699 lines
24 KiB
Python
699 lines
24 KiB
Python
# Copyright 2014 - 2021 The Matrix.org Foundation C.I.C.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import importlib.util
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import logging
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import os
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import re
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from collections import Counter
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from typing import Collection, Generator, Iterable, List, Optional, TextIO, Tuple
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import attr
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from typing_extensions import Counter as CounterType
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from synapse.config.homeserver import HomeServerConfig
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from synapse.storage.database import LoggingDatabaseConnection
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from synapse.storage.engines import BaseDatabaseEngine
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from synapse.storage.engines.postgres import PostgresEngine
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from synapse.storage.schema import SCHEMA_COMPAT_VERSION, SCHEMA_VERSION
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from synapse.storage.types import Cursor
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logger = logging.getLogger(__name__)
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schema_path = os.path.join(os.path.abspath(os.path.dirname(__file__)), "schema")
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class PrepareDatabaseException(Exception):
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pass
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class UpgradeDatabaseException(PrepareDatabaseException):
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pass
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OUTDATED_SCHEMA_ON_WORKER_ERROR = (
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"Expected database schema version %i but got %i: run the main synapse process to "
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"upgrade the database schema before starting worker processes."
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)
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EMPTY_DATABASE_ON_WORKER_ERROR = (
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"Uninitialised database: run the main synapse process to prepare the database "
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"schema before starting worker processes."
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)
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UNAPPLIED_DELTA_ON_WORKER_ERROR = (
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"Database schema delta %s has not been applied: run the main synapse process to "
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"upgrade the database schema before starting worker processes."
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)
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@attr.s
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class _SchemaState:
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current_version: int = attr.ib()
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"""The current schema version of the database"""
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compat_version: Optional[int] = attr.ib()
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"""The SCHEMA_VERSION of the oldest version of Synapse for this database
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If this is None, we have an old version of the database without the necessary
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table.
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"""
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applied_deltas: Collection[str] = attr.ib(factory=tuple)
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"""Any delta files for `current_version` which have already been applied"""
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upgraded: bool = attr.ib(default=False)
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"""Whether the current state was reached by applying deltas.
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If False, we have run the full schema for `current_version`, and have applied no
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deltas since. If True, we have run some deltas since the original creation."""
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def prepare_database(
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db_conn: LoggingDatabaseConnection,
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database_engine: BaseDatabaseEngine,
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config: Optional[HomeServerConfig],
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databases: Collection[str] = ("main", "state"),
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):
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"""Prepares a physical database for usage. Will either create all necessary tables
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or upgrade from an older schema version.
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If `config` is None then prepare_database will assert that no upgrade is
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necessary, *or* will create a fresh database if the database is empty.
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Args:
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db_conn:
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database_engine:
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config :
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application config, or None if we are connecting to an existing
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database which we expect to be configured already
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databases: The name of the databases that will be used
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with this physical database. Defaults to all databases.
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"""
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try:
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cur = db_conn.cursor(txn_name="prepare_database")
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# sqlite does not automatically start transactions for DDL / SELECT statements,
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# so we start one before running anything. This ensures that any upgrades
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# are either applied completely, or not at all.
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#
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# (psycopg2 automatically starts a transaction as soon as we run any statements
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# at all, so this is redundant but harmless there.)
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cur.execute("BEGIN TRANSACTION")
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logger.info("%r: Checking existing schema version", databases)
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version_info = _get_or_create_schema_state(cur, database_engine)
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if version_info:
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logger.info(
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"%r: Existing schema is %i (+%i deltas)",
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databases,
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version_info.current_version,
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len(version_info.applied_deltas),
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)
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# config should only be None when we are preparing an in-memory SQLite db,
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# which should be empty.
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if config is None:
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raise ValueError(
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"config==None in prepare_database, but database is not empty"
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)
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# if it's a worker app, refuse to upgrade the database, to avoid multiple
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# workers doing it at once.
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if (
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config.worker_app is not None
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and version_info.current_version != SCHEMA_VERSION
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):
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raise UpgradeDatabaseException(
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OUTDATED_SCHEMA_ON_WORKER_ERROR
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% (SCHEMA_VERSION, version_info.current_version)
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)
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_upgrade_existing_database(
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cur,
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version_info,
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database_engine,
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config,
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databases=databases,
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)
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else:
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logger.info("%r: Initialising new database", databases)
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# if it's a worker app, refuse to upgrade the database, to avoid multiple
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# workers doing it at once.
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if config and config.worker_app is not None:
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raise UpgradeDatabaseException(EMPTY_DATABASE_ON_WORKER_ERROR)
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_setup_new_database(cur, database_engine, databases=databases)
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# check if any of our configured dynamic modules want a database
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if config is not None:
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_apply_module_schemas(cur, database_engine, config)
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cur.close()
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db_conn.commit()
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except Exception:
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db_conn.rollback()
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raise
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def _setup_new_database(
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cur: Cursor, database_engine: BaseDatabaseEngine, databases: Collection[str]
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) -> None:
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"""Sets up the physical database by finding a base set of "full schemas" and
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then applying any necessary deltas, including schemas from the given data
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stores.
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The "full_schemas" directory has subdirectories named after versions. This
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function searches for the highest version less than or equal to
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`SCHEMA_VERSION` and executes all .sql files in that directory.
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The function will then apply all deltas for all versions after the base
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version.
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Example directory structure:
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schema/
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common/
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delta/
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...
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full_schemas/
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11/
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foo.sql
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main/
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delta/
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...
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full_schemas/
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3/
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test.sql
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...
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11/
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bar.sql
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...
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In the example foo.sql and bar.sql would be run, and then any delta files
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for versions strictly greater than 11.
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Note: we apply the full schemas and deltas from the `schema/common`
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folder as well those in the databases specified.
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Args:
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cur: a database cursor
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database_engine
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databases: The names of the databases to instantiate on the given physical database.
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"""
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# We're about to set up a brand new database so we check that its
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# configured to our liking.
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database_engine.check_new_database(cur)
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full_schemas_dir = os.path.join(schema_path, "common", "full_schemas")
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# First we find the highest full schema version we have
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valid_versions = []
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for filename in os.listdir(full_schemas_dir):
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try:
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ver = int(filename)
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except ValueError:
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continue
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if ver <= SCHEMA_VERSION:
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valid_versions.append(ver)
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if not valid_versions:
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raise PrepareDatabaseException(
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"Could not find a suitable base set of full schemas"
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)
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max_current_ver = max(valid_versions)
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logger.debug("Initialising schema v%d", max_current_ver)
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# Now let's find all the full schema files, both in the common schema and
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# in database schemas.
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directories = [os.path.join(full_schemas_dir, str(max_current_ver))]
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directories.extend(
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os.path.join(
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schema_path,
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database,
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"full_schemas",
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str(max_current_ver),
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)
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for database in databases
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)
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directory_entries: List[_DirectoryListing] = []
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for directory in directories:
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directory_entries.extend(
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_DirectoryListing(file_name, os.path.join(directory, file_name))
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for file_name in os.listdir(directory)
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)
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if isinstance(database_engine, PostgresEngine):
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specific = "postgres"
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else:
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specific = "sqlite"
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directory_entries.sort()
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for entry in directory_entries:
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if entry.file_name.endswith(".sql") or entry.file_name.endswith(
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".sql." + specific
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):
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logger.debug("Applying schema %s", entry.absolute_path)
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executescript(cur, entry.absolute_path)
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cur.execute(
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"INSERT INTO schema_version (version, upgraded) VALUES (?,?)",
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(max_current_ver, False),
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)
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_upgrade_existing_database(
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cur,
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_SchemaState(current_version=max_current_ver, compat_version=None),
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database_engine=database_engine,
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config=None,
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databases=databases,
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is_empty=True,
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)
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def _upgrade_existing_database(
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cur: Cursor,
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current_schema_state: _SchemaState,
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database_engine: BaseDatabaseEngine,
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config: Optional[HomeServerConfig],
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databases: Collection[str],
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is_empty: bool = False,
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) -> None:
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"""Upgrades an existing physical database.
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Delta files can either be SQL stored in *.sql files, or python modules
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in *.py.
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There can be multiple delta files per version. Synapse will keep track of
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which delta files have been applied, and will apply any that haven't been
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even if there has been no version bump. This is useful for development
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where orthogonal schema changes may happen on separate branches.
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Different delta files for the same version *must* be orthogonal and give
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the same result when applied in any order. No guarantees are made on the
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order of execution of these scripts.
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This is a no-op of current_version == SCHEMA_VERSION.
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Example directory structure:
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schema/
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delta/
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11/
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foo.sql
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...
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12/
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foo.sql
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bar.py
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...
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full_schemas/
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...
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In the example, if current_version is 11, then foo.sql will be run if and
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only if `upgraded` is True. Then `foo.sql` and `bar.py` would be run in
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some arbitrary order.
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Note: we apply the delta files from the specified data stores as well as
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those in the top-level schema. We apply all delta files across data stores
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for a version before applying those in the next version.
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Args:
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cur
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current_schema_state: The current version of the schema, as
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returned by _get_or_create_schema_state
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database_engine
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config:
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None if we are initialising a blank database, otherwise the application
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config
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databases: The names of the databases to instantiate
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on the given physical database.
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is_empty: Is this a blank database? I.e. do we need to run the
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upgrade portions of the delta scripts.
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"""
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if is_empty:
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assert not current_schema_state.applied_deltas
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else:
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assert config
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is_worker = config and config.worker_app is not None
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if (
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current_schema_state.compat_version is not None
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and current_schema_state.compat_version > SCHEMA_VERSION
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):
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raise ValueError(
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"Cannot use this database as it is too "
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+ "new for the server to understand"
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)
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# some of the deltas assume that config.server_name is set correctly, so now
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# is a good time to run the sanity check.
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if not is_empty and "main" in databases:
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from synapse.storage.databases.main import check_database_before_upgrade
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assert config is not None
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check_database_before_upgrade(cur, database_engine, config)
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# update schema_compat_version before we run any upgrades, so that if synapse
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# gets downgraded again, it won't try to run against the upgraded database.
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if (
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current_schema_state.compat_version is None
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or current_schema_state.compat_version < SCHEMA_COMPAT_VERSION
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):
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cur.execute("DELETE FROM schema_compat_version")
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cur.execute(
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"INSERT INTO schema_compat_version(compat_version) VALUES (?)",
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(SCHEMA_COMPAT_VERSION,),
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)
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start_ver = current_schema_state.current_version
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# if we got to this schema version by running a full_schema rather than a series
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# of deltas, we should not run the deltas for this version.
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if not current_schema_state.upgraded:
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start_ver += 1
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logger.debug("applied_delta_files: %s", current_schema_state.applied_deltas)
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if isinstance(database_engine, PostgresEngine):
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specific_engine_extension = ".postgres"
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else:
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specific_engine_extension = ".sqlite"
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specific_engine_extensions = (".sqlite", ".postgres")
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for v in range(start_ver, SCHEMA_VERSION + 1):
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if not is_worker:
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logger.info("Applying schema deltas for v%d", v)
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cur.execute("DELETE FROM schema_version")
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cur.execute(
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"INSERT INTO schema_version (version, upgraded) VALUES (?,?)",
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(v, True),
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)
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else:
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logger.info("Checking schema deltas for v%d", v)
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# We need to search both the global and per data store schema
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# directories for schema updates.
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# First we find the directories to search in
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delta_dir = os.path.join(schema_path, "common", "delta", str(v))
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directories = [delta_dir]
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for database in databases:
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directories.append(os.path.join(schema_path, database, "delta", str(v)))
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# Used to check if we have any duplicate file names
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file_name_counter: CounterType[str] = Counter()
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# Now find which directories have anything of interest.
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directory_entries: List[_DirectoryListing] = []
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for directory in directories:
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logger.debug("Looking for schema deltas in %s", directory)
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try:
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file_names = os.listdir(directory)
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directory_entries.extend(
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_DirectoryListing(file_name, os.path.join(directory, file_name))
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for file_name in file_names
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)
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for file_name in file_names:
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file_name_counter[file_name] += 1
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except FileNotFoundError:
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# Data stores can have empty entries for a given version delta.
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pass
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except OSError:
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raise UpgradeDatabaseException(
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"Could not open delta dir for version %d: %s" % (v, directory)
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)
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duplicates = {
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file_name for file_name, count in file_name_counter.items() if count > 1
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}
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if duplicates:
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# We don't support using the same file name in the same delta version.
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raise PrepareDatabaseException(
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"Found multiple delta files with the same name in v%d: %s"
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% (
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v,
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duplicates,
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)
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)
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# We sort to ensure that we apply the delta files in a consistent
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# order (to avoid bugs caused by inconsistent directory listing order)
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directory_entries.sort()
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for entry in directory_entries:
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file_name = entry.file_name
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relative_path = os.path.join(str(v), file_name)
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absolute_path = entry.absolute_path
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logger.debug("Found file: %s (%s)", relative_path, absolute_path)
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if relative_path in current_schema_state.applied_deltas:
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continue
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root_name, ext = os.path.splitext(file_name)
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if ext == ".py":
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# This is a python upgrade module. We need to import into some
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# package and then execute its `run_upgrade` function.
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if is_worker:
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raise PrepareDatabaseException(
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UNAPPLIED_DELTA_ON_WORKER_ERROR % relative_path
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)
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module_name = "synapse.storage.v%d_%s" % (v, root_name)
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spec = importlib.util.spec_from_file_location(
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module_name, absolute_path
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)
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module = importlib.util.module_from_spec(spec)
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spec.loader.exec_module(module) # type: ignore
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logger.info("Running script %s", relative_path)
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module.run_create(cur, database_engine) # type: ignore
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if not is_empty:
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module.run_upgrade(cur, database_engine, config=config) # type: ignore
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elif ext == ".pyc" or file_name == "__pycache__":
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# Sometimes .pyc files turn up anyway even though we've
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# disabled their generation; e.g. from distribution package
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# installers. Silently skip it
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continue
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elif ext == ".sql":
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# A plain old .sql file, just read and execute it
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if is_worker:
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raise PrepareDatabaseException(
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UNAPPLIED_DELTA_ON_WORKER_ERROR % relative_path
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)
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logger.info("Applying schema %s", relative_path)
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executescript(cur, absolute_path)
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elif ext == specific_engine_extension and root_name.endswith(".sql"):
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# A .sql file specific to our engine; just read and execute it
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if is_worker:
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raise PrepareDatabaseException(
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UNAPPLIED_DELTA_ON_WORKER_ERROR % relative_path
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)
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logger.info("Applying engine-specific schema %s", relative_path)
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executescript(cur, absolute_path)
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elif ext in specific_engine_extensions and root_name.endswith(".sql"):
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# A .sql file for a different engine; skip it.
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continue
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else:
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# Not a valid delta file.
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logger.warning(
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"Found directory entry that did not end in .py or .sql: %s",
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relative_path,
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)
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continue
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# Mark as done.
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cur.execute(
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"INSERT INTO applied_schema_deltas (version, file) VALUES (?,?)",
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(v, relative_path),
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)
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logger.info("Schema now up to date")
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def _apply_module_schemas(
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txn: Cursor, database_engine: BaseDatabaseEngine, config: HomeServerConfig
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) -> None:
|
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"""Apply the module schemas for the dynamic modules, if any
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|
|
Args:
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cur: database cursor
|
|
database_engine:
|
|
config: application config
|
|
"""
|
|
for (mod, _config) in config.password_providers:
|
|
if not hasattr(mod, "get_db_schema_files"):
|
|
continue
|
|
modname = ".".join((mod.__module__, mod.__name__))
|
|
_apply_module_schema_files(
|
|
txn, database_engine, modname, mod.get_db_schema_files()
|
|
)
|
|
|
|
|
|
def _apply_module_schema_files(
|
|
cur: Cursor,
|
|
database_engine: BaseDatabaseEngine,
|
|
modname: str,
|
|
names_and_streams: Iterable[Tuple[str, TextIO]],
|
|
) -> None:
|
|
"""Apply the module schemas for a single module
|
|
|
|
Args:
|
|
cur: database cursor
|
|
database_engine: synapse database engine class
|
|
modname: fully qualified name of the module
|
|
names_and_streams: the names and streams of schemas to be applied
|
|
"""
|
|
cur.execute(
|
|
"SELECT file FROM applied_module_schemas WHERE module_name = ?",
|
|
(modname,),
|
|
)
|
|
applied_deltas = {d for d, in cur}
|
|
for (name, stream) in names_and_streams:
|
|
if name in applied_deltas:
|
|
continue
|
|
|
|
root_name, ext = os.path.splitext(name)
|
|
if ext != ".sql":
|
|
raise PrepareDatabaseException(
|
|
"only .sql files are currently supported for module schemas"
|
|
)
|
|
|
|
logger.info("applying schema %s for %s", name, modname)
|
|
execute_statements_from_stream(cur, stream)
|
|
|
|
# Mark as done.
|
|
cur.execute(
|
|
"INSERT INTO applied_module_schemas (module_name, file) VALUES (?,?)",
|
|
(modname, name),
|
|
)
|
|
|
|
|
|
def get_statements(f: Iterable[str]) -> Generator[str, None, None]:
|
|
statement_buffer = ""
|
|
in_comment = False # If we're in a /* ... */ style comment
|
|
|
|
for line in f:
|
|
line = line.strip()
|
|
|
|
if in_comment:
|
|
# Check if this line contains an end to the comment
|
|
comments = line.split("*/", 1)
|
|
if len(comments) == 1:
|
|
continue
|
|
line = comments[1]
|
|
in_comment = False
|
|
|
|
# Remove inline block comments
|
|
line = re.sub(r"/\*.*\*/", " ", line)
|
|
|
|
# Does this line start a comment?
|
|
comments = line.split("/*", 1)
|
|
if len(comments) > 1:
|
|
line = comments[0]
|
|
in_comment = True
|
|
|
|
# Deal with line comments
|
|
line = line.split("--", 1)[0]
|
|
line = line.split("//", 1)[0]
|
|
|
|
# Find *all* semicolons. We need to treat first and last entry
|
|
# specially.
|
|
statements = line.split(";")
|
|
|
|
# We must prepend statement_buffer to the first statement
|
|
first_statement = "%s %s" % (statement_buffer.strip(), statements[0].strip())
|
|
statements[0] = first_statement
|
|
|
|
# Every entry, except the last, is a full statement
|
|
for statement in statements[:-1]:
|
|
yield statement.strip()
|
|
|
|
# The last entry did *not* end in a semicolon, so we store it for the
|
|
# next semicolon we find
|
|
statement_buffer = statements[-1].strip()
|
|
|
|
|
|
def executescript(txn: Cursor, schema_path: str) -> None:
|
|
with open(schema_path) as f:
|
|
execute_statements_from_stream(txn, f)
|
|
|
|
|
|
def execute_statements_from_stream(cur: Cursor, f: TextIO) -> None:
|
|
for statement in get_statements(f):
|
|
cur.execute(statement)
|
|
|
|
|
|
def _get_or_create_schema_state(
|
|
txn: Cursor, database_engine: BaseDatabaseEngine
|
|
) -> Optional[_SchemaState]:
|
|
# Bluntly try creating the schema_version tables.
|
|
sql_path = os.path.join(schema_path, "common", "schema_version.sql")
|
|
executescript(txn, sql_path)
|
|
|
|
txn.execute("SELECT version, upgraded FROM schema_version")
|
|
row = txn.fetchone()
|
|
|
|
if row is None:
|
|
# new database
|
|
return None
|
|
|
|
current_version = int(row[0])
|
|
upgraded = bool(row[1])
|
|
|
|
compat_version: Optional[int] = None
|
|
txn.execute("SELECT compat_version FROM schema_compat_version")
|
|
row = txn.fetchone()
|
|
if row is not None:
|
|
compat_version = int(row[0])
|
|
|
|
txn.execute(
|
|
"SELECT file FROM applied_schema_deltas WHERE version >= ?",
|
|
(current_version,),
|
|
)
|
|
applied_deltas = tuple(d for d, in txn)
|
|
|
|
return _SchemaState(
|
|
current_version=current_version,
|
|
compat_version=compat_version,
|
|
applied_deltas=applied_deltas,
|
|
upgraded=upgraded,
|
|
)
|
|
|
|
|
|
@attr.s(slots=True)
|
|
class _DirectoryListing:
|
|
"""Helper class to store schema file name and the
|
|
absolute path to it.
|
|
|
|
These entries get sorted, so for consistency we want to ensure that
|
|
`file_name` attr is kept first.
|
|
"""
|
|
|
|
file_name = attr.ib(type=str)
|
|
absolute_path = attr.ib(type=str)
|