"""

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

platform-specific details from the core.

"""

from i18n import _

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

import os, stat, threading, time, calendar, glob, osutil

import imp

# Python compatibility

_md5 = None

def md5(s):

    global _md5

    if _md5 is None:

        try:

            import hashlib

            _md5 = hashlib.md5

        except ImportError:

            import md5

            _md5 = md5.md5

    return _md5(s)

_sha1 = None

def sha1(s):

    global _sha1

    if _sha1 is None:

        try:

            import hashlib

            _sha1 = hashlib.sha1

        except ImportError:

            import sha

            _sha1 = sha.sha

    return _sha1(s)

try:

    import subprocess

    subprocess.Popen  # trigger ImportError early

    closefds = os.name == 'posix'

    def popen2(cmd, mode='t', bufsize=-1):

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

                             close_fds=closefds,

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

        return p.stdin, p.stdout

    def popen3(cmd, mode='t', bufsize=-1):

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

                             close_fds=closefds,

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

                             stderr=subprocess.PIPE)

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

    def Popen3(cmd, capturestderr=False, bufsize=-1):

        stderr = capturestderr and subprocess.PIPE or None

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

                             close_fds=closefds,

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

                             stderr=stderr)

        p.fromchild = p.stdout

        p.tochild = p.stdin

        p.childerr = p.stderr

        return p

except ImportError:

    subprocess = None

    from popen2 import Popen3

    popen2 = os.popen2

    popen3 = os.popen3

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:%SP',

    '%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

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'''

    (pin, pout) = popen2(cmd, 'b')

    def writer():

        try:

            pin.write(s)

            pin.close()

        except IOError, inst:

            if inst.errno != errno.EPIPE:

                raise

    # we should use select instead on UNIX, but this will work on most

    # systems, including Windows

    w = threading.Thread(target=writer)

    w.start()

    f = pout.read()

    pout.close()

    w.join()

    return f

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, explain_exit(code)))

        return open(outname, 'rb').read()

    finally:

        try:

            if inname: os.unlink(inname)

        except: pass

        try:

            if outname: os.unlink(outname)

        except: 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 patkind(name, default):

    """Split a string into an optional pattern kind prefix and the

    actual pattern."""

    for prefix in 're', 'glob', 'path', 'relglob', 'relpath', 'relre':

        if name.startswith(prefix + ':'): return name.split(':', 1)

    return default, name

def globre(pat, head='^', tail='$'):

    "convert a glob pattern into a regexp"

    i, n = 0, len(pat)

    res = ''

    group = 0

    def peek(): return i < n and pat[i]

    while i < n:

        c = pat[i]

        i = i+1

        if c == '*':

            if peek() == '*':

                i += 1

                res += '.*'

            else:

                res += '[^/]*'

        elif c == '?':

            res += '.'

        elif c == '[':

            j = i

            if j < n and pat[j] in '!]':

                j += 1

            while j < n and pat[j] != ']':

                j += 1

            if j >= n:

                res += '\\['

            else:

                stuff = pat[i:j].replace('\\','\\\\')

                i = j + 1

                if stuff[0] == '!':

                    stuff = '^' + stuff[1:]

                elif stuff[0] == '^':

                    stuff = '\\' + stuff

                res = '%s[%s]' % (res, stuff)

        elif c == '{':

            group += 1

            res += '(?:'

        elif c == '}' and group:

            res += ')'

            group -= 1

        elif c == ',' and group:

            res += '|'

        elif c == '\\':

            p = peek()

            if p:

                i += 1

                res += re.escape(p)

            else:

                res += re.escape(c)

        else:

            res += re.escape(c)

    return head + res + tail

_globchars = {'[': 1, '{': 1, '*': 1, '?': 1}

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 '.'

def canonpath(root, cwd, myname):

    """return the canonical path of myname, given cwd and root"""

    if root == os.sep:

        rootsep = os.sep

    elif endswithsep(root):

        rootsep = root

    else:

        rootsep = root + os.sep

    name = myname

    if not os.path.isabs(name):

        name = os.path.join(root, cwd, name)

    name = os.path.normpath(name)

    audit_path = path_auditor(root)

    if name != rootsep and name.startswith(rootsep):

        name = name[len(rootsep):]

        audit_path(name)

        return pconvert(name)

    elif name == root:

        return ''

    else:

        # Determine whether `name' is in the hierarchy at or beneath `root',

        # by iterating name=dirname(name) until that causes no change (can't

        # check name == '/', because that doesn't work on windows).  For each

        # `name', compare dev/inode numbers.  If they match, the list `rel'

        # holds the reversed list of components making up the relative file

        # name we want.

        root_st = os.stat(root)

        rel = []

        while True:

            try:

                name_st = os.stat(name)

            except OSError:

                break

            if samestat(name_st, root_st):

                if not rel:

                    # name was actually the same as root (maybe a symlink)

                    return ''

                rel.reverse()

                name = os.path.join(*rel)

                audit_path(name)

                return pconvert(name)