~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.errors import BzrError, BzrCheckError
from bzrlib import errors
from bzrlib.inventory import Inventory
from bzrlib.osutils import fingerprint_file
import bzrlib.revision
from bzrlib.trace import mutter, note

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 conflicts(self):
        """Get a list of the conflicts in the tree.

        Each conflict is an instance of bzrlib.conflicts.Conflict.
        """
        return []

    def get_parent_ids(self):
        """Get the parent ids for this tree. 

        :return: a list of parent ids. [] is returned to indicate
        a tree with no parents.
        :raises: BzrError if the parents are not known.
        """
        raise NotImplementedError(self.get_parent_ids)
    
    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)

    def has_or_had_id(self, file_id):
        if file_id == self.inventory.root.file_id:
            return True
        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 kind(self, file_id):
        raise NotImplementedError("subclasses must implement kind")

    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 lock_read(self):
        pass

    def unknowns(self):
        """What files are present in this tree and unknown.
        
        :return: an iterator over the unknown files.
        """
        return iter([])

    def unlock(self):
        pass

    def filter_unversioned_files(self, paths):
        """Filter out paths that are not versioned.

        :return: set of paths.
        """
        # NB: we specifically *don't* call self.has_filename, because for
        # WorkingTrees that can indicate files that exist on disk but that 
        # are not versioned.
        pred = self.inventory.has_filename
        return set((p for p in paths if not pred(p)))
        
        
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, branch, inv, revision_id):
        # for compatability the 'branch' parameter has not been renamed to 
        # repository at this point. However, we should change RevisionTree's
        # construction to always be via Repository and not via direct 
        # construction - this will mean that we can change the constructor
        # with much less chance of breaking client code.
        self._repository = branch
        self._weave_store = branch.weave_store
        self._inventory = inv
        self._revision_id = revision_id

    def get_parent_ids(self):
        """See Tree.get_parent_ids.

        A RevisionTree's parents match the revision graph.
        """
        parent_ids = self._repository.get_revision(self._revision_id).parent_ids
        return parent_ids
        
    def get_revision_id(self):
        """Return the revision id associated with this tree."""
        return self._revision_id

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

    def get_file_lines(self, file_id):
        ie = self._inventory[file_id]
        weave = self.get_weave(file_id)
        return weave.get_lines(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, path=None):
        ie = self._inventory[file_id]
        if ie.kind == "file":
            return ie.text_sha1
        return None

    def get_file_mtime(self, file_id, path=None):
        ie = self._inventory[file_id]
        revision = self._repository.get_revision(ie.revision)
        return revision.timestamp

    def is_executable(self, file_id, path=None):
        ie = self._inventory[file_id]
        if ie.kind != "file":
            return None 
        return self._inventory[file_id].executable

    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, entry

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

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

    def lock_read(self):
        self._repository.lock_read()

    def unlock(self):
        self._repository.unlock()


class EmptyTree(Tree):

    def __init__(self):
        self._inventory = Inventory()

    def get_parent_ids(self):
        """See Tree.get_parent_ids.

        An EmptyTree always has NULL_REVISION as the only parent.
        """
        return []

    def get_symlink_target(self, file_id):
        return None

    def has_filename(self, filename):
        return False

    def kind(self, file_id):
        assert self._inventory[file_id].kind == "root_directory"
        return "root_directory"

    def list_files(self):
        return iter([])
    
    def __contains__(self, file_id):
        return file_id in self._inventory

    def get_file_sha1(self, file_id, path=None):
        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)
            

def find_ids_across_trees(filenames, trees, require_versioned=True):
    """Find the ids corresponding to specified filenames.
    
    All matches in all trees will be used, and all children of matched
    directories will be used.

    :param filenames: The filenames to find file_ids for
    :param trees: The trees to find file_ids within
    :param require_versioned: if true, all specified filenames must occur in
    at least one tree.
    :return: a set of file ids for the specified filenames and their children.
    """
    if not filenames:
        return None
    specified_ids = _find_filename_ids_across_trees(filenames, trees, 
                                                    require_versioned)
    return _find_children_across_trees(specified_ids, trees)


def _find_filename_ids_across_trees(filenames, trees, require_versioned):
    """Find the ids corresponding to specified filenames.
    
    All matches in all trees will be used.

    :param filenames: The filenames to find file_ids for
    :param trees: The trees to find file_ids within
    :param require_versioned: if true, all specified filenames must occur in
    at least one tree.
    :return: a set of file ids for the specified filenames
    """
    not_versioned = []
    interesting_ids = set()
    for tree_path in filenames:
        not_found = True
        for tree in trees:
            file_id = tree.inventory.path2id(tree_path)
            if file_id is not None:
                interesting_ids.add(file_id)
                not_found = False
        if not_found:
            not_versioned.append(tree_path)
    if len(not_versioned) > 0 and require_versioned:
        raise errors.PathsNotVersionedError(not_versioned)
    return interesting_ids


def _find_children_across_trees(specified_ids, trees):
    """Return a set including specified ids and their children
    
    All matches in all trees will be used.

    :param trees: The trees to find file_ids within
    :return: a set containing all specified ids and their children 
    """
    interesting_ids = set(specified_ids)
    pending = interesting_ids
    # now handle children of interesting ids
    # we loop so that we handle all children of each id in both trees
    while len(pending) > 0:
        new_pending = set()
        for file_id in pending:
            for tree in trees:
                if file_id not in tree:
                    continue
                entry = tree.inventory[file_id]
                for child in getattr(entry, 'children', {}).itervalues():
                    if child.file_id not in interesting_ids:
                        new_pending.add(child.file_id)
        interesting_ids.update(new_pending)
        pending = new_pending
    return interesting_ids