mercurial/lock.py
author Matt Harbison <matt_harbison@yahoo.com>
Sun, 12 Apr 2015 01:39:21 -0400
changeset 24790 baa11dde8c0e
parent 23032 f484be02bd35
child 25660 328739ea70c3
permissions -rw-r--r--
match: add a subclass for dirstate normalizing of the matched patterns This class is only needed on case insensitive filesystems, and only for wdir context matches. It allows the user to not match the case of the items in the filesystem- especially for naming directories, which dirstate doesn't handle[1]. Making dirstate handle mismatched directory cases is too expensive[2]. Since dirstate doesn't apply to committed csets, this is only created by overriding basectx.match() in workingctx, and only on icasefs. The default arguments have been dropped, because the ctx must be passed to the matcher in order to function. For operations that can apply to both wdir and some other context, this ends up normalizing the filename to the case as it exists in the filesystem, and using that case for the lookup in the other context. See the diff example in the test. Previously, given a directory with an inexact case: - add worked as expected - diff, forget and status would silently ignore the request - files would exit with 1 - commit, revert and remove would fail (even when the commands leading up to them worked): $ hg ci -m "AbCDef" capsdir1/capsdir abort: CapsDir1/CapsDir: no match under directory! $ hg revert -r '.^' capsdir1/capsdir capsdir1\capsdir: no such file in rev 64dae27060b7 $ hg remove capsdir1/capsdir not removing capsdir1\capsdir: no tracked files [1] Globs are normalized, so that the -I and -X don't need to be specified with a case match. Without that, the second last remove (with -X) removes the files, leaving nothing for the last remove. However, specifying the files as 'glob:**.Txt' does not work. Perhaps this requires 're.IGNORECASE'? There are only a handful of places that create matchers directly, instead of being routed through the context.match() method. Some may benefit from changing over to using ctx.match() as a factory function: revset.checkstatus() revset.contains() revset.filelog() revset._matchfiles() localrepository._loadfilter() ignore.ignore() fileset.subrepo() filemerge._picktool() overrides.addlargefiles() lfcommands.lfconvert() kwtemplate.__init__() eolfile.__init__() eolfile.checkrev() acl.buildmatch() Currently, a toplevel subrepo can be named with an inexact case. However, the path auditor gets in the way of naming _anything_ in the subrepo if the top level case doesn't match. That is trickier to handle, because there's the user provided case, the case in the filesystem, and the case stored in .hgsub. This can be fixed next cycle. --- a/tests/test-subrepo-deep-nested-change.t +++ b/tests/test-subrepo-deep-nested-change.t @@ -170,8 +170,15 @@ R sub1/sub2/test.txt $ hg update -Cq $ touch sub1/sub2/folder/bar +#if icasefs + $ hg addremove Sub1/sub2 + abort: path 'Sub1\sub2' is inside nested repo 'Sub1' + [255] + $ hg -q addremove sub1/sub2 +#else $ hg addremove sub1/sub2 adding sub1/sub2/folder/bar (glob) +#endif $ hg status -S A sub1/sub2/folder/bar ? foo/bar/abc The narrowmatcher class may need to be tweaked when that is fixed. [1] http://www.selenic.com/pipermail/mercurial-devel/2015-April/068183.html [2] http://www.selenic.com/pipermail/mercurial-devel/2015-April/068191.html

# lock.py - simple advisory locking scheme for mercurial
#
# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import util, error
import errno, os, socket, time
import warnings

class lock(object):
    '''An advisory lock held by one process to control access to a set
    of files.  Non-cooperating processes or incorrectly written scripts
    can ignore Mercurial's locking scheme and stomp all over the
    repository, so don't do that.

    Typically used via localrepository.lock() to lock the repository
    store (.hg/store/) or localrepository.wlock() to lock everything
    else under .hg/.'''

    # lock is symlink on platforms that support it, file on others.

    # symlink is used because create of directory entry and contents
    # are atomic even over nfs.

    # old-style lock: symlink to pid
    # new-style lock: symlink to hostname:pid

    _host = None

    def __init__(self, vfs, file, timeout=-1, releasefn=None, desc=None):
        self.vfs = vfs
        self.f = file
        self.held = 0
        self.timeout = timeout
        self.releasefn = releasefn
        self.desc = desc
        self.postrelease  = []
        self.pid = os.getpid()
        self.delay = self.lock()

    def __del__(self):
        if self.held:
            warnings.warn("use lock.release instead of del lock",
                    category=DeprecationWarning,
                    stacklevel=2)

            # ensure the lock will be removed
            # even if recursive locking did occur
            self.held = 1

        self.release()

    def lock(self):
        timeout = self.timeout
        while True:
            try:
                self.trylock()
                return self.timeout - timeout
            except error.LockHeld, inst:
                if timeout != 0:
                    time.sleep(1)
                    if timeout > 0:
                        timeout -= 1
                    continue
                raise error.LockHeld(errno.ETIMEDOUT, inst.filename, self.desc,
                                     inst.locker)

    def trylock(self):
        if self.held:
            self.held += 1
            return
        if lock._host is None:
            lock._host = socket.gethostname()
        lockname = '%s:%s' % (lock._host, self.pid)
        while not self.held:
            try:
                self.vfs.makelock(lockname, self.f)
                self.held = 1
            except (OSError, IOError), why:
                if why.errno == errno.EEXIST:
                    locker = self.testlock()
                    if locker is not None:
                        raise error.LockHeld(errno.EAGAIN,
                                             self.vfs.join(self.f), self.desc,
                                             locker)
                else:
                    raise error.LockUnavailable(why.errno, why.strerror,
                                                why.filename, self.desc)

    def testlock(self):
        """return id of locker if lock is valid, else None.

        If old-style lock, we cannot tell what machine locker is on.
        with new-style lock, if locker is on this machine, we can
        see if locker is alive.  If locker is on this machine but
        not alive, we can safely break lock.

        The lock file is only deleted when None is returned.

        """
        try:
            locker = self.vfs.readlock(self.f)
        except (OSError, IOError), why:
            if why.errno == errno.ENOENT:
                return None
            raise
        try:
            host, pid = locker.split(":", 1)
        except ValueError:
            return locker
        if host != lock._host:
            return locker
        try:
            pid = int(pid)
        except ValueError:
            return locker
        if util.testpid(pid):
            return locker
        # if locker dead, break lock.  must do this with another lock
        # held, or can race and break valid lock.
        try:
            l = lock(self.vfs, self.f + '.break', timeout=0)
            self.vfs.unlink(self.f)
            l.release()
        except error.LockError:
            return locker

    def release(self):
        """release the lock and execute callback function if any

        If the lock has been acquired multiple times, the actual release is
        delayed to the last release call."""
        if self.held > 1:
            self.held -= 1
        elif self.held == 1:
            self.held = 0
            if os.getpid() != self.pid:
                # we forked, and are not the parent
                return
            try:
                if self.releasefn:
                    self.releasefn()
            finally:
                try:
                    self.vfs.unlink(self.f)
                except OSError:
                    pass
            for callback in self.postrelease:
                callback()

def release(*locks):
    for lock in locks:
        if lock is not None:
            lock.release()