path: root/libbe/storage/util/upgrade.py

# Copyright (C) 2009 W. Trevor King <wking@drexel.edu>
#
# 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.

"""
Handle conversion between the various BE storage formats.
"""

import codecs
import os, os.path
import sys

import libbe
import libbe.bug as bug
import libbe.util.encoding as encoding
import libbe.storage.util.mapfile as mapfile

if libbe.TESTING == True:
    import doctest

# a list of all past versions
BUGDIR_DISK_VERSIONS = ["Bugs Everywhere Tree 1 0",
                        "Bugs Everywhere Directory v1.1",
                        "Bugs Everywhere Directory v1.2",
                        "Bugs Everywhere Directory v1.3"]

# the current version
BUGDIR_DISK_VERSION = BUGDIR_DISK_VERSIONS[-1]

class Upgrader (object):
    "Class for converting between different on-disk BE storage formats."
    initial_version = None
    final_version = None
    def __init__(self, root):
        self.root = root

    def get_path(self, *args):
        """
        Return a path relative to .root.
        """
        dir = os.path.join(self.root, '.be')
        if len(args) == 0:
            return dir
        assert args[0] in ['version', 'settings', 'bugs'], str(args)
        return os.path.join(dir, *args)

    def check_initial_version(self):
        path = self.get_path('version')
        version = self.vcs.get_file_contents(path).rstrip('\n')
        assert version == self.initial_version, version

    def set_version(self):
        path = self.get_path("version")
        self.vcs.set_file_contents(path, self.final_version+"\n")

    def upgrade(self):
        print >> sys.stderr, "upgrading bugdir from '%s' to '%s'" \
            % (self.initial_version, self.final_version)
        self.check_initial_version()
        self.set_version()
        self._upgrade()

    def _upgrade(self):
        raise NotImplementedError


class Upgrade_1_0_to_1_1 (Upgrader):
    initial_version = "Bugs Everywhere Tree 1 0"
    final_version = "Bugs Everywhere Directory v1.1"
    def _upgrade_mapfile(self, path):
        contents = self.vcs.get_file_contents(path)
        old_format = False
        for line in contents.splitlines():
            if len(line.split("=")) == 2:
                old_format = True
                break
        if old_format == True:
            # translate to YAML.
            newlines = []
            for line in contents.splitlines():
                line = line.rstrip('\n')
                if len(line) == 0:
                    continue
                fields = line.split("=")
                if len(fields) == 2:
                    key,value = fields
                    newlines.append('%s: "%s"' % (key, value.replace('"','\\"')))
                else:
                    newlines.append(line)
            contents = '\n'.join(newlines)
            # load the YAML and save
            map = mapfile.parse(contents)
            mapfile.map_save(self.vcs, path, map)

    def _upgrade(self):
        """
        Comment value field "From" -> "Author".
        Homegrown mapfile -> YAML.
        """
        path = self.get_path("settings")
        self._upgrade_mapfile(path)
        for bug_uuid in os.listdir(self.get_path("bugs")):
            path = self.get_path("bugs", bug_uuid, "values")
            self._upgrade_mapfile(path)
            c_path = ["bugs", bug_uuid, "comments"]
            if not os.path.exists(self.get_path(*c_path)):
                continue # no comments for this bug
            for comment_uuid in os.listdir(self.get_path(*c_path)):
                path_list = c_path + [comment_uuid, "values"]
                path = self.get_path(*path_list)
                self._upgrade_mapfile(path)
                settings = mapfile.map_load(self.vcs, path)
                if "From" in settings:
                    settings["Author"] = settings.pop("From")
                    mapfile.map_save(self.vcs, path, settings)


class Upgrade_1_1_to_1_2 (Upgrader):
    initial_version = "Bugs Everywhere Directory v1.1"
    final_version = "Bugs Everywhere Directory v1.2"
    def _upgrade(self):
        """
        BugDir settings field "rcs_name" -> "vcs_name".
        """
        path = self.get_path("settings")
        settings = mapfile.map_load(self.vcs, path)
        if "rcs_name" in settings:
            settings["vcs_name"] = settings.pop("rcs_name")
            mapfile.map_save(self.vcs, path, settings)

class Upgrade_1_2_to_1_3 (Upgrader):
    initial_version = "Bugs Everywhere Directory v1.2"
    final_version = "Bugs Everywhere Directory v1.3"
    def __init__(self, *args, **kwargs):
        Upgrader.__init__(self, *args, **kwargs)
        self._targets = {} # key: target text,value: new target bug
        path = self.get_path('settings')
        settings = mapfile.map_load(self.vcs, path)
        if 'vcs_name' in settings:
            old_vcs = self.vcs
            self.vcs = vcs.vcs_by_name(settings['vcs_name'])
            self.vcs.root(self.root)
            self.vcs.encoding = old_vcs.encoding

    def _target_bug(self, target_text):
        if target_text not in self._targets:
            _bug = bug.Bug(bugdir=self, summary=target_text)
            # note: we're not a bugdir, but all Bug.save() needs is
            # .root, .vcs, and .get_path(), which we have.
            _bug.severity = 'target'
            self._targets[target_text] = _bug
        return self._targets[target_text]

    def _upgrade_bugdir_mapfile(self):
        path = self.get_path('settings')
        settings = mapfile.map_load(self.vcs, path)
        if 'target' in settings:
            settings['target'] = self._target_bug(settings['target']).uuid
            mapfile.map_save(self.vcs, path, settings)

    def _upgrade_bug_mapfile(self, bug_uuid):
        import becommands.depend
        path = self.get_path('bugs', bug_uuid, 'values')
        settings = mapfile.map_load(self.vcs, path)
        if 'target' in settings:
            target_bug = self._target_bug(settings['target'])
            _bug = bug.Bug(bugdir=self, uuid=bug_uuid, from_disk=True)
            # note: we're not a bugdir, but all Bug.load_settings()
            # needs is .root, .vcs, and .get_path(), which we have.
            becommands.depend.add_block(target_bug, _bug)
            _bug.settings.pop('target')
            _bug.save()

    def _upgrade(self):
        """
        Bug value field "target" -> target bugs.
        Bugdir value field "target" -> pointer to current target bug.
        """
        for bug_uuid in os.listdir(self.get_path('bugs')):
            self._upgrade_bug_mapfile(bug_uuid)
        self._upgrade_bugdir_mapfile()
        for _bug in self._targets.values():
            _bug.save()

upgraders = [Upgrade_1_0_to_1_1,
             Upgrade_1_1_to_1_2,
             Upgrade_1_2_to_1_3]
upgrade_classes = {}
for upgrader in upgraders:
    upgrade_classes[(upgrader.initial_version,upgrader.final_version)]=upgrader

def upgrade(path, current_version,
            target_version=BUGDIR_DISK_VERSION):
    """
    Call the appropriate upgrade function to convert current_version
    to target_version.  If a direct conversion function does not exist,
    use consecutive conversion functions.
    """
    if current_version not in BUGDIR_DISK_VERSIONS:
        raise NotImplementedError, \
            "Cannot handle version '%s' yet." % version
    if target_version not in BUGDIR_DISK_VERSIONS:
        raise NotImplementedError, \
            "Cannot handle version '%s' yet." % version

    if (current_version, target_version) in upgrade_classes:
        # direct conversion
        upgrade_class = upgrade_classes[(current_version, target_version)]
        u = upgrade_class(path)
        u.upgrade()
    else:
        # consecutive single-step conversion
        i = BUGDIR_DISK_VERSIONS.index(current_version)
        while True:
            version_a = BUGDIR_DISK_VERSIONS[i]
            version_b = BUGDIR_DISK_VERSIONS[i+1]
            try:
                upgrade_class = upgrade_classes[(version_a, version_b)]
            except KeyError:
                raise NotImplementedError, \
                    "Cannot convert version '%s' to '%s' yet." \
                    % (version_a, version_b)
            u = upgrade_class(path)
            u.upgrade()
            if version_b == target_version:
                break
            i += 1

if libbe.TESTING == True:
    suite = doctest.DocTestSuite()