~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

"""Tree classes, representing directory at point in time.
"""

import os
from cStringIO import StringIO

import bzrlib
from bzrlib.trace import mutter, note
from bzrlib.errors import BzrError, BzrCheckError
from bzrlib.inventory import Inventory
from bzrlib.osutils import pumpfile, appendpath, fingerprint_file


exporters = {}

class Tree(object):
    """Abstract file tree.

    There are several subclasses:
    
    * `WorkingTree` exists as files on disk editable by the user.

    * `RevisionTree` is a tree as recorded at some point in the past.

    * `EmptyTree`

    Trees contain an `Inventory` object, and also know how to retrieve
    file texts mentioned in the inventory, either from a working
    directory or from a store.

    It is possible for trees to contain files that are not described
    in their inventory or vice versa; for this use `filenames()`.

    Trees can be compared, etc, regardless of whether they are working
    trees or versioned trees.
    """
    
    def has_filename(self, filename):
        """True if the tree has given filename."""
        raise NotImplementedError()

    def has_id(self, file_id):
        return self.inventory.has_id(file_id)

    __contains__ = has_id

    def __iter__(self):
        return iter(self.inventory)

    def id2path(self, file_id):
        return self.inventory.id2path(file_id)

    def _get_inventory(self):
        return self._inventory
    
    def get_file_by_path(self, path):
        return self.get_file(self._inventory.path2id(path))

    inventory = property(_get_inventory,
                         doc="Inventory of this Tree")

    def _check_retrieved(self, ie, f):
        if not __debug__:
            return  
        fp = fingerprint_file(f)
        f.seek(0)
        
        if ie.text_size != None:
            if ie.text_size != fp['size']:
                raise BzrError("mismatched size for file %r in %r" % (ie.file_id, self._store),
                        ["inventory expects %d bytes" % ie.text_size,
                         "file is actually %d bytes" % fp['size'],
                         "store is probably damaged/corrupt"])

        if ie.text_sha1 != fp['sha1']:
            raise BzrError("wrong SHA-1 for file %r in %r" % (ie.file_id, self._store),
                    ["inventory expects %s" % ie.text_sha1,
                     "file is actually %s" % fp['sha1'],
                     "store is probably damaged/corrupt"])


    def print_file(self, file_id):
        """Print file with id `file_id` to stdout."""
        import sys
        sys.stdout.write(self.get_file_text(file_id))
        
        
    def export(self, dest, format='dir', root=None):
        """Export this tree."""
        try:
            exporter = exporters[format]
        except KeyError:
            from bzrlib.errors import BzrCommandError
            raise BzrCommandError("export format %r not supported" % format)
        exporter(self, dest, root)



class RevisionTree(Tree):
    """Tree viewing a previous revision.

    File text can be retrieved from the text store.

    TODO: Some kind of `__repr__` method, but a good one
           probably means knowing the branch and revision number,
           or at least passing a description to the constructor.
    """
    
    def __init__(self, weave_store, inv, revision_id):
        self._weave_store = weave_store
        self._inventory = inv
        self._revision_id = revision_id

    def get_weave(self, file_id):
        return self._weave_store.get_weave(file_id)


    def get_file_lines(self, file_id):
        ie = self._inventory[file_id]
        weave = self.get_weave(file_id)
        return weave.get(ie.revision)
        

    def get_file_text(self, file_id):
        return ''.join(self.get_file_lines(file_id))


    def get_file(self, file_id):
        return StringIO(self.get_file_text(file_id))

    def get_file_size(self, file_id):
        return self._inventory[file_id].text_size

    def get_file_sha1(self, file_id):
        ie = self._inventory[file_id]
        if ie.kind == "file":
            return ie.text_sha1

    def has_filename(self, filename):
        return bool(self.inventory.path2id(filename))

    def list_files(self):
        # The only files returned by this are those from the version
        for path, entry in self.inventory.iter_entries():
            yield path, 'V', entry.kind, entry.file_id

    def get_symlink_target(self, file_id):
        ie = self._inventory[file_id]
        return ie.symlink_target;

class EmptyTree(Tree):
    def __init__(self):
        self._inventory = Inventory()

    def get_symlink_target(self, file_id):
        return None

    def has_filename(self, filename):
        return False

    def list_files(self):
        if False:  # just to make it a generator
            yield None
    
    def __contains__(self, file_id):
        return file_id in self._inventory

    def get_file_sha1(self, file_id):
        assert self._inventory[file_id].kind == "root_directory"
        return None




######################################################################
# diff

# TODO: Merge these two functions into a single one that can operate
# on either a whole tree or a set of files.

# TODO: Return the diff in order by filename, not by category or in
# random order.  Can probably be done by lock-stepping through the
# filenames from both trees.


def file_status(filename, old_tree, new_tree):
    """Return single-letter status, old and new names for a file.

    The complexity here is in deciding how to represent renames;
    many complex cases are possible.
    """
    old_inv = old_tree.inventory
    new_inv = new_tree.inventory
    new_id = new_inv.path2id(filename)
    old_id = old_inv.path2id(filename)

    if not new_id and not old_id:
        # easy: doesn't exist in either; not versioned at all
        if new_tree.is_ignored(filename):
            return 'I', None, None
        else:
            return '?', None, None
    elif new_id:
        # There is now a file of this name, great.
        pass
    else:
        # There is no longer a file of this name, but we can describe
        # what happened to the file that used to have
        # this name.  There are two possibilities: either it was
        # deleted entirely, or renamed.
        assert old_id
        if new_inv.has_id(old_id):
            return 'X', old_inv.id2path(old_id), new_inv.id2path(old_id)
        else:
            return 'D', old_inv.id2path(old_id), None

    # if the file_id is new in this revision, it is added
    if new_id and not old_inv.has_id(new_id):
        return 'A'

    # if there used to be a file of this name, but that ID has now
    # disappeared, it is deleted
    if old_id and not new_inv.has_id(old_id):
        return 'D'

    return 'wtf?'

    

def find_renames(old_inv, new_inv):
    for file_id in old_inv:
        if file_id not in new_inv:
            continue
        old_name = old_inv.id2path(file_id)
        new_name = new_inv.id2path(file_id)
        if old_name != new_name:
            yield (old_name, new_name)
            


######################################################################
# export

def dir_exporter(tree, dest, root):
    """Export this tree to a new directory.

    `dest` should not exist, and will be created holding the
    contents of this tree.

    TODO: To handle subdirectories we need to create the
           directories first.

    :note: If the export fails, the destination directory will be
           left in a half-assed state.
    """
    import os
    os.mkdir(dest)
    mutter('export version %r' % tree)
    inv = tree.inventory
    for dp, ie in inv.iter_entries():
        kind = ie.kind
        fullpath = appendpath(dest, dp)
        if kind == 'directory':
            os.mkdir(fullpath)
        elif kind == 'file':
            pumpfile(tree.get_file(ie.file_id), file(fullpath, 'wb'))
        elif kind == 'symlink':
            try:
                os.symlink(ie.symlink_target, fullpath)
            except OSError,e:
                raise BzrError("Failed to create symlink %r -> %r, error: %s" % (fullpath, ie.symlink_target, e))
        else:
            raise BzrError("don't know how to export {%s} of kind %r" % (ie.file_id, kind))
        mutter("  export {%s} kind %s to %s" % (ie.file_id, kind, fullpath))
exporters['dir'] = dir_exporter

try:
    import tarfile
except ImportError:
    pass
else:
    def get_root_name(dest):
        """Get just the root name for a tarball.

        >>> get_root_name('mytar.tar')
        'mytar'
        >>> get_root_name('mytar.tar.bz2')
        'mytar'
        >>> get_root_name('tar.tar.tar.tgz')
        'tar.tar.tar'
        >>> get_root_name('bzr-0.0.5.tar.gz')
        'bzr-0.0.5'
        >>> get_root_name('a/long/path/mytar.tgz')
        'mytar'
        >>> get_root_name('../parent/../dir/other.tbz2')
        'other'
        """
        endings = ['.tar', '.tar.gz', '.tgz', '.tar.bz2', '.tbz2']
        dest = os.path.basename(dest)
        for end in endings:
            if dest.endswith(end):
                return dest[:-len(end)]

    def tar_exporter(tree, dest, root, compression=None):
        """Export this tree to a new tar file.

        `dest` will be created holding the contents of this tree; if it
        already exists, it will be clobbered, like with "tar -c".
        """
        from time import time
        now = time()
        compression = str(compression or '')
        if root is None:
            root = get_root_name(dest)
        try:
            ball = tarfile.open(dest, 'w:' + compression)
        except tarfile.CompressionError, e:
            raise BzrError(str(e))
        mutter('export version %r' % tree)
        inv = tree.inventory
        for dp, ie in inv.iter_entries():
            mutter("  export {%s} kind %s to %s" % (ie.file_id, ie.kind, dest))
            item = tarfile.TarInfo(os.path.join(root, dp))
            # TODO: would be cool to actually set it to the timestamp of the
            # revision it was last changed
            item.mtime = now
            if ie.kind == 'directory':
                item.type = tarfile.DIRTYPE
                fileobj = None
                item.name += '/'
                item.size = 0
                item.mode = 0755
            elif ie.kind == 'file':
                item.type = tarfile.REGTYPE
                fileobj = tree.get_file(ie.file_id)
                item.size = _find_file_size(fileobj)
                item.mode = 0644
            else:
                raise BzrError("don't know how to export {%s} of kind %r" %
                        (ie.file_id, ie.kind))

            ball.addfile(item, fileobj)
        ball.close()
    exporters['tar'] = tar_exporter

    def tgz_exporter(tree, dest, root):
        tar_exporter(tree, dest, root, compression='gz')
    exporters['tgz'] = tgz_exporter

    def tbz_exporter(tree, dest, root):
        tar_exporter(tree, dest, root, compression='bz2')
    exporters['tbz2'] = tbz_exporter


def _find_file_size(fileobj):
    offset = fileobj.tell()
    try:
        fileobj.seek(0, 2)
        size = fileobj.tell()
    except TypeError:
        # gzip doesn't accept second argument to seek()
        fileobj.seek(0)
        size = 0
        while True:
            nread = len(fileobj.read())
            if nread == 0:
                break
            size += nread
    fileobj.seek(offset)
    return size