.

wcfs/wcfs.go

@@ -488,10 +488,23 @@ type Watch struct {
 type Watcher struct {
 	sk *FileSock
 
-	// XXX
-	// fileTab:	BigFile ->
-	//			at
-	//			pinned = ...		XXX
+	// established file watchers.
+	// XXX in-progress - where?
+	// XXX locking?
+	fileTab map[*FileWatch]struct{}
+}
+
+// FileWatch represents watching for 1 BigFile.
+type FileWatch struct {
+	link *Watcher // link to client
+	file *BigFile	// XXX needed?
+
+	// XXX locking
+
+	// requested to be watched @at
+	at zodb.Tid
+
+	// XXX pinned
 }
 
 // /(head|<rev>)/bigfile/		- served by BigFileDir.
@@ -538,11 +551,10 @@ type BigFile struct {
 	loadMu  sync.Mutex
 	loading map[int64]*blkLoadState // #blk -> {... blkdata}
 
-	// XXX mappings where client(s) requested isolation guarantee
-	//mappings ...	XXX -> watchers?
-
 	// watchers attached to this file
-	watchers map[*Watcher]struct{}
+	// XXX already in "established" state (i.e. initial watch request was answered with "ok")
+	// XXX locking -> watchMu?
+	watchers map[*FileWatch]struct{}
 }
 
 // blkLoadState represents a ZBlk load state/result.
@@ -556,7 +568,7 @@ type blkLoadState struct {
 	err      error
 }
 
-// -------- 3) ZODB invariant --------
+// -------- 3) Cache invariant --------
 
 // zodbCacheControl implements zodb.LiveCacheControl to tune ZODB to never evict
 // LOBTree/LOBucket from live cache. We want to keep LOBTree/LOBucket always alive

wcfs/wcfs_test.py

@@ -613,6 +613,8 @@ def test_wcfs():
 
     # XXX access to block not previously accessed but invalidated in ZODB
 
+    # XXX new watch request while previous watch request is in progress (over the same /head/watch handle)
+
 
 
 def test_wcfs_invproto():