Add support for kqueue's EVFILT_VNODE (filesystem monitoring), and add test for it.

lib/pure/ioselectors.nim

@@ -44,14 +44,21 @@ when defined(nimdoc):
 
     Event* {.pure.} = enum
       ## An enum which hold event types
-      Read,    ## Descriptor is available for read
-      Write,   ## Descriptor is available for write
-      Timer,   ## Timer descriptor is completed
-      Signal,  ## Signal is raised
-      Process, ## Process is finished
-      Vnode,   ## Currently not supported
-      User,    ## User event is raised
-      Error    ## Error happens while waiting, for descriptor
+      Read,        ## Descriptor is available for read
+      Write,       ## Descriptor is available for write
+      Timer,       ## Timer descriptor is completed
+      Signal,      ## Signal is raised
+      Process,     ## Process is finished
+      Vnode,       ## BSD specific file change happens
+      User,        ## User event is raised
+      Error,       ## Error happens while waiting, for descriptor
+      VnodeWrite,  ## NOTE_WRITE (BSD specific, write to file occured)
+      VnodeDelete, ## NOTE_DELETE (BSD specific, unlink of file occured)
+      VnodeExtend, ## NOTE_EXTEND (BSD specific, file extended)
+      VnodeAttrib, ## NOTE_ATTRIB (BSD specific, file attributes changed)
+      VnodeLink,   ## NOTE_LINK (BSD specific, file link count changed)
+      VnodeRename, ## NOTE_RENAME (BSD specific, file renamed)
+      VnodeRevoke  ## NOTE_REVOKE (BSD specific, file revoke occured)
 
     ReadyKey*[T] = object
       ## An object which holds result for descriptor
@@ -107,6 +114,15 @@ when defined(nimdoc):
     ## ``data`` application-defined data, which to be passed, when
     ## ``ev`` happens.
 
+  proc registerVnode*[T](s: Selector[T], fd: cint, events: set[Event],
+                         data: T) =
+    ## Registers selector BSD/MacOSX specific vnode events for file
+    ## descriptor ``fd`` and events ``events``.
+    ## ``data`` application-defined data, which to be passed, when
+    ## vnode event happens.
+    ##
+    ## This function is supported only by BSD and MacOSX.
+
   proc newSelectEvent*(): SelectEvent =
     ## Creates new event ``SelectEvent``.
 
@@ -194,7 +210,9 @@ else:
       deallocShared(cast[pointer](sa))
   type
     Event* {.pure.} = enum
-      Read, Write, Timer, Signal, Process, Vnode, User, Error, Oneshot
+      Read, Write, Timer, Signal, Process, Vnode, User, Error, Oneshot,
+      VnodeWrite, VnodeDelete, VnodeExtend, VnodeAttrib, VnodeLink,
+      VnodeRename, VnodeRevoke
 
     ReadyKey*[T] = object
       fd* : int

lib/pure/ioselects/ioselectors_kqueue.nim

@@ -262,6 +262,30 @@ proc registerEvent*[T](s: Selector[T], ev: SelectEvent, data: T) =
   modifyKQueue(s, fdi.uint, EVFILT_READ, EV_ADD, 0, 0, nil)
   inc(s.count)
 
+template processVnodeEvents(events: set[Event]): cuint =
+  var rfflags = 0.cuint
+  if events == {Event.VnodeWrite, Event.VnodeDelete, Event.VnodeExtend,
+                Event.VnodeAttrib, Event.VnodeLink, Event.VnodeRename,
+                Event.VnodeRevoke}:
+    rfflags = NOTE_DELETE or NOTE_WRITE or NOTE_EXTEND or NOTE_ATTRIB or
+              NOTE_LINK or NOTE_RENAME or NOTE_REVOKE
+  else:
+    if Event.VnodeDelete in events: rfflags = rfflags or NOTE_DELETE
+    if Event.VnodeWrite in events: rfflags = rfflags or NOTE_WRITE
+    if Event.VnodeExtend in events: rfflags = rfflags or NOTE_EXTEND
+    if Event.VnodeAttrib in events: rfflags = rfflags or NOTE_ATTRIB
+    if Event.VnodeLink in events: rfflags = rfflags or NOTE_LINK
+    if Event.VnodeRename in events: rfflags = rfflags or NOTE_RENAME
+    if Event.VnodeRevoke in events: rfflags = rfflags or NOTE_REVOKE
+  rfflags
+
+proc registerVnode*[T](s: Selector[T], fd: cint, events: set[Event], data: T) =
+  let fdi = fd.int
+  setKey(s, fdi, fdi, {Event.Vnode} + events, 0, data)
+  var fflags = processVnodeEvents(events)
+  modifyKQueue(s, fdi.uint, EVFILT_VNODE, EV_ADD or EV_CLEAR, fflags, 0, nil)
+  inc(s.count)
+
 proc unregister*[T](s: Selector[T], fd: int|SocketHandle) =
   let fdi = int(fd)
   s.checkFd(fdi)
@@ -295,6 +319,9 @@ proc unregister*[T](s: Selector[T], fd: int|SocketHandle) =
       discard posix.close(cint(pkey.key.fd))
       modifyKQueue(s, fdi.uint, EVFILT_PROC, EV_DELETE, 0, 0, nil)
       dec(s.count)
+    elif Event.Vnode in pkey.events:
+      modifyKQueue(s, fdi.uint, EVFILT_VNODE, EV_DELETE, 0, 0, nil)
+      dec(s.count)
     elif Event.User in pkey.events:
       modifyKQueue(s, fdi.uint, EVFILT_READ, EV_DELETE, 0, 0, nil)
       dec(s.count)
@@ -392,6 +419,20 @@ proc selectInto*[T](s: Selector[T], timeout: int,
         of EVFILT_VNODE:
           pkey = addr(s.fds[kevent.ident.int])
           pkey.key.events = {Event.Vnode}
+          if (kevent.fflags and NOTE_DELETE) != 0:
+            pkey.key.events.incl(Event.VnodeDelete)
+          if (kevent.fflags and NOTE_WRITE) != 0:
+            pkey.key.events.incl(Event.VnodeWrite)
+          if (kevent.fflags and NOTE_EXTEND) != 0:
+            pkey.key.events.incl(Event.VnodeExtend)
+          if (kevent.fflags and NOTE_ATTRIB) != 0:
+            pkey.key.events.incl(Event.VnodeAttrib)
+          if (kevent.fflags and NOTE_LINK) != 0:
+            pkey.key.events.incl(Event.VnodeLink)
+          if (kevent.fflags and NOTE_RENAME) != 0:
+            pkey.key.events.incl(Event.VnodeRename)
+          if (kevent.fflags and NOTE_REVOKE) != 0:
+            pkey.key.events.incl(Event.VnodeRevoke)
         of EVFILT_SIGNAL:
           pkey = addr(s.fds[cast[int](kevent.udata)])
           pkey.key.events = {Event.Signal}