X rebuild: tests: Don't exercise keys from keys2 that already became tracked...

X rebuild: tests: Don't exercise keys from keys2 that already became tracked after Track(keys1) + Update

58s -> 14s  (in -short mode)

wcfs/internal/xbtree/path-reverse.patch

-To reduce allocs  -> no change in t
-diff --git a/wcfs/internal/xbtree/pptreesubset.go b/wcfs/internal/xbtree/pptreesubset.go
-index 43bd37e5..d8c15d9b 100644
---- a/wcfs/internal/xbtree/pptreesubset.go
-+++ b/wcfs/internal/xbtree/pptreesubset.go
-@@ -77,7 +77,7 @@ func (S PPTreeSubSet) Path(oid zodb.Oid) (path []zodb.Oid) {
- 			panicf("node %s is not in the set  <- %v", oid, path)
- 		}
- 
--		path = append([]zodb.Oid{oid}, path...)
-+		path = append(path, oid) // in reverse
- 		oid = t.parent
- 
- 		if oid == zodb.InvalidOid {
-@@ -85,6 +85,11 @@ func (S PPTreeSubSet) Path(oid zodb.Oid) (path []zodb.Oid) {
- 		}
- 	}
- 
-+	// we've built path in reverse order - revert it back
-+	for i, j := 0, len(path)-1; i<j; i, j = i+1, j-1 {
-+		path[i], path[j] = path[j], path[i]
-+	}
-+
- 	return path
- }
- 

wcfs/internal/xbtree/pptreesubset-noptr.patch

-To reduce allocs  -> no change in t
-diff --git a/wcfs/internal/xbtree/pptreesubset.go b/wcfs/internal/xbtree/pptreesubset.go
-index 43bd37e5..b304a2d0 100644
---- a/wcfs/internal/xbtree/pptreesubset.go
-+++ b/wcfs/internal/xbtree/pptreesubset.go
-@@ -52,7 +52,7 @@ const debugPPSet = false
- // Every node in the set comes with .parent pointer.
- //
- // XXX we only allow single parent/root case and report "tree corrupt" otherwise.
--type PPTreeSubSet map[zodb.Oid]*nodeInTree
-+type PPTreeSubSet map[zodb.Oid]nodeInTree // NOTE _not_ *nodeInTree to reduce preesure on GC
- 
- // nodeInTree represents tracking information about a node.
- // XXX -> treeNode ?
-@@ -77,7 +77,7 @@ func (S PPTreeSubSet) Path(oid zodb.Oid) (path []zodb.Oid) {
- 			panicf("node %s is not in the set  <- %v", oid, path)
- 		}
- 
--		path = append([]zodb.Oid{oid}, path...)
-+		path = append([]zodb.Oid{oid}, path...) // XXX less copy/alloc
- 		oid = t.parent
- 
- 		if oid == zodb.InvalidOid {
-@@ -106,7 +106,6 @@ func (S PPTreeSubSet) AddPath(path []zodb.Oid) {
- 
- 	// go through path and add nodes to the set
- 	parent := zodb.InvalidOid
--	var pt *nodeInTree = nil
- 	for _, oid := range path {
- 		if oid == zodb.InvalidOid {
- 			panicf("path has node with invalid oid: %v", path)
-@@ -114,7 +113,7 @@ func (S PPTreeSubSet) AddPath(path []zodb.Oid) {
- 
- 		t, already := S[oid]
- 		if !already {
--			t = &nodeInTree{parent: parent, nchild: 0}
-+			t = nodeInTree{parent: parent, nchild: 0}
- 			S[oid] = t
- 		}
- 		if t.parent != parent {
-@@ -123,12 +122,13 @@ func (S PPTreeSubSet) AddPath(path []zodb.Oid) {
- 				oid, t.parent, parent)
- 		}
- 
--		if pt != nil && !already {
-+		if parent != zodb.InvalidOid && !already {
-+			pt := S[parent]
- 			pt.nchild++
-+			S[parent] = pt
- 		}
- 
- 		parent = oid
--		pt = t
- 	}
- }
- 
-@@ -226,7 +226,7 @@ func (A PPTreeSubSet) xUnionInplace(B PPTreeSubSet) {
- 	for oid, t2 := range B {
- 		t, already := A[oid]
- 		if !already {
--			t = &nodeInTree{parent: t2.parent, nchild: 0}
-+			t = nodeInTree{parent: t2.parent, nchild: 0}
- 			A[oid] = t
- 			// remember to nchild++ in parent
- 			if t.parent != zodb.InvalidOid {
-@@ -306,6 +306,7 @@ func (A PPTreeSubSet) xfixup(sign int, δnchild map[zodb.Oid]int) {
- 	for oid, δnc := range δnchild {
- 		t := A[oid] // t != nil as A is PP-connected
- 		t.nchild += sign*δnc
-+		A[oid] = t
- 		if t.nchild == 0 {
- 			gcq = append(gcq, oid)
- 		}
-@@ -332,6 +333,7 @@ func (S PPTreeSubSet) gc1(oid zodb.Oid) {
- 	for oid != zodb.InvalidOid {
- 		t := S[oid]
- 		t.nchild--
-+		S[oid] = t
- 		if t.nchild > 0 {
- 			break
- 		}
-@@ -398,7 +400,7 @@ func (S PPTreeSubSet) verify() {
- func (orig PPTreeSubSet) Clone() PPTreeSubSet {
- 	klon := make(PPTreeSubSet, len(orig))
- 	for oid, t := range orig {
--		klon[oid] = &nodeInTree{parent: t.parent, nchild: t.nchild}
-+		klon[oid] = nodeInTree{parent: t.parent, nchild: t.nchild}
- 	}
- 	return klon
- }
-diff --git a/wcfs/internal/xbtree/δbtail_test.go b/wcfs/internal/xbtree/δbtail_test.go
-index ad4b4a13..4d9b126d 100644
---- a/wcfs/internal/xbtree/δbtail_test.go
-+++ b/wcfs/internal/xbtree/δbtail_test.go
-@@ -359,7 +359,7 @@ func (rbs RBucketSet) _trackSetWithCov(tracked SetKey, outKeyCover *RangedKeySet
- 		if kb.oid != zodb.InvalidOid {
- 			track, already := trackSet[kb.oid]
- 			if !already {
--				track = &nodeInTree{parent: kb.parent.oid, nchild: 0}
-+				track = nodeInTree{parent: kb.parent.oid, nchild: 0}
- 				trackSet[kb.oid] = track
- 				newNode = true
- 			}
-@@ -378,7 +378,7 @@ func (rbs RBucketSet) _trackSetWithCov(tracked SetKey, outKeyCover *RangedKeySet
- 			newParent := false
- 			pt, already := trackSet[p.oid]
- 			if !already {
--				pt = &nodeInTree{parent: ppoid, nchild: 0}
-+				pt = nodeInTree{parent: ppoid, nchild: 0}
- 				trackSet[p.oid] = pt
- 				newParent = true
- 			}
-@@ -388,6 +388,7 @@ func (rbs RBucketSet) _trackSetWithCov(tracked SetKey, outKeyCover *RangedKeySet
- 
- 			if newNode {
- 				pt.nchild++
-+				trackSet[p.oid] = pt
- 			}
- 			newNode = newParent
- 			p = p.parent

wcfs/internal/xbtree/δbtail_test.go

@@ -973,9 +973,9 @@ func xverifyΔBTail_rebuild(t *testing.T, db *zodb.DB, treeRoot zodb.Oid, t0, t1
 			t2.at: "at2",
 		}
 
-		fmt.Printf("@%s:  %v\n", xat[t0.at], t0.xkv.Flatten())
-		fmt.Printf("@%s:  %v\n", xat[t1.at], t1.xkv.Flatten())
-		fmt.Printf("@%s:  %v\n", xat[t2.at], t2.xkv.Flatten())
+		//fmt.Printf("@%s:  %v\n", xat[t0.at], t0.xkv.Flatten())
+		//fmt.Printf("@%s:  %v\n", xat[t1.at], t1.xkv.Flatten())
+		//fmt.Printf("@%s:  %v\n", xat[t2.at], t2.xkv.Flatten())
 
 		kadj10 := KAdj(t1,t0, allTestKeys(t0,t1,t2))
 		kadj21 := KAdj(t2,t1, allTestKeys(t0,t1,t2))
@@ -1060,8 +1060,17 @@ func xverifyΔBTail_rebuild(t *testing.T, db *zodb.DB, treeRoot zodb.Oid, t0, t1
 						/*trackSet=*/ Tkeys1R2,
 						/*vδT=*/ δkv1_k1R2, δkv2_k1R2)
 
-					// tRestKeys2 = tAllKeys - keys1
-					tRestKeys2 := tAllKeys.Difference(keys1)
+					// tRestKeys2      = tAllKeys - keys1
+					// reduce that to  = tAllKeys - keys1R2   in short mode
+					// ( if key from keys2 already became tracked after Track(keys1) + Update,
+					//   adding Track(that-key), is not adding much testing coverage to recompute paths )
+					var tRestKeys2 SetKey
+					if testing.Short() {
+						tRestKeys2 = tAllKeys.Difference(keys1R2)
+					} else {
+						tRestKeys2 = tAllKeys.Difference(keys1)
+					}
+
 					tRestKeyv2 := tRestKeys2.SortedElements()
 					for k2idx := range IntSets(len(tRestKeyv2)) {
 						keys2 := SetKey{}
@@ -1100,8 +1109,8 @@ func xverifyΔBTail_rebuild(t *testing.T, db *zodb.DB, treeRoot zodb.Oid, t0, t1
 
 
 						// δkvX_k12R2 = tX.δxkv / keys12R2
-						δkv1_k12R2 := map[Key]Δstring{}
-						δkv2_k12R2 := map[Key]Δstring{}
+						δkv1_k12R2 := make(map[Key]Δstring, len(t1.δxkv))
+						δkv2_k12R2 := make(map[Key]Δstring, len(t2.δxkv))
 						for k := range keys12R2 {
 							δv1, ok := t1.δxkv[k]
 							if ok {