~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 cStringIO import StringIO
import errno
from ntpath import (abspath as _nt_abspath,
                    join as _nt_join,
                    normpath as _nt_normpath,
                    realpath as _nt_realpath,
                    )
import os
from os import listdir
import posixpath
import re
import sha
import shutil
from shutil import copyfile
import stat
from stat import (S_ISREG, S_ISDIR, S_ISLNK, ST_MODE, ST_SIZE,
                  S_ISCHR, S_ISBLK, S_ISFIFO, S_ISSOCK)
import string
import sys
import time
import types
import tempfile
import unicodedata

import bzrlib
from bzrlib.errors import (BzrError,
                           BzrBadParameterNotUnicode,
                           NoSuchFile,
                           PathNotChild,
                           IllegalPath,
                           )
from bzrlib.symbol_versioning import *
from bzrlib.trace import mutter
import bzrlib.win32console


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


_directory_kind = 'directory'

_formats = {
    stat.S_IFDIR:_directory_kind,
    stat.S_IFCHR:'chardev',
    stat.S_IFBLK:'block',
    stat.S_IFREG:'file',
    stat.S_IFIFO:'fifo',
    stat.S_IFLNK:'symlink',
    stat.S_IFSOCK:'socket',
}


def file_kind_from_stat_mode(stat_mode, _formats=_formats, _unknown='unknown'):
    """Generate a file kind from a stat mode. This is used in walkdirs.

    Its performance is critical: Do not mutate without careful benchmarking.
    """
    try:
        return _formats[stat_mode & 0170000]
    except KeyError:
        return _unknown


def file_kind(f, _lstat=os.lstat, _mapper=file_kind_from_stat_mode):
    return _mapper(_lstat(f).st_mode)


def kind_marker(kind):
    if kind == 'file':
        return ''
    elif kind == _directory_kind:
        return '/'
    elif kind == 'symlink':
        return '@'
    else:
        raise BzrError('invalid file kind %r' % kind)

lexists = getattr(os.path, 'lexists', None)
if lexists is None:
    def 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)


# 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 _posix_abspath(path):
    # jam 20060426 rather than encoding to fsencoding
    # copy posixpath.abspath, but use os.getcwdu instead
    if not posixpath.isabs(path):
        path = posixpath.join(getcwd(), path)
    return posixpath.normpath(path)


def _posix_realpath(path):
    return posixpath.realpath(path.encode(_fs_enc)).decode(_fs_enc)


def _win32_abspath(path):
    # Real _nt_abspath doesn't have a problem with a unicode cwd
    return _nt_abspath(unicode(path)).replace('\\', '/')


def _win32_realpath(path):
    # Real _nt_realpath doesn't have a problem with a unicode cwd
    return _nt_realpath(unicode(path)).replace('\\', '/')


def _win32_pathjoin(*args):
    return _nt_join(*args).replace('\\', '/')


def _win32_normpath(path):
    return _nt_normpath(unicode(path)).replace('\\', '/')


def _win32_getcwd():
    return os.getcwdu().replace('\\', '/')


def _win32_mkdtemp(*args, **kwargs):
    return tempfile.mkdtemp(*args, **kwargs).replace('\\', '/')


def _win32_rename(old, new):
    fancy_rename(old, new, rename_func=os.rename, unlink_func=os.unlink)


# Default is to just use the python builtins, but these can be rebound on
# particular platforms.
abspath = _posix_abspath
realpath = _posix_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
rmtree = shutil.rmtree

MIN_ABS_PATHLENGTH = 1


if sys.platform == 'win32':
    abspath = _win32_abspath
    realpath = _win32_realpath
    pathjoin = _win32_pathjoin
    normpath = _win32_normpath
    getcwd = _win32_getcwd
    mkdtemp = _win32_mkdtemp
    rename = _win32_rename

    MIN_ABS_PATHLENGTH = 3

    def _win32_delete_readonly(function, path, excinfo):
        """Error handler for shutil.rmtree function [for win32]
        Helps to remove files and dirs marked as read-only.
        """
        type_, value = excinfo[:2]
        if function in (os.remove, os.rmdir) \
            and type_ == OSError \
            and value.errno == errno.EACCES:
            bzrlib.osutils.make_writable(path)
            function(path)
        else:
            raise

    def rmtree(path, ignore_errors=False, onerror=_win32_delete_readonly):
        """Replacer for shutil.rmtree: could remove readonly dirs/files"""
        return shutil.rmtree(path, ignore_errors, onerror)


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 is_inside_or_parent_of_any(dir_list, fname):
    """True if fname is a child or a parent of any of the given files."""
    for dirname in dir_list:
        if is_inside(dirname, fname) or is_inside(fname, dirname):
            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)


@deprecated_function(zero_nine)
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."""
    lines = s.split('\n')
    result = [line + '\n' for line in lines[:-1]]
    if lines[-1]:
        result.append(lines[-1])
    return result


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 delete_any(full_path):
    """Delete a file or directory."""
    try:
        os.unlink(full_path)
    except OSError, e:
    # We may be renaming a dangling inventory id
        if e.errno not in (errno.EISDIR, errno.EACCES, errno.EPERM):
            raise
        os.rmdir(full_path)


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.
    """

    assert len(base) >= MIN_ABS_PATHLENGTH, ('Length of base must be equal or'
        ' exceed the platform minimum length (which is %d)' % 
        MIN_ABS_PATHLENGTH)

    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:
        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)


_platform_normalizes_filenames = False
if sys.platform == 'darwin':
    _platform_normalizes_filenames = True


def normalizes_filenames():
    """Return True if this platform normalizes unicode filenames.

    Mac OSX does, Windows/Linux do not.
    """
    return _platform_normalizes_filenames


if _platform_normalizes_filenames:
    def unicode_filename(path):
        """Make sure 'path' is a properly normalized filename.

        On platforms where the system normalizes filenames (Mac OSX),
        you can access a file by any path which will normalize
        correctly.
        Internally, bzr only supports NFC/NFKC normalization, since
        that is the standard for XML documents.
        So we return an normalized path, and indicate this has been
        properly normalized.

        :return: (path, is_normalized) Return a path which can
                access the file, and whether or not this path is
                normalized.
        """
        return unicodedata.normalize('NFKC', path), True
else:
    def unicode_filename(path):
        """Make sure 'path' is a properly normalized filename.

        On platforms where the system does not normalize filenames 
        (Windows, Linux), you have to access a file by its exact path.
        Internally, bzr only supports NFC/NFKC normalization, since
        that is the standard for XML documents.
        So we return the original path, and indicate if this is
        properly normalized.

        :return: (path, is_normalized) Return a path which can
                access the file, and whether or not this path is
                normalized.
        """
        return path, unicodedata.normalize('NFKC', path) == path


def terminal_width():
    """Return estimated terminal width."""
    if sys.platform == 'win32':
        import bzrlib.win32console
        return bzrlib.win32console.get_console_size()[0]
    width = 0
    try:
        import struct, fcntl, termios
        s = struct.pack('HHHH', 0, 0, 0, 0)
        x = fcntl.ioctl(1, termios.TIOCGWINSZ, s)
        width = struct.unpack('HHHH', x)[1]
    except IOError:
        pass
    if width <= 0:
        try:
            width = int(os.environ['COLUMNS'])
        except:
            pass
    if width <= 0:
        width = 80

    return width

def supports_executable():
    return sys.platform != "win32"


_validWin32PathRE = re.compile(r'^([A-Za-z]:[/\\])?[^:<>*"?\|]*$')


def check_legal_path(path):
    """Check whether the supplied path is legal.  
    This is only required on Windows, so we don't test on other platforms
    right now.
    """
    if sys.platform != "win32":
        return
    if _validWin32PathRE.match(path) is None:
        raise IllegalPath(path)


def walkdirs(top):
    """Yield data about all the directories in a tree.
    
    This yields all the data about the contents of a directory at a time.
    After each directory has been yielded, if the caller has mutated the list
    to exclude some directories, they are then not descended into.
    
    The data yielded is of the form:
    [(relpath, basename, kind, lstat, path_from_top), ...]

    :return: an iterator over the dirs.
    """
    lstat = os.lstat
    pending = []
    _directory = _directory_kind
    _listdir = listdir
    pending = [("", "", _directory, None, top)]
    while pending:
        dirblock = []
        currentdir = pending.pop()
        # 0 - relpath, 1- basename, 2- kind, 3- stat, 4-toppath
        top = currentdir[4]
        if currentdir[0]:
            relroot = currentdir[0] + '/'
        else:
            relroot = ""
        for name in sorted(_listdir(top)):
            abspath = top + '/' + name
            statvalue = lstat(abspath)
            dirblock.append ((relroot + name, name, file_kind_from_stat_mode(statvalue.st_mode), statvalue, abspath))
        yield dirblock
        # push the user specified dirs from dirblock
        for dir in reversed(dirblock):
            if dir[2] == _directory:
                pending.append(dir)