.

wcfs/__init__.py

@@ -88,181 +88,6 @@ class WCFS(_WCFS):
     pass
 
 """
-# Conn represents logical connection that provides view of data on wcfs
-# filesystem as of particular database state.
-#
-# It uses /head/bigfile/* and notifications received from /head/watch to
-# maintain isolated database view while at the same time sharing most of data
-# cache in OS pagecache of /head/bigfile/*.
-#
-# Use WCFS.connect(at) to create Conn.
-# Use .mmap to create new Mappings.
-# Use .resync to resync Conn onto different database view.
-#
-# Conn logically mirrors ZODB.Connection .
-class Conn(object):
-    # ._wc          WCFS
-    # .at           Tid
-    # ._wlink       WatchLink watch/receive pins for created mappings
-    #
-    # ._filemu      sync.Mutex
-    # ._filetab     {} foid -> _File
-    #
-    # ._pinWG
-    # ._pinCancel
-    pass
-
-# _File represent isolated file view under Conn.
-class _File(object):
-    # .wconn        Conn
-    # .foid         hex of ZBigFile root object ID
-    # .blksize      block size of this file
-    # .headf        file object of head/file
-    # .headfsize    head/file size is known to be at least headfsize (size ↑=)
-    # .pinned       {} blk -> rev   that wcfs already sent us for this file
-    # .mmaps        []_Mapping ↑blk_start    mappings of this file
-    pass
-
-
-# _Mapping represents one mapping of _File.
-class _Mapping(object):
-    # .file         _File
-    # .blk_start    offset of this mapping in file
-    # .mem          mmaped memory
-
-    @property
-    def blk_stop(mmap):
-        assert len(mmap.mem) % mmap.file.blksize == 0
-        return mmap.blk_start + len(mmap.mem) // mmap.file.blksize
-
-
-# connect creates new Conn viewing WCFS state as of @at.
-@func(WCFS)
-def connect(wc, at): # -> Conn
-    wconn = Conn()
-
-    # TODO support !isolated mode
-    wconn._wc       = wc
-    wconn.at        = at
-    wconn._wlink    = WatchLink(wc)
-    wconn._filemu   = sync.Mutex()
-    wconn._filetab  = {}
-
-    pinCtx, wconn._pinCancel = context.with_cancel(context.background())
-    wconn._pinWG = sync.WorkGroup(pinCtx)
-    wconn._pinWG.go(wconn._pinner)
-
-    return wconn
-
-# close releases resources associated with wconn.
-# XXX what happens to file mmappings?
-@func(Conn)
-def close(wconn):
-    wconn._wlink.close()
-    wconn._pinCancel()
-    try:
-        wconn._pinWG.wait()
-    except Exception as e:  # canceled - ok
-        if e is not context.canceled:
-            raise
-
-    # close all files - both that have no mappings and that still have opened mappings.
-    # XXX after file is closed mappings continue to survive, but we can no
-    # longer maintain consistent view.
-    with wconn._filemu:
-        for f in wconn._filetab.values():
-            f.headf.close()
-            f.headf = None
-
-            # XXX stop watching f
-
-        wconn._filetab = None
-
-# _pinner receives pin messages from wcfs and adjusts wconn mappings.
-#
-# XXX must be running without GIL: access to wcfs mmaped memory could come from
-# python code (thus with GIL taken).
-@func(Conn)
-def _pinner(wconn, ctx):
-    # if pinner fails, wcfs will kill us.
-    # log pinner exception so the error is not hidden.
-    # print to stderr as well as by default log does not print to there.
-    def _():
-        exc = sys.exc_info()[1]
-        if exc in (None, context.canceled): # canceled = .close asks pinner to stop
-            return
-        log.critical('pinner failed:', exc_info=1)
-        print('CRITICAL: pinner failed:', file=sys.stderr)
-        traceback.print_exc(file=sys.stderr)
-        print('\nCRITICAL: wcfs server will likely kill us soon.', file=sys.stderr)
-    defer(_)
-
-    def trace(msg):
-        return
-        print('pinner: %s' % msg)
-    trace('start')
-    while 1:
-        trace('recvReq ...')
-        req = wconn._wlink.recvReq(ctx)
-        trace('-> %r' % req)
-        if req is None:
-            return  # XXX ok? (EOF - when wcfs closes wlink)
-
-        # we received request to pin/unpin file block. perform it
-        wconn._pin1(req)
-
-# pin1 handles one pin request received from wcfs
-@func(Conn)
-def _pin1(wconn, req):
-    # reply either ack or nak on error
-    def _():
-        ack = "ack"
-        exc = sys.exc_info()[1]
-        if exc is not None:
-            ack = "nak: %s" % exc
-        #req.reply(ack)
-        ctx = context.background()  # XXX ok?
-        wconn._wlink.replyReq(ctx, req, ack)
-    defer(_)
-
-    def trace(msg):
-        return
-        print('pin1: %s' % msg)
-
-    trace('lock _filemu ...')
-    with wconn._filemu:
-        trace('_filemu locked')
-        f = wconn._filetab.get(req.foid)
-        if f is None:
-            1/0     # XXX we are not watching the file - why wcfs sent us this update?
-
-        trace(f)
-
-        # XXX relock wconn -> f ?
-
-        for mmap in f.mmaps:    # XXX use ↑blk_start for binary search
-            trace('\t%s' % mmap)
-            if not (mmap.blk_start <= req.blk < mmap.blk_stop):
-                continue    # blk ∉ mmap
-
-            trace('\tremmapblk %d @%s' % (req.blk, (h(req.at) if req.at else "head")))
-            # FIXME check if virtmem did not dirtied page corresponding to this block already
-            #virt_lock()
-            #if not fileh_blk_isdirty(mmap.fileh, req.blk):
-            if 1:
-                mmap._remmapblk(req.blk, req.at)
-            #virt_unlock()
-            trace('\t-> remmaped')
-
-        # update f.pinned
-        # XXX do it before ^^^ remmapblk (so that e.g. concurrent
-        # discard/writeout see correct f.pinned) ?
-        if req.at is None:
-            f.pinned.pop(req.blk, None)     # = delete(f.pinned, req.blk)  -- unpin to @head
-        else:
-            f.pinned[req.blk] = req.at
-
-
 # mmap creates file mapping representing file[blk_start +blk_len) data as of wconn.at database state.
 @func(Conn)
 def mmap(wconn, foid, blk_start, blk_len): # -> Mapping

wcfs/internal/wcfs_virtmem.cpp

@@ -107,7 +107,6 @@ pair<Conn, error> WCFS::connect(zodb::Tid at) {
     wconn->at       = at;
     wconn->_wlink   = wlink;
 
-
     context::Context pinCtx;
     tie(pinCtx, wconn->_pinCancel) = context::with_cancel(context::background());
     wconn->_pinWG = sync::NewWorkGroup(pinCtx);
@@ -120,7 +119,7 @@ pair<Conn, error> WCFS::connect(zodb::Tid at) {
 
 // close releases resources associated with wconn.
 // XXX what happens to file mmappings?
-error _Conn::close() {   // XXX error -> void?
+error _Conn::close() {
     _Conn& wconn = *this;
     // XXX err ctx
     error err;