path: root/src/carquinyol/datastore.py

# Copyright (C) 2008, One Laptop Per Child
# Based on code Copyright (C) 2007, ObjectRealms, LLC
#
# 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 St, Fifth Floor, Boston, MA  02110-1301  USA

import logging
import uuid
import time
import os
import traceback

import dbus
import dbus.service
import gobject

from sugar import mime

from carquinyol import layoutmanager
from carquinyol import migration
from carquinyol.layoutmanager import MAX_QUERY_LIMIT
from carquinyol.metadatastore import MetadataStore
from carquinyol.indexstore import IndexStore
from carquinyol.filestore import FileStore
from carquinyol.optimizer import Optimizer

# the name used by the logger
DS_LOG_CHANNEL = 'org.laptop.sugar.DataStore'

DS_SERVICE = "org.laptop.sugar.DataStore"
DS_DBUS_INTERFACE = "org.laptop.sugar.DataStore"
DS_OBJECT_PATH = "/org/laptop/sugar/DataStore"

logger = logging.getLogger(DS_LOG_CHANNEL)


class DataStore(dbus.service.Object):
    """D-Bus API and logic for connecting all the other components.
    """

    def __init__(self, **options):
        bus_name = dbus.service.BusName(DS_SERVICE,
                                        bus=dbus.SessionBus(),
                                        replace_existing=False,
                                        allow_replacement=False)
        dbus.service.Object.__init__(self, bus_name, DS_OBJECT_PATH)

        migrated = self._migrate()

        self._metadata_store = MetadataStore()
        self._file_store = FileStore()
        self._optimizer = Optimizer(self._file_store, self._metadata_store)
        self._index_store = IndexStore()
        self._index_updating = False

        if migrated:
            self._rebuild_index()
            return

        try:
            self._index_store.open_index()
        except Exception:
            logging.exception('Failed to open index, will rebuild')
            self._rebuild_index()
            return

        if not self._index_store.index_updated:
            logging.debug('Index is not up-to-date, will update')
            self._update_index()

    def _migrate(self):
        """Check version of data store on disk and migrate if necessary.

        Returns True if migration was done and an index rebuild is required,
        False otherwise.
        """
        layout_manager = layoutmanager.get_instance()
        old_version = layout_manager.get_version()
        if old_version == layoutmanager.CURRENT_LAYOUT_VERSION:
            return False

        if old_version == 0:
            migration.migrate_from_0()

        layout_manager.set_version(layoutmanager.CURRENT_LAYOUT_VERSION)
        return True

    def _rebuild_index(self):
        """Remove and recreate index."""
        self._index_store.close_index()
        self._index_store.remove_index()
        self._index_store.open_index()
        self._update_index()

    def _update_index(self):
        """Find entries that are not yet in the index and add them."""
        uids = layoutmanager.get_instance().find_all()
        logging.debug('Going to update the index with object_ids %r',
            uids)
        self._index_updating = True
        gobject.idle_add(lambda: self.__update_index_cb(uids),
                            priority=gobject.PRIORITY_LOW)

    def __update_index_cb(self, uids):
        if uids:
            uid = uids.pop()

            logging.debug('Updating entry %r in index. %d to go.', uid,
                len(uids))

            if not self._index_store.contains(uid):
                try:
                    update_metadata = False
                    props = self._metadata_store.retrieve(uid)
                    if 'filesize' not in props:
                        path = self._file_store.get_file_path(uid)
                        if os.path.exists(path):
                            props['filesize'] = os.stat(path).st_size
                            update_metadata = True
                    if 'creation_time' not in props:
                        if 'ctime' in props:
                            try:
                                props['creation_time'] = time.mktime(
                                        time.strptime(props['ctime'],
                                            migration.DATE_FORMAT))
                            except (TypeError, ValueError):
                                pass
                        if 'creation_time' not in props:
                            props['creation_time'] = props['timestamp']
                        update_metadata = True
                    if update_metadata:
                        self._metadata_store.store(uid, props)
                    self._index_store.store(uid, props)
                except Exception:
                    logging.exception('Error processing %r', uid)

        if not uids:
            self._index_store.flush()
            self._index_updating = False
            logging.debug('Finished updating index.')
            return False
        else:
            return True

    def _create_completion_cb(self, async_cb, async_err_cb, uid, exc=None):
        logger.debug('_create_completion_cb(%r, %r, %r, %r)', async_cb,
            async_err_cb, uid, exc)
        if exc is not None:
            async_err_cb(exc)
            return

        self.Created(uid)
        self._optimizer.optimize(uid)
        logger.debug('created %s', uid)
        async_cb(uid)

    @dbus.service.method(DS_DBUS_INTERFACE,
                         in_signature='a{sv}sb',
                         out_signature='s',
                         async_callbacks=('async_cb', 'async_err_cb'),
                         byte_arrays=True)
    def create(self, props, file_path, transfer_ownership,
               async_cb, async_err_cb):
        uid = str(uuid.uuid4())
        logging.debug('datastore.create %r', uid)

        if not props.get('timestamp', ''):
            props['timestamp'] = int(time.time())

        # FIXME: Support for the deprecated ctime property. Remove in 0.92.
        if 'ctime' in props:
            try:
                props['creation_time'] = time.mktime(time.strptime(
                    migration.DATE_FORMAT, props['ctime']))
            except (TypeError, ValueError):
                pass

        if 'creation_time' not in props:
            props['creation_time'] = props['timestamp']

        if os.path.exists(file_path):
            stat = os.stat(file_path)
            props['filesize'] = stat.st_size
        else:
            props['filesize'] = 0

        self._metadata_store.store(uid, props)
        self._index_store.store(uid, props)
        self._file_store.store(uid, file_path, transfer_ownership,
                lambda *args: self._create_completion_cb(async_cb,
                                                         async_err_cb,
                                                         uid,
                                                         *args))

    @dbus.service.signal(DS_DBUS_INTERFACE, signature="s")
    def Created(self, uid):
        pass

    def _update_completion_cb(self, async_cb, async_err_cb, uid, exc=None):
        logger.debug('_update_completion_cb() called with %r / %r, exc %r',
            async_cb, async_err_cb, exc)
        if exc is not None:
            async_err_cb(exc)
            return

        self.Updated(uid)
        self._optimizer.optimize(uid)
        logger.debug('updated %s', uid)
        async_cb()

    @dbus.service.method(DS_DBUS_INTERFACE,
             in_signature='sa{sv}sb',
             out_signature='',
             async_callbacks=('async_cb', 'async_err_cb'),
             byte_arrays=True)
    def update(self, uid, props, file_path, transfer_ownership,
               async_cb, async_err_cb):
        logging.debug('datastore.update %r', uid)

        if not props.get('timestamp', ''):
            props['timestamp'] = int(time.time())

        # FIXME: Support for the deprecated ctime property. Remove in 0.92.
        if 'ctime' in props:
            try:
                props['creation_time'] = time.mktime(time.strptime(
                    migration.DATE_FORMAT, props['ctime']))
            except (TypeError, ValueError):
                pass

        if 'creation_time' not in props:
            props['creation_time'] = props['timestamp']

        if os.path.exists(file_path):
            stat = os.stat(file_path)
            props['filesize'] = stat.st_size
        else:
            props['filesize'] = 0

        self._metadata_store.store(uid, props)
        self._index_store.store(uid, props)

        if os.path.exists(self._file_store.get_file_path(uid)) and \
                (not file_path or os.path.exists(file_path)):
            self._optimizer.remove(uid)
        self._file_store.store(uid, file_path, transfer_ownership,
                lambda *args: self._update_completion_cb(async_cb,
                                                         async_err_cb,
                                                         uid,
                                                         *args))

    @dbus.service.signal(DS_DBUS_INTERFACE, signature="s")
    def Updated(self, uid):
        pass

    @dbus.service.method(DS_DBUS_INTERFACE,
             in_signature='a{sv}as',
             out_signature='aa{sv}u')
    def find(self, query, properties):
        logging.debug('datastore.find %r', query)
        t = time.time()

        if not self._index_updating:
            try:
                uids, count = self._index_store.find(query)
            except Exception:
                logging.exception('Failed to query index, will rebuild')
                self._rebuild_index()

        if self._index_updating:
            logging.warning('Index updating, returning all entries')
            return self._find_all(query, properties)

        entries = []
        for uid in uids:
            entry_path = layoutmanager.get_instance().get_entry_path(uid)
            if not os.path.exists(entry_path):
                logging.warning(
                    'Inconsistency detected, returning all entries')
                self._rebuild_index()
                return self._find_all(query, properties)

            metadata = self._metadata_store.retrieve(uid, properties)
            entries.append(metadata)

        logger.debug('find(): %r', time.time() - t)

        return entries, count

    def _find_all(self, query, properties):
        uids = layoutmanager.get_instance().find_all()
        count = len(uids)

        offset = query.get('offset', 0)
        limit = query.get('limit', MAX_QUERY_LIMIT)
        uids = uids[offset:offset + limit]

        entries = []
        for uid in uids:
            metadata = self._metadata_store.retrieve(uid, properties)
            entries.append(metadata)

        return entries, count

    @dbus.service.method(DS_DBUS_INTERFACE,
             in_signature='s',
             out_signature='s',
             sender_keyword='sender')
    def get_filename(self, uid, sender=None):
        logging.debug('datastore.get_filename %r', uid)
        user_id = dbus.Bus().get_unix_user(sender)
        extension = self._get_extension(uid)
        return self._file_store.retrieve(uid, user_id, extension)

    def _get_extension(self, uid):
        mime_type = self._metadata_store.get_property(uid, 'mime_type')
        if mime_type is None or not mime_type:
            return ''
        return mime.get_primary_extension(mime_type)

    @dbus.service.method(DS_DBUS_INTERFACE,
                         in_signature='s',
                         out_signature='a{sv}')
    def get_properties(self, uid):
        logging.debug('datastore.get_properties %r', uid)
        metadata = self._metadata_store.retrieve(uid)
        return metadata

    @dbus.service.method(DS_DBUS_INTERFACE,
                         in_signature='sa{sv}',
                         out_signature='as')
    def get_uniquevaluesfor(self, propertyname, query=None):
        if propertyname != 'activity':
            raise ValueError('Only ''activity'' is a supported property name')
        if query:
            raise ValueError('The query parameter is not supported')
        if not self._index_updating:
            return self._index_store.get_activities()
        else:
            logging.warning('Index updating, returning an empty list')
            return []

    @dbus.service.method(DS_DBUS_INTERFACE,
             in_signature='s',
             out_signature='')
    def delete(self, uid):
        self._optimizer.remove(uid)

        self._index_store.delete(uid)
        self._file_store.delete(uid)
        self._metadata_store.delete(uid)

        entry_path = layoutmanager.get_instance().get_entry_path(uid)
        os.removedirs(entry_path)

        self.Deleted(uid)
        logger.debug('deleted %s', uid)

    @dbus.service.signal(DS_DBUS_INTERFACE, signature="s")
    def Deleted(self, uid):
        pass

    def stop(self):
        """shutdown the service"""
        self._index_store.close_index()
        self.Stopped()

    @dbus.service.signal(DS_DBUS_INTERFACE)
    def Stopped(self):
        pass

    @dbus.service.method(DS_DBUS_INTERFACE,
                         in_signature="sa{sv}",
                         out_signature='s')
    def mount(self, uri, options=None):
        return ''

    @dbus.service.method(DS_DBUS_INTERFACE,
                         in_signature="",
                         out_signature="aa{sv}")
    def mounts(self):
        return [{'id': 1}]

    @dbus.service.method(DS_DBUS_INTERFACE,
                         in_signature="s",
                         out_signature="")
    def unmount(self, mountpoint_id):
        pass

    @dbus.service.signal(DS_DBUS_INTERFACE, signature="a{sv}")
    def Mounted(self, descriptior):
        pass

    @dbus.service.signal(DS_DBUS_INTERFACE, signature="a{sv}")
    def Unmounted(self, descriptor):
        pass