[refactor] create client _database module

4 files changed, 8 insertions, 982 deletions

diff --git a/common/src/leap/soledad/common/l2db/__init__.py b/common/src/leap/soledad/common/l2db/__init__.py
index 568897c4..ebbf546a 100644
--- a/common/src/leap/soledad/common/l2db/__init__.py
+++ b/common/src/leap/soledad/common/l2db/__init__.py
@@ -37,8 +37,8 @@ def open(path, create, document_factory=None):
         parameters as Document.__init__.
     :return: An instance of Database.
     """
-    from leap.soledad.common.l2db.backends import sqlite_backend
-    return sqlite_backend.SQLiteDatabase.open_database(
+    from leap.soledad.client._database import sqlite
+    return sqlite.SQLiteDatabase.open_database(
         path, create=create, document_factory=document_factory)
 
 
diff --git a/common/src/leap/soledad/common/l2db/backends/dbschema.sql b/common/src/leap/soledad/common/l2db/backends/dbschema.sql
deleted file mode 100644
index ae027fc5..00000000
--- a/common/src/leap/soledad/common/l2db/backends/dbschema.sql
+++ /dev/null
@@ -1,42 +0,0 @@
--- Database schema
-CREATE TABLE transaction_log (
-    generation INTEGER PRIMARY KEY AUTOINCREMENT,
-    doc_id TEXT NOT NULL,
-    transaction_id TEXT NOT NULL
-);
-CREATE TABLE document (
-    doc_id TEXT PRIMARY KEY,
-    doc_rev TEXT NOT NULL,
-    content TEXT
-);
-CREATE TABLE document_fields (
-    doc_id TEXT NOT NULL,
-    field_name TEXT NOT NULL,
-    value TEXT
-);
-CREATE INDEX document_fields_field_value_doc_idx
-    ON document_fields(field_name, value, doc_id);
-
-CREATE TABLE sync_log (
-    replica_uid TEXT PRIMARY KEY,
-    known_generation INTEGER,
-    known_transaction_id TEXT
-);
-CREATE TABLE conflicts (
-    doc_id TEXT,
-    doc_rev TEXT,
-    content TEXT,
-    CONSTRAINT conflicts_pkey PRIMARY KEY (doc_id, doc_rev)
-);
-CREATE TABLE index_definitions (
-    name TEXT,
-    offset INT,
-    field TEXT,
-    CONSTRAINT index_definitions_pkey PRIMARY KEY (name, offset)
-);
-create index index_definitions_field on index_definitions(field);
-CREATE TABLE u1db_config (
-    name TEXT PRIMARY KEY,
-    value TEXT
-);
-INSERT INTO u1db_config VALUES ('sql_schema', '0');
diff --git a/common/src/leap/soledad/common/l2db/backends/sqlite_backend.py b/common/src/leap/soledad/common/l2db/backends/sqlite_backend.py
deleted file mode 100644
index 4f7b1259..00000000
--- a/common/src/leap/soledad/common/l2db/backends/sqlite_backend.py
+++ /dev/null
@@ -1,930 +0,0 @@
-# Copyright 2011 Canonical Ltd.
-# Copyright 2016 LEAP Encryption Access Project
-#
-# This file is part of u1db.
-#
-# u1db is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3
-# as published by the Free Software Foundation.
-#
-# u1db 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 Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with u1db.  If not, see <http://www.gnu.org/licenses/>.
-
-"""
-A L2DB implementation that uses SQLite as its persistence layer.
-"""
-
-import errno
-import os
-import json
-import sys
-import time
-import uuid
-import pkg_resources
-
-from sqlite3 import dbapi2
-
-from leap.soledad.common.l2db.backends import CommonBackend, CommonSyncTarget
-from leap.soledad.common.l2db import (
-    Document, errors,
-    query_parser, vectorclock)
-
-
-class SQLiteDatabase(CommonBackend):
-    """A U1DB implementation that uses SQLite as its persistence layer."""
-
-    _sqlite_registry = {}
-
-    def __init__(self, sqlite_file, document_factory=None):
-        """Create a new sqlite file."""
-        self._db_handle = dbapi2.connect(sqlite_file)
-        self._real_replica_uid = None
-        self._ensure_schema()
-        self._factory = document_factory or Document
-
-    def set_document_factory(self, factory):
-        self._factory = factory
-
-    def get_sync_target(self):
-        return SQLiteSyncTarget(self)
-
-    @classmethod
-    def _which_index_storage(cls, c):
-        try:
-            c.execute("SELECT value FROM u1db_config"
-                      " WHERE name = 'index_storage'")
-        except dbapi2.OperationalError as e:
-            # The table does not exist yet
-            return None, e
-        else:
-            return c.fetchone()[0], None
-
-    WAIT_FOR_PARALLEL_INIT_HALF_INTERVAL = 0.5
-
-    @classmethod
-    def _open_database(cls, sqlite_file, document_factory=None):
-        if not os.path.isfile(sqlite_file):
-            raise errors.DatabaseDoesNotExist()
-        tries = 2
-        while True:
-            # Note: There seems to be a bug in sqlite 3.5.9 (with python2.6)
-            #       where without re-opening the database on Windows, it
-            #       doesn't see the transaction that was just committed
-            db_handle = dbapi2.connect(sqlite_file)
-            c = db_handle.cursor()
-            v, err = cls._which_index_storage(c)
-            db_handle.close()
-            if v is not None:
-                break
-            # possibly another process is initializing it, wait for it to be
-            # done
-            if tries == 0:
-                raise err  # go for the richest error?
-            tries -= 1
-            time.sleep(cls.WAIT_FOR_PARALLEL_INIT_HALF_INTERVAL)
-        return SQLiteDatabase._sqlite_registry[v](
-            sqlite_file, document_factory=document_factory)
-
-    @classmethod
-    def open_database(cls, sqlite_file, create, backend_cls=None,
-                      document_factory=None):
-        try:
-            return cls._open_database(
-                sqlite_file, document_factory=document_factory)
-        except errors.DatabaseDoesNotExist:
-            if not create:
-                raise
-            if backend_cls is None:
-                # default is SQLitePartialExpandDatabase
-                backend_cls = SQLitePartialExpandDatabase
-            return backend_cls(sqlite_file, document_factory=document_factory)
-
-    @staticmethod
-    def delete_database(sqlite_file):
-        try:
-            os.unlink(sqlite_file)
-        except OSError as ex:
-            if ex.errno == errno.ENOENT:
-                raise errors.DatabaseDoesNotExist()
-            raise
-
-    @staticmethod
-    def register_implementation(klass):
-        """Register that we implement an SQLiteDatabase.
-
-        The attribute _index_storage_value will be used as the lookup key.
-        """
-        SQLiteDatabase._sqlite_registry[klass._index_storage_value] = klass
-
-    def _get_sqlite_handle(self):
-        """Get access to the underlying sqlite database.
-
-        This should only be used by the test suite, etc, for examining the
-        state of the underlying database.
-        """
-        return self._db_handle
-
-    def _close_sqlite_handle(self):
-        """Release access to the underlying sqlite database."""
-        self._db_handle.close()
-
-    def close(self):
-        self._close_sqlite_handle()
-
-    def _is_initialized(self, c):
-        """Check if this database has been initialized."""
-        c.execute("PRAGMA case_sensitive_like=ON")
-        try:
-            c.execute("SELECT value FROM u1db_config"
-                      " WHERE name = 'sql_schema'")
-        except dbapi2.OperationalError:
-            # The table does not exist yet
-            val = None
-        else:
-            val = c.fetchone()
-        if val is not None:
-            return True
-        return False
-
-    def _initialize(self, c):
-        """Create the schema in the database."""
-        # read the script with sql commands
-        # TODO: Change how we set up the dependency. Most likely use something
-        #   like lp:dirspec to grab the file from a common resource
-        #   directory. Doesn't specifically need to be handled until we get
-        #   to the point of packaging this.
-        schema_content = pkg_resources.resource_string(
-            __name__, 'dbschema.sql')
-        # Note: We'd like to use c.executescript() here, but it seems that
-        #       executescript always commits, even if you set
-        #       isolation_level = None, so if we want to properly handle
-        #       exclusive locking and rollbacks between processes, we need
-        #       to execute it line-by-line
-        for line in schema_content.split(';'):
-            if not line:
-                continue
-            c.execute(line)
-        # add extra fields
-        self._extra_schema_init(c)
-        # A unique identifier should be set for this replica. Implementations
-        # don't have to strictly use uuid here, but we do want the uid to be
-        # unique amongst all databases that will sync with each other.
-        # We might extend this to using something with hostname for easier
-        # debugging.
-        self._set_replica_uid_in_transaction(uuid.uuid4().hex)
-        c.execute("INSERT INTO u1db_config VALUES" " ('index_storage', ?)",
-                  (self._index_storage_value,))
-
-    def _ensure_schema(self):
-        """Ensure that the database schema has been created."""
-        old_isolation_level = self._db_handle.isolation_level
-        c = self._db_handle.cursor()
-        if self._is_initialized(c):
-            return
-        try:
-            # autocommit/own mgmt of transactions
-            self._db_handle.isolation_level = None
-            with self._db_handle:
-                # only one execution path should initialize the db
-                c.execute("begin exclusive")
-                if self._is_initialized(c):
-                    return
-                self._initialize(c)
-        finally:
-            self._db_handle.isolation_level = old_isolation_level
-
-    def _extra_schema_init(self, c):
-        """Add any extra fields, etc to the basic table definitions."""
-
-    def _parse_index_definition(self, index_field):
-        """Parse a field definition for an index, returning a Getter."""
-        # Note: We may want to keep a Parser object around, and cache the
-        #       Getter objects for a greater length of time. Specifically, if
-        #       you create a bunch of indexes, and then insert 50k docs, you'll
-        #       re-parse the indexes between puts. The time to insert the docs
-        #       is still likely to dominate put_doc time, though.
-        parser = query_parser.Parser()
-        getter = parser.parse(index_field)
-        return getter
-
-    def _update_indexes(self, doc_id, raw_doc, getters, db_cursor):
-        """Update document_fields for a single document.
-
-        :param doc_id: Identifier for this document
-        :param raw_doc: The python dict representation of the document.
-        :param getters: A list of [(field_name, Getter)]. Getter.get will be
-            called to evaluate the index definition for this document, and the
-            results will be inserted into the db.
-        :param db_cursor: An sqlite Cursor.
-        :return: None
-        """
-        values = []
-        for field_name, getter in getters:
-            for idx_value in getter.get(raw_doc):
-                values.append((doc_id, field_name, idx_value))
-        if values:
-            db_cursor.executemany(
-                "INSERT INTO document_fields VALUES (?, ?, ?)", values)
-
-    def _set_replica_uid(self, replica_uid):
-        """Force the replica_uid to be set."""
-        with self._db_handle:
-            self._set_replica_uid_in_transaction(replica_uid)
-
-    def _set_replica_uid_in_transaction(self, replica_uid):
-        """Set the replica_uid. A transaction should already be held."""
-        c = self._db_handle.cursor()
-        c.execute("INSERT OR REPLACE INTO u1db_config"
-                  " VALUES ('replica_uid', ?)",
-                  (replica_uid,))
-        self._real_replica_uid = replica_uid
-
-    def _get_replica_uid(self):
-        if self._real_replica_uid is not None:
-            return self._real_replica_uid
-        c = self._db_handle.cursor()
-        c.execute("SELECT value FROM u1db_config WHERE name = 'replica_uid'")
-        val = c.fetchone()
-        if val is None:
-            return None
-        self._real_replica_uid = val[0]
-        return self._real_replica_uid
-
-    _replica_uid = property(_get_replica_uid)
-
-    def _get_generation(self):
-        c = self._db_handle.cursor()
-        c.execute('SELECT max(generation) FROM transaction_log')
-        val = c.fetchone()[0]
-        if val is None:
-            return 0
-        return val
-
-    def _get_generation_info(self):
-        c = self._db_handle.cursor()
-        c.execute(
-            'SELECT max(generation), transaction_id FROM transaction_log ')
-        val = c.fetchone()
-        if val[0] is None:
-            return(0, '')
-        return val
-
-    def _get_trans_id_for_gen(self, generation):
-        if generation == 0:
-            return ''
-        c = self._db_handle.cursor()
-        c.execute(
-            'SELECT transaction_id FROM transaction_log WHERE generation = ?',
-            (generation,))
-        val = c.fetchone()
-        if val is None:
-            raise errors.InvalidGeneration
-        return val[0]
-
-    def _get_transaction_log(self):
-        c = self._db_handle.cursor()
-        c.execute("SELECT doc_id, transaction_id FROM transaction_log"
-                  " ORDER BY generation")
-        return c.fetchall()
-
-    def _get_doc(self, doc_id, check_for_conflicts=False):
-        """Get just the document content, without fancy handling."""
-        c = self._db_handle.cursor()
-        if check_for_conflicts:
-            c.execute(
-                "SELECT document.doc_rev, document.content, "
-                "count(conflicts.doc_rev) FROM document LEFT OUTER JOIN "
-                "conflicts ON conflicts.doc_id = document.doc_id WHERE "
-                "document.doc_id = ? GROUP BY document.doc_id, "
-                "document.doc_rev, document.content;", (doc_id,))
-        else:
-            c.execute(
-                "SELECT doc_rev, content, 0 FROM document WHERE doc_id = ?",
-                (doc_id,))
-        val = c.fetchone()
-        if val is None:
-            return None
-        doc_rev, content, conflicts = val
-        doc = self._factory(doc_id, doc_rev, content)
-        doc.has_conflicts = conflicts > 0
-        return doc
-
-    def _has_conflicts(self, doc_id):
-        c = self._db_handle.cursor()
-        c.execute("SELECT 1 FROM conflicts WHERE doc_id = ? LIMIT 1",
-                  (doc_id,))
-        val = c.fetchone()
-        if val is None:
-            return False
-        else:
-            return True
-
-    def get_doc(self, doc_id, include_deleted=False):
-        doc = self._get_doc(doc_id, check_for_conflicts=True)
-        if doc is None:
-            return None
-        if doc.is_tombstone() and not include_deleted:
-            return None
-        return doc
-
-    def get_all_docs(self, include_deleted=False):
-        """Get all documents from the database."""
-        generation = self._get_generation()
-        results = []
-        c = self._db_handle.cursor()
-        c.execute(
-            "SELECT document.doc_id, document.doc_rev, document.content, "
-            "count(conflicts.doc_rev) FROM document LEFT OUTER JOIN conflicts "
-            "ON conflicts.doc_id = document.doc_id GROUP BY document.doc_id, "
-            "document.doc_rev, document.content;")
-        rows = c.fetchall()
-        for doc_id, doc_rev, content, conflicts in rows:
-            if content is None and not include_deleted:
-                continue
-            doc = self._factory(doc_id, doc_rev, content)
-            doc.has_conflicts = conflicts > 0
-            results.append(doc)
-        return (generation, results)
-
-    def put_doc(self, doc):
-        if doc.doc_id is None:
-            raise errors.InvalidDocId()
-        self._check_doc_id(doc.doc_id)
-        self._check_doc_size(doc)
-        with self._db_handle:
-            old_doc = self._get_doc(doc.doc_id, check_for_conflicts=True)
-            if old_doc and old_doc.has_conflicts:
-                raise errors.ConflictedDoc()
-            if old_doc and doc.rev is None and old_doc.is_tombstone():
-                new_rev = self._allocate_doc_rev(old_doc.rev)
-            else:
-                if old_doc is not None:
-                        if old_doc.rev != doc.rev:
-                            raise errors.RevisionConflict()
-                else:
-                    if doc.rev is not None:
-                        raise errors.RevisionConflict()
-                new_rev = self._allocate_doc_rev(doc.rev)
-            doc.rev = new_rev
-            self._put_and_update_indexes(old_doc, doc)
-        return new_rev
-
-    def _expand_to_fields(self, doc_id, base_field, raw_doc, save_none):
-        """Convert a dict representation into named fields.
-
-        So something like: {'key1': 'val1', 'key2': 'val2'}
-        gets converted into: [(doc_id, 'key1', 'val1', 0)
-                              (doc_id, 'key2', 'val2', 0)]
-        :param doc_id: Just added to every record.
-        :param base_field: if set, these are nested keys, so each field should
-            be appropriately prefixed.
-        :param raw_doc: The python dictionary.
-        """
-        # TODO: Handle lists
-        values = []
-        for field_name, value in raw_doc.iteritems():
-            if value is None and not save_none:
-                continue
-            if base_field:
-                full_name = base_field + '.' + field_name
-            else:
-                full_name = field_name
-            if value is None or isinstance(value, (int, float, basestring)):
-                values.append((doc_id, full_name, value, len(values)))
-            else:
-                subvalues = self._expand_to_fields(doc_id, full_name, value,
-                                                   save_none)
-                for _, subfield_name, val, _ in subvalues:
-                    values.append((doc_id, subfield_name, val, len(values)))
-        return values
-
-    def _put_and_update_indexes(self, old_doc, doc):
-        """Actually insert a document into the database.
-
-        This both updates the existing documents content, and any indexes that
-        refer to this document.
-        """
-        raise NotImplementedError(self._put_and_update_indexes)
-
-    def whats_changed(self, old_generation=0):
-        c = self._db_handle.cursor()
-        c.execute("SELECT generation, doc_id, transaction_id"
-                  " FROM transaction_log"
-                  " WHERE generation > ? ORDER BY generation DESC",
-                  (old_generation,))
-        results = c.fetchall()
-        cur_gen = old_generation
-        seen = set()
-        changes = []
-        newest_trans_id = ''
-        for generation, doc_id, trans_id in results:
-            if doc_id not in seen:
-                changes.append((doc_id, generation, trans_id))
-                seen.add(doc_id)
-        if changes:
-            cur_gen = changes[0][1]  # max generation
-            newest_trans_id = changes[0][2]
-            changes.reverse()
-        else:
-            c.execute("SELECT generation, transaction_id"
-                      " FROM transaction_log ORDER BY generation DESC LIMIT 1")
-            results = c.fetchone()
-            if not results:
-                cur_gen = 0
-                newest_trans_id = ''
-            else:
-                cur_gen, newest_trans_id = results
-
-        return cur_gen, newest_trans_id, changes
-
-    def delete_doc(self, doc):
-        with self._db_handle:
-            old_doc = self._get_doc(doc.doc_id, check_for_conflicts=True)
-            if old_doc is None:
-                raise errors.DocumentDoesNotExist
-            if old_doc.rev != doc.rev:
-                raise errors.RevisionConflict()
-            if old_doc.is_tombstone():
-                raise errors.DocumentAlreadyDeleted
-            if old_doc.has_conflicts:
-                raise errors.ConflictedDoc()
-            new_rev = self._allocate_doc_rev(doc.rev)
-            doc.rev = new_rev
-            doc.make_tombstone()
-            self._put_and_update_indexes(old_doc, doc)
-        return new_rev
-
-    def _get_conflicts(self, doc_id):
-        c = self._db_handle.cursor()
-        c.execute("SELECT doc_rev, content FROM conflicts WHERE doc_id = ?",
-                  (doc_id,))
-        return [self._factory(doc_id, doc_rev, content)
-                for doc_rev, content in c.fetchall()]
-
-    def get_doc_conflicts(self, doc_id):
-        with self._db_handle:
-            conflict_docs = self._get_conflicts(doc_id)
-            if not conflict_docs:
-                return []
-            this_doc = self._get_doc(doc_id)
-            this_doc.has_conflicts = True
-            return [this_doc] + conflict_docs
-
-    def _get_replica_gen_and_trans_id(self, other_replica_uid):
-        c = self._db_handle.cursor()
-        c.execute("SELECT known_generation, known_transaction_id FROM sync_log"
-                  " WHERE replica_uid = ?",
-                  (other_replica_uid,))
-        val = c.fetchone()
-        if val is None:
-            other_gen = 0
-            trans_id = ''
-        else:
-            other_gen = val[0]
-            trans_id = val[1]
-        return other_gen, trans_id
-
-    def _set_replica_gen_and_trans_id(self, other_replica_uid,
-                                      other_generation, other_transaction_id):
-        with self._db_handle:
-            self._do_set_replica_gen_and_trans_id(
-                other_replica_uid, other_generation, other_transaction_id)
-
-    def _do_set_replica_gen_and_trans_id(self, other_replica_uid,
-                                         other_generation,
-                                         other_transaction_id):
-            c = self._db_handle.cursor()
-            c.execute("INSERT OR REPLACE INTO sync_log VALUES (?, ?, ?)",
-                      (other_replica_uid, other_generation,
-                       other_transaction_id))
-
-    def _put_doc_if_newer(self, doc, save_conflict, replica_uid=None,
-                          replica_gen=None, replica_trans_id=None):
-        return super(SQLiteDatabase, self)._put_doc_if_newer(
-            doc,
-            save_conflict=save_conflict,
-            replica_uid=replica_uid, replica_gen=replica_gen,
-            replica_trans_id=replica_trans_id)
-
-    def _add_conflict(self, c, doc_id, my_doc_rev, my_content):
-        c.execute("INSERT INTO conflicts VALUES (?, ?, ?)",
-                  (doc_id, my_doc_rev, my_content))
-
-    def _delete_conflicts(self, c, doc, conflict_revs):
-        deleting = [(doc.doc_id, c_rev) for c_rev in conflict_revs]
-        c.executemany("DELETE FROM conflicts"
-                      " WHERE doc_id=? AND doc_rev=?", deleting)
-        doc.has_conflicts = self._has_conflicts(doc.doc_id)
-
-    def _prune_conflicts(self, doc, doc_vcr):
-        if self._has_conflicts(doc.doc_id):
-            autoresolved = False
-            c_revs_to_prune = []
-            for c_doc in self._get_conflicts(doc.doc_id):
-                c_vcr = vectorclock.VectorClockRev(c_doc.rev)
-                if doc_vcr.is_newer(c_vcr):
-                    c_revs_to_prune.append(c_doc.rev)
-                elif doc.same_content_as(c_doc):
-                    c_revs_to_prune.append(c_doc.rev)
-                    doc_vcr.maximize(c_vcr)
-                    autoresolved = True
-            if autoresolved:
-                doc_vcr.increment(self._replica_uid)
-                doc.rev = doc_vcr.as_str()
-            c = self._db_handle.cursor()
-            self._delete_conflicts(c, doc, c_revs_to_prune)
-
-    def _force_doc_sync_conflict(self, doc):
-        my_doc = self._get_doc(doc.doc_id)
-        c = self._db_handle.cursor()
-        self._prune_conflicts(doc, vectorclock.VectorClockRev(doc.rev))
-        self._add_conflict(c, doc.doc_id, my_doc.rev, my_doc.get_json())
-        doc.has_conflicts = True
-        self._put_and_update_indexes(my_doc, doc)
-
-    def resolve_doc(self, doc, conflicted_doc_revs):
-        with self._db_handle:
-            cur_doc = self._get_doc(doc.doc_id)
-            # TODO: https://bugs.launchpad.net/u1db/+bug/928274
-            #       I think we have a logic bug in resolve_doc
-            #       Specifically, cur_doc.rev is always in the final vector
-            #       clock of revisions that we supersede, even if it wasn't in
-            #       conflicted_doc_revs. We still add it as a conflict, but the
-            #       fact that _put_doc_if_newer propagates resolutions means I
-            #       think that conflict could accidentally be resolved. We need
-            #       to add a test for this case first. (create a rev, create a
-            #       conflict, create another conflict, resolve the first rev
-            #       and first conflict, then make sure that the resolved
-            #       rev doesn't supersede the second conflict rev.) It *might*
-            #       not matter, because the superseding rev is in as a
-            #       conflict, but it does seem incorrect
-            new_rev = self._ensure_maximal_rev(cur_doc.rev,
-                                               conflicted_doc_revs)
-            superseded_revs = set(conflicted_doc_revs)
-            c = self._db_handle.cursor()
-            doc.rev = new_rev
-            if cur_doc.rev in superseded_revs:
-                self._put_and_update_indexes(cur_doc, doc)
-            else:
-                self._add_conflict(c, doc.doc_id, new_rev, doc.get_json())
-            # TODO: Is there some way that we could construct a rev that would
-            #       end up in superseded_revs, such that we add a conflict, and
-            #       then immediately delete it?
-            self._delete_conflicts(c, doc, superseded_revs)
-
-    def list_indexes(self):
-        """Return the list of indexes and their definitions."""
-        c = self._db_handle.cursor()
-        # TODO: How do we test the ordering?
-        c.execute("SELECT name, field FROM index_definitions"
-                  " ORDER BY name, offset")
-        definitions = []
-        cur_name = None
-        for name, field in c.fetchall():
-            if cur_name != name:
-                definitions.append((name, []))
-                cur_name = name
-            definitions[-1][-1].append(field)
-        return definitions
-
-    def _get_index_definition(self, index_name):
-        """Return the stored definition for a given index_name."""
-        c = self._db_handle.cursor()
-        c.execute("SELECT field FROM index_definitions"
-                  " WHERE name = ? ORDER BY offset", (index_name,))
-        fields = [x[0] for x in c.fetchall()]
-        if not fields:
-            raise errors.IndexDoesNotExist
-        return fields
-
-    @staticmethod
-    def _strip_glob(value):
-        """Remove the trailing * from a value."""
-        assert value[-1] == '*'
-        return value[:-1]
-
-    def _format_query(self, definition, key_values):
-        # First, build the definition. We join the document_fields table
-        # against itself, as many times as the 'width' of our definition.
-        # We then do a query for each key_value, one-at-a-time.
-        # Note: All of these strings are static, we could cache them, etc.
-        tables = ["document_fields d%d" % i for i in range(len(definition))]
-        novalue_where = ["d.doc_id = d%d.doc_id"
-                         " AND d%d.field_name = ?"
-                         % (i, i) for i in range(len(definition))]
-        wildcard_where = [novalue_where[i] +
-                          (" AND d%d.value NOT NULL" % (i,))
-                          for i in range(len(definition))]
-        exact_where = [novalue_where[i] +
-                       (" AND d%d.value = ?" % (i,))
-                       for i in range(len(definition))]
-        like_where = [novalue_where[i] +
-                      (" AND d%d.value GLOB ?" % (i,))
-                      for i in range(len(definition))]
-        is_wildcard = False
-        # Merge the lists together, so that:
-        # [field1, field2, field3], [val1, val2, val3]
-        # Becomes:
-        # (field1, val1, field2, val2, field3, val3)
-        args = []
-        where = []
-        for idx, (field, value) in enumerate(zip(definition, key_values)):
-            args.append(field)
-            if value.endswith('*'):
-                if value == '*':
-                    where.append(wildcard_where[idx])
-                else:
-                    # This is a glob match
-                    if is_wildcard:
-                        # We can't have a partial wildcard following
-                        # another wildcard
-                        raise errors.InvalidGlobbing
-                    where.append(like_where[idx])
-                    args.append(value)
-                is_wildcard = True
-            else:
-                if is_wildcard:
-                    raise errors.InvalidGlobbing
-                where.append(exact_where[idx])
-                args.append(value)
-        statement = (
-            "SELECT d.doc_id, d.doc_rev, d.content, count(c.doc_rev) FROM "
-            "document d, %s LEFT OUTER JOIN conflicts c ON c.doc_id = "
-            "d.doc_id WHERE %s GROUP BY d.doc_id, d.doc_rev, d.content ORDER "
-            "BY %s;" % (', '.join(tables), ' AND '.join(where), ', '.join(
-                ['d%d.value' % i for i in range(len(definition))])))
-        return statement, args
-
-    def get_from_index(self, index_name, *key_values):
-        definition = self._get_index_definition(index_name)
-        if len(key_values) != len(definition):
-            raise errors.InvalidValueForIndex()
-        statement, args = self._format_query(definition, key_values)
-        c = self._db_handle.cursor()
-        try:
-            c.execute(statement, tuple(args))
-        except dbapi2.OperationalError as e:
-            raise dbapi2.OperationalError(
-                str(e) +
-                '\nstatement: %s\nargs: %s\n' % (statement, args))
-        res = c.fetchall()
-        results = []
-        for row in res:
-            doc = self._factory(row[0], row[1], row[2])
-            doc.has_conflicts = row[3] > 0
-            results.append(doc)
-        return results
-
-    def _format_range_query(self, definition, start_value, end_value):
-        tables = ["document_fields d%d" % i for i in range(len(definition))]
-        novalue_where = [
-            "d.doc_id = d%d.doc_id AND d%d.field_name = ?" % (i, i) for i in
-            range(len(definition))]
-        wildcard_where = [
-            novalue_where[i] + (" AND d%d.value NOT NULL" % (i,)) for i in
-            range(len(definition))]
-        like_where = [
-            novalue_where[i] + (
-                " AND (d%d.value < ? OR d%d.value GLOB ?)" % (i, i)) for i in
-            range(len(definition))]
-        range_where_lower = [
-            novalue_where[i] + (" AND d%d.value >= ?" % (i,)) for i in
-            range(len(definition))]
-        range_where_upper = [
-            novalue_where[i] + (" AND d%d.value <= ?" % (i,)) for i in
-            range(len(definition))]
-        args = []
-        where = []
-        if start_value:
-            if isinstance(start_value, basestring):
-                start_value = (start_value,)
-            if len(start_value) != len(definition):
-                raise errors.InvalidValueForIndex()
-            is_wildcard = False
-            for idx, (field, value) in enumerate(zip(definition, start_value)):
-                args.append(field)
-                if value.endswith('*'):
-                    if value == '*':
-                        where.append(wildcard_where[idx])
-                    else:
-                        # This is a glob match
-                        if is_wildcard:
-                            # We can't have a partial wildcard following
-                            # another wildcard
-                            raise errors.InvalidGlobbing
-                        where.append(range_where_lower[idx])
-                        args.append(self._strip_glob(value))
-                    is_wildcard = True
-                else:
-                    if is_wildcard:
-                        raise errors.InvalidGlobbing
-                    where.append(range_where_lower[idx])
-                    args.append(value)
-        if end_value:
-            if isinstance(end_value, basestring):
-                end_value = (end_value,)
-            if len(end_value) != len(definition):
-                raise errors.InvalidValueForIndex()
-            is_wildcard = False
-            for idx, (field, value) in enumerate(zip(definition, end_value)):
-                args.append(field)
-                if value.endswith('*'):
-                    if value == '*':
-                        where.append(wildcard_where[idx])
-                    else:
-                        # This is a glob match
-                        if is_wildcard:
-                            # We can't have a partial wildcard following
-                            # another wildcard
-                            raise errors.InvalidGlobbing
-                        where.append(like_where[idx])
-                        args.append(self._strip_glob(value))
-                        args.append(value)
-                    is_wildcard = True
-                else:
-                    if is_wildcard:
-                        raise errors.InvalidGlobbing
-                    where.append(range_where_upper[idx])
-                    args.append(value)
-        statement = (
-            "SELECT d.doc_id, d.doc_rev, d.content, count(c.doc_rev) FROM "
-            "document d, %s LEFT OUTER JOIN conflicts c ON c.doc_id = "
-            "d.doc_id WHERE %s GROUP BY d.doc_id, d.doc_rev, d.content ORDER "
-            "BY %s;" % (', '.join(tables), ' AND '.join(where), ', '.join(
-                ['d%d.value' % i for i in range(len(definition))])))
-        return statement, args
-
-    def get_range_from_index(self, index_name, start_value=None,
-                             end_value=None):
-        """Return all documents with key values in the specified range."""
-        definition = self._get_index_definition(index_name)
-        statement, args = self._format_range_query(
-            definition, start_value, end_value)
-        c = self._db_handle.cursor()
-        try:
-            c.execute(statement, tuple(args))
-        except dbapi2.OperationalError as e:
-            raise dbapi2.OperationalError(
-                str(e) +
-                '\nstatement: %s\nargs: %s\n' % (statement, args))
-        res = c.fetchall()
-        results = []
-        for row in res:
-            doc = self._factory(row[0], row[1], row[2])
-            doc.has_conflicts = row[3] > 0
-            results.append(doc)
-        return results
-
-    def get_index_keys(self, index_name):
-        c = self._db_handle.cursor()
-        definition = self._get_index_definition(index_name)
-        value_fields = ', '.join([
-            'd%d.value' % i for i in range(len(definition))])
-        tables = ["document_fields d%d" % i for i in range(len(definition))]
-        novalue_where = [
-            "d.doc_id = d%d.doc_id AND d%d.field_name = ?" % (i, i) for i in
-            range(len(definition))]
-        where = [
-            novalue_where[i] + (" AND d%d.value NOT NULL" % (i,)) for i in
-            range(len(definition))]
-        statement = (
-            "SELECT %s FROM document d, %s WHERE %s GROUP BY %s;" % (
-                value_fields, ', '.join(tables), ' AND '.join(where),
-                value_fields))
-        try:
-            c.execute(statement, tuple(definition))
-        except dbapi2.OperationalError as e:
-            raise dbapi2.OperationalError(
-                str(e) +
-                '\nstatement: %s\nargs: %s\n' % (statement, tuple(definition)))
-        return c.fetchall()
-
-    def delete_index(self, index_name):
-        with self._db_handle:
-            c = self._db_handle.cursor()
-            c.execute("DELETE FROM index_definitions WHERE name = ?",
-                      (index_name,))
-            c.execute(
-                "DELETE FROM document_fields WHERE document_fields.field_name "
-                " NOT IN (SELECT field from index_definitions)")
-
-
-class SQLiteSyncTarget(CommonSyncTarget):
-
-    def get_sync_info(self, source_replica_uid):
-        source_gen, source_trans_id = self._db._get_replica_gen_and_trans_id(
-            source_replica_uid)
-        my_gen, my_trans_id = self._db._get_generation_info()
-        return (
-            self._db._replica_uid, my_gen, my_trans_id, source_gen,
-            source_trans_id)
-
-    def record_sync_info(self, source_replica_uid, source_replica_generation,
-                         source_replica_transaction_id):
-        if self._trace_hook:
-            self._trace_hook('record_sync_info')
-        self._db._set_replica_gen_and_trans_id(
-            source_replica_uid, source_replica_generation,
-            source_replica_transaction_id)
-
-
-class SQLitePartialExpandDatabase(SQLiteDatabase):
-    """An SQLite Backend that expands documents into a document_field table.
-
-    It stores the original document text in document.doc. For fields that are
-    indexed, the data goes into document_fields.
-    """
-
-    _index_storage_value = 'expand referenced'
-
-    def _get_indexed_fields(self):
-        """Determine what fields are indexed."""
-        c = self._db_handle.cursor()
-        c.execute("SELECT field FROM index_definitions")
-        return set([x[0] for x in c.fetchall()])
-
-    def _evaluate_index(self, raw_doc, field):
-        parser = query_parser.Parser()
-        getter = parser.parse(field)
-        return getter.get(raw_doc)
-
-    def _put_and_update_indexes(self, old_doc, doc):
-        c = self._db_handle.cursor()
-        if doc and not doc.is_tombstone():
-            raw_doc = json.loads(doc.get_json())
-        else:
-            raw_doc = {}
-        if old_doc is not None:
-            c.execute("UPDATE document SET doc_rev=?, content=?"
-                      " WHERE doc_id = ?",
-                      (doc.rev, doc.get_json(), doc.doc_id))
-            c.execute("DELETE FROM document_fields WHERE doc_id = ?",
-                      (doc.doc_id,))
-        else:
-            c.execute("INSERT INTO document (doc_id, doc_rev, content)"
-                      " VALUES (?, ?, ?)",
-                      (doc.doc_id, doc.rev, doc.get_json()))
-        indexed_fields = self._get_indexed_fields()
-        if indexed_fields:
-            # It is expected that len(indexed_fields) is shorter than
-            # len(raw_doc)
-            getters = [(field, self._parse_index_definition(field))
-                       for field in indexed_fields]
-            self._update_indexes(doc.doc_id, raw_doc, getters, c)
-        trans_id = self._allocate_transaction_id()
-        c.execute("INSERT INTO transaction_log(doc_id, transaction_id)"
-                  " VALUES (?, ?)", (doc.doc_id, trans_id))
-
-    def create_index(self, index_name, *index_expressions):
-        with self._db_handle:
-            c = self._db_handle.cursor()
-            cur_fields = self._get_indexed_fields()
-            definition = [(index_name, idx, field)
-                          for idx, field in enumerate(index_expressions)]
-            try:
-                c.executemany("INSERT INTO index_definitions VALUES (?, ?, ?)",
-                              definition)
-            except dbapi2.IntegrityError as e:
-                stored_def = self._get_index_definition(index_name)
-                if stored_def == [x[-1] for x in definition]:
-                    return
-                raise errors.IndexNameTakenError(
-                    str(e) +
-                    str(sys.exc_info()[2])
-                )
-            new_fields = set(
-                [f for f in index_expressions if f not in cur_fields])
-            if new_fields:
-                self._update_all_indexes(new_fields)
-
-    def _iter_all_docs(self):
-        c = self._db_handle.cursor()
-        c.execute("SELECT doc_id, content FROM document")
-        while True:
-            next_rows = c.fetchmany()
-            if not next_rows:
-                break
-            for row in next_rows:
-                yield row
-
-    def _update_all_indexes(self, new_fields):
-        """Iterate all the documents, and add content to document_fields.
-
-        :param new_fields: The index definitions that need to be added.
-        """
-        getters = [(field, self._parse_index_definition(field))
-                   for field in new_fields]
-        c = self._db_handle.cursor()
-        for doc_id, doc in self._iter_all_docs():
-            if doc is None:
-                continue
-            raw_doc = json.loads(doc)
-            self._update_indexes(doc_id, raw_doc, getters, c)
-
-
-SQLiteDatabase.register_implementation(SQLitePartialExpandDatabase)
diff --git a/common/src/leap/soledad/common/l2db/remote/server_state.py b/common/src/leap/soledad/common/l2db/remote/server_state.py
index e20b4679..89ac5742 100644
--- a/common/src/leap/soledad/common/l2db/remote/server_state.py
+++ b/common/src/leap/soledad/common/l2db/remote/server_state.py
@@ -42,10 +42,9 @@ class ServerState(object):
 
     def open_database(self, path):
         """Open a database at the given location."""
-        from u1db.backends import sqlite_backend
+        from leap.soledad.client._database import sqlite
         full_path = self._relpath(path)
-        return sqlite_backend.SQLiteDatabase.open_database(full_path,
-                                                           create=False)
+        return sqlite.SQLiteDatabase.open_database(full_path, create=False)
 
     def check_database(self, path):
         """Check if the database at the given location exists.
@@ -57,14 +56,13 @@ class ServerState(object):
 
     def ensure_database(self, path):
         """Ensure database at the given location."""
-        from u1db.backends import sqlite_backend
+        from leap.soledad.client._database import sqlite
         full_path = self._relpath(path)
-        db = sqlite_backend.SQLiteDatabase.open_database(full_path,
-                                                         create=True)
+        db = sqlite.SQLiteDatabase.open_database(full_path, create=True)
         return db, db._replica_uid
 
     def delete_database(self, path):
         """Delete database at the given location."""
-        from u1db.backends import sqlite_backend
+        from leap.soledad.client._database import sqlite
         full_path = self._relpath(path)
-        sqlite_backend.SQLiteDatabase.delete_database(full_path)
+        sqlite.SQLiteDatabase.delete_database(full_path)