.

wcfs/wcfs.go

@@ -51,7 +51,7 @@
 //	...
 //
 // where head/ represents latest data as stored in upstream ZODB, and
-// @<revX>/ represents data as of revision <revX>.
+// @<revX>/ represents data as of database revision <revX>.
 //
 // head/ has the following structure:
 //
@@ -150,13 +150,19 @@
 //
 // A later request from the client for the same <bigfileX> but with different
 // <at>, overrides previous watch request for that file. A client can use "-"
-// instead of "@<at>" to stop watching the file.
+// instead of "@<at>" to stop watching a file.
 //
 // A single client can send several watch requests through single head/watch
 // open, as well as it can use several head/watch opens simultaneously.
 // The server sends pin notifications for all files requested to be watched via
 // every head/watch open.
 //
+// Note: a client could use a single watch to manage its several views for the same
+// file but with different <at>. This could be achieved via watching with
+// @<at_min>, and then deciding internally which views needs to be adjusted and
+// which views need not. Wcfs does not oblige clients to do so though, and a
+// client is free to use as many head/watch openenings as it needs to.
+//
 // When clients are done with @<revX>/bigfile/<bigfileX> (i.e. client's
 // transaction ends and array is unmapped), the server sees number of opened
 // files to @<revX>/bigfile/<bigfileX> drops to zero, and automatically
@@ -170,8 +176,8 @@
 // server will become blocked waiting for pin acknowledgments, and thus all
 // other clients, that try to work with the same file, will get stuck.
 //
-// The problem could be avoided, if wcfs would reside in OS kernel and this way
-// could be able to manipulate clients address space directly (then
+// The problem could be avoided, if wcfs would reside inside OS kernel and this
+// way could be able to manipulate clients address space directly (then
 // invalidation protocol won't be needed). It is also possible to imagine
 // mechanism, where wcfs would synchronously change clients' address space via
 // injecting trusted code and running it on client side via ptrace to adjust