~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005 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

"""Implementation of Transport for the local filesystem.

"""

from bzrlib.transport import Transport, register_transport, \

    TransportError, NoSuchFile, FileExists

import os, errno

class LocalTransportError(TransportError):

    pass

class LocalTransport(Transport):

    """This is the transport agent for local filesystem access."""

    def __init__(self, base):

        """Set the base path where files will be stored."""

        if base.startswith('file://'):

            base = base[7:]

        super(LocalTransport, self).__init__(os.path.realpath(base))

    def should_cache(self):

        return False

    def clone(self, offset=None):

        """Return a new LocalTransport with root at self.base + offset

        Because the local filesystem does not require a connection, 

        we can just return a new object.

        """

        if offset is None:

            return LocalTransport(self.base)

        else:

            return LocalTransport(self.abspath(offset))

    def abspath(self, relpath):

        """Return the full url to the given relative path.

        This can be supplied with a string or a list

        """

        if isinstance(relpath, basestring):

            relpath = [relpath]

        return os.path.join(self.base, *relpath)

    def relpath(self, abspath):

        """Return the local path portion from a given absolute path.

        """

        from bzrlib.branch import _relpath

        return _relpath(self.base, abspath)

    def has(self, relpath):

        return os.access(self.abspath(relpath), os.F_OK)

    def get(self, relpath):

        """Get the file at the given relative path.

        :param relpath: The relative path to the file

        """

        try:

            path = self.abspath(relpath)

            return open(path, 'rb')

        except IOError,e:

            if e.errno == errno.ENOENT:

                raise NoSuchFile('File %r does not exist' % path, orig_error=e)

            raise LocalTransportError(orig_error=e)

    def get_partial(self, relpath, start, length=None):

        """Get just part of a file.

        :param relpath: Path to the file, relative to base

        :param start: The starting position to read from

        :param length: The length to read. A length of None indicates

                       read to the end of the file.

        :return: A file-like object containing at least the specified bytes.

                 Some implementations may return objects which can be read

                 past this length, but this is not guaranteed.

        """

        # LocalTransport.get_partial() doesn't care about the length

        # argument, because it is using a local file, and thus just

        # returns the file seek'ed to the appropriate location.

        try:

            path = self.abspath(relpath)

            f = open(path, 'rb')

            f.seek(start, 0)

            return f

        except IOError,e:

            if e.errno == errno.ENOENT:

                raise NoSuchFile('File %r does not exist' % path, orig_error=e)

            raise LocalTransportError(orig_error=e)

    def put(self, relpath, f):

        """Copy the file-like or string object into the location.

        :param relpath: Location to put the contents, relative to base.

        :param f:       File-like or string object.

        """

        from bzrlib.atomicfile import AtomicFile

        try:

            path = self.abspath(relpath)

            fp = AtomicFile(path, 'wb')

        except IOError, e:

            if e.errno == errno.ENOENT:

                raise NoSuchFile('File %r does not exist' % path, orig_error=e)

            raise LocalTransportError(orig_error=e)

        try:

            self._pump(f, fp)

            fp.commit()

        finally:

            fp.close()

    def mkdir(self, relpath):

        """Create a directory at the given path."""

        try:

            os.mkdir(self.abspath(relpath))

        except OSError,e:

            if e.errno == errno.EEXIST:

                raise FileExists(orig_error=e)

            elif e.errno == errno.ENOENT:

                raise NoSuchFile(orig_error=e)

            raise LocalTransportError(orig_error=e)

    def append(self, relpath, f):

        """Append the text in the file-like object into the final

        location.

        """

        fp = open(self.abspath(relpath), 'ab')

        self._pump(f, fp)

    def copy(self, rel_from, rel_to):

        """Copy the item at rel_from to the location at rel_to"""

        import shutil

        path_from = self.abspath(rel_from)

        path_to = self.abspath(rel_to)

        try:

            shutil.copy(path_from, path_to)

        except OSError,e:

            raise LocalTransportError(orig_error=e)

    def move(self, rel_from, rel_to):

        """Move the item at rel_from to the location at rel_to"""

        path_from = self.abspath(rel_from)

        path_to = self.abspath(rel_to)

        try:

            os.rename(path_from, path_to)

        except OSError,e:

            raise LocalTransportError(orig_error=e)

    def delete(self, relpath):

        """Delete the item at relpath"""

        try:

            os.remove(self.abspath(relpath))

        except OSError,e:

            raise LocalTransportError(orig_error=e)

    def copy_to(self, relpaths, other, pb=None):

        """Copy a set of entries from self into another Transport.

        :param relpaths: A list/generator of entries to be copied.

        """

        if isinstance(other, LocalTransport):

            # Both from & to are on the local filesystem

            # Unfortunately, I can't think of anything faster than just

            # copying them across, one by one :(

            import shutil

            total = self._get_total(relpaths)

            count = 0

            for path in relpaths:

                self._update_pb(pb, 'copy-to', count, total)

                shutil.copy(self.abspath(path), other.abspath(path))

                count += 1

            return count

        else:

            return super(LocalTransport, self).copy_to(relpaths, other, pb=pb)

    def list_dir(self, relpath):

        """Return a list of all files at the given location.

        WARNING: many transports do not support this, so trying avoid using

        it if at all possible.

        """

        try:

            return os.listdir(self.abspath(relpath))

        except OSError,e:

            raise LocalTransportError(orig_error=e)

    def stat(self, relpath):

        """Return the stat information for a file.

        """

        try:

            return os.stat(self.abspath(relpath))

        except OSError,e:

            raise LocalTransportError(orig_error=e)

    def lock_read(self, relpath):

        """Lock the given file for shared (read) access.

        :return: A lock object, which should be passed to Transport.unlock()

        """

        from bzrlib.lock import ReadLock

        return ReadLock(self.abspath(relpath))

    def lock_write(self, relpath):

        """Lock the given file for exclusive (write) access.

        WARNING: many transports do not support this, so trying avoid using it

        :return: A lock object, which should be passed to Transport.unlock()

        """

        from bzrlib.lock import WriteLock

        return WriteLock(self.abspath(relpath))

# If nothing else matches, try the LocalTransport

register_transport(None, LocalTransport)

register_transport('file://', LocalTransport)