view hgext/fsmonitor/state.py @ 29382:e4b777fe1576

templates: add support for summary webcommand in json style

Change summary webcommand to yield each element of the shortlog instead of the
entire list.

This makes generated json more readable since each entry can be formatted
separately, instead of returning all the shortlog content in a single string.

# 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

_version = 4
_versionformat = ">I"

class state(object):
    def __init__(self, repo):
        self._opener = repo.opener
        self._ui = repo.ui
        self._rootdir = pathutil.normasprefix(repo.root)
        self._lastclock = None

        self.mode = self._ui.config('fsmonitor', 'mode', default='on')
        self.walk_on_invalidate = self._ui.configbool(
            'fsmonitor', 'walk_on_invalidate', False)
        self.timeout = float(self._ui.config(
            'fsmonitor', 'timeout', default='2'))

    def get(self):
        try:
            file = self._opener('fsmonitor.state', 'rb')
        except IOError as inst:
            if inst.errno != errno.ENOENT:
                raise
            return None, None, None

        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
            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

        try:
            file = self._opener('fsmonitor.state', 'wb')
        except (IOError, OSError):
            self._ui.warn(_("warning: unable to write out fsmonitor state\n"))
            return

        try:
            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')
        finally:
            file.close()

    def invalidate(self):
        try:
            os.unlink(os.path.join(self._rootdir, '.hg', 'fsmonitor.state'))
        except OSError as inst:
            if inst.errno != errno.ENOENT:
                raise

    def setlastclock(self, clock):
        self._lastclock = clock

    def getlastclock(self):
        return self._lastclock