Monkey patch sqlite3 to use pysqlcipher.dbapi2.

1 files changed, 10 insertions, 131 deletions

diff --git a/backends/sqlcipher.py b/backends/sqlcipher.py
index a2ec9840..5d2569bf 100644
--- a/backends/sqlcipher.py
+++ b/backends/sqlcipher.py
@@ -1,30 +1,16 @@
-# Copyright 2011 Canonical Ltd.
-#
-# 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 U1DB backend that uses SQLCipher as its persistence layer."""
 
 import os
 from pysqlcipher import dbapi2
-from sqlite3 import dbapi2 as sqlite3_dbapi2
 import time
 
-from u1db.backends.sqlite_backend import (
-    SQLiteDatabase,
-    SQLitePartialExpandDatabase,
+from leap import util
+from u1db.backends import sqlite_backend
+util.logger.debug(
+    "Monkey-patching u1db.backends.sqlite_backend with pysqlcipher.dbapi2..."
 )
+sqlite_backend.dbapi2 = dbapi2
+
 from u1db import (
     errors,
 )
@@ -57,7 +43,7 @@ class DatabaseIsNotEncrypted(Exception):
     pass
 
 
-class SQLCipherDatabase(SQLitePartialExpandDatabase):
+class SQLCipherDatabase(sqlite_backend.SQLitePartialExpandDatabase):
     """A U1DB implementation that uses SQLCipher as its persistence layer."""
 
     _index_storage_value = 'expand referenced encrypted'
@@ -91,9 +77,9 @@ class SQLCipherDatabase(SQLitePartialExpandDatabase):
             try:
                 # try to open an encrypted database with the regular u1db
                 # backend should raise a DatabaseError exception.
-                SQLitePartialExpandDatabase(sqlite_file)
+                sqlite_backend.SQLitePartialExpandDatabase(sqlite_file)
                 raise DatabaseIsNotEncrypted()
-            except sqlite3_dbapi2.DatabaseError:
+            except dbapi2.DatabaseError:
                 pass
 
     @classmethod
@@ -174,111 +160,4 @@ class SQLCipherDatabase(SQLitePartialExpandDatabase):
             doc.syncable = bool(c.fetchone()[0])
         return doc
 
-    # TODO: remove methods below after solving Exception handling problem.
-    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 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, 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_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, 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, 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)")
-
-    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, e, 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)
-
-SQLiteDatabase.register_implementation(SQLCipherDatabase)
+sqlite_backend.SQLiteDatabase.register_implementation(SQLCipherDatabase)