/brz/remove-bazaar

# Copyright (C) 2009 Jelmer Vernooij <jelmer@samba.org>

#

# 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

"""Map from Git sha's to Bazaar objects."""

import bzrlib

from bzrlib.errors import NoSuchRevision

import os

def check_pysqlite_version(sqlite3):

    """Check that sqlite library is compatible.

    """

    if (sqlite3.sqlite_version_info[0] < 3 or 

            (sqlite3.sqlite_version_info[0] == 3 and 

             sqlite3.sqlite_version_info[1] < 3)):

        warning('Needs at least sqlite 3.3.x')

        raise bzrlib.errors.BzrError("incompatible sqlite library")

try:

    try:

        import sqlite3

        check_pysqlite_version(sqlite3)

    except (ImportError, bzrlib.errors.BzrError), e: 

        from pysqlite2 import dbapi2 as sqlite3

        check_pysqlite_version(sqlite3)

except:

    warning('Needs at least Python2.5 or Python2.4 with the pysqlite2 '

            'module')

    raise bzrlib.errors.BzrError("missing sqlite library")

class GitShaMap(object):

    """Git<->Bzr revision id mapping database."""

    def add_entry(self, sha, type, type_data):

        """Add a new entry to the database.

        """

        raise NotImplementedError(self.add_entry)

    def lookup_git_sha(self, sha):

        """Lookup a Git sha in the database.

        :param sha: Git object sha

        :return: (type, type_data) with type_data:

            revision: revid, tree sha

        """

        raise NotImplementedError(self.lookup_git_sha)

    def revids(self):

        """List the revision ids known."""

        raise NotImplementedError(self.revids)

    def commit(self):

        """Commit any pending changes."""

class DictGitShaMap(GitShaMap):

    def __init__(self):

        self.dict = {}

    def add_entry(self, sha, type, type_data):

        self.dict[sha] = (type, type_data)

    def lookup_git_sha(self, sha):

        return self.dict[sha]

    def revids(self):

        for key, (type, type_data) in self.dict.iteritems():

            if type == "commit":

                yield type_data[0]

class SqliteGitShaMap(GitShaMap):

    def __init__(self, transport=None):

        self.transport = transport

        if transport is None:

            self.db = sqlite3.connect(":memory:")

        else:

            self.db = sqlite3.connect(

                os.path.join(self.transport.local_abspath("."), "git.db"))

        self.db.executescript("""

        create table if not exists commits(sha1 text, revid text, tree_sha text);

        create index if not exists commit_sha1 on commits(sha1);

        create table if not exists blobs(sha1 text, fileid text, revid text);

        create index if not exists blobs_sha1 on blobs(sha1);

        create table if not exists trees(sha1 text, path text, revid text);

        create index if not exists trees_sha1 on trees(sha1);

""")

    def _parent_lookup(self, revid):

        return self.db.execute("select sha1 from commits where revid = ?", (revid,)).fetchone()[0].encode("utf-8")

    def commit(self):

        self.db.commit()

    def add_entry(self, sha, type, type_data):

        """Add a new entry to the database.

        """

        assert isinstance(type_data, tuple)

        assert isinstance(sha, str), "type was %r" % sha

        if type == "commit":

            self.db.execute("replace into commits (sha1, revid, tree_sha) values (?, ?, ?)", (sha, type_data[0], type_data[1]))

        elif type == "blob":

            self.db.execute("replace into blobs (sha1, fileid, revid) values (?, ?, ?)", (sha, type_data[0], type_data[1]))

        elif type == "tree":

            self.db.execute("replace into trees (sha1, path, revid) values (?, ?, ?)", (sha, type_data[0], type_data[1]))

        else:

            raise AssertionError("Unknown type %s" % type)

    def lookup_git_sha(self, sha):

        """Lookup a Git sha in the database.

        :param sha: Git object sha

        :return: (type, type_data) with type_data:

            revision: revid, tree sha

        """

        row = self.db.execute("select revid, tree_sha from commits where sha1 = ?", (sha,)).fetchone()

        if row is not None:

            return ("commit", row)

        row = self.db.execute("select fileid, revid from blobs where sha1 = ?", (sha,)).fetchone()

        if row is not None:

            return ("blob", row)

        row = self.db.execute("select path, revid from trees where sha1 = ?", (sha,)).fetchone()

        if row is not None:

            return ("tree", row)

        raise KeyError(sha)

    def revids(self):

        """List the revision ids known."""

        for row in self.db.execute("select revid from commits").fetchall():

            yield row[0]