##// END OF EJS Templates
ssh: avoid reading beyond the end of stream when using compression...
ssh: avoid reading beyond the end of stream when using compression Compressed streams can be used as part of getbundle. The normal read() operation of bufferedinputpipe will try to fulfill the request exactly and can deadlock if the server sends less as it is done. At the same time, the bundle2 logic will stop reading when it believes it has gotten all parts of the bundle, which can leave behind end of stream markers as used by bzip2 and zstd. To solve this, introduce a new optional unbufferedread interface and provided it in bufferedinputpipe and doublepipe. If there is buffered data left, it will be returned, otherwise it will issue a single read request and return whatever it obtains. Reorganize the decompression handlers to try harder to read until the end of stream, especially if the requested read can already be fulfilled. Check for end of stream is messy with Python 2, none of the standard compression modules properly exposes it. At least with zstd and bzip2, decompressing will remember EOS and fail for empty input after the EOS has been seen. For zlib, the only way to detect it with Python 2 is to duplicate the decompressobj and force some additional data into it. The common handler can be further optimized, but works as PoC. Differential Revision: https://phab.mercurial-scm.org/D3937

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state.py
134 lines | 4.4 KiB | text/x-python | PythonLexer
# state.py - fsmonitor persistent state
#
# Copyright 2013-2016 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import errno
import os
import socket
import struct
from mercurial.i18n import _
from mercurial import (
pathutil,
util,
)
_version = 4
_versionformat = ">I"
class state(object):
def __init__(self, repo):
self._vfs = repo.vfs
self._ui = repo.ui
self._rootdir = pathutil.normasprefix(repo.root)
self._lastclock = None
self._identity = util.filestat(None)
self.mode = self._ui.config('fsmonitor', 'mode')
self.walk_on_invalidate = self._ui.configbool(
'fsmonitor', 'walk_on_invalidate')
self.timeout = float(self._ui.config('fsmonitor', 'timeout'))
def get(self):
try:
file = self._vfs('fsmonitor.state', 'rb')
except IOError as inst:
self._identity = util.filestat(None)
if inst.errno != errno.ENOENT:
raise
return None, None, None
self._identity = util.filestat.fromfp(file)
versionbytes = file.read(4)
if len(versionbytes) < 4:
self._ui.log(
'fsmonitor', 'fsmonitor: state file only has %d bytes, '
'nuking state\n' % len(versionbytes))
self.invalidate()
return None, None, None
try:
diskversion = struct.unpack(_versionformat, versionbytes)[0]
if diskversion != _version:
# different version, nuke state and start over
self._ui.log(
'fsmonitor', 'fsmonitor: version switch from %d to '
'%d, nuking state\n' % (diskversion, _version))
self.invalidate()
return None, None, None
state = file.read().split('\0')
# state = hostname\0clock\0ignorehash\0 + list of files, each
# followed by a \0
if len(state) < 3:
self._ui.log(
'fsmonitor', 'fsmonitor: state file truncated (expected '
'3 chunks, found %d), nuking state\n', len(state))
self.invalidate()
return None, None, None
diskhostname = state[0]
hostname = socket.gethostname()
if diskhostname != hostname:
# file got moved to a different host
self._ui.log('fsmonitor', 'fsmonitor: stored hostname "%s" '
'different from current "%s", nuking state\n' %
(diskhostname, hostname))
self.invalidate()
return None, None, None
clock = state[1]
ignorehash = state[2]
# discard the value after the last \0
notefiles = state[3:-1]
finally:
file.close()
return clock, ignorehash, notefiles
def set(self, clock, ignorehash, notefiles):
if clock is None:
self.invalidate()
return
# Read the identity from the file on disk rather than from the open file
# pointer below, because the latter is actually a brand new file.
identity = util.filestat.frompath(self._vfs.join('fsmonitor.state'))
if identity != self._identity:
self._ui.debug('skip updating fsmonitor.state: identity mismatch\n')
return
try:
file = self._vfs('fsmonitor.state', 'wb', atomictemp=True,
checkambig=True)
except (IOError, OSError):
self._ui.warn(_("warning: unable to write out fsmonitor state\n"))
return
with file:
file.write(struct.pack(_versionformat, _version))
file.write(socket.gethostname() + '\0')
file.write(clock + '\0')
file.write(ignorehash + '\0')
if notefiles:
file.write('\0'.join(notefiles))
file.write('\0')
def invalidate(self):
try:
os.unlink(os.path.join(self._rootdir, '.hg', 'fsmonitor.state'))
except OSError as inst:
if inst.errno != errno.ENOENT:
raise
self._identity = util.filestat(None)
def setlastclock(self, clock):
self._lastclock = clock
def getlastclock(self):
return self._lastclock