# util.py - Mercurial utility functions and platform specfic implementations

#

#  Copyright 2005 K. Thananchayan <thananck@yahoo.com>

#  Copyright 2005-2007 Matt Mackall <mpm@selenic.com>

#  Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2 or any later version.

"""Mercurial utility functions and platform specfic implementations.

This contains helper routines that are independent of the SCM core and

hide platform-specific details from the core.

"""

from i18n import _

import error, osutil, encoding

import errno, re, shutil, sys, tempfile, traceback

import imp, socket, urllib

# Python compatibility

def sha1(s):

    return _fastsha1(s)

def _fastsha1(s):

    # This function will import sha1 from hashlib or sha (whichever is

    # available) and overwrite itself with it on the first call.

    # Subsequent calls will go directly to the imported function.

    if sys.version_info >= (2, 5):

        from hashlib import sha1 as _sha1

    else:

        from sha import sha as _sha1

    global _fastsha1, sha1

    _fastsha1 = sha1 = _sha1

    return _sha1(s)

import __builtin__

if sys.version_info[0] < 3:

    def fakebuffer(sliceable, offset=0):

        return sliceable[offset:]

else:

    def fakebuffer(sliceable, offset=0):

        return memoryview(sliceable)[offset:]

try:

    buffer

except NameError:

    __builtin__.buffer = fakebuffer

import subprocess

closefds = os.name == 'posix'

def popen2(cmd, env=None, newlines=False):

    # Setting bufsize to -1 lets the system decide the buffer size.

    # The default for bufsize is 0, meaning unbuffered. This leads to

    # poor performance on Mac OS X: http://bugs.python.org/issue4194

    p = subprocess.Popen(cmd, shell=True, bufsize=-1,

                         close_fds=closefds,

                         stdin=subprocess.PIPE, stdout=subprocess.PIPE,

                         universal_newlines=newlines,

                         env=env)

    return p.stdin, p.stdout

def popen3(cmd, env=None, newlines=False):

    p = subprocess.Popen(cmd, shell=True, bufsize=-1,

                         close_fds=closefds,

                         stdin=subprocess.PIPE, stdout=subprocess.PIPE,

                         stderr=subprocess.PIPE,

                         universal_newlines=newlines,

                         env=env)

    return p.stdin, p.stdout, p.stderr

def version():

    """Return version information if available."""

    try:

        import __version__

        return __version__.version

    except ImportError:

        return 'unknown'

# used by parsedate

defaultdateformats = (

    '%Y-%m-%d %H:%M:%S',

    '%Y-%m-%d %I:%M:%S%p',

    '%Y-%m-%d %H:%M',

    '%Y-%m-%d %I:%M%p',

    '%Y-%m-%d',

    '%m-%d',

    '%m/%d',

    '%m/%d/%y',

    '%m/%d/%Y',

    '%a %b %d %H:%M:%S %Y',

    '%a %b %d %I:%M:%S%p %Y',

    '%a, %d %b %Y %H:%M:%S',        #  GNU coreutils "/bin/date --rfc-2822"

    '%b %d %H:%M:%S %Y',

    '%b %d %I:%M:%S%p %Y',

    '%b %d %H:%M:%S',

    '%b %d %I:%M:%S%p',

    '%b %d %H:%M',

    '%b %d %I:%M%p',

    '%b %d %Y',

    '%b %d',

    '%H:%M:%S',

    '%I:%M:%S%p',

    '%H:%M',

    '%I:%M%p',

)

extendeddateformats = defaultdateformats + (

    "%Y",

    "%Y-%m",

    "%b",

    "%b %Y",

    )

def cachefunc(func):

    '''cache the result of function calls'''

    # XXX doesn't handle keywords args

    cache = {}

    if func.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

def lrucachefunc(func):

    '''cache most recent results of function calls'''

    cache = {}

    order = []

    if func.func_code.co_argcount == 1:

        def f(arg):

            if arg not in cache:

                if len(cache) > 20:

                    del cache[order.pop(0)]

                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.pop(0)]

                cache[args] = func(*args)

            else:

                order.remove(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)

        setattr(obj, self.name, result)

        return result

def pipefilter(s, cmd):

    '''filter string S through command CMD, returning its output'''

    p = subprocess.Popen(cmd, shell=True, close_fds=closefds,

                         stdin=subprocess.PIPE, stdout=subprocess.PIPE)

    pout, perr = p.communicate(s)

    return pout

def tempfilter(s, cmd):

    '''filter string S through a pair of temporary files with CMD.

    CMD is used as a template to create the real command to be run,

    with the strings INFILE and OUTFILE replaced by the real names of

    the temporary files generated.'''

    inname, outname = None, None

    try:

        infd, inname = tempfile.mkstemp(prefix='hg-filter-in-')

        fp = os.fdopen(infd, 'wb')

        fp.write(s)

        fp.close()

        outfd, outname = tempfile.mkstemp(prefix='hg-filter-out-')

        os.close(outfd)

        cmd = cmd.replace('INFILE', inname)

        cmd = cmd.replace('OUTFILE', outname)

        code = os.system(cmd)

        if sys.platform == 'OpenVMS' and code & 1:

            code = 0

        if code:

            raise Abort(_("command '%s' failed: %s") %

                        (cmd, explainexit(code)))

        fp = open(outname, 'rb')

        r = fp.read()

        fp.close()

        return r

    finally:

        try:

            if inname:

                os.unlink(inname)

        except OSError:

            pass

        try:

            if outname:

                os.unlink(outname)

        except OSError:

            pass

filtertable = {

    'tempfile:': tempfilter,

    'pipe:': pipefilter,

    }

def filter(s, cmd):

    "filter a string through a command that transforms its input to its output"

    for name, fn in filtertable.iteritems():

        if cmd.startswith(name):

            return fn(s, cmd[len(name):].lstrip())

    return pipefilter(s, cmd)

def binary(s):

    """return true if a string is binary data"""

    return bool(s and '\0' in s)

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:

            x >>= 1

            i += 1

        return i - 1

    buf = []

    blen = 0

    for chunk in source:

        buf.append(chunk)

        blen += len(chunk)

        if blen >= min:

            if min < max:

                min = min << 1

                nmin = 1 << log2(blen)

                if nmin > min:

                    min = nmin

                if min > max:

                    min = max

            yield ''.join(buf)

            blen = 0

            buf = []

    if buf:

        yield ''.join(buf)

Abort = error.Abort

def always(fn):

    return True

def never(fn):

    return False

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

    n2 should use "/" to separate directories

    returns an os.sep-separated path.

    If n1 is a relative path, it's assumed it's

    relative to root.

    n2 should always be relative to root.

    '''

    if not n1:

        return localpath(n2)

    if os.path.isabs(n1):

        if os.path.splitdrive(root)[0] != os.path.splitdrive(n1)[0]:

            return os.path.join(root, localpath(n2))

        n2 = '/'.join((pconvert(root), n2))

    a, b = splitpath(n1), n2.split('/')

    a.reverse()

    b.reverse()

    while a and b and a[-1] == b[-1]:

        a.pop()

        b.pop()

    b.reverse()

    return os.sep.join((['..'] * len(a)) + b) or '.'

_hgexecutable = None

def mainfrozen():

    """return True if we are a frozen executable.

    The code supports py2exe (most common, Windows only) and tools/freeze

    (portable, not much used).

    """

    return (hasattr(sys, "frozen") or # new py2exe

            hasattr(sys, "importers") or # old py2exe

            imp.is_frozen("__main__")) # tools/freeze

def hgexecutable():

    """return location of the 'hg' executable.

    Defaults to $HG or 'hg' in the search path.

    """

    if _hgexecutable is None:

        hg = os.environ.get('HG')

        if hg:

            _sethgexecutable(hg)

        elif mainfrozen():

            _sethgexecutable(sys.executable)

        else:

            exe = findexe('hg') or os.path.basename(sys.argv[0])

            _sethgexecutable(exe)

    return _hgexecutable

def _sethgexecutable(path):

    """set location of the 'hg' executable"""

    global _hgexecutable

    _hgexecutable = path

def system(cmd, environ={}, cwd=None, onerr=None, errprefix=None, out=None):

    '''enhanced shell command execution.

    run with environment maybe modified, maybe in different dir.

    if command fails and onerr is None, return status.  if ui object,

    print error message and return status, else raise onerr object as

    exception.

    if out is specified, it is assumed to be a file-like object that has a

    write() method. stdout and stderr will be redirected to out.'''

    try:

        sys.stdout.flush()

    except Exception:

        pass

    def py2shell(val):

        'convert python object into string that is useful to shell'

        if val is None or val is False:

            return '0'

        if val is True:

            return '1'

        return str(val)

    origcmd = cmd

    cmd = quotecommand(cmd)

    env = dict(os.environ)

    env.update((k, py2shell(v)) for k, v in environ.iteritems())

    env['HG'] = hgexecutable()

    if out is None or out == sys.__stdout__:

        rc = subprocess.call(cmd, shell=True, close_fds=closefds,

                             env=env, cwd=cwd)

    else:

        proc = subprocess.Popen(cmd, shell=True, close_fds=closefds,

                                env=env, cwd=cwd, stdout=subprocess.PIPE,

                                stderr=subprocess.STDOUT)

        for line in proc.stdout:

            out.write(line)

        proc.wait()

        rc = proc.returncode

    if sys.platform == 'OpenVMS' and rc & 1:

        rc = 0

    if rc and onerr:

        errmsg = '%s %s' % (os.path.basename(origcmd.split(None, 1)[0]),

                            explainexit(rc)[0])

        if errprefix:

            errmsg = '%s: %s' % (errprefix, errmsg)

        try:

            onerr.warn(errmsg + '\n')

        except AttributeError:

            raise onerr(errmsg)

    return rc