mercurial/util.py

43075:57875cf423c9

import sys
import time
import traceback
import warnings

from .thirdparty import (
    attr,
)
from hgdemandimport import tracing
from . import (
    encoding,
    error,
    i18n,

# Python compatibility

_notset = object()

def bitsfrom(container):
    bits = 0
    for bit in container:
        bits |= bit
    return bits

# python 2.6 still have deprecation warning enabled by default. We do not want
# to display anything to standard user so detect if we are running test and
# only use python deprecation warning in this case.
_dowarn = bool(encoding.environ.get('HGEMITWARNINGS'))

    warnings.filterwarnings(r'default', r'', DeprecationWarning, r'mercurial')
    warnings.filterwarnings(r'default', r'', DeprecationWarning, r'hgext')
    warnings.filterwarnings(r'default', r'', DeprecationWarning, r'hgext3rd')
if _dowarn and pycompat.ispy3:
    # silence warning emitted by passing user string to re.sub()
    warnings.filterwarnings(r'ignore', r'bad escape', DeprecationWarning,
                            r'mercurial')
    warnings.filterwarnings(r'ignore', r'invalid escape sequence',
                            DeprecationWarning, r'mercurial')
    # TODO: reinvent imp.is_frozen()
    warnings.filterwarnings(r'ignore', r'the imp module is deprecated',
                            DeprecationWarning, r'mercurial')

def nouideprecwarn(msg, version, stacklevel=1):
    """Issue an python native deprecation warning

    This is a noop outside of tests, use 'ui.deprecwarn' when possible.
    """
    if _dowarn:
        msg += ("\n(compatibility will be dropped after Mercurial-%s,"
                " update your code.)") % version
        warnings.warn(pycompat.sysstr(msg), DeprecationWarning, stacklevel + 1)

DIGESTS = {
    'md5': hashlib.md5,
    'sha1': hashlib.sha1,
    'sha512': hashlib.sha512,

# List of digest types from strongest to weakest
DIGESTS_BY_STRENGTH = ['sha512', 'sha1', 'md5']

for k in DIGESTS_BY_STRENGTH:
    assert k in DIGESTS

class digester(object):
    """helper to compute digests.

    This helper can be used to compute one or more digests given their name.

        for k in DIGESTS_BY_STRENGTH:
            if k in supported:
                return k
        return None

class digestchecker(object):
    """file handle wrapper that additionally checks content against a given
    size and digests.

        d = digestchecker(fh, size, {'md5': '...'})

        self._got += len(content)
        return content

    def validate(self):
        if self._size != self._got:
            raise error.Abort(_('size mismatch: expected %d, got %d') %
                              (self._size, self._got))
        for k, v in self._digests.items():
            if v != self._digester[k]:
                # i18n: first parameter is a digest name
                raise error.Abort(_('%s mismatch: expected %s, got %s') %
                                  (k, v, self._digester[k]))

try:
    buffer = buffer
except NameError:
    def buffer(sliceable, offset=0, length=None):
        if length is not None:
            return memoryview(sliceable)[offset:offset + length]
        return memoryview(sliceable)[offset:]

_chunksize = 4096

class bufferedinputpipe(object):
    """a manually buffered input pipe

    Python will not let us use buffered IO and lazy reading with 'polling' at

    empty from the output (allowing collaboration of the buffer with polling).

    This class lives in the 'util' module because it makes use of the 'os'
    module from the python stdlib.
    """
    def __new__(cls, fh):
        # If we receive a fileobjectproxy, we need to use a variation of this
        # class that notifies observers about activity.
        if isinstance(fh, fileobjectproxy):
            cls = observedbufferedinputpipe

        while (not self._eof) and lfi < 0:
            self._fillbuffer()
            if self._buffer:
                lfi = self._buffer[-1].find('\n')
        size = lfi + 1
        if lfi < 0: # end of file
            size = self._lenbuf
        elif len(self._buffer) > 1:
            # we need to take previous chunks into account
            size += self._lenbuf - len(self._buffer[-1])
        return self._frombuffer(size)

        buf = self._buffer[0]
        if len(self._buffer) > 1:
            buf = ''.join(self._buffer)

        data = buf[:size]
        buf = buf[len(data):]
        if buf:
            self._buffer = [buf]
            self._lenbuf = len(buf)
        else:
            self._buffer = []

        else:
            self._lenbuf += len(data)
            self._buffer.append(data)

        return data

def mmapread(fp):
    try:
        fd = getattr(fp, 'fileno', lambda: fp)()
        return mmap.mmap(fd, 0, access=mmap.ACCESS_READ)

        # if the file is empty, and if so, return an empty buffer.
        if os.fstat(fd).st_size == 0:
            return ''
        raise

class fileobjectproxy(object):
    """A proxy around file objects that tells a watcher when events occur.

    This type is intended to only be used for testing purposes. Think hard
    before using it in important code.
    """
    __slots__ = (
        r'_orig',
        r'_observer',
    )

        object.__setattr__(self, r'_observer', observer)

    def __getattribute__(self, name):
        ours = {
            r'_observer',

            # IOBase
            r'close',
            # closed if a property
            r'fileno',
            r'flush',

        return res

    def close(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'close', *args, **kwargs)

    def fileno(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'fileno', *args, **kwargs)

    def flush(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'flush', *args, **kwargs)

    def isatty(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'isatty', *args, **kwargs)

    def readable(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'readable', *args, **kwargs)

    def readline(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'readline', *args, **kwargs)

    def readlines(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'readlines', *args, **kwargs)

    def seek(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'seek', *args, **kwargs)

    def seekable(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'seekable', *args, **kwargs)

    def tell(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'tell', *args, **kwargs)

    def truncate(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'truncate', *args, **kwargs)

    def writable(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'writable', *args, **kwargs)

    def writelines(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'writelines', *args, **kwargs)

    def read(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'read', *args, **kwargs)

    def readall(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'readall', *args, **kwargs)

    def readinto(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'readinto', *args, **kwargs)

    def write(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'write', *args, **kwargs)

    def detach(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'detach', *args, **kwargs)

    def read1(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'read1', *args, **kwargs)

class observedbufferedinputpipe(bufferedinputpipe):
    """A variation of bufferedinputpipe that is aware of fileobjectproxy.

    ``bufferedinputpipe`` makes low-level calls to ``os.read()`` that

    This variation of ``bufferedinputpipe`` can notify observers about
    ``os.read()`` events. It also re-publishes other events, such as
    ``read()`` and ``readline()``.
    """
    def _fillbuffer(self):
        res = super(observedbufferedinputpipe, self)._fillbuffer()

        fn = getattr(self._input._observer, r'osread', None)
        if fn:

        fn = getattr(self._input._observer, r'bufferedreadline', None)
        if fn:
            fn(res)

        return res

PROXIED_SOCKET_METHODS = {
    r'makefile',
    r'recv',
    r'recvfrom',

    r'settimeout',
    r'gettimeout',
    r'setsockopt',
}

class socketproxy(object):
    """A proxy around a socket that tells a watcher when events occur.

    This is like ``fileobjectproxy`` except for sockets.

    This type is intended to only be used for testing purposes. Think hard
    before using it in important code.
    """
    __slots__ = (
        r'_orig',
        r'_observer',
    )

        return res

    def makefile(self, *args, **kwargs):
        res = object.__getattribute__(self, r'_observedcall')(
            r'makefile', *args, **kwargs)

        # The file object may be used for I/O. So we turn it into a
        # proxy using our observer.
        observer = object.__getattribute__(self, r'_observer')
        return makeloggingfileobject(observer.fh, res, observer.name,
                                     reads=observer.reads,
                                     writes=observer.writes,
                                     logdata=observer.logdata,
                                     logdataapis=observer.logdataapis)

    def recv(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'recv', *args, **kwargs)

    def recvfrom(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'recvfrom', *args, **kwargs)

    def recvfrom_into(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'recvfrom_into', *args, **kwargs)

    def recv_into(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'recv_info', *args, **kwargs)

    def send(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'send', *args, **kwargs)

    def sendall(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'sendall', *args, **kwargs)

    def sendto(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'sendto', *args, **kwargs)

    def setblocking(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'setblocking', *args, **kwargs)

    def settimeout(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'settimeout', *args, **kwargs)

    def gettimeout(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'gettimeout', *args, **kwargs)

    def setsockopt(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'setsockopt', *args, **kwargs)

class baseproxyobserver(object):
    def _writedata(self, data):
        if not self.logdata:
            if self.logdataapis:

        # Simple case writes all data on a single line.
        if b'\n' not in data:
            if self.logdataapis:
                self.fh.write(': %s\n' % stringutil.escapestr(data))
            else:
                self.fh.write('%s>     %s\n'
                              % (self.name, stringutil.escapestr(data)))
            self.fh.flush()
            return

        # Data with newlines is written to multiple lines.
        if self.logdataapis:
            self.fh.write(':\n')

        lines = data.splitlines(True)
        for line in lines:
            self.fh.write('%s>     %s\n'
                          % (self.name, stringutil.escapestr(line)))
        self.fh.flush()

class fileobjectobserver(baseproxyobserver):
    """Logs file object activity."""
    def __init__(self, fh, name, reads=True, writes=True, logdata=False,
                 logdataapis=True):
        self.fh = fh
        self.name = name
        self.logdata = logdata
        self.logdataapis = logdataapis
        self.reads = reads

    def readinto(self, res, dest):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write('%s> readinto(%d) -> %r' % (self.name, len(dest),
                                                      res))

        data = dest[0:res] if res is not None else b''

        # _writedata() uses "in" operator and is confused by memoryview because
        # characters are ints on Python 3.

    def bufferedread(self, res, size):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write('%s> bufferedread(%d) -> %d' % (
                self.name, size, len(res)))

        self._writedata(res)

    def bufferedreadline(self, res):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write('%s> bufferedreadline() -> %d' % (
                self.name, len(res)))

        self._writedata(res)

def makeloggingfileobject(logh, fh, name, reads=True, writes=True,
                          logdata=False, logdataapis=True):
    """Turn a file object into a logging file object."""

    observer = fileobjectobserver(logh, name, reads=reads, writes=writes,
                                  logdata=logdata, logdataapis=logdataapis)
    return fileobjectproxy(fh, observer)

class socketobserver(baseproxyobserver):
    """Logs socket activity."""
    def __init__(self, fh, name, reads=True, writes=True, states=True,
                 logdata=False, logdataapis=True):
        self.fh = fh
        self.name = name
        self.reads = reads
        self.writes = writes
        self.states = states

    def makefile(self, res, mode=None, bufsize=None):
        if not self.states:
            return

        self.fh.write('%s> makefile(%r, %r)\n' % (
            self.name, mode, bufsize))

    def recv(self, res, size, flags=0):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write('%s> recv(%d, %d) -> %d' % (
                self.name, size, flags, len(res)))
        self._writedata(res)

    def recvfrom(self, res, size, flags=0):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write('%s> recvfrom(%d, %d) -> %d' % (
                self.name, size, flags, len(res[0])))

        self._writedata(res[0])

    def recvfrom_into(self, res, buf, size, flags=0):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write('%s> recvfrom_into(%d, %d) -> %d' % (
                self.name, size, flags, res[0]))

        self._writedata(buf[0:res[0]])

    def recv_into(self, res, buf, size=0, flags=0):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write('%s> recv_into(%d, %d) -> %d' % (
                self.name, size, flags, res))

        self._writedata(buf[0:res])

    def send(self, res, data, flags=0):
        if not self.writes:
            return

        self.fh.write('%s> send(%d, %d) -> %d' % (
            self.name, len(data), flags, len(res)))
        self._writedata(data)

    def sendall(self, res, data, flags=0):
        if not self.writes:
            return

        if self.logdataapis:
            # Returns None on success. So don't bother reporting return value.
            self.fh.write('%s> sendall(%d, %d)' % (
                self.name, len(data), flags))

        self._writedata(data)

    def sendto(self, res, data, flagsoraddress, address=None):
        if not self.writes:

            flags = flagsoraddress
        else:
            flags = 0

        if self.logdataapis:
            self.fh.write('%s> sendto(%d, %d, %r) -> %d' % (
                self.name, len(data), flags, address, res))

        self._writedata(data)

    def setblocking(self, res, flag):
        if not self.states:

    def setsockopt(self, res, level, optname, value):
        if not self.states:
            return

        self.fh.write('%s> setsockopt(%r, %r, %r) -> %r\n' % (
            self.name, level, optname, value, res))

def makeloggingsocket(logh, fh, name, reads=True, writes=True, states=True,
                      logdata=False, logdataapis=True):
    """Turn a socket into a logging socket."""

    observer = socketobserver(logh, name, reads=reads, writes=writes,
                              states=states, logdata=logdata,
                              logdataapis=logdataapis)
    return socketproxy(fh, observer)

def version():
    """Return version information if available."""
    try:
        from . import __version__
        return __version__.version
    except ImportError:
        return 'unknown'

def versiontuple(v=None, n=4):
    """Parses a Mercurial version string into an N-tuple.

    The version string to be parsed is specified with the ``v`` argument.

    if n == 3:
        return (vints[0], vints[1], vints[2])
    if n == 4:
        return (vints[0], vints[1], vints[2], extra)

def cachefunc(func):
    '''cache the result of function calls'''
    # XXX doesn't handle keywords args
    if func.__code__.co_argcount == 0:
        cache = []
        def f():
            if len(cache) == 0:
                cache.append(func())
            return cache[0]
        return f
    cache = {}
    if func.__code__.co_argcount == 1:
        # we gain a small amount of time because
        # we don't need to pack/unpack the list
        def f(arg):
            if arg not in cache:
                cache[arg] = func(arg)
            return cache[arg]
    else:
        def f(*args):
            if args not in cache:
                cache[args] = func(*args)
            return cache[args]

    return f

class cow(object):
    """helper class to make copy-on-write easier

    Call preparewrite before doing any writes.

    def copy(self):
        """always do a cheap copy"""
        self._copied = getattr(self, '_copied', 0) + 1
        return self

class sortdict(collections.OrderedDict):
    '''a simple sorted dictionary

    >>> d1 = sortdict([(b'a', 0), (b'b', 1)])

        def update(self, src):
            if isinstance(src, dict):
                src = src.iteritems()
            for k, v in src:
                self[k] = v

class cowdict(cow, dict):
    """copy-on-write dict

    Be sure to call d = d.preparewrite() before writing to d.

    False
    >>> b is b.preparewrite()
    True
    """

class cowsortdict(cow, sortdict):
    """copy-on-write sortdict

    Be sure to call d = d.preparewrite() before writing to d.
    """

class transactional(object):
    """Base class for making a transactional type into a context manager."""
    __metaclass__ = abc.ABCMeta

    @abc.abstractmethod
    def close(self):
        """Successfully closes the transaction."""

        try:
            if exc_type is None:
                self.close()
        finally:
            self.release()

@contextlib.contextmanager
def acceptintervention(tr=None):
    """A context manager that closes the transaction on InterventionRequired

        tr.close()
        raise
    finally:
        tr.release()

@contextlib.contextmanager
def nullcontextmanager():
    yield

class _lrucachenode(object):
    """A node in a doubly linked list.

    Holds a reference to nodes on either side as well as a key-value
    pair for the dictionary entry.
    """
    __slots__ = (r'next', r'prev', r'key', r'value', r'cost')

    def __init__(self):
        self.next = None
        self.prev = None

    def markempty(self):
        """Mark the node as emptied."""
        self.key = _notset
        self.value = None
        self.cost = 0

class lrucachedict(object):
    """Dict that caches most recent accesses and sets.

    The dict consists of an actual backing dict - indexed by original

    cause the total cost of the cache to go beyond the maximum cost limit,
    nodes will be evicted to make room for the new code. This can be used
    to e.g. set a max memory limit and associate an estimated bytes size
    cost to each item in the cache. By default, no maximum cost is enforced.
    """
    def __init__(self, max, maxcost=0):
        self._cache = {}

        self._head = head = _lrucachenode()
        head.prev = head

            del self._cache[n.key]
            self.totalcost -= n.cost
            n.markempty()
            n = n.prev

def lrucachefunc(func):
    '''cache most recent results of function calls'''
    cache = {}
    order = collections.deque()
    if func.__code__.co_argcount == 1:
        def f(arg):
            if arg not in cache:
                if len(cache) > 20:
                    del cache[order.popleft()]
                cache[arg] = func(arg)
            else:
                order.remove(arg)
            order.append(arg)
            return cache[arg]
    else:
        def f(*args):
            if args not in cache:
                if len(cache) > 20:
                    del cache[order.popleft()]
                cache[args] = func(*args)

            order.append(args)
            return cache[args]

    return f

class propertycache(object):
    def __init__(self, func):
        self.func = func
        self.name = func.__name__
    def __get__(self, obj, type=None):
        result = self.func(obj)
        self.cachevalue(obj, result)
        return result

    def cachevalue(self, obj, value):
        # __dict__ assignment required to bypass __setattr__ (eg: repoview)
        obj.__dict__[self.name] = value

def clearcachedproperty(obj, prop):
    '''clear a cached property value, if one has been set'''
    prop = pycompat.sysstr(prop)
    if prop in obj.__dict__:
        del obj.__dict__[prop]

def increasingchunks(source, min=1024, max=65536):
    '''return no less than min bytes per chunk while data remains,
    doubling min after each chunk until it reaches max'''
    def log2(x):
        if not x:
            return 0
        i = 0
        while x:

            blen = 0
            buf = []
    if buf:
        yield ''.join(buf)

def always(fn):
    return True

def never(fn):
    return False

def nogc(func):
    """disable garbage collector

    Python's garbage collector triggers a GC each time a certain number of

    containers.

    This garbage collector issue have been fixed in 2.7. But it still affect
    CPython's performance.
    """
    def wrapper(*args, **kwargs):
        gcenabled = gc.isenabled()
        gc.disable()
        try:
            return func(*args, **kwargs)
        finally:
            if gcenabled:
                gc.enable()
    return wrapper

if pycompat.ispypy:
    # PyPy runs slower with gc disabled
    nogc = lambda x: x

def pathto(root, n1, n2):
    '''return the relative path from one place to another.
    root should use os.sep to separate directories
    n1 should use os.sep to separate directories

        a.pop()
        b.pop()
    b.reverse()
    return pycompat.ossep.join((['..'] * len(a)) + b) or '.'

# the location of data files matching the source code
if procutil.mainfrozen() and getattr(sys, 'frozen', None) != 'macosx_app':
    # executable version (py2exe) doesn't support __file__
    datapath = os.path.dirname(pycompat.sysexecutable)
else:
    datapath = os.path.dirname(pycompat.fsencode(__file__))

i18n.setdatapath(datapath)

def checksignature(func):
    '''wrap a function with code to check for calling errors'''
    def check(*args, **kwargs):
        try:
            return func(*args, **kwargs)
        except TypeError:
            if len(traceback.extract_tb(sys.exc_info()[2])) == 1:
                raise error.SignatureError
            raise

    return check

# a whilelist of known filesystems where hardlink works reliably
_hardlinkfswhitelist = {
    'apfs',
    'btrfs',

    'tmpfs',
    'ufs',
    'xfs',
    'zfs',
}

def copyfile(src, dest, hardlink=False, copystat=False, checkambig=False):
    '''copy a file, preserving mode and optionally other stat info like
    atime/mtime

    if hardlink:
        try:
            oslink(src, dest)
            return
        except (IOError, OSError):
            pass # fall back to normal copy
    if os.path.islink(src):
        os.symlink(os.readlink(src), dest)
        # copytime is ignored for symlinks, but in general copytime isn't needed
        # for them anyway
    else:

                if oldstat and oldstat.stat:
                    newstat = filestat.frompath(dest)
                    if newstat.isambig(oldstat):
                        # stat of copied file is ambiguous to original one
                        advanced = (
                            oldstat.stat[stat.ST_MTIME] + 1) & 0x7fffffff
                        os.utime(dest, (advanced, advanced))
        except shutil.Error as inst:
            raise error.Abort(str(inst))

def copyfiles(src, dst, hardlink=None, progress=None):
    """Copy a directory tree using hardlinks if possible."""
    num = 0

    def settopic():
        if progress:
            progress.topic = _('linking') if hardlink else _('copying')

    if os.path.isdir(src):
        if hardlink is None:
            hardlink = (os.stat(src).st_dev ==
                        os.stat(os.path.dirname(dst)).st_dev)
        settopic()
        os.mkdir(dst)
        for name, kind in listdir(src):
            srcname = os.path.join(src, name)
            dstname = os.path.join(dst, name)
            hardlink, n = copyfiles(srcname, dstname, hardlink, progress)
            num += n
    else:
        if hardlink is None:
            hardlink = (os.stat(os.path.dirname(src)).st_dev ==
                        os.stat(os.path.dirname(dst)).st_dev)
        settopic()

        if hardlink:
            try:
                oslink(src, dst)

        if progress:
            progress.increment()

    return hardlink, num

_winreservednames = {
    'con', 'prn', 'aux', 'nul',
    'com1', 'com2', 'com3', 'com4', 'com5', 'com6', 'com7', 'com8', 'com9',
    'lpt1', 'lpt2', 'lpt3', 'lpt4', 'lpt5', 'lpt6', 'lpt7', 'lpt8', 'lpt9',
}
_winreservedchars = ':*?"<>|'
def checkwinfilename(path):
    r'''Check that the base-relative path is a valid filename on Windows.
    Returns None if the path is ok, or a UI string describing the problem.

    >>> checkwinfilename(b"just/a/normal/path")

    for n in path.replace('\\', '/').split('/'):
        if not n:
            continue
        for c in _filenamebytestr(n):
            if c in _winreservedchars:
                return _("filename contains '%s', which is reserved "
                         "on Windows") % c
            if ord(c) <= 31:
                return _("filename contains '%s', which is invalid "
                         "on Windows") % stringutil.escapestr(c)
        base = n.split('.')[0]
        if base and base.lower() in _winreservednames:
            return _("filename contains '%s', which is reserved "
                     "on Windows") % base
        t = n[-1:]
        if t in '. ' and n not in '..':
            return _("filename ends with '%s', which is not allowed "
                     "on Windows") % t

if pycompat.iswindows:
    checkosfilename = checkwinfilename
    timer = time.clock
else:
    checkosfilename = platform.checkosfilename
    timer = time.time

if safehasattr(time, "perf_counter"):
    timer = time.perf_counter

def makelock(info, pathname):
    """Create a lock file atomically if possible

    This may leave a stale lock file if symlink isn't supported and signal

    try:
        return os.symlink(info, pathname)
    except OSError as why:
        if why.errno == errno.EEXIST:
            raise
    except AttributeError: # no symlink in os
        pass

    flags = os.O_CREAT | os.O_WRONLY | os.O_EXCL | getattr(os, 'O_BINARY', 0)
    ld = os.open(pathname, flags)
    os.write(ld, info)
    os.close(ld)

def readlock(pathname):
    try:
        return readlink(pathname)
    except OSError as why:
        if why.errno not in (errno.EINVAL, errno.ENOSYS):
            raise
    except AttributeError: # no symlink in os
        pass
    with posixfile(pathname, 'rb') as fp:
        return fp.read()

def fstat(fp):
    '''stat file object that may not have fileno method.'''
    try:
        return os.fstat(fp.fileno())
    except AttributeError:
        return os.stat(fp.name)

# File system features

def fscasesensitive(path):
    """
    Return true if the given path is on a case-sensitive filesystem

    d, b = os.path.split(path)
    b2 = b.upper()
    if b == b2:
        b2 = b.lower()
        if b == b2:
            return True # no evidence against case sensitivity
    p2 = os.path.join(d, b2)
    try:
        s2 = os.lstat(p2)
        if s2 == s1:
            return False
        return True
    except OSError:
        return True

try:
    import re2
    _re2 = None
except ImportError:
    _re2 = False

class _re(object):
    def _checkre2(self):
        global _re2
        try:

        if _re2:
            return re2.escape
        else:
            return remod.escape

re = _re()

_fspathcache = {}
def fspath(name, root):
    '''Get name in the case stored in the filesystem

    The name should be relative to root, and be normcase-ed for efficiency.

    Note that this function is unnecessary, and should not be
    called, for case-sensitive filesystems (simply because it's expensive).

    The root should be normcase-ed, too.
    '''
    def _makefspathcacheentry(dir):
        return dict((normcase(n), n) for n in os.listdir(dir))

    seps = pycompat.ossep
    if pycompat.osaltsep:
        seps = seps + pycompat.osaltsep
    # Protect backslashes. This gets silly very quickly.
    seps.replace('\\','\\\\')
    pattern = remod.compile(br'([^%s]+)|([%s]+)' % (seps, seps))
    dir = os.path.normpath(root)
    result = []
    for part, sep in pattern.findall(name):
        if sep:

        result.append(found or part)
        dir = os.path.join(dir, part)

    return ''.join(result)

def checknlink(testfile):
    '''check whether hardlink count reporting works properly'''

    # testfile may be open, so we need a separate file for checking to
    # work around issue2543 (or testfile may get lost on Samba shares)
    f1, f2, fp = None, None, None
    try:
        fd, f1 = pycompat.mkstemp(prefix='.%s-' % os.path.basename(testfile),
                                  suffix='1~', dir=os.path.dirname(testfile))
        os.close(fd)
        f2 = '%s2~' % f1[:-2]

        oslink(f1, f2)
        # nlinks() may behave differently for files on Windows shares if

                if f is not None:
                    os.unlink(f)
            except OSError:
                pass

def endswithsep(path):
    '''Check path ends with os.sep or os.altsep.'''
    return (path.endswith(pycompat.ossep)
            or pycompat.osaltsep and path.endswith(pycompat.osaltsep))

def splitpath(path):
    '''Split path by os.sep.
    Note that this function does not use os.altsep because this is
    an alternative of simple "xxx.split(os.sep)".
    It is recommended to use os.path.normpath() before using this
    function if need.'''
    return path.split(pycompat.ossep)

def mktempcopy(name, emptyok=False, createmode=None, enforcewritable=False):
    """Create a temporary file with the same contents from name

    The permission bits are copied from the original file.

        ofp = posixfile(temp, "wb")
        for chunk in filechunkiter(ifp):
            ofp.write(chunk)
        ifp.close()
        ofp.close()
    except: # re-raises
        try:
            os.unlink(temp)
        except OSError:
            pass
        raise
    return temp

class filestat(object):
    """help to exactly detect change of a file

    'stat' attribute is result of 'os.stat()' if specified 'path'
    exists. Otherwise, it is None. This can avoid preparative
    'exists()' examination on client side of this class.
    """
    def __init__(self, stat):
        self.stat = stat

    @classmethod
    def frompath(cls, path):

    def __eq__(self, old):
        try:
            # if ambiguity between stat of new and old file is
            # avoided, comparison of size, ctime and mtime is enough
            # to exactly detect change of a file regardless of platform
            return (self.stat.st_size == old.stat.st_size and
                    self.stat[stat.ST_CTIME] == old.stat[stat.ST_CTIME] and
                    self.stat[stat.ST_MTIME] == old.stat[stat.ST_MTIME])
        except AttributeError:
            pass
        try:
            return self.stat is None and old.stat is None
        except AttributeError:

        Advancing mtime "if isambig(oldstat)" ensures "S[n-1].mtime !=
        S[n].mtime", even if size of a file isn't changed.
        """
        try:
            return (self.stat[stat.ST_CTIME] == old.stat[stat.ST_CTIME])
        except AttributeError:
            return False

    def avoidambig(self, path, old):
        """Change file stat of specified path to avoid ambiguity

        appropriate privileges for 'path'. This returns False in this
        case.

        Otherwise, this returns True, as "ambiguity is avoided".
        """
        advanced = (old.stat[stat.ST_MTIME] + 1) & 0x7fffffff
        try:
            os.utime(path, (advanced, advanced))
        except OSError as inst:
            if inst.errno == errno.EPERM:
                # utime() on the file created by another user causes EPERM,

        return True

    def __ne__(self, other):
        return not self == other

class atomictempfile(object):
    '''writable file object that atomically updates a file

    All writes will go to a temporary copy of the original file. Call
    close() when you are done writing, and atomictempfile will rename

    checkambig argument of constructor is used with filestat, and is
    useful only if target file is guarded by any lock (e.g. repo.lock
    or repo.wlock).
    '''
    def __init__(self, name, mode='w+b', createmode=None, checkambig=False):
        self.__name = name      # permanent name
        self._tempname = mktempcopy(name, emptyok=('w' in mode),
                                    createmode=createmode,
                                    enforcewritable=('w' in mode))

        self._fp = posixfile(self._tempname, mode)
        self._checkambig = checkambig

        # delegated methods

            if oldstat and oldstat.stat:
                rename(self._tempname, filename)
                newstat = filestat.frompath(filename)
                if newstat.isambig(oldstat):
                    # stat of changed file is ambiguous to original one
                    advanced = (oldstat.stat[stat.ST_MTIME] + 1) & 0x7fffffff
                    os.utime(filename, (advanced, advanced))
            else:
                rename(self._tempname, filename)

    def discard(self):

            except OSError:
                pass
            self._fp.close()

    def __del__(self):
        if safehasattr(self, '_fp'): # constructor actually did something
            self.discard()

    def __enter__(self):
        return self

    def __exit__(self, exctype, excvalue, traceback):
        if exctype is not None:
            self.discard()
        else:
            self.close()

def unlinkpath(f, ignoremissing=False, rmdir=True):
    """unlink and remove the directory if it is empty"""
    if ignoremissing:
        tryunlink(f)

        try:
            removedirs(os.path.dirname(f))
        except OSError:
            pass

def tryunlink(f):
    """Attempt to remove a file, ignoring ENOENT errors."""
    try:
        unlink(f)
    except OSError as e:
        if e.errno != errno.ENOENT:
            raise

def makedirs(name, mode=None, notindexed=False):
    """recursive directory creation with parent mode inheritance

    Newly created directories are marked as "not to be indexed by

                return
            raise
    if mode is not None:
        os.chmod(name, mode)

def readfile(path):
    with open(path, 'rb') as fp:
        return fp.read()

def writefile(path, text):
    with open(path, 'wb') as fp:
        fp.write(text)

def appendfile(path, text):
    with open(path, 'ab') as fp:
        fp.write(text)

class chunkbuffer(object):
    """Allow arbitrary sized chunks of data to be efficiently read from an
    iterator over chunks of arbitrary size."""

    def __init__(self, in_iter):
        """in_iter is the iterator that's iterating over the input chunks."""
        def splitbig(chunks):
            for chunk in chunks:
                if len(chunk) > 2**20:
                    pos = 0
                    while pos < len(chunk):
                        end = pos + 2 ** 18
                        yield chunk[pos:end]
                        pos = end
                else:
                    yield chunk
        self.iter = splitbig(in_iter)
        self._queue = collections.deque()
        self._chunkoffset = 0

    def read(self, l=None):

        buf = []
        queue = self._queue
        while left > 0:
            # refill the queue
            if not queue:
                target = 2**18
                for chunk in self.iter:
                    queue.append(chunk)
                    target -= len(chunk)
                    if target <= 0:
                        break

                buf.append(chunk[offset:])
                self._chunkoffset = 0

            # Partial chunk needed.
            else:
                buf.append(chunk[offset:offset + left])
                self._chunkoffset += left
                left -= chunkremaining

        return ''.join(buf)

def filechunkiter(f, size=131072, limit=None):
    """Create a generator that produces the data in the file size
    (default 131072) bytes at a time, up to optional limit (default is
    to read all data).  Chunks may be less than size bytes if the

            break
        if limit:
            limit -= len(s)
        yield s

class cappedreader(object):
    """A file object proxy that allows reading up to N bytes.

    Given a source file object, instances of this type allow reading up to
    N bytes from that source file object. Attempts to read past the allowed

    It is assumed that I/O is not performed on the original file object
    in addition to I/O that is performed by this instance. If there is,
    state tracking will get out of sync and unexpected results will ensue.
    """
    def __init__(self, fh, limit):
        """Allow reading up to <limit> bytes from <fh>."""
        self._fh = fh
        self._left = limit

    def readinto(self, b):
        res = self.read(len(b))
        if res is None:
            return None

        b[0:len(res)] = res
        return len(res)

def unitcountfn(*unittable):
    '''return a function that renders a readable count of some quantity'''

    def go(count):

            if abs(count) >= divisor * multiplier:
                return format % (count / float(divisor))
        return unittable[-1][2] % count

    return go

def processlinerange(fromline, toline):
    """Check that linerange <fromline>:<toline> makes sense and return a
    0-based range.

        raise error.ParseError(_("line range must be positive"))
    if fromline < 1:
        raise error.ParseError(_("fromline must be strictly positive"))
    return fromline - 1, toline

bytecount = unitcountfn(
    (100, 1 << 30, _('%.0f GB')),
    (10, 1 << 30, _('%.1f GB')),
    (1, 1 << 30, _('%.2f GB')),
    (100, 1 << 20, _('%.0f MB')),

    (1, 1 << 20, _('%.2f MB')),
    (100, 1 << 10, _('%.0f KB')),
    (10, 1 << 10, _('%.1f KB')),
    (1, 1 << 10, _('%.2f KB')),
    (1, 1, _('%.0f bytes')),
    )

class transformingwriter(object):
    """Writable file wrapper to transform data by function"""

    def __init__(self, fp, encode):

    def flush(self):
        self._fp.flush()

    def write(self, data):
        return self._fp.write(self._encode(data))

# Matches a single EOL which can either be a CRLF where repeated CR
# are removed or a LF. We do not care about old Macintosh files, so a
# stray CR is an error.
_eolre = remod.compile(br'\r*\n')

def tolf(s):
    return _eolre.sub('\n', s)

def tocrlf(s):
    return _eolre.sub('\r\n', s)

def _crlfwriter(fp):
    return transformingwriter(fp, tocrlf)

if pycompat.oslinesep == '\r\n':
    tonativeeol = tocrlf
    fromnativeeol = tolf
    nativeeolwriter = _crlfwriter
else:
    tonativeeol = pycompat.identity
    fromnativeeol = pycompat.identity
    nativeeolwriter = pycompat.identity

if (pyplatform.python_implementation() == 'CPython' and
    sys.version_info < (3, 0)):
    # There is an issue in CPython that some IO methods do not handle EINTR
    # correctly. The following table shows what CPython version (and functions)
    # are affected (buggy: has the EINTR bug, okay: otherwise):
    #
    #                | < 2.7.4 | 2.7.4 to 2.7.12 | >= 3.0

    # to minimize the performance impact.
    if sys.version_info >= (2, 7, 4):
        # fp.readline deals with EINTR correctly, use it as a workaround.
        def _safeiterfile(fp):
            return iter(fp.readline, '')
    else:
        # fp.read* are broken too, manually deal with EINTR in a stupid way.
        # note: this may block longer than necessary because of bufsize.
        def _safeiterfile(fp, bufsize=4096):
            fd = fp.fileno()

            fastpath = stat.S_ISREG(os.fstat(fp.fileno()).st_mode)
        if fastpath:
            return fp
        else:
            return _safeiterfile(fp)
else:
    # PyPy and CPython 3 do not have the EINTR issue thus no workaround needed.
    def iterfile(fp):
        return fp

def iterlines(iterator):
    for chunk in iterator:
        for line in chunk.splitlines():
            yield line

def expandpath(path):
    return os.path.expanduser(os.path.expandvars(path))

def interpolate(prefix, mapping, s, fn=None, escape_prefix=False):
    """Return the result of interpolating items in the mapping into string s.

    prefix is a single character string, or a two character string with

            prefix_char = prefix
        mapping[prefix_char] = prefix_char
    r = remod.compile(br'%s(%s)' % (prefix, patterns))
    return r.sub(lambda x: fn(mapping[x.group()[1:]]), s)

def getport(port):
    """Return the port for a given network service.

    If port is an integer, it's returned as is. If it's a string, it's
    looked up using socket.getservbyname(). If there's no matching

        pass

    try:
        return socket.getservbyname(pycompat.sysstr(port))
    except socket.error:
        raise error.Abort(_("no port number associated with service '%s'")
                          % port)

class url(object):
    r"""Reliable URL parser.

    This parses URLs and provides attributes for the following

                    self.user, self.passwd = self.user.split(':', 1)
                if not self.host:
                    self.host = None

            # Don't split on colons in IPv6 addresses without ports
            if (self.host and ':' in self.host and
                not (self.host.startswith('[') and self.host.endswith(']'))):
                self._hostport = self.host
                self.host, self.port = self.host.rsplit(':', 1)
                if not self.host:
                    self.host = None

            if (self.host and self.scheme == 'file' and
                self.host not in ('localhost', '127.0.0.1', '[::1]')):
                raise error.Abort(_('file:// URLs can only refer to localhost'))

        self.path = path

        # leave the query string escaped
        for a in ('user', 'passwd', 'host', 'port',
                  'path', 'fragment'):
            v = getattr(self, a)
            if v is not None:
                setattr(self, a, urlreq.unquote(v))

    @encoding.strmethod
    def __repr__(self):
        attrs = []
        for a in ('scheme', 'user', 'passwd', 'host', 'port', 'path',
                  'query', 'fragment'):
            v = getattr(self, a)
            if v is not None:
                attrs.append('%s: %r' % (a, pycompat.bytestr(v)))
        return '<url %s>' % ', '.join(attrs)

            return s

        s = self.scheme + ':'
        if self.user or self.passwd or self.host:
            s += '//'
        elif self.scheme and (not self.path or self.path.startswith('/')
                              or hasdriveletter(self.path)):
            s += '//'
            if hasdriveletter(self.path):
                s += '/'
        if self.user:
            s += urlreq.quote(self.user, safe=self._safechars)

            return (s, None)
        # authinfo[1] is passed to urllib2 password manager, and its
        # URIs must not contain credentials. The host is passed in the
        # URIs list because Python < 2.4.3 uses only that to search for
        # a password.
        return (s, (None, (s, self.host),
                    self.user, self.passwd or ''))

    def isabs(self):
        if self.scheme and self.scheme != 'file':
            return True # remote URL
        if hasdriveletter(self.path):
            return True # absolute for our purposes - can't be joined()
        if self.path.startswith(br'\\'):
            return True # Windows UNC path
        if self.path.startswith('/'):
            return True # POSIX-style
        return False

    def localpath(self):
        if self.scheme == 'file' or self.scheme == 'bundle':
            path = self.path or '/'
            # For Windows, we need to promote hosts containing drive
            # letters to paths with drive letters.
            if hasdriveletter(self._hostport):
                path = self._hostport + '/' + self.path
            elif (self.host is not None and self.path
                  and not hasdriveletter(path)):
                path = '/' + path
            return path
        return self._origpath

    def islocal(self):
        '''whether localpath will return something that posixfile can open'''
        return (not self.scheme or self.scheme == 'file'
                or self.scheme == 'bundle')

def hasscheme(path):
    return bool(url(path).scheme)

def hasdriveletter(path):
    return path and path[1:2] == ':' and path[0:1].isalpha()

def urllocalpath(path):
    return url(path, parsequery=False, parsefragment=False).localpath()

def checksafessh(path):
    """check if a path / url is a potentially unsafe ssh exploit (SEC)

    This is a sanity check for ssh urls. ssh will parse the first item as

    Raises an error.Abort when the url is unsafe.
    """
    path = urlreq.unquote(path)
    if path.startswith('ssh://-') or path.startswith('svn+ssh://-'):
        raise error.Abort(_('potentially unsafe url: %r') %
                          (pycompat.bytestr(path),))

def hidepassword(u):
    '''hide user credential in a url string'''
    u = url(u)
    if u.passwd:
        u.passwd = '***'
    return bytes(u)

def removeauth(u):
    '''remove all authentication information from a url string'''
    u = url(u)
    u.user = u.passwd = None
    return bytes(u)

timecount = unitcountfn(
    (1, 1e3, _('%.0f s')),
    (100, 1, _('%.1f s')),
    (10, 1, _('%.2f s')),

    (10, 0.000001, _('%.2f us')),
    (1, 0.000001, _('%.3f us')),
    (100, 0.000000001, _('%.1f ns')),
    (10, 0.000000001, _('%.2f ns')),
    (1, 0.000000001, _('%.3f ns')),
    )

@attr.s
class timedcmstats(object):
    """Stats information produced by the timedcm context manager on entering."""

    def __bytes__(self):
        return timecount(self.elapsed) if self.elapsed else '<unknown>'

    __str__ = encoding.strmethod(__bytes__)

@contextlib.contextmanager
def timedcm(whencefmt, *whenceargs):
    """A context manager that produces timing information for a given context.

            yield timing_stats
    finally:
        timing_stats.elapsed = timer() - timing_stats.start
        timedcm._nested -= 1

timedcm._nested = 0

def timed(func):
    '''Report the execution time of a function call to stderr.

    During development, use as a decorator when you need to measure

    def wrapper(*args, **kwargs):
        with timedcm(pycompat.bytestr(func.__name__)) as time_stats:
            result = func(*args, **kwargs)
        stderr = procutil.stderr
        stderr.write('%s%s: %s\n' % (
            ' ' * time_stats.level * 2, pycompat.bytestr(func.__name__),
            time_stats))
        return result
    return wrapper

_sizeunits = (('m', 2**20), ('k', 2**10), ('g', 2**30),
              ('kb', 2**10), ('mb', 2**20), ('gb', 2**30), ('b', 1))

def sizetoint(s):
    '''Convert a space specifier to a byte count.

    >>> sizetoint(b'30')

    '''
    t = s.strip().lower()
    try:
        for k, u in _sizeunits:
            if t.endswith(k):
                return int(float(t[:-len(k)]) * u)
        return int(t)
    except ValueError:
        raise error.ParseError(_("couldn't parse size: %s") % s)

class hooks(object):
    '''A collection of hook functions that can be used to extend a
    function's behavior. Hooks are called in lexicographic order,
    based on the names of their sources.'''

        self._hooks.sort(key=lambda x: x[0])
        results = []
        for source, hook in self._hooks:
            results.append(hook(*args))
        return results

def getstackframes(skip=0, line=' %-*s in %s\n', fileline='%s:%d', depth=0):
    '''Yields lines for a nicely formatted stacktrace.
    Skips the 'skip' last entries, then return the last 'depth' entries.
    Each file+linenumber is formatted according to fileline.

      filepath+linenumber,
      function

    Not be used in production code but very convenient while developing.
    '''
    entries = [(fileline % (pycompat.sysbytes(fn), ln), pycompat.sysbytes(func))
        for fn, ln, func, _text in traceback.extract_stack()[:-skip - 1]
        ][-depth:]
    if entries:
        fnmax = max(len(entry[0]) for entry in entries)
        for fnln, func in entries:
            if line is None:
                yield (fnmax, fnln, func)
            else:
                yield line % (fnmax, fnln, func)

def debugstacktrace(msg='stacktrace', skip=0,
                    f=procutil.stderr, otherf=procutil.stdout, depth=0):
    '''Writes a message to f (stderr) with a nicely formatted stacktrace.
    Skips the 'skip' entries closest to the call, then show 'depth' entries.
    By default it will flush stdout first.
    It can be used everywhere and intentionally does not require an ui object.
    Not be used in production code but very convenient while developing.

    f.write('%s at:\n' % msg.rstrip())
    for line in getstackframes(skip + 1, depth=depth):
        f.write(line)
    f.flush()

class dirs(object):
    '''a multiset of directory names from a dirstate or manifest'''

    def __init__(self, map, skip=None):
        self._dirs = {}

        if isinstance(map, dict) and skip is not None:
            for f, s in map.iteritems():
                if s[0] != skip:
                    addpath(f)
        elif skip is not None:
            raise error.ProgrammingError("skip character is only supported "
                                         "with a dict source")
        else:
            for f in map:
                addpath(f)

    def addpath(self, path):

        return iter(self._dirs)

    def __contains__(self, d):
        return d in self._dirs

if safehasattr(parsers, 'dirs'):
    dirs = parsers.dirs

if rustdirs is not None:
    dirs = rustdirs

def finddirs(path):
    pos = path.rfind('/')
    while pos != -1:
        yield path[:pos]

    yield ''


# convenient shortcut
dst = debugstacktrace

def safename(f, tag, ctx, others=None):
    """
    Generate a name that it is safe to rename f to in the given context.

    for n in itertools.count(1):
        fn = '%s~%s~%s' % (f, tag, n)
        if fn not in ctx and fn not in others:
            return fn

def readexactly(stream, n):
    '''read n bytes from stream.read and abort if less was available'''
    s = stream.read(n)
    if len(s) < n:
        raise error.Abort(_("stream ended unexpectedly"
                           " (got %d bytes, expected %d)")
                          % (len(s), n))
    return s

def uvarintencode(value):
    """Encode an unsigned integer value to a varint.

    A varint is a variable length integer of 1 or more bytes. Each byte

    Traceback (most recent call last):
        ...
    ProgrammingError: negative value for uvarint: -1
    """
    if value < 0:
        raise error.ProgrammingError('negative value for uvarint: %d'
                                     % value)
    bits = value & 0x7f
    value >>= 7
    bytes = []
    while value:
        bytes.append(pycompat.bytechr(0x80 | bits))
        bits = value & 0x7f
        value >>= 7
    bytes.append(pycompat.bytechr(bits))

    return ''.join(bytes)

def uvarintdecodestream(fh):
    """Decode an unsigned variable length integer from a stream.

    The passed argument is anything that has a ``.read(N)`` method.

    """
    result = 0
    shift = 0
    while True:
        byte = ord(readexactly(fh, 1))
        result |= ((byte & 0x7f) << shift)
        if not (byte & 0x80):
            return result
        shift += 7

43076:2372284d9457

import sys
import time
import traceback
import warnings

from .thirdparty import attr
from hgdemandimport import tracing
from . import (
    encoding,
    error,
    i18n,

# Python compatibility

_notset = object()


def bitsfrom(container):
    bits = 0
    for bit in container:
        bits |= bit
    return bits


# python 2.6 still have deprecation warning enabled by default. We do not want
# to display anything to standard user so detect if we are running test and
# only use python deprecation warning in this case.
_dowarn = bool(encoding.environ.get('HGEMITWARNINGS'))

    warnings.filterwarnings(r'default', r'', DeprecationWarning, r'mercurial')
    warnings.filterwarnings(r'default', r'', DeprecationWarning, r'hgext')
    warnings.filterwarnings(r'default', r'', DeprecationWarning, r'hgext3rd')
if _dowarn and pycompat.ispy3:
    # silence warning emitted by passing user string to re.sub()
    warnings.filterwarnings(
        r'ignore', r'bad escape', DeprecationWarning, r'mercurial'
    )
    warnings.filterwarnings(
        r'ignore', r'invalid escape sequence', DeprecationWarning, r'mercurial'
    )
    # TODO: reinvent imp.is_frozen()
    warnings.filterwarnings(
        r'ignore',
        r'the imp module is deprecated',
        DeprecationWarning,
        r'mercurial',
    )


def nouideprecwarn(msg, version, stacklevel=1):
    """Issue an python native deprecation warning

    This is a noop outside of tests, use 'ui.deprecwarn' when possible.
    """
    if _dowarn:
        msg += (
            "\n(compatibility will be dropped after Mercurial-%s,"
            " update your code.)"
        ) % version
        warnings.warn(pycompat.sysstr(msg), DeprecationWarning, stacklevel + 1)


DIGESTS = {
    'md5': hashlib.md5,
    'sha1': hashlib.sha1,
    'sha512': hashlib.sha512,

# List of digest types from strongest to weakest
DIGESTS_BY_STRENGTH = ['sha512', 'sha1', 'md5']

for k in DIGESTS_BY_STRENGTH:
    assert k in DIGESTS


class digester(object):
    """helper to compute digests.

    This helper can be used to compute one or more digests given their name.

        for k in DIGESTS_BY_STRENGTH:
            if k in supported:
                return k
        return None


class digestchecker(object):
    """file handle wrapper that additionally checks content against a given
    size and digests.

        d = digestchecker(fh, size, {'md5': '...'})

        self._got += len(content)
        return content

    def validate(self):
        if self._size != self._got:
            raise error.Abort(
                _('size mismatch: expected %d, got %d')
                % (self._size, self._got)
            )
        for k, v in self._digests.items():
            if v != self._digester[k]:
                # i18n: first parameter is a digest name
                raise error.Abort(
                    _('%s mismatch: expected %s, got %s')
                    % (k, v, self._digester[k])
                )


try:
    buffer = buffer
except NameError:

    def buffer(sliceable, offset=0, length=None):
        if length is not None:
            return memoryview(sliceable)[offset : offset + length]
        return memoryview(sliceable)[offset:]


_chunksize = 4096


class bufferedinputpipe(object):
    """a manually buffered input pipe

    Python will not let us use buffered IO and lazy reading with 'polling' at

    empty from the output (allowing collaboration of the buffer with polling).

    This class lives in the 'util' module because it makes use of the 'os'
    module from the python stdlib.
    """

    def __new__(cls, fh):
        # If we receive a fileobjectproxy, we need to use a variation of this
        # class that notifies observers about activity.
        if isinstance(fh, fileobjectproxy):
            cls = observedbufferedinputpipe

        while (not self._eof) and lfi < 0:
            self._fillbuffer()
            if self._buffer:
                lfi = self._buffer[-1].find('\n')
        size = lfi + 1
        if lfi < 0:  # end of file
            size = self._lenbuf
        elif len(self._buffer) > 1:
            # we need to take previous chunks into account
            size += self._lenbuf - len(self._buffer[-1])
        return self._frombuffer(size)

        buf = self._buffer[0]
        if len(self._buffer) > 1:
            buf = ''.join(self._buffer)

        data = buf[:size]
        buf = buf[len(data) :]
        if buf:
            self._buffer = [buf]
            self._lenbuf = len(buf)
        else:
            self._buffer = []

        else:
            self._lenbuf += len(data)
            self._buffer.append(data)

        return data


def mmapread(fp):
    try:
        fd = getattr(fp, 'fileno', lambda: fp)()
        return mmap.mmap(fd, 0, access=mmap.ACCESS_READ)

        # if the file is empty, and if so, return an empty buffer.
        if os.fstat(fd).st_size == 0:
            return ''
        raise


class fileobjectproxy(object):
    """A proxy around file objects that tells a watcher when events occur.

    This type is intended to only be used for testing purposes. Think hard
    before using it in important code.
    """

    __slots__ = (
        r'_orig',
        r'_observer',
    )

        object.__setattr__(self, r'_observer', observer)

    def __getattribute__(self, name):
        ours = {
            r'_observer',
            # IOBase
            r'close',
            # closed if a property
            r'fileno',
            r'flush',

        return res

    def close(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'close', *args, **kwargs
        )

    def fileno(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'fileno', *args, **kwargs
        )

    def flush(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'flush', *args, **kwargs
        )

    def isatty(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'isatty', *args, **kwargs
        )

    def readable(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'readable', *args, **kwargs
        )

    def readline(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'readline', *args, **kwargs
        )

    def readlines(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'readlines', *args, **kwargs
        )

    def seek(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'seek', *args, **kwargs
        )

    def seekable(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'seekable', *args, **kwargs
        )

    def tell(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'tell', *args, **kwargs
        )

    def truncate(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'truncate', *args, **kwargs
        )

    def writable(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'writable', *args, **kwargs
        )

    def writelines(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'writelines', *args, **kwargs
        )

    def read(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'read', *args, **kwargs
        )

    def readall(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'readall', *args, **kwargs
        )

    def readinto(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'readinto', *args, **kwargs
        )

    def write(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'write', *args, **kwargs
        )

    def detach(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'detach', *args, **kwargs
        )

    def read1(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'read1', *args, **kwargs
        )


class observedbufferedinputpipe(bufferedinputpipe):
    """A variation of bufferedinputpipe that is aware of fileobjectproxy.

    ``bufferedinputpipe`` makes low-level calls to ``os.read()`` that

    This variation of ``bufferedinputpipe`` can notify observers about
    ``os.read()`` events. It also re-publishes other events, such as
    ``read()`` and ``readline()``.
    """

    def _fillbuffer(self):
        res = super(observedbufferedinputpipe, self)._fillbuffer()

        fn = getattr(self._input._observer, r'osread', None)
        if fn:

        fn = getattr(self._input._observer, r'bufferedreadline', None)
        if fn:
            fn(res)

        return res


PROXIED_SOCKET_METHODS = {
    r'makefile',
    r'recv',
    r'recvfrom',

    r'settimeout',
    r'gettimeout',
    r'setsockopt',
}


class socketproxy(object):
    """A proxy around a socket that tells a watcher when events occur.

    This is like ``fileobjectproxy`` except for sockets.

    This type is intended to only be used for testing purposes. Think hard
    before using it in important code.
    """

    __slots__ = (
        r'_orig',
        r'_observer',
    )

        return res

    def makefile(self, *args, **kwargs):
        res = object.__getattribute__(self, r'_observedcall')(
            r'makefile', *args, **kwargs
        )

        # The file object may be used for I/O. So we turn it into a
        # proxy using our observer.
        observer = object.__getattribute__(self, r'_observer')
        return makeloggingfileobject(
            observer.fh,
            res,
            observer.name,
            reads=observer.reads,
            writes=observer.writes,
            logdata=observer.logdata,
            logdataapis=observer.logdataapis,
        )

    def recv(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'recv', *args, **kwargs
        )

    def recvfrom(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'recvfrom', *args, **kwargs
        )

    def recvfrom_into(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'recvfrom_into', *args, **kwargs
        )

    def recv_into(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'recv_info', *args, **kwargs
        )

    def send(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'send', *args, **kwargs
        )

    def sendall(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'sendall', *args, **kwargs
        )

    def sendto(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'sendto', *args, **kwargs
        )

    def setblocking(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'setblocking', *args, **kwargs
        )

    def settimeout(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'settimeout', *args, **kwargs
        )

    def gettimeout(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'gettimeout', *args, **kwargs
        )

    def setsockopt(self, *args, **kwargs):
        return object.__getattribute__(self, r'_observedcall')(
            r'setsockopt', *args, **kwargs
        )


class baseproxyobserver(object):
    def _writedata(self, data):
        if not self.logdata:
            if self.logdataapis:

        # Simple case writes all data on a single line.
        if b'\n' not in data:
            if self.logdataapis:
                self.fh.write(': %s\n' % stringutil.escapestr(data))
            else:
                self.fh.write(
                    '%s>     %s\n' % (self.name, stringutil.escapestr(data))
                )
            self.fh.flush()
            return

        # Data with newlines is written to multiple lines.
        if self.logdataapis:
            self.fh.write(':\n')

        lines = data.splitlines(True)
        for line in lines:
            self.fh.write(
                '%s>     %s\n' % (self.name, stringutil.escapestr(line))
            )
        self.fh.flush()


class fileobjectobserver(baseproxyobserver):
    """Logs file object activity."""

    def __init__(
        self, fh, name, reads=True, writes=True, logdata=False, logdataapis=True
    ):
        self.fh = fh
        self.name = name
        self.logdata = logdata
        self.logdataapis = logdataapis
        self.reads = reads

    def readinto(self, res, dest):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write(
                '%s> readinto(%d) -> %r' % (self.name, len(dest), res)
            )

        data = dest[0:res] if res is not None else b''

        # _writedata() uses "in" operator and is confused by memoryview because
        # characters are ints on Python 3.

    def bufferedread(self, res, size):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write(
                '%s> bufferedread(%d) -> %d' % (self.name, size, len(res))
            )

        self._writedata(res)

    def bufferedreadline(self, res):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write(
                '%s> bufferedreadline() -> %d' % (self.name, len(res))
            )

        self._writedata(res)


def makeloggingfileobject(
    logh, fh, name, reads=True, writes=True, logdata=False, logdataapis=True
):
    """Turn a file object into a logging file object."""

    observer = fileobjectobserver(
        logh,
        name,
        reads=reads,
        writes=writes,
        logdata=logdata,
        logdataapis=logdataapis,
    )
    return fileobjectproxy(fh, observer)


class socketobserver(baseproxyobserver):
    """Logs socket activity."""

    def __init__(
        self,
        fh,
        name,
        reads=True,
        writes=True,
        states=True,
        logdata=False,
        logdataapis=True,
    ):
        self.fh = fh
        self.name = name
        self.reads = reads
        self.writes = writes
        self.states = states

    def makefile(self, res, mode=None, bufsize=None):
        if not self.states:
            return

        self.fh.write('%s> makefile(%r, %r)\n' % (self.name, mode, bufsize))

    def recv(self, res, size, flags=0):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write(
                '%s> recv(%d, %d) -> %d' % (self.name, size, flags, len(res))
            )
        self._writedata(res)

    def recvfrom(self, res, size, flags=0):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write(
                '%s> recvfrom(%d, %d) -> %d'
                % (self.name, size, flags, len(res[0]))
            )

        self._writedata(res[0])

    def recvfrom_into(self, res, buf, size, flags=0):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write(
                '%s> recvfrom_into(%d, %d) -> %d'
                % (self.name, size, flags, res[0])
            )

        self._writedata(buf[0 : res[0]])

    def recv_into(self, res, buf, size=0, flags=0):
        if not self.reads:
            return

        if self.logdataapis:
            self.fh.write(
                '%s> recv_into(%d, %d) -> %d' % (self.name, size, flags, res)
            )

        self._writedata(buf[0:res])

    def send(self, res, data, flags=0):
        if not self.writes:
            return

        self.fh.write(
            '%s> send(%d, %d) -> %d' % (self.name, len(data), flags, len(res))
        )
        self._writedata(data)

    def sendall(self, res, data, flags=0):
        if not self.writes:
            return

        if self.logdataapis:
            # Returns None on success. So don't bother reporting return value.
            self.fh.write('%s> sendall(%d, %d)' % (self.name, len(data), flags))

        self._writedata(data)

    def sendto(self, res, data, flagsoraddress, address=None):
        if not self.writes:

            flags = flagsoraddress
        else:
            flags = 0

        if self.logdataapis:
            self.fh.write(
                '%s> sendto(%d, %d, %r) -> %d'
                % (self.name, len(data), flags, address, res)
            )

        self._writedata(data)

    def setblocking(self, res, flag):
        if not self.states:

    def setsockopt(self, res, level, optname, value):
        if not self.states:
            return

        self.fh.write(
            '%s> setsockopt(%r, %r, %r) -> %r\n'
            % (self.name, level, optname, value, res)
        )


def makeloggingsocket(
    logh,
    fh,
    name,
    reads=True,
    writes=True,
    states=True,
    logdata=False,
    logdataapis=True,
):
    """Turn a socket into a logging socket."""

    observer = socketobserver(
        logh,
        name,
        reads=reads,
        writes=writes,
        states=states,
        logdata=logdata,
        logdataapis=logdataapis,
    )
    return socketproxy(fh, observer)


def version():
    """Return version information if available."""
    try:
        from . import __version__

        return __version__.version
    except ImportError:
        return 'unknown'


def versiontuple(v=None, n=4):
    """Parses a Mercurial version string into an N-tuple.

    The version string to be parsed is specified with the ``v`` argument.

    if n == 3:
        return (vints[0], vints[1], vints[2])
    if n == 4:
        return (vints[0], vints[1], vints[2], extra)


def cachefunc(func):
    '''cache the result of function calls'''
    # XXX doesn't handle keywords args
    if func.__code__.co_argcount == 0:
        cache = []

        def f():
            if len(cache) == 0:
                cache.append(func())
            return cache[0]

        return f
    cache = {}
    if func.__code__.co_argcount == 1:
        # we gain a small amount of time because
        # we don't need to pack/unpack the list
        def f(arg):
            if arg not in cache:
                cache[arg] = func(arg)
            return cache[arg]

    else:

        def f(*args):
            if args not in cache:
                cache[args] = func(*args)
            return cache[args]

    return f


class cow(object):
    """helper class to make copy-on-write easier

    Call preparewrite before doing any writes.

    def copy(self):
        """always do a cheap copy"""
        self._copied = getattr(self, '_copied', 0) + 1
        return self


class sortdict(collections.OrderedDict):
    '''a simple sorted dictionary

    >>> d1 = sortdict([(b'a', 0), (b'b', 1)])

        def update(self, src):
            if isinstance(src, dict):
                src = src.iteritems()
            for k, v in src:
                self[k] = v


class cowdict(cow, dict):
    """copy-on-write dict

    Be sure to call d = d.preparewrite() before writing to d.

    False
    >>> b is b.preparewrite()
    True
    """


class cowsortdict(cow, sortdict):
    """copy-on-write sortdict

    Be sure to call d = d.preparewrite() before writing to d.
    """


class transactional(object):
    """Base class for making a transactional type into a context manager."""

    __metaclass__ = abc.ABCMeta

    @abc.abstractmethod
    def close(self):
        """Successfully closes the transaction."""

        try:
            if exc_type is None:
                self.close()
        finally:
            self.release()


@contextlib.contextmanager
def acceptintervention(tr=None):
    """A context manager that closes the transaction on InterventionRequired

        tr.close()
        raise
    finally:
        tr.release()


@contextlib.contextmanager
def nullcontextmanager():
    yield


class _lrucachenode(object):
    """A node in a doubly linked list.

    Holds a reference to nodes on either side as well as a key-value
    pair for the dictionary entry.
    """

    __slots__ = (r'next', r'prev', r'key', r'value', r'cost')

    def __init__(self):
        self.next = None
        self.prev = None

    def markempty(self):
        """Mark the node as emptied."""
        self.key = _notset
        self.value = None
        self.cost = 0


class lrucachedict(object):
    """Dict that caches most recent accesses and sets.

    The dict consists of an actual backing dict - indexed by original

    cause the total cost of the cache to go beyond the maximum cost limit,
    nodes will be evicted to make room for the new code. This can be used
    to e.g. set a max memory limit and associate an estimated bytes size
    cost to each item in the cache. By default, no maximum cost is enforced.
    """

    def __init__(self, max, maxcost=0):
        self._cache = {}

        self._head = head = _lrucachenode()
        head.prev = head

            del self._cache[n.key]
            self.totalcost -= n.cost
            n.markempty()
            n = n.prev


def lrucachefunc(func):
    '''cache most recent results of function calls'''
    cache = {}
    order = collections.deque()
    if func.__code__.co_argcount == 1:

        def f(arg):
            if arg not in cache:
                if len(cache) > 20:
                    del cache[order.popleft()]
                cache[arg] = func(arg)
            else:
                order.remove(arg)
            order.append(arg)
            return cache[arg]

    else:

        def f(*args):
            if args not in cache:
                if len(cache) > 20:
                    del cache[order.popleft()]
                cache[args] = func(*args)

            order.append(args)
            return cache[args]

    return f


class propertycache(object):
    def __init__(self, func):
        self.func = func
        self.name = func.__name__

    def __get__(self, obj, type=None):
        result = self.func(obj)
        self.cachevalue(obj, result)
        return result

    def cachevalue(self, obj, value):
        # __dict__ assignment required to bypass __setattr__ (eg: repoview)
        obj.__dict__[self.name] = value


def clearcachedproperty(obj, prop):
    '''clear a cached property value, if one has been set'''
    prop = pycompat.sysstr(prop)
    if prop in obj.__dict__:
        del obj.__dict__[prop]


def increasingchunks(source, min=1024, max=65536):
    '''return no less than min bytes per chunk while data remains,
    doubling min after each chunk until it reaches max'''

    def log2(x):
        if not x:
            return 0
        i = 0
        while x:

            blen = 0
            buf = []
    if buf:
        yield ''.join(buf)


def always(fn):
    return True


def never(fn):
    return False


def nogc(func):
    """disable garbage collector

    Python's garbage collector triggers a GC each time a certain number of

    containers.

    This garbage collector issue have been fixed in 2.7. But it still affect
    CPython's performance.
    """

    def wrapper(*args, **kwargs):
        gcenabled = gc.isenabled()
        gc.disable()
        try:
            return func(*args, **kwargs)
        finally:
            if gcenabled:
                gc.enable()

    return wrapper


if pycompat.ispypy:
    # PyPy runs slower with gc disabled
    nogc = lambda x: x


def pathto(root, n1, n2):
    '''return the relative path from one place to another.
    root should use os.sep to separate directories
    n1 should use os.sep to separate directories

        a.pop()
        b.pop()
    b.reverse()
    return pycompat.ossep.join((['..'] * len(a)) + b) or '.'


# the location of data files matching the source code
if procutil.mainfrozen() and getattr(sys, 'frozen', None) != 'macosx_app':
    # executable version (py2exe) doesn't support __file__
    datapath = os.path.dirname(pycompat.sysexecutable)
else:
    datapath = os.path.dirname(pycompat.fsencode(__file__))

i18n.setdatapath(datapath)


def checksignature(func):
    '''wrap a function with code to check for calling errors'''

    def check(*args, **kwargs):
        try:
            return func(*args, **kwargs)
        except TypeError:
            if len(traceback.extract_tb(sys.exc_info()[2])) == 1:
                raise error.SignatureError
            raise

    return check


# a whilelist of known filesystems where hardlink works reliably
_hardlinkfswhitelist = {
    'apfs',
    'btrfs',

    'tmpfs',
    'ufs',
    'xfs',
    'zfs',
}


def copyfile(src, dest, hardlink=False, copystat=False, checkambig=False):
    '''copy a file, preserving mode and optionally other stat info like
    atime/mtime

    if hardlink:
        try:
            oslink(src, dest)
            return
        except (IOError, OSError):
            pass  # fall back to normal copy
    if os.path.islink(src):
        os.symlink(os.readlink(src), dest)
        # copytime is ignored for symlinks, but in general copytime isn't needed
        # for them anyway
    else:

                if oldstat and oldstat.stat:
                    newstat = filestat.frompath(dest)
                    if newstat.isambig(oldstat):
                        # stat of copied file is ambiguous to original one
                        advanced = (
                            oldstat.stat[stat.ST_MTIME] + 1
                        ) & 0x7FFFFFFF
                        os.utime(dest, (advanced, advanced))
        except shutil.Error as inst:
            raise error.Abort(str(inst))


def copyfiles(src, dst, hardlink=None, progress=None):
    """Copy a directory tree using hardlinks if possible."""
    num = 0

    def settopic():
        if progress:
            progress.topic = _('linking') if hardlink else _('copying')

    if os.path.isdir(src):
        if hardlink is None:
            hardlink = (
                os.stat(src).st_dev == os.stat(os.path.dirname(dst)).st_dev
            )
        settopic()
        os.mkdir(dst)
        for name, kind in listdir(src):
            srcname = os.path.join(src, name)
            dstname = os.path.join(dst, name)
            hardlink, n = copyfiles(srcname, dstname, hardlink, progress)
            num += n
    else:
        if hardlink is None:
            hardlink = (
                os.stat(os.path.dirname(src)).st_dev
                == os.stat(os.path.dirname(dst)).st_dev
            )
        settopic()

        if hardlink:
            try:
                oslink(src, dst)

        if progress:
            progress.increment()

    return hardlink, num


_winreservednames = {
    'con',
    'prn',
    'aux',
    'nul',
    'com1',
    'com2',
    'com3',
    'com4',
    'com5',
    'com6',
    'com7',
    'com8',
    'com9',
    'lpt1',
    'lpt2',
    'lpt3',
    'lpt4',
    'lpt5',
    'lpt6',
    'lpt7',
    'lpt8',
    'lpt9',
}
_winreservedchars = ':*?"<>|'


def checkwinfilename(path):
    r'''Check that the base-relative path is a valid filename on Windows.
    Returns None if the path is ok, or a UI string describing the problem.

    >>> checkwinfilename(b"just/a/normal/path")

    for n in path.replace('\\', '/').split('/'):
        if not n:
            continue
        for c in _filenamebytestr(n):
            if c in _winreservedchars:
                return (
                    _("filename contains '%s', which is reserved " "on Windows")
                    % c
                )
            if ord(c) <= 31:
                return _(
                    "filename contains '%s', which is invalid " "on Windows"
                ) % stringutil.escapestr(c)
        base = n.split('.')[0]
        if base and base.lower() in _winreservednames:
            return (
                _("filename contains '%s', which is reserved " "on Windows")
                % base
            )
        t = n[-1:]
        if t in '. ' and n not in '..':
            return (
                _("filename ends with '%s', which is not allowed " "on Windows")
                % t
            )


if pycompat.iswindows:
    checkosfilename = checkwinfilename
    timer = time.clock
else:
    checkosfilename = platform.checkosfilename
    timer = time.time

if safehasattr(time, "perf_counter"):
    timer = time.perf_counter


def makelock(info, pathname):
    """Create a lock file atomically if possible

    This may leave a stale lock file if symlink isn't supported and signal

    try:
        return os.symlink(info, pathname)
    except OSError as why:
        if why.errno == errno.EEXIST:
            raise
    except AttributeError:  # no symlink in os
        pass

    flags = os.O_CREAT | os.O_WRONLY | os.O_EXCL | getattr(os, 'O_BINARY', 0)
    ld = os.open(pathname, flags)
    os.write(ld, info)
    os.close(ld)


def readlock(pathname):
    try:
        return readlink(pathname)
    except OSError as why:
        if why.errno not in (errno.EINVAL, errno.ENOSYS):
            raise
    except AttributeError:  # no symlink in os
        pass
    with posixfile(pathname, 'rb') as fp:
        return fp.read()


def fstat(fp):
    '''stat file object that may not have fileno method.'''
    try:
        return os.fstat(fp.fileno())
    except AttributeError:
        return os.stat(fp.name)


# File system features


def fscasesensitive(path):
    """
    Return true if the given path is on a case-sensitive filesystem

    d, b = os.path.split(path)
    b2 = b.upper()
    if b == b2:
        b2 = b.lower()
        if b == b2:
            return True  # no evidence against case sensitivity
    p2 = os.path.join(d, b2)
    try:
        s2 = os.lstat(p2)
        if s2 == s1:
            return False
        return True
    except OSError:
        return True


try:
    import re2

    _re2 = None
except ImportError:
    _re2 = False


class _re(object):
    def _checkre2(self):
        global _re2
        try:

        if _re2:
            return re2.escape
        else:
            return remod.escape


re = _re()

_fspathcache = {}


def fspath(name, root):
    '''Get name in the case stored in the filesystem

    The name should be relative to root, and be normcase-ed for efficiency.

    Note that this function is unnecessary, and should not be
    called, for case-sensitive filesystems (simply because it's expensive).

    The root should be normcase-ed, too.
    '''

    def _makefspathcacheentry(dir):
        return dict((normcase(n), n) for n in os.listdir(dir))

    seps = pycompat.ossep
    if pycompat.osaltsep:
        seps = seps + pycompat.osaltsep
    # Protect backslashes. This gets silly very quickly.
    seps.replace('\\', '\\\\')
    pattern = remod.compile(br'([^%s]+)|([%s]+)' % (seps, seps))
    dir = os.path.normpath(root)
    result = []
    for part, sep in pattern.findall(name):
        if sep:

        result.append(found or part)
        dir = os.path.join(dir, part)

    return ''.join(result)


def checknlink(testfile):
    '''check whether hardlink count reporting works properly'''

    # testfile may be open, so we need a separate file for checking to
    # work around issue2543 (or testfile may get lost on Samba shares)
    f1, f2, fp = None, None, None
    try:
        fd, f1 = pycompat.mkstemp(
            prefix='.%s-' % os.path.basename(testfile),
            suffix='1~',
            dir=os.path.dirname(testfile),
        )
        os.close(fd)
        f2 = '%s2~' % f1[:-2]

        oslink(f1, f2)
        # nlinks() may behave differently for files on Windows shares if

                if f is not None:
                    os.unlink(f)
            except OSError:
                pass


def endswithsep(path):
    '''Check path ends with os.sep or os.altsep.'''
    return (
        path.endswith(pycompat.ossep)
        or pycompat.osaltsep
        and path.endswith(pycompat.osaltsep)
    )


def splitpath(path):
    '''Split path by os.sep.
    Note that this function does not use os.altsep because this is
    an alternative of simple "xxx.split(os.sep)".
    It is recommended to use os.path.normpath() before using this
    function if need.'''
    return path.split(pycompat.ossep)


def mktempcopy(name, emptyok=False, createmode=None, enforcewritable=False):
    """Create a temporary file with the same contents from name

    The permission bits are copied from the original file.

        ofp = posixfile(temp, "wb")
        for chunk in filechunkiter(ifp):
            ofp.write(chunk)
        ifp.close()
        ofp.close()
    except:  # re-raises
        try:
            os.unlink(temp)
        except OSError:
            pass
        raise
    return temp


class filestat(object):
    """help to exactly detect change of a file

    'stat' attribute is result of 'os.stat()' if specified 'path'
    exists. Otherwise, it is None. This can avoid preparative
    'exists()' examination on client side of this class.
    """

    def __init__(self, stat):
        self.stat = stat

    @classmethod
    def frompath(cls, path):

    def __eq__(self, old):
        try:
            # if ambiguity between stat of new and old file is
            # avoided, comparison of size, ctime and mtime is enough
            # to exactly detect change of a file regardless of platform
            return (
                self.stat.st_size == old.stat.st_size
                and self.stat[stat.ST_CTIME] == old.stat[stat.ST_CTIME]
                and self.stat[stat.ST_MTIME] == old.stat[stat.ST_MTIME]
            )
        except AttributeError:
            pass
        try:
            return self.stat is None and old.stat is None
        except AttributeError:

        Advancing mtime "if isambig(oldstat)" ensures "S[n-1].mtime !=
        S[n].mtime", even if size of a file isn't changed.
        """
        try:
            return self.stat[stat.ST_CTIME] == old.stat[stat.ST_CTIME]
        except AttributeError:
            return False

    def avoidambig(self, path, old):
        """Change file stat of specified path to avoid ambiguity

        appropriate privileges for 'path'. This returns False in this
        case.

        Otherwise, this returns True, as "ambiguity is avoided".
        """
        advanced = (old.stat[stat.ST_MTIME] + 1) & 0x7FFFFFFF
        try:
            os.utime(path, (advanced, advanced))
        except OSError as inst:
            if inst.errno == errno.EPERM:
                # utime() on the file created by another user causes EPERM,

        return True

    def __ne__(self, other):
        return not self == other


class atomictempfile(object):
    '''writable file object that atomically updates a file

    All writes will go to a temporary copy of the original file. Call
    close() when you are done writing, and atomictempfile will rename

    checkambig argument of constructor is used with filestat, and is
    useful only if target file is guarded by any lock (e.g. repo.lock
    or repo.wlock).
    '''

    def __init__(self, name, mode='w+b', createmode=None, checkambig=False):
        self.__name = name  # permanent name
        self._tempname = mktempcopy(
            name,
            emptyok=('w' in mode),
            createmode=createmode,
            enforcewritable=('w' in mode),
        )

        self._fp = posixfile(self._tempname, mode)
        self._checkambig = checkambig

        # delegated methods

            if oldstat and oldstat.stat:
                rename(self._tempname, filename)
                newstat = filestat.frompath(filename)
                if newstat.isambig(oldstat):
                    # stat of changed file is ambiguous to original one
                    advanced = (oldstat.stat[stat.ST_MTIME] + 1) & 0x7FFFFFFF
                    os.utime(filename, (advanced, advanced))
            else:
                rename(self._tempname, filename)

    def discard(self):

            except OSError:
                pass
            self._fp.close()

    def __del__(self):
        if safehasattr(self, '_fp'):  # constructor actually did something
            self.discard()

    def __enter__(self):
        return self

    def __exit__(self, exctype, excvalue, traceback):
        if exctype is not None:
            self.discard()
        else:
            self.close()


def unlinkpath(f, ignoremissing=False, rmdir=True):
    """unlink and remove the directory if it is empty"""
    if ignoremissing:
        tryunlink(f)

        try:
            removedirs(os.path.dirname(f))
        except OSError:
            pass


def tryunlink(f):
    """Attempt to remove a file, ignoring ENOENT errors."""
    try:
        unlink(f)
    except OSError as e:
        if e.errno != errno.ENOENT:
            raise


def makedirs(name, mode=None, notindexed=False):
    """recursive directory creation with parent mode inheritance

    Newly created directories are marked as "not to be indexed by

                return
            raise
    if mode is not None:
        os.chmod(name, mode)


def readfile(path):
    with open(path, 'rb') as fp:
        return fp.read()


def writefile(path, text):
    with open(path, 'wb') as fp:
        fp.write(text)


def appendfile(path, text):
    with open(path, 'ab') as fp:
        fp.write(text)


class chunkbuffer(object):
    """Allow arbitrary sized chunks of data to be efficiently read from an
    iterator over chunks of arbitrary size."""

    def __init__(self, in_iter):
        """in_iter is the iterator that's iterating over the input chunks."""

        def splitbig(chunks):
            for chunk in chunks:
                if len(chunk) > 2 ** 20:
                    pos = 0
                    while pos < len(chunk):
                        end = pos + 2 ** 18
                        yield chunk[pos:end]
                        pos = end
                else:
                    yield chunk

        self.iter = splitbig(in_iter)
        self._queue = collections.deque()
        self._chunkoffset = 0

    def read(self, l=None):

        buf = []
        queue = self._queue
        while left > 0:
            # refill the queue
            if not queue:
                target = 2 ** 18
                for chunk in self.iter:
                    queue.append(chunk)
                    target -= len(chunk)
                    if target <= 0:
                        break

                buf.append(chunk[offset:])
                self._chunkoffset = 0

            # Partial chunk needed.
            else:
                buf.append(chunk[offset : offset + left])
                self._chunkoffset += left
                left -= chunkremaining

        return ''.join(buf)


def filechunkiter(f, size=131072, limit=None):
    """Create a generator that produces the data in the file size
    (default 131072) bytes at a time, up to optional limit (default is
    to read all data).  Chunks may be less than size bytes if the

            break
        if limit:
            limit -= len(s)
        yield s


class cappedreader(object):
    """A file object proxy that allows reading up to N bytes.

    Given a source file object, instances of this type allow reading up to
    N bytes from that source file object. Attempts to read past the allowed

    It is assumed that I/O is not performed on the original file object
    in addition to I/O that is performed by this instance. If there is,
    state tracking will get out of sync and unexpected results will ensue.
    """

    def __init__(self, fh, limit):
        """Allow reading up to <limit> bytes from <fh>."""
        self._fh = fh
        self._left = limit

    def readinto(self, b):
        res = self.read(len(b))
        if res is None:
            return None

        b[0 : len(res)] = res
        return len(res)


def unitcountfn(*unittable):
    '''return a function that renders a readable count of some quantity'''

    def go(count):

            if abs(count) >= divisor * multiplier:
                return format % (count / float(divisor))
        return unittable[-1][2] % count

    return go


def processlinerange(fromline, toline):
    """Check that linerange <fromline>:<toline> makes sense and return a
    0-based range.

        raise error.ParseError(_("line range must be positive"))
    if fromline < 1:
        raise error.ParseError(_("fromline must be strictly positive"))
    return fromline - 1, toline


bytecount = unitcountfn(
    (100, 1 << 30, _('%.0f GB')),
    (10, 1 << 30, _('%.1f GB')),
    (1, 1 << 30, _('%.2f GB')),
    (100, 1 << 20, _('%.0f MB')),

    (1, 1 << 20, _('%.2f MB')),
    (100, 1 << 10, _('%.0f KB')),
    (10, 1 << 10, _('%.1f KB')),
    (1, 1 << 10, _('%.2f KB')),
    (1, 1, _('%.0f bytes')),
)


class transformingwriter(object):
    """Writable file wrapper to transform data by function"""

    def __init__(self, fp, encode):

    def flush(self):
        self._fp.flush()

    def write(self, data):
        return self._fp.write(self._encode(data))


# Matches a single EOL which can either be a CRLF where repeated CR
# are removed or a LF. We do not care about old Macintosh files, so a
# stray CR is an error.
_eolre = remod.compile(br'\r*\n')


def tolf(s):
    return _eolre.sub('\n', s)


def tocrlf(s):
    return _eolre.sub('\r\n', s)


def _crlfwriter(fp):
    return transformingwriter(fp, tocrlf)


if pycompat.oslinesep == '\r\n':
    tonativeeol = tocrlf
    fromnativeeol = tolf
    nativeeolwriter = _crlfwriter
else:
    tonativeeol = pycompat.identity
    fromnativeeol = pycompat.identity
    nativeeolwriter = pycompat.identity

if pyplatform.python_implementation() == 'CPython' and sys.version_info < (
    3,
    0,
):
    # There is an issue in CPython that some IO methods do not handle EINTR
    # correctly. The following table shows what CPython version (and functions)
    # are affected (buggy: has the EINTR bug, okay: otherwise):
    #
    #                | < 2.7.4 | 2.7.4 to 2.7.12 | >= 3.0

    # to minimize the performance impact.
    if sys.version_info >= (2, 7, 4):
        # fp.readline deals with EINTR correctly, use it as a workaround.
        def _safeiterfile(fp):
            return iter(fp.readline, '')

    else:
        # fp.read* are broken too, manually deal with EINTR in a stupid way.
        # note: this may block longer than necessary because of bufsize.
        def _safeiterfile(fp, bufsize=4096):
            fd = fp.fileno()

            fastpath = stat.S_ISREG(os.fstat(fp.fileno()).st_mode)
        if fastpath:
            return fp
        else:
            return _safeiterfile(fp)


else:
    # PyPy and CPython 3 do not have the EINTR issue thus no workaround needed.
    def iterfile(fp):
        return fp


def iterlines(iterator):
    for chunk in iterator:
        for line in chunk.splitlines():
            yield line


def expandpath(path):
    return os.path.expanduser(os.path.expandvars(path))


def interpolate(prefix, mapping, s, fn=None, escape_prefix=False):
    """Return the result of interpolating items in the mapping into string s.

    prefix is a single character string, or a two character string with

            prefix_char = prefix
        mapping[prefix_char] = prefix_char
    r = remod.compile(br'%s(%s)' % (prefix, patterns))
    return r.sub(lambda x: fn(mapping[x.group()[1:]]), s)


def getport(port):
    """Return the port for a given network service.

    If port is an integer, it's returned as is. If it's a string, it's
    looked up using socket.getservbyname(). If there's no matching

        pass

    try:
        return socket.getservbyname(pycompat.sysstr(port))
    except socket.error:
        raise error.Abort(
            _("no port number associated with service '%s'") % port
        )


class url(object):
    r"""Reliable URL parser.

    This parses URLs and provides attributes for the following

                    self.user, self.passwd = self.user.split(':', 1)
                if not self.host:
                    self.host = None

            # Don't split on colons in IPv6 addresses without ports
            if (
                self.host
                and ':' in self.host
                and not (self.host.startswith('[') and self.host.endswith(']'))
            ):
                self._hostport = self.host
                self.host, self.port = self.host.rsplit(':', 1)
                if not self.host:
                    self.host = None

            if (
                self.host
                and self.scheme == 'file'
                and self.host not in ('localhost', '127.0.0.1', '[::1]')
            ):
                raise error.Abort(_('file:// URLs can only refer to localhost'))

        self.path = path

        # leave the query string escaped
        for a in ('user', 'passwd', 'host', 'port', 'path', 'fragment'):
            v = getattr(self, a)
            if v is not None:
                setattr(self, a, urlreq.unquote(v))

    @encoding.strmethod
    def __repr__(self):
        attrs = []
        for a in (
            'scheme',
            'user',
            'passwd',
            'host',
            'port',
            'path',
            'query',
            'fragment',
        ):
            v = getattr(self, a)
            if v is not None:
                attrs.append('%s: %r' % (a, pycompat.bytestr(v)))
        return '<url %s>' % ', '.join(attrs)

            return s

        s = self.scheme + ':'
        if self.user or self.passwd or self.host:
            s += '//'
        elif self.scheme and (
            not self.path
            or self.path.startswith('/')
            or hasdriveletter(self.path)
        ):
            s += '//'
            if hasdriveletter(self.path):
                s += '/'
        if self.user:
            s += urlreq.quote(self.user, safe=self._safechars)

            return (s, None)
        # authinfo[1] is passed to urllib2 password manager, and its
        # URIs must not contain credentials. The host is passed in the
        # URIs list because Python < 2.4.3 uses only that to search for
        # a password.
        return (s, (None, (s, self.host), self.user, self.passwd or ''))

    def isabs(self):
        if self.scheme and self.scheme != 'file':
            return True  # remote URL
        if hasdriveletter(self.path):
            return True  # absolute for our purposes - can't be joined()
        if self.path.startswith(br'\\'):
            return True  # Windows UNC path
        if self.path.startswith('/'):
            return True  # POSIX-style
        return False

    def localpath(self):
        if self.scheme == 'file' or self.scheme == 'bundle':
            path = self.path or '/'
            # For Windows, we need to promote hosts containing drive
            # letters to paths with drive letters.
            if hasdriveletter(self._hostport):
                path = self._hostport + '/' + self.path
            elif (
                self.host is not None and self.path and not hasdriveletter(path)
            ):
                path = '/' + path
            return path
        return self._origpath

    def islocal(self):
        '''whether localpath will return something that posixfile can open'''
        return (
            not self.scheme or self.scheme == 'file' or self.scheme == 'bundle'
        )


def hasscheme(path):
    return bool(url(path).scheme)


def hasdriveletter(path):
    return path and path[1:2] == ':' and path[0:1].isalpha()


def urllocalpath(path):
    return url(path, parsequery=False, parsefragment=False).localpath()


def checksafessh(path):
    """check if a path / url is a potentially unsafe ssh exploit (SEC)

    This is a sanity check for ssh urls. ssh will parse the first item as

    Raises an error.Abort when the url is unsafe.
    """
    path = urlreq.unquote(path)
    if path.startswith('ssh://-') or path.startswith('svn+ssh://-'):
        raise error.Abort(
            _('potentially unsafe url: %r') % (pycompat.bytestr(path),)
        )


def hidepassword(u):
    '''hide user credential in a url string'''
    u = url(u)
    if u.passwd:
        u.passwd = '***'
    return bytes(u)


def removeauth(u):
    '''remove all authentication information from a url string'''
    u = url(u)
    u.user = u.passwd = None
    return bytes(u)


timecount = unitcountfn(
    (1, 1e3, _('%.0f s')),
    (100, 1, _('%.1f s')),
    (10, 1, _('%.2f s')),

    (10, 0.000001, _('%.2f us')),
    (1, 0.000001, _('%.3f us')),
    (100, 0.000000001, _('%.1f ns')),
    (10, 0.000000001, _('%.2f ns')),
    (1, 0.000000001, _('%.3f ns')),
)


@attr.s
class timedcmstats(object):
    """Stats information produced by the timedcm context manager on entering."""

    def __bytes__(self):
        return timecount(self.elapsed) if self.elapsed else '<unknown>'

    __str__ = encoding.strmethod(__bytes__)


@contextlib.contextmanager
def timedcm(whencefmt, *whenceargs):
    """A context manager that produces timing information for a given context.

            yield timing_stats
    finally:
        timing_stats.elapsed = timer() - timing_stats.start
        timedcm._nested -= 1


timedcm._nested = 0


def timed(func):
    '''Report the execution time of a function call to stderr.

    During development, use as a decorator when you need to measure

    def wrapper(*args, **kwargs):
        with timedcm(pycompat.bytestr(func.__name__)) as time_stats:
            result = func(*args, **kwargs)
        stderr = procutil.stderr
        stderr.write(
            '%s%s: %s\n'
            % (
                ' ' * time_stats.level * 2,
                pycompat.bytestr(func.__name__),
                time_stats,
            )
        )
        return result

    return wrapper


_sizeunits = (
    ('m', 2 ** 20),
    ('k', 2 ** 10),
    ('g', 2 ** 30),
    ('kb', 2 ** 10),
    ('mb', 2 ** 20),
    ('gb', 2 ** 30),
    ('b', 1),
)


def sizetoint(s):
    '''Convert a space specifier to a byte count.

    >>> sizetoint(b'30')

    '''
    t = s.strip().lower()
    try:
        for k, u in _sizeunits:
            if t.endswith(k):
                return int(float(t[: -len(k)]) * u)
        return int(t)
    except ValueError:
        raise error.ParseError(_("couldn't parse size: %s") % s)


class hooks(object):
    '''A collection of hook functions that can be used to extend a
    function's behavior. Hooks are called in lexicographic order,
    based on the names of their sources.'''

        self._hooks.sort(key=lambda x: x[0])
        results = []
        for source, hook in self._hooks:
            results.append(hook(*args))
        return results


def getstackframes(skip=0, line=' %-*s in %s\n', fileline='%s:%d', depth=0):
    '''Yields lines for a nicely formatted stacktrace.
    Skips the 'skip' last entries, then return the last 'depth' entries.
    Each file+linenumber is formatted according to fileline.

      filepath+linenumber,
      function

    Not be used in production code but very convenient while developing.
    '''
    entries = [
        (fileline % (pycompat.sysbytes(fn), ln), pycompat.sysbytes(func))
        for fn, ln, func, _text in traceback.extract_stack()[: -skip - 1]
    ][-depth:]
    if entries:
        fnmax = max(len(entry[0]) for entry in entries)
        for fnln, func in entries:
            if line is None:
                yield (fnmax, fnln, func)
            else:
                yield line % (fnmax, fnln, func)


def debugstacktrace(
    msg='stacktrace', skip=0, f=procutil.stderr, otherf=procutil.stdout, depth=0
):
    '''Writes a message to f (stderr) with a nicely formatted stacktrace.
    Skips the 'skip' entries closest to the call, then show 'depth' entries.
    By default it will flush stdout first.
    It can be used everywhere and intentionally does not require an ui object.
    Not be used in production code but very convenient while developing.

    f.write('%s at:\n' % msg.rstrip())
    for line in getstackframes(skip + 1, depth=depth):
        f.write(line)
    f.flush()


class dirs(object):
    '''a multiset of directory names from a dirstate or manifest'''

    def __init__(self, map, skip=None):
        self._dirs = {}

        if isinstance(map, dict) and skip is not None:
            for f, s in map.iteritems():
                if s[0] != skip:
                    addpath(f)
        elif skip is not None:
            raise error.ProgrammingError(
                "skip character is only supported " "with a dict source"
            )
        else:
            for f in map:
                addpath(f)

    def addpath(self, path):

        return iter(self._dirs)

    def __contains__(self, d):
        return d in self._dirs


if safehasattr(parsers, 'dirs'):
    dirs = parsers.dirs

if rustdirs is not None:
    dirs = rustdirs


def finddirs(path):
    pos = path.rfind('/')
    while pos != -1:
        yield path[:pos]

    yield ''


# convenient shortcut
dst = debugstacktrace


def safename(f, tag, ctx, others=None):
    """
    Generate a name that it is safe to rename f to in the given context.

    for n in itertools.count(1):
        fn = '%s~%s~%s' % (f, tag, n)
        if fn not in ctx and fn not in others:
            return fn


def readexactly(stream, n):
    '''read n bytes from stream.read and abort if less was available'''
    s = stream.read(n)
    if len(s) < n:
        raise error.Abort(
            _("stream ended unexpectedly" " (got %d bytes, expected %d)")
            % (len(s), n)
        )
    return s


def uvarintencode(value):
    """Encode an unsigned integer value to a varint.

    A varint is a variable length integer of 1 or more bytes. Each byte

    Traceback (most recent call last):
        ...
    ProgrammingError: negative value for uvarint: -1
    """
    if value < 0:
        raise error.ProgrammingError('negative value for uvarint: %d' % value)
    bits = value & 0x7F
    value >>= 7
    bytes = []
    while value:
        bytes.append(pycompat.bytechr(0x80 | bits))
        bits = value & 0x7F
        value >>= 7
    bytes.append(pycompat.bytechr(bits))

    return ''.join(bytes)


def uvarintdecodestream(fh):
    """Decode an unsigned variable length integer from a stream.

    The passed argument is anything that has a ``.read(N)`` method.

    """
    result = 0
    shift = 0
    while True:
        byte = ord(readexactly(fh, 1))
        result |= (byte & 0x7F) << shift
        if not (byte & 0x80):
            return result
        shift += 7