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