.

wcfs/δbtail.go

@@ -66,9 +66,11 @@ type Value  = zodb.Oid // XXX assumes key points to IPersistent
 //
 //   .Track(path)		- start tracking tree nodes and keys; root=path[0], keys=path[-1].keys
 //
-//   .Update(δZ) -> δB		- update BTree δ tail given raw ZODB changes
-//   .ForgetPast(revCut)	- forget changes past revCut
-//   .Get(root, key, at)	- get root[key] @at assuming root[key] ∈ tracked
+//   .Update(δZ) -> δB				- update BTree δ tail given raw ZODB changes
+//   .ForgetPast(revCut)			- forget changes past revCut
+//   .SliceByRev(lo, hi) -> []δB		- XXX
+//   .SliceByRootRev(root, lo, hi) -> []δT	- XXX
+//   .Get(root, key, at)			- get root[key] @at assuming root[key] ∈ tracked
 //
 // An example for tracked set is a set of visited BTree paths.
 // There is no requirement that tracked set belongs to only one single BTree.
@@ -95,7 +97,7 @@ type ΔBtail struct {
 	// tracked index: BTree|Bucket -> top tree element.
 	trackIdx map[zodb.Oid]SetTree // oid -> {} roots		XXX root -> oid?
 
-	// tracked objects that are not yet taken into in current δBtail
+	// tracked objects that are not yet taken into account in current δBtail
 	trackNew map[zodb.Oid]struct{}	// XXX SetOid
 }
 
@@ -342,7 +344,15 @@ func (δBtail *ΔBtail) SliceByRev(lo, hi zodb.Tid) /*readonly*/ []ΔB {
 	panic("TODO")
 }
 
-// XXX
+// SliceByRootRev returns history of a tree changes in (lo, hi] range.
+//
+// it must be called with the following condition:
+//
+//	tail ≤ lo ≤ hi ≤ head
+//
+// the caller must not modify returned slice.
+//
+// Note: contrary to regular go slicing, low is exclusive while high is inclusive.
 func (δBtail *ΔBtail) SliceByRootRev(root *Tree, lo, hi zodb.Tid) /*readonly*/[]ΔTree {
 	δassertSlice(δBtail, lo, hi)
 
@@ -397,7 +407,7 @@ func (δBtail *ΔBtail) SliceByRootRev(root *Tree, lo, hi zodb.Tid) /*readonly*/
 // . +k(blk) -> invalidate #blk (e.g. if blk was previously read as hole)
 
 
-// misc
+// ---- misc ----
 
 // δassertSlice asserts that δ.tail ≤ lo ≤ hi ≤ δ.head
 func δassertSlice(δ interface { Head() zodb.Tid; Tail() zodb.Tid }, lo, hi zodb.Tid) {

wcfs/δftail.go

@@ -44,8 +44,8 @@ import (
 //
 // ΔFtail provides the following operations:
 //
-//   .Track(file, blkTreePath)			- add file and block reached via BTree path to
-//						  tracked set.
+//   .Track(file, blkTreePath)		- add file and block reached via BTree path to tracked set.
+//
 //   .Update(δZ) -> δF				- update files δ tail given raw ZODB changes
 //   .ForgetPast(revCut)			- forget changes past revCut
 //   .SliceByRev(lo, hi) -> []δF		- query for all files changes with rev ∈ (lo, hi]
@@ -162,12 +162,21 @@ func (δFtail *ΔFtail) SliceByRev(lo, hi zodb.Tid) /*readonly*/ []ΔF {
 	panic("TODO")
 }
 
-// XXX
-func (δFtail *ΔFtail) SliceByFileRev(f *BigFile, lo, hi zodb.Tid) /*readonly*/[]Δfile {
+// SliceByFileRev returns history of file changes in (lo, hi] range.
+//
+// it must be called with the following condition:
+//
+//	tail ≤ lo ≤ hi ≤ head
+//
+// the caller must not modify returned slice.
+//
+// Note: contrary to regular go slicing, low is exclusive while high is inclusive.
+func (δFtail *ΔFtail) SliceByFileRev(file *BigFile, lo, hi zodb.Tid) /*readonly*/[]Δfile {
 	δassertSlice(δFtail, lo, hi)
 
 	// XXX activate zfile?
-	vδT := δFtail.δBtail.SliceByRootRev(f.zfile.blktab, lo, hi)
+	vδT := δFtail.δBtail.SliceByRootRev(file.zfile.blktab, lo, hi)
+	//kv = kvAtTail
 
 	_ = vδT
 	panic("TODO")