XXX also needs vδT clone here?
 		δTtail := δBtail.vδTbyRoot[root] // must be there
 		if len(δT) > 0 { // an object might be resaved without change
-			δTtail.vδT = append(δTtail.vδT, ΔTree{Rev: δZ.Tid, ΔKV: δT})
+			δTtail.vδT = append(δTtail.vδT, ΔTree{Rev: δZ.Tid, KV: δT})
 		}
 
 		δBtail.trackSet.ApplyΔ(δtrack)
@@ -808,10 +810,10 @@ func (δBtail *ΔBtail) GetAt(root zodb.Oid, key Key, at zodb.Tid) (value Value,
 		panicf("δBtail: root<%s> not tracked", root)
 	}
 
-	// XXX -> index lastXXXOf(key) | linear scan ↓ looking for change <= at
+	// TODO -> index lastRevOf(key) | linear scan ↓ looking for change <= at
 	for i := len(δTtail.vδT)-1; i >= 0; i-- {
 		δT := δTtail.vδT[i]
-		δvalue, ok_ := δT.ΔKV[key]
+		δvalue, ok_ := δT.KV[key]
 		if ok_ {
 			valueExact = true
 			if δT.Rev > at {

wcfs/internal/xbtree/δbtail_test.go

@@ -1186,12 +1186,12 @@ func TestΔBtailSliceByRootRev(t_ *testing.T) {
 	t := xbtreetest.NewT(t_)
 	X := exc.Raiseif
 
-	// ΔT is similar to ΔTree but uses Δstring instead of ΔValue for ΔKV
+	// ΔT is similar to ΔTree but uses Δstring instead of ΔValue for KV
 	type ΔT struct {
 		Rev zodb.Tid
-		ΔKV map[Key]Δstring
+		KV  map[Key]Δstring
 	}
-	// δ is shorthand for ΔKV
+	// δ is shorthand for ΔT.KV
 	type δ = map[Key]Δstring
 
 	t0 := t.CommitTree("T2/B1:a-B2:f")
@@ -1219,7 +1219,7 @@ func TestΔBtailSliceByRootRev(t_ *testing.T) {
 		var vδT_ []ΔT
 		for _, δT := range vδT {
 			tj := t.XGetCommit(δT.Rev)
-			δt := ΔT{δT.Rev, xgetδKV(tj.Prev, tj, δT.ΔKV)}
+			δt := ΔT{δT.Rev, xgetδKV(tj.Prev, tj, δT.KV)}
 			vδT_ = append(vδT_, δt)
 		}
 
@@ -1228,11 +1228,11 @@ func TestΔBtailSliceByRootRev(t_ *testing.T) {
 		}
 		have := []string{}
 		for _, δT := range vδT_ {
-			have = append(have, fmt.Sprintf("@%s·%v", t.AtSymb(δT.Rev), δT.ΔKV))
+			have = append(have, fmt.Sprintf("@%s·%v", t.AtSymb(δT.Rev), δT.KV))
 		}
 		want := []string{}
 		for _, δT := range vδTok {
-			want = append(want, fmt.Sprintf("@%s·%v", t.AtSymb(δT.Rev), δT.ΔKV))
+			want = append(want, fmt.Sprintf("@%s·%v", t.AtSymb(δT.Rev), δT.KV))
 		}
 		t.Errorf("%s:\nhave: %s\nwant: %s", subj, have, want)
 	}
@@ -1254,16 +1254,16 @@ func TestΔBtailSliceByRootRev(t_ *testing.T) {
 	// sXX should be all aliased to vδT
 	gg, _ := t0.XGetBlkByName("g")
 	hh, _ := t0.XGetBlkByName("h")
-	vδT[0].Rev = t0.At; δkv0 := vδT[0].ΔKV; vδT[0].ΔKV = map[Key]ΔValue{11:{gg,gg}}
-	vδT[1].Rev = t0.At; δkv1 := vδT[1].ΔKV; vδT[1].ΔKV = map[Key]ΔValue{12:{hh,hh}}
+	vδT[0].Rev = t0.At; δkv0 := vδT[0].KV; vδT[0].KV = map[Key]ΔValue{11:{gg,gg}}
+	vδT[1].Rev = t0.At; δkv1 := vδT[1].KV; vδT[1].KV = map[Key]ΔValue{12:{hh,hh}}
 	assertvδT("t2.vδT*", vδT,        ΔT{t0.At, δ{11:{g,g}}},  ΔT{t0.At, δ{12:{h,h}}})
 	assertvδT("t2.s00*", s00)
 	assertvδT("t2.s01*", s01,        ΔT{t0.At, δ{11:{g,g}}})
 	assertvδT("t2.s02*", s02,        ΔT{t0.At, δ{11:{g,g}}},  ΔT{t0.At, δ{12:{h,h}}})
 	assertvδT("t2.s12*", s12,                                 ΔT{t0.At, δ{12:{h,h}}})
 	assertvδT("2.s22*",  s22)
-	vδT[0].Rev = t1.At; vδT[0].ΔKV = δkv0
-	vδT[1].Rev = t2.At; vδT[1].ΔKV = δkv1
+	vδT[0].Rev = t1.At; vδT[0].KV = δkv0
+	vδT[1].Rev = t2.At; vδT[1].KV = δkv1
 	assertvδT("t2.vδT+", vδT,        ΔT{t1.At, δ{2:{f,g}}},   ΔT{t2.At, δ{2:{g,h}}})
 	assertvδT("t2.s00+", s00)
 	assertvδT("t2.s01+", s01,        ΔT{t1.At, δ{2:{f,g}}})
@@ -1299,8 +1299,8 @@ func TestΔBtailSliceByRootRev(t_ *testing.T) {
 	// sXX_ should be all aliased to vδT, but not sXX
 	bb, _ := t0.XGetBlkByName("b")
 	cc, _ := t0.XGetBlkByName("c")
-	vδT[0].Rev = t0.At; δkv0 = vδT[0].ΔKV; vδT[0].ΔKV = map[Key]ΔValue{111:{bb,bb}}
-	vδT[1].Rev = t0.At; δkv1 = vδT[1].ΔKV; vδT[1].ΔKV = map[Key]ΔValue{112:{cc,cc}}
+	vδT[0].Rev = t0.At; δkv0 = vδT[0].KV; vδT[0].KV = map[Key]ΔValue{111:{bb,bb}}
+	vδT[1].Rev = t0.At; δkv1 = vδT[1].KV; vδT[1].KV = map[Key]ΔValue{112:{cc,cc}}
 	assertvδT("t12.vδT*",  vδT,     ΔT{t0.At, δ{111:{b,b}}},        ΔT{t0.At, δ{112:{c,c}}})
 	assertvδT("t12.s00*",  s00)
 	assertvδT("t12.s00_*", s00_)
@@ -1313,8 +1313,8 @@ func TestΔBtailSliceByRootRev(t_ *testing.T) {
 	assertvδT("t12.s22*",  s22)
 	assertvδT("t12.s22_*", s22_)
 
-	vδT[0].Rev = t1.At; vδT[0].ΔKV = δkv0
-	vδT[1].Rev = t2.At; vδT[1].ΔKV = δkv1
+	vδT[0].Rev = t1.At; vδT[0].KV = δkv0
+	vδT[1].Rev = t2.At; vδT[1].KV = δkv1
 	assertvδT("t12.vδT+",  vδT,     ΔT{t1.At, δ{1:{a,b},2:{f,g}}},  ΔT{t2.At,  δ{1:{b,c},2:{g,h}}})
 	assertvδT("t12.s00+",  s00)
 	assertvδT("t12.s00_+", s00_)
@@ -1547,7 +1547,7 @@ func assertΔTtail(t *testing.T, subj string, δbtail *ΔBtail, tj *xbtreetest.C
 	atPrev := t0.At
 	for _, δToid := range vδToid {
 		vat = append(vat, δToid.Rev)
-		δT := xgetδKV(T.XGetCommit(atPrev), T.XGetCommit(δToid.Rev), δToid.ΔKV) // {} k -> δ(ZBlk(oid).data)
+		δT := xgetδKV(T.XGetCommit(atPrev), T.XGetCommit(δToid.Rev), δToid.KV) // {} k -> δ(ZBlk(oid).data)
 		vδT = append(vδT, δT)
 		atPrev = δToid.Rev
 	}

wcfs/internal/zdata/δftail.go

@@ -707,7 +707,7 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 		// changes to 2 should not be present at all.
 		ZinblkAdj := map[zodb.Oid]setI64{}
 		for _, δT := range vδT {
-			for blk, δzblk := range δT.ΔKV {
+			for blk, δzblk := range δT.KV {
 				if δzblk.Old != xbtree.VDEL {
 					inblk, ok := ZinblkAdj[δzblk.Old]
 					if ok {
@@ -756,8 +756,8 @@ func (δFtail *ΔFtail) SliceByFileRev(zfile *ZBigFile, lo, hi zodb.Tid) /*reado
 			// δT -> adjust Zinblk + update δf
 			if it >= 0 {
 				δT := vδT[it]
-				//fmt.Printf("δT @%s  %v\n", δT.Rev, δT.ΔKV)
-				for blk, δzblk := range δT.ΔKV {
+				//fmt.Printf("δT @%s  %v\n", δT.Rev, δT.KV)
+				for blk, δzblk := range δT.KV {
 					// apply in reverse as we go ←
 					if δzblk.New != xbtree.VDEL {
 						inblk, ok := Zinblk[δzblk.New]