From 8d33adfbbbd01a9a85e862ad2bd21ae45230e710 Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Mon, 2 Mar 2015 18:23:55 +0000 Subject: SYN-67: Begin changing the way we handle schema versioning --- synapse/storage/__init__.py | 144 ++++++++++++++++++++++++++++++++------------ 1 file changed, 106 insertions(+), 38 deletions(-) diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py index d6ec446bd2..a08c74fac1 100644 --- a/synapse/storage/__init__.py +++ b/synapse/storage/__init__.py @@ -45,8 +45,10 @@ from syutil.jsonutil import encode_canonical_json from synapse.crypto.event_signing import compute_event_reference_hash +import imp import logging import os +import sqlite3 logger = logging.getLogger(__name__) @@ -610,49 +612,115 @@ class UpgradeDatabaseException(PrepareDatabaseException): def prepare_database(db_conn): - """ Set up all the dbs. Since all the *.sql have IF NOT EXISTS, so we - don't have to worry about overwriting existing content. + """Prepares a database for usage. Will either create all necessary tables + or upgrade from an older schema version. """ - c = db_conn.cursor() - c.execute("PRAGMA user_version") - row = c.fetchone() + cur = db_conn.cursor() + version_info = get_schema_state(cur) - if row and row[0]: - user_version = row[0] + if version_info: + user_version, delta_files = version_info + _upgrade_existing_database(cur, user_version, delta_files) + else: + _setup_new_database(cur) + + cur.execute("PRAGMA user_version = %d" % (SCHEMA_VERSION,)) + db_conn.commit() + + cur.close() + + +def _setup_new_database(cur): + sql_script = "BEGIN TRANSACTION;\n" + for sql_loc in SCHEMAS: + logger.debug("Applying schema %r", sql_loc) + sql_script += read_schema(sql_loc) + sql_script += "\n" + sql_script += "COMMIT TRANSACTION;" + cur.executescript(sql_script) + + +def _upgrade_existing_database(cur, user_version, delta_files): + """Upgrades an existing database. + + Delta files can either be SQL stored in *.sql files, or python modules + in *.py. + + There can be multiple delta files per version. Synapse will keep track of + which delta files have been applied, and will apply any that haven't been + even if there has been no version bump. This is useful for development + where orthogonal schema changes may happen on separate branches. + """ + + if user_version > SCHEMA_VERSION: + raise ValueError( + "Cannot use this database as it is too " + + "new for the server to understand" + ) - if user_version > SCHEMA_VERSION: - raise ValueError( - "Cannot use this database as it is too " + - "new for the server to understand" + for v in range(user_version, SCHEMA_VERSION + 1): + delta_dir = os.path.join(dir_path, "schema", "delta", v) + directory_entries = os.listdir(delta_dir) + + for file_name in directory_entries: + relative_path = os.path.join(v, file_name) + if relative_path in delta_files: + continue + + absolute_path = os.path.join( + dir_path, "schema", "delta", relative_path, ) - elif user_version < SCHEMA_VERSION: - logger.info( - "Upgrading database from version %d", - user_version + root_name, ext = os.path.splitext(file_name) + if ext == ".py": + module_name = "synapse.storage.schema.v%d_%s" % ( + v, root_name + ) + with open(absolute_path) as schema_file: + module = imp.load_source( + module_name, absolute_path, schema_file + ) + module.run_upgrade(cur) + elif ext == ".sql": + with open(absolute_path) as schema_file: + delta_schema = schema_file.read() + cur.executescript(delta_schema) + else: + # Not a valid delta file. + logger.warn( + "Found directory entry that did not end in .py or" + " .sql: %s", + relative_path, + ) + continue + + # Mark as done. + cur.execute( + "INSERT INTO schema_version (version, file)" + " VALUES (?,?)", + (v, relative_path) ) - # Run every version since after the current version. - for v in range(user_version + 1, SCHEMA_VERSION + 1): - if v in (10, 14,): - raise UpgradeDatabaseException( - "No delta for version 10" - ) - sql_script = read_schema("delta/v%d" % (v,)) - c.executescript(sql_script) - db_conn.commit() - else: - logger.info("Database is at version %r", user_version) +def get_schema_state(txn): + sql = ( + "SELECT MAX(version), file FROM schema_version" + " WHERE version = (SELECT MAX(version) FROM schema_version)" + ) - else: - sql_script = "BEGIN TRANSACTION;\n" - for sql_loc in SCHEMAS: - logger.debug("Applying schema %r", sql_loc) - sql_script += read_schema(sql_loc) - sql_script += "\n" - sql_script += "COMMIT TRANSACTION;" - c.executescript(sql_script) - db_conn.commit() - c.execute("PRAGMA user_version = %d" % SCHEMA_VERSION) - - c.close() + try: + txn.execute(sql) + res = txn.fetchall() + + if res: + current_verison = max(r[0] for r in res) + applied_delta = [r[1] for r in res] + + return current_verison, applied_delta + except sqlite3.OperationalError: + txn.execute("PRAGMA user_version") + row = txn.fetchone() + if row and row[0]: + # FIXME: We need to create schema_version table! + return row[0], [] + + return None -- cgit 1.4.1