/brz/remove-bazaar

# Copyright (C) 2009 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Functionality for doing annotations in the 'optimal' way"""

from bzrlib import (

    annotate,

    errors,

    graph as _mod_graph,

    osutils,

    patiencediff,

    )

class AnnotatorPolicy(object):

    """Variables that define annotations."""

class Annotator(object):

    """Class that drives performing annotations."""

    def __init__(self, vf):

        """Create a new Annotator from a VersionedFile."""

        self._vf = vf

        self._parent_map = {}

        self._lines_cache = {}

        self._annotations_cache = {}

        self._heads_provider = None

    def _get_needed_texts(self, key):

        graph = _mod_graph.Graph(self._vf)

        parent_map = dict((k, v) for k, v in graph.iter_ancestry([key])

                          if v is not None)

        self._parent_map.update(parent_map)

        keys = parent_map.keys()

        return keys

    def _get_heads_provider(self):

        if self._heads_provider is None:

            self._heads_provider = _mod_graph.KnownGraph(self._parent_map)

        return self._heads_provider

    def _reannotate_one_parent(self, annotations, lines, key, parent_key):

        """Reannotate this text relative to its first parent."""

        parent_lines = self._lines_cache[parent_key]

        parent_annotations = self._annotations_cache[parent_key]

        # PatienceSequenceMatcher should probably be part of Policy

        matcher = patiencediff.PatienceSequenceMatcher(None,

            parent_lines, lines)

        matching_blocks = matcher.get_matching_blocks()

        for parent_idx, lines_idx, match_len in matching_blocks:

            # For all matching regions we copy across the parent annotations

            annotations[lines_idx:lines_idx + match_len] = \

                parent_annotations[parent_idx:parent_idx + match_len]

    def annotate(self, key):

        """Return annotated fulltext for the given key."""

        keys = self._get_needed_texts(key)

        heads_provider = self._get_heads_provider

        for record in self._vf.get_record_stream(keys, 'topological', True):

            this_key = record.key

            lines = osutils.chunks_to_lines(record.get_bytes_as('chunked'))

            annotations = [(this_key,)]*len(lines)

            self._lines_cache[this_key] = lines

            self._annotations_cache[this_key] = annotations

            parents = self._parent_map[this_key]

            if not parents:

                continue

            self._reannotate_one_parent(annotations, lines, key, parents[0])

        try:

            annotations = self._annotations_cache[key]

        except KeyError:

            raise errors.RevisionNotPresent(key, self._vf)

        return annotations, self._lines_cache[key]