comparison hgext/fsmonitor/__init__.py @ 32335:354329178dee

fsmonitor: don't attempt state-leave if we didn't state-enter

The state-enter command may not have been successful; for example, the watchman
client session may have timed out if the user was busy/idle for a long period
during a merge conflict resolution earlier in processing a rebase for a stack
of diffs.

It's cleaner (from the perspective of the watchman logs) to avoid issuing the
state-leave command in these cases.

Test Plan:
ran

`hg rebase --tool :merge -r '(draft() & date(-14)) - master::' -d master`

and didn't observe any errors in the watchman logs or in the output from

`watchman -p -j <<<'["subscribe", "/data/users/wez/fbsource", "wez", {"expression": ["name", ".hg/updatestate"]}]'`

32334:6e0d1043e8fc

        self.repo = repo
        self.node = node
        self.distance = distance
        self.partial = partial
        self._lock = None

    def __enter__(self):
        # We explicitly need to take a lock here, before we proceed to update
        # watchman about the update operation, so that we don't race with
        # some other actor.  merge.update is going to take the wlock almost
        # immediately anyway, so this is effectively extending the lock
        # around a couple of short sanity checks.
        self._lock = self.repo.wlock()
        self._state('state-enter')
        return self

    def __exit__(self, type_, value, tb):
        try:
            status = 'ok' if type_ is None else 'failed'
            self._state('state-leave', status=status)
        finally:
            if self._lock:
                self._lock.release()

    def _state(self, cmd, status='ok'):
        if not util.safehasattr(self.repo, '_watchmanclient'):
            return
        try:
            commithash = self.repo[self.node].hex()
            self.repo._watchmanclient.command(cmd, {
                'name': 'hg.update',
                'metadata': {

                    # success/failure (only really meaningful for state-leave)
                    'status': status,
                    # whether the working copy parent is changing
                    'partial': self.partial,
            }})
        except Exception as e:
            # Swallow any errors; fire and forget
            self.repo.ui.log(
                'watchman', 'Exception %s while running %s\n', e, cmd)

# Bracket working copy updates with calls to the watchman state-enter
# and state-leave commands.  This allows clients to perform more intelligent
# settling during bulk file change scenarios
# https://facebook.github.io/watchman/docs/cmd/subscribe.html#advanced-settling

32335:354329178dee

        self.repo = repo
        self.node = node
        self.distance = distance
        self.partial = partial
        self._lock = None
        self.need_leave = False

    def __enter__(self):
        # We explicitly need to take a lock here, before we proceed to update
        # watchman about the update operation, so that we don't race with
        # some other actor.  merge.update is going to take the wlock almost
        # immediately anyway, so this is effectively extending the lock
        # around a couple of short sanity checks.
        self._lock = self.repo.wlock()
        self.need_leave = self._state('state-enter')
        return self

    def __exit__(self, type_, value, tb):
        try:
            if self.need_leave:
                status = 'ok' if type_ is None else 'failed'
                self._state('state-leave', status=status)
        finally:
            if self._lock:
                self._lock.release()

    def _state(self, cmd, status='ok'):
        if not util.safehasattr(self.repo, '_watchmanclient'):
            return False
        try:
            commithash = self.repo[self.node].hex()
            self.repo._watchmanclient.command(cmd, {
                'name': 'hg.update',
                'metadata': {

                    # success/failure (only really meaningful for state-leave)
                    'status': status,
                    # whether the working copy parent is changing
                    'partial': self.partial,
            }})
            return True
        except Exception as e:
            # Swallow any errors; fire and forget
            self.repo.ui.log(
                'watchman', 'Exception %s while running %s\n', e, cmd)
            return False

# Bracket working copy updates with calls to the watchman state-enter
# and state-leave commands.  This allows clients to perform more intelligent
# settling during bulk file change scenarios
# https://facebook.github.io/watchman/docs/cmd/subscribe.html#advanced-settling