~bzr-pqm/bzr/bzr.dev

# Bazaar-NG -- distributed version control

#

# Copyright (C) 2005 by Canonical Ltd

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

from shutil import copyfile

from stat import (S_ISREG, S_ISDIR, S_ISLNK, ST_MODE, ST_SIZE,

                  S_ISCHR, S_ISBLK, S_ISFIFO, S_ISSOCK)

from cStringIO import StringIO

import errno

import os

import re

import sha

import string

import sys

import time

import types

import tempfile

import bzrlib

from bzrlib.errors import (BzrError,

                           BzrBadParameterNotUnicode,

                           NoSuchFile,

                           PathNotChild,

                           )

from bzrlib.trace import mutter

def make_readonly(filename):

    """Make a filename read-only."""

    mod = os.stat(filename).st_mode

    mod = mod & 0777555

    os.chmod(filename, mod)

def make_writable(filename):

    mod = os.stat(filename).st_mode

    mod = mod | 0200

    os.chmod(filename, mod)

_QUOTE_RE = None

def quotefn(f):

    """Return a quoted filename filename

    This previously used backslash quoting, but that works poorly on

    Windows."""

    # TODO: I'm not really sure this is the best format either.x

    global _QUOTE_RE

    if _QUOTE_RE == None:

        _QUOTE_RE = re.compile(r'([^a-zA-Z0-9.,:/\\_~-])')

    if _QUOTE_RE.search(f):

        return '"' + f + '"'

    else:

        return f

def file_kind(f):

    mode = os.lstat(f)[ST_MODE]

    if S_ISREG(mode):

        return 'file'

    elif S_ISDIR(mode):

        return 'directory'

    elif S_ISLNK(mode):

        return 'symlink'

    elif S_ISCHR(mode):

        return 'chardev'

    elif S_ISBLK(mode):

        return 'block'

    elif S_ISFIFO(mode):

        return 'fifo'

    elif S_ISSOCK(mode):

        return 'socket'

    else:

        return 'unknown'

def kind_marker(kind):

    if kind == 'file':

        return ''

    elif kind == 'directory':

        return '/'

    elif kind == 'symlink':

        return '@'

    else:

        raise BzrError('invalid file kind %r' % kind)

def lexists(f):

    if hasattr(os.path, 'lexists'):

        return os.path.lexists(f)

    try:

        if hasattr(os, 'lstat'):

            os.lstat(f)

        else:

            os.stat(f)

        return True

    except OSError,e:

        if e.errno == errno.ENOENT:

            return False;

        else:

            raise BzrError("lstat/stat of (%r): %r" % (f, e))

def fancy_rename(old, new, rename_func, unlink_func):

    """A fancy rename, when you don't have atomic rename.

    :param old: The old path, to rename from

    :param new: The new path, to rename to

    :param rename_func: The potentially non-atomic rename function

    :param unlink_func: A way to delete the target file if the full rename succeeds

    """

    # sftp rename doesn't allow overwriting, so play tricks:

    import random

    base = os.path.basename(new)

    dirname = os.path.dirname(new)

    tmp_name = u'tmp.%s.%.9f.%d.%s' % (base, time.time(), os.getpid(), rand_chars(10))

    tmp_name = pathjoin(dirname, tmp_name)

    # Rename the file out of the way, but keep track if it didn't exist

    # We don't want to grab just any exception

    # something like EACCES should prevent us from continuing

    # The downside is that the rename_func has to throw an exception

    # with an errno = ENOENT, or NoSuchFile

    file_existed = False

    try:

        rename_func(new, tmp_name)

    except (NoSuchFile,), e:

        pass

    except IOError, e:

        # RBC 20060103 abstraction leakage: the paramiko SFTP clients rename

        # function raises an IOError with errno == None when a rename fails.

        # This then gets caught here.

        if e.errno not in (None, errno.ENOENT, errno.ENOTDIR):

            raise

    except Exception, e:

        if (not hasattr(e, 'errno') 

            or e.errno not in (errno.ENOENT, errno.ENOTDIR)):

            raise

    else:

        file_existed = True

    success = False

    try:

        # This may throw an exception, in which case success will

        # not be set.

        rename_func(old, new)

        success = True

    finally:

        if file_existed:

            # If the file used to exist, rename it back into place

            # otherwise just delete it from the tmp location

            if success:

                unlink_func(tmp_name)

            else:

                rename_func(tmp_name, new)

# Default is to just use the python builtins

abspath = os.path.abspath

realpath = os.path.realpath

pathjoin = os.path.join

normpath = os.path.normpath

getcwd = os.getcwdu

mkdtemp = tempfile.mkdtemp

rename = os.rename

dirname = os.path.dirname

basename = os.path.basename

if os.name == "posix":

    # In Python 2.4.2 and older, os.path.abspath and os.path.realpath

    # choke on a Unicode string containing a relative path if

    # os.getcwd() returns a non-sys.getdefaultencoding()-encoded

    # string.

    _fs_enc = sys.getfilesystemencoding()

    def abspath(path):

        return os.path.abspath(path.encode(_fs_enc)).decode(_fs_enc)

    def realpath(path):

        return os.path.realpath(path.encode(_fs_enc)).decode(_fs_enc)

if sys.platform == 'win32':

    # We need to use the Unicode-aware os.path.abspath and

    # os.path.realpath on Windows systems.

    def abspath(path):

        return os.path.abspath(path).replace('\\', '/')

    def realpath(path):

        return os.path.realpath(path).replace('\\', '/')

    def pathjoin(*args):

        return os.path.join(*args).replace('\\', '/')

    def normpath(path):

        return os.path.normpath(path).replace('\\', '/')

    def getcwd():

        return os.getcwdu().replace('\\', '/')

    def mkdtemp(*args, **kwargs):

        return tempfile.mkdtemp(*args, **kwargs).replace('\\', '/')

    def rename(old, new):

        fancy_rename(old, new, rename_func=os.rename, unlink_func=os.unlink)

def normalizepath(f):

    if hasattr(os.path, 'realpath'):

        F = realpath

    else:

        F = abspath

    [p,e] = os.path.split(f)

    if e == "" or e == "." or e == "..":

        return F(f)

    else:

        return pathjoin(F(p), e)

def backup_file(fn):

    """Copy a file to a backup.

    Backups are named in GNU-style, with a ~ suffix.

    If the file is already a backup, it's not copied.

    """

    if fn[-1] == '~':

        return

    bfn = fn + '~'

    if has_symlinks() and os.path.islink(fn):

        target = os.readlink(fn)

        os.symlink(target, bfn)

        return

    inf = file(fn, 'rb')

    try:

        content = inf.read()

    finally:

        inf.close()

    outf = file(bfn, 'wb')

    try:

        outf.write(content)

    finally:

        outf.close()

def isdir(f):

    """True if f is an accessible directory."""

    try:

        return S_ISDIR(os.lstat(f)[ST_MODE])

    except OSError:

        return False

def isfile(f):

    """True if f is a regular file."""

    try:

        return S_ISREG(os.lstat(f)[ST_MODE])

    except OSError:

        return False

def islink(f):

    """True if f is a symlink."""

    try:

        return S_ISLNK(os.lstat(f)[ST_MODE])

    except OSError:

        return False

def is_inside(dir, fname):

    """True if fname is inside dir.

    The parameters should typically be passed to osutils.normpath first, so

    that . and .. and repeated slashes are eliminated, and the separators

    are canonical for the platform.

    The empty string as a dir name is taken as top-of-tree and matches 

    everything.

    >>> is_inside('src', pathjoin('src', 'foo.c'))

    True

    >>> is_inside('src', 'srccontrol')

    False

    >>> is_inside('src', pathjoin('src', 'a', 'a', 'a', 'foo.c'))

    True

    >>> is_inside('foo.c', 'foo.c')

    True

    >>> is_inside('foo.c', '')

    False

    >>> is_inside('', 'foo.c')

    True

    """

    # XXX: Most callers of this can actually do something smarter by 

    # looking at the inventory

    if dir == fname:

        return True

    if dir == '':

        return True

    if dir[-1] != '/':

        dir += '/'

    return fname.startswith(dir)

def is_inside_any(dir_list, fname):

    """True if fname is inside any of given dirs."""

    for dirname in dir_list:

        if is_inside(dirname, fname):

            return True

    else:

        return False

def pumpfile(fromfile, tofile):

    """Copy contents of one file to another."""

    BUFSIZE = 32768

    while True:

        b = fromfile.read(BUFSIZE)

        if not b:

            break

        tofile.write(b)

def file_iterator(input_file, readsize=32768):

    while True:

        b = input_file.read(readsize)

        if len(b) == 0:

            break

        yield b

def sha_file(f):

    if hasattr(f, 'tell'):

        assert f.tell() == 0

    s = sha.new()

    BUFSIZE = 128<<10

    while True:

        b = f.read(BUFSIZE)

        if not b:

            break

        s.update(b)

    return s.hexdigest()

def sha_strings(strings):

    """Return the sha-1 of concatenation of strings"""

    s = sha.new()

    map(s.update, strings)

    return s.hexdigest()

def sha_string(f):

    s = sha.new()

    s.update(f)

    return s.hexdigest()

def fingerprint_file(f):

    s = sha.new()

    b = f.read()

    s.update(b)

    size = len(b)

    return {'size': size,

            'sha1': s.hexdigest()}

def compare_files(a, b):

    """Returns true if equal in contents"""

    BUFSIZE = 4096

    while True:

        ai = a.read(BUFSIZE)

        bi = b.read(BUFSIZE)

        if ai != bi:

            return False

        if ai == '':

            return True

def local_time_offset(t=None):

    """Return offset of local zone from GMT, either at present or at time t."""

    # python2.3 localtime() can't take None

    if t == None:

        t = time.time()

    if time.localtime(t).tm_isdst and time.daylight:

        return -time.altzone

    else:

        return -time.timezone

def format_date(t, offset=0, timezone='original', date_fmt=None, 

                show_offset=True):

    ## TODO: Perhaps a global option to use either universal or local time?

    ## Or perhaps just let people set $TZ?

    assert isinstance(t, float)

    if timezone == 'utc':

        tt = time.gmtime(t)

        offset = 0

    elif timezone == 'original':

        if offset == None:

            offset = 0

        tt = time.gmtime(t + offset)

    elif timezone == 'local':

        tt = time.localtime(t)

        offset = local_time_offset(t)

    else:

        raise BzrError("unsupported timezone format %r" % timezone,

                       ['options are "utc", "original", "local"'])

    if date_fmt is None:

        date_fmt = "%a %Y-%m-%d %H:%M:%S"

    if show_offset:

        offset_str = ' %+03d%02d' % (offset / 3600, (offset / 60) % 60)

    else:

        offset_str = ''

    return (time.strftime(date_fmt, tt) +  offset_str)

def compact_date(when):

    return time.strftime('%Y%m%d%H%M%S', time.gmtime(when))

def filesize(f):

    """Return size of given open file."""

    return os.fstat(f.fileno())[ST_SIZE]

# Define rand_bytes based on platform.

try:

    # Python 2.4 and later have os.urandom,

    # but it doesn't work on some arches

    os.urandom(1)

    rand_bytes = os.urandom

except (NotImplementedError, AttributeError):

    # If python doesn't have os.urandom, or it doesn't work,

    # then try to first pull random data from /dev/urandom

    if os.path.exists("/dev/urandom"):

        rand_bytes = file('/dev/urandom', 'rb').read

    # Otherwise, use this hack as a last resort

    else:

        # not well seeded, but better than nothing

        def rand_bytes(n):

            import random

            s = ''

            while n:

                s += chr(random.randint(0, 255))

                n -= 1

            return s

ALNUM = '0123456789abcdefghijklmnopqrstuvwxyz'

def rand_chars(num):

    """Return a random string of num alphanumeric characters

    The result only contains lowercase chars because it may be used on 

    case-insensitive filesystems.

    """

    s = ''

    for raw_byte in rand_bytes(num):

        s += ALNUM[ord(raw_byte) % 36]

    return s

## TODO: We could later have path objects that remember their list

## decomposition (might be too tricksy though.)

def splitpath(p):

    """Turn string into list of parts.

    >>> splitpath('a')

    ['a']

    >>> splitpath('a/b')

    ['a', 'b']

    >>> splitpath('a/./b')

    ['a', 'b']

    >>> splitpath('a/.b')

    ['a', '.b']

    >>> splitpath('a/../b')

    Traceback (most recent call last):

    ...

    BzrError: sorry, '..' not allowed in path

    """

    assert isinstance(p, types.StringTypes)

    # split on either delimiter because people might use either on

    # Windows

    ps = re.split(r'[\\/]', p)

    rps = []

    for f in ps:

        if f == '..':

            raise BzrError("sorry, %r not allowed in path" % f)

        elif (f == '.') or (f == ''):

            pass

        else:

            rps.append(f)

    return rps

def joinpath(p):

    assert isinstance(p, list)

    for f in p:

        if (f == '..') or (f == None) or (f == ''):

            raise BzrError("sorry, %r not allowed in path" % f)

    return pathjoin(*p)

def appendpath(p1, p2):

    if p1 == '':

        return p2

    else:

        return pathjoin(p1, p2)

def split_lines(s):

    """Split s into lines, but without removing the newline characters."""

    return StringIO(s).readlines()

def hardlinks_good():

    return sys.platform not in ('win32', 'cygwin', 'darwin')

def link_or_copy(src, dest):

    """Hardlink a file, or copy it if it can't be hardlinked."""

    if not hardlinks_good():

        copyfile(src, dest)

        return

    try:

        os.link(src, dest)

    except (OSError, IOError), e:

        if e.errno != errno.EXDEV:

            raise

        copyfile(src, dest)

def has_symlinks():

    if hasattr(os, 'symlink'):

        return True

    else:

        return False

def contains_whitespace(s):

    """True if there are any whitespace characters in s."""

    for ch in string.whitespace:

        if ch in s:

            return True

    else:

        return False

def contains_linebreaks(s):

    """True if there is any vertical whitespace in s."""

    for ch in '\f\n\r':

        if ch in s:

            return True

    else:

        return False

def relpath(base, path):

    """Return path relative to base, or raise exception.

    The path may be either an absolute path or a path relative to the

    current working directory.

    os.path.commonprefix (python2.4) has a bad bug that it works just

    on string prefixes, assuming that '/u' is a prefix of '/u2'.  This

    avoids that problem.

    """

    if sys.platform != "win32":

        minlength = 1

    else:

        minlength = 3

    assert len(base) >= minlength, ('Length of base must be equal or exceed the'

        ' platform minimum length (which is %d)' % minlength)

    rp = abspath(path)

    s = []

    head = rp

    while len(head) >= len(base):

        if head == base:

            break

        head, tail = os.path.split(head)

        if tail:

            s.insert(0, tail)

    else:

        # XXX This should raise a NotChildPath exception, as its not tied

        # to branch anymore.

        raise PathNotChild(rp, base)

    if s:

        return pathjoin(*s)

    else:

        return ''

def safe_unicode(unicode_or_utf8_string):

    """Coerce unicode_or_utf8_string into unicode.

    If it is unicode, it is returned.

    Otherwise it is decoded from utf-8. If a decoding error

    occurs, it is wrapped as a If the decoding fails, the exception is wrapped 

    as a BzrBadParameter exception.

    """

    if isinstance(unicode_or_utf8_string, unicode):

        return unicode_or_utf8_string

    try:

        return unicode_or_utf8_string.decode('utf8')

    except UnicodeDecodeError:

        raise BzrBadParameterNotUnicode(unicode_or_utf8_string)

def terminal_width():

    """Return estimated terminal width."""

    # TODO: Do something smart on Windows?

    # TODO: Is there anything that gets a better update when the window

    # is resized while the program is running? We could use the Python termcap

    # library.

    try:

        return int(os.environ['COLUMNS'])

    except (IndexError, KeyError, ValueError):

        return 80

def supports_executable():

    return sys.platform != "win32"