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Edit File: asyncpg.py
# postgresql/asyncpg.py # Copyright (C) 2005-2023 the SQLAlchemy authors and contributors <see AUTHORS # file> # # This module is part of SQLAlchemy and is released under # the MIT License: https://www.opensource.org/licenses/mit-license.php r""" .. dialect:: postgresql+asyncpg :name: asyncpg :dbapi: asyncpg :connectstring: postgresql+asyncpg://user:password@host:port/dbname[?key=value&key=value...] :url: https://magicstack.github.io/asyncpg/ The asyncpg dialect is SQLAlchemy's first Python asyncio dialect. Using a special asyncio mediation layer, the asyncpg dialect is usable as the backend for the :ref:`SQLAlchemy asyncio <asyncio_toplevel>` extension package. This dialect should normally be used only with the :func:`_asyncio.create_async_engine` engine creation function:: from sqlalchemy.ext.asyncio import create_async_engine engine = create_async_engine("postgresql+asyncpg://user:pass@hostname/dbname") The dialect can also be run as a "synchronous" dialect within the :func:`_sa.create_engine` function, which will pass "await" calls into an ad-hoc event loop. This mode of operation is of **limited use** and is for special testing scenarios only. The mode can be enabled by adding the SQLAlchemy-specific flag ``async_fallback`` to the URL in conjunction with :func:`_sa.create_engine`:: # for testing purposes only; do not use in production! engine = create_engine("postgresql+asyncpg://user:pass@hostname/dbname?async_fallback=true") .. versionadded:: 1.4 .. note:: By default asyncpg does not decode the ``json`` and ``jsonb`` types and returns them as strings. SQLAlchemy sets default type decoder for ``json`` and ``jsonb`` types using the python builtin ``json.loads`` function. The json implementation used can be changed by setting the attribute ``json_deserializer`` when creating the engine with :func:`create_engine` or :func:`create_async_engine`. .. _asyncpg_prepared_statement_cache: Prepared Statement Cache -------------------------- The asyncpg SQLAlchemy dialect makes use of ``asyncpg.connection.prepare()`` for all statements. The prepared statement objects are cached after construction which appears to grant a 10% or more performance improvement for statement invocation. The cache is on a per-DBAPI connection basis, which means that the primary storage for prepared statements is within DBAPI connections pooled within the connection pool. The size of this cache defaults to 100 statements per DBAPI connection and may be adjusted using the ``prepared_statement_cache_size`` DBAPI argument (note that while this argument is implemented by SQLAlchemy, it is part of the DBAPI emulation portion of the asyncpg dialect, therefore is handled as a DBAPI argument, not a dialect argument):: engine = create_async_engine("postgresql+asyncpg://user:pass@hostname/dbname?prepared_statement_cache_size=500") To disable the prepared statement cache, use a value of zero:: engine = create_async_engine("postgresql+asyncpg://user:pass@hostname/dbname?prepared_statement_cache_size=0") .. versionadded:: 1.4.0b2 Added ``prepared_statement_cache_size`` for asyncpg. .. warning:: The ``asyncpg`` database driver necessarily uses caches for PostgreSQL type OIDs, which become stale when custom PostgreSQL datatypes such as ``ENUM`` objects are changed via DDL operations. Additionally, prepared statements themselves which are optionally cached by SQLAlchemy's driver as described above may also become "stale" when DDL has been emitted to the PostgreSQL database which modifies the tables or other objects involved in a particular prepared statement. The SQLAlchemy asyncpg dialect will invalidate these caches within its local process when statements that represent DDL are emitted on a local connection, but this is only controllable within a single Python process / database engine. If DDL changes are made from other database engines and/or processes, a running application may encounter asyncpg exceptions ``InvalidCachedStatementError`` and/or ``InternalServerError("cache lookup failed for type <oid>")`` if it refers to pooled database connections which operated upon the previous structures. The SQLAlchemy asyncpg dialect will recover from these error cases when the driver raises these exceptions by clearing its internal caches as well as those of the asyncpg driver in response to them, but cannot prevent them from being raised in the first place if the cached prepared statement or asyncpg type caches have gone stale, nor can it retry the statement as the PostgreSQL transaction is invalidated when these errors occur. Disabling the PostgreSQL JIT to improve ENUM datatype handling --------------------------------------------------------------- Asyncpg has an `issue <https://github.com/MagicStack/asyncpg/issues/727>`_ when using PostgreSQL ENUM datatypes, where upon the creation of new database connections, an expensive query may be emitted in order to retrieve metadata regarding custom types which has been shown to negatively affect performance. To mitigate this issue, the PostgreSQL "jit" setting may be disabled from the client using this setting passed to :func:`_asyncio.create_async_engine`:: engine = create_async_engine( "postgresql+asyncpg://user:password@localhost/tmp", connect_args={"server_settings": {"jit": "off"}}, ) .. seealso:: https://github.com/MagicStack/asyncpg/issues/727 """ # noqa import collections import decimal import json as _py_json import re import time from . import json from .base import _DECIMAL_TYPES from .base import _FLOAT_TYPES from .base import _INT_TYPES from .base import ENUM from .base import INTERVAL from .base import OID from .base import PGCompiler from .base import PGDialect from .base import PGExecutionContext from .base import PGIdentifierPreparer from .base import REGCLASS from .base import UUID from ... import exc from ... import pool from ... import processors from ... import util from ...engine import AdaptedConnection from ...sql import sqltypes from ...util.concurrency import asyncio from ...util.concurrency import await_fallback from ...util.concurrency import await_only try: from uuid import UUID as _python_UUID # noqa except ImportError: _python_UUID = None class AsyncpgTime(sqltypes.Time): def get_dbapi_type(self, dbapi): if self.timezone: return dbapi.TIME_W_TZ else: return dbapi.TIME class AsyncpgDate(sqltypes.Date): def get_dbapi_type(self, dbapi): return dbapi.DATE class AsyncpgDateTime(sqltypes.DateTime): def get_dbapi_type(self, dbapi): if self.timezone: return dbapi.TIMESTAMP_W_TZ else: return dbapi.TIMESTAMP class AsyncpgBoolean(sqltypes.Boolean): def get_dbapi_type(self, dbapi): return dbapi.BOOLEAN class AsyncPgInterval(INTERVAL): def get_dbapi_type(self, dbapi): return dbapi.INTERVAL @classmethod def adapt_emulated_to_native(cls, interval, **kw): return AsyncPgInterval(precision=interval.second_precision) class AsyncPgEnum(ENUM): def get_dbapi_type(self, dbapi): return dbapi.ENUM class AsyncpgInteger(sqltypes.Integer): def get_dbapi_type(self, dbapi): return dbapi.INTEGER class AsyncpgBigInteger(sqltypes.BigInteger): def get_dbapi_type(self, dbapi): return dbapi.BIGINTEGER class AsyncpgJSON(json.JSON): def get_dbapi_type(self, dbapi): return dbapi.JSON def result_processor(self, dialect, coltype): return None class AsyncpgJSONB(json.JSONB): def get_dbapi_type(self, dbapi): return dbapi.JSONB def result_processor(self, dialect, coltype): return None class AsyncpgJSONIndexType(sqltypes.JSON.JSONIndexType): def get_dbapi_type(self, dbapi): raise NotImplementedError("should not be here") class AsyncpgJSONIntIndexType(sqltypes.JSON.JSONIntIndexType): def get_dbapi_type(self, dbapi): return dbapi.INTEGER class AsyncpgJSONStrIndexType(sqltypes.JSON.JSONStrIndexType): def get_dbapi_type(self, dbapi): return dbapi.STRING class AsyncpgJSONPathType(json.JSONPathType): def bind_processor(self, dialect): def process(value): assert isinstance(value, util.collections_abc.Sequence) tokens = [util.text_type(elem) for elem in value] return tokens return process class AsyncpgUUID(UUID): def get_dbapi_type(self, dbapi): return dbapi.UUID def bind_processor(self, dialect): if not self.as_uuid and dialect.use_native_uuid: def process(value): if value is not None: value = _python_UUID(value) return value return process def result_processor(self, dialect, coltype): if not self.as_uuid and dialect.use_native_uuid: def process(value): if value is not None: value = str(value) return value return process class AsyncpgNumeric(sqltypes.Numeric): def get_dbapi_type(self, dbapi): return dbapi.NUMBER def bind_processor(self, dialect): return None def result_processor(self, dialect, coltype): if self.asdecimal: if coltype in _FLOAT_TYPES: return processors.to_decimal_processor_factory( decimal.Decimal, self._effective_decimal_return_scale ) elif coltype in _DECIMAL_TYPES or coltype in _INT_TYPES: # pg8000 returns Decimal natively for 1700 return None else: raise exc.InvalidRequestError( "Unknown PG numeric type: %d" % coltype ) else: if coltype in _FLOAT_TYPES: # pg8000 returns float natively for 701 return None elif coltype in _DECIMAL_TYPES or coltype in _INT_TYPES: return processors.to_float else: raise exc.InvalidRequestError( "Unknown PG numeric type: %d" % coltype ) class AsyncpgFloat(AsyncpgNumeric): def get_dbapi_type(self, dbapi): return dbapi.FLOAT class AsyncpgREGCLASS(REGCLASS): def get_dbapi_type(self, dbapi): return dbapi.STRING class AsyncpgOID(OID): def get_dbapi_type(self, dbapi): return dbapi.INTEGER class PGExecutionContext_asyncpg(PGExecutionContext): def handle_dbapi_exception(self, e): if isinstance( e, ( self.dialect.dbapi.InvalidCachedStatementError, self.dialect.dbapi.InternalServerError, ), ): self.dialect._invalidate_schema_cache() def pre_exec(self): if self.isddl: self.dialect._invalidate_schema_cache() self.cursor._invalidate_schema_cache_asof = ( self.dialect._invalidate_schema_cache_asof ) if not self.compiled: return # we have to exclude ENUM because "enum" not really a "type" # we can cast to, it has to be the name of the type itself. # for now we just omit it from casting self.exclude_set_input_sizes = {AsyncAdapt_asyncpg_dbapi.ENUM} def create_server_side_cursor(self): return self._dbapi_connection.cursor(server_side=True) class PGCompiler_asyncpg(PGCompiler): pass class PGIdentifierPreparer_asyncpg(PGIdentifierPreparer): pass class AsyncAdapt_asyncpg_cursor: __slots__ = ( "_adapt_connection", "_connection", "_rows", "description", "arraysize", "rowcount", "_inputsizes", "_cursor", "_invalidate_schema_cache_asof", ) server_side = False def __init__(self, adapt_connection): self._adapt_connection = adapt_connection self._connection = adapt_connection._connection self._rows = [] self._cursor = None self.description = None self.arraysize = 1 self.rowcount = -1 self._inputsizes = None self._invalidate_schema_cache_asof = 0 def close(self): self._rows[:] = [] def _handle_exception(self, error): self._adapt_connection._handle_exception(error) def _parameter_placeholders(self, params): if not self._inputsizes: return tuple("$%d" % idx for idx, _ in enumerate(params, 1)) else: return tuple( "$%d::%s" % (idx, typ) if typ else "$%d" % idx for idx, typ in enumerate( (_pg_types.get(typ) for typ in self._inputsizes), 1 ) ) async def _prepare_and_execute(self, operation, parameters): adapt_connection = self._adapt_connection async with adapt_connection._execute_mutex: if not adapt_connection._started: await adapt_connection._start_transaction() if parameters is not None: operation = operation % self._parameter_placeholders( parameters ) else: parameters = () try: prepared_stmt, attributes = await adapt_connection._prepare( operation, self._invalidate_schema_cache_asof ) if attributes: self.description = [ ( attr.name, attr.type.oid, None, None, None, None, None, ) for attr in attributes ] else: self.description = None if self.server_side: self._cursor = await prepared_stmt.cursor(*parameters) self.rowcount = -1 else: self._rows = await prepared_stmt.fetch(*parameters) status = prepared_stmt.get_statusmsg() reg = re.match( r"(?:UPDATE|DELETE|INSERT \d+) (\d+)", status ) if reg: self.rowcount = int(reg.group(1)) else: self.rowcount = -1 except Exception as error: self._handle_exception(error) async def _executemany(self, operation, seq_of_parameters): adapt_connection = self._adapt_connection async with adapt_connection._execute_mutex: await adapt_connection._check_type_cache_invalidation( self._invalidate_schema_cache_asof ) if not adapt_connection._started: await adapt_connection._start_transaction() operation = operation % self._parameter_placeholders( seq_of_parameters[0] ) try: return await self._connection.executemany( operation, seq_of_parameters ) except Exception as error: self._handle_exception(error) def execute(self, operation, parameters=None): self._adapt_connection.await_( self._prepare_and_execute(operation, parameters) ) def executemany(self, operation, seq_of_parameters): return self._adapt_connection.await_( self._executemany(operation, seq_of_parameters) ) def setinputsizes(self, *inputsizes): self._inputsizes = inputsizes def __iter__(self): while self._rows: yield self._rows.pop(0) def fetchone(self): if self._rows: return self._rows.pop(0) else: return None def fetchmany(self, size=None): if size is None: size = self.arraysize retval = self._rows[0:size] self._rows[:] = self._rows[size:] return retval def fetchall(self): retval = self._rows[:] self._rows[:] = [] return retval class AsyncAdapt_asyncpg_ss_cursor(AsyncAdapt_asyncpg_cursor): server_side = True __slots__ = ("_rowbuffer",) def __init__(self, adapt_connection): super(AsyncAdapt_asyncpg_ss_cursor, self).__init__(adapt_connection) self._rowbuffer = None def close(self): self._cursor = None self._rowbuffer = None def _buffer_rows(self): new_rows = self._adapt_connection.await_(self._cursor.fetch(50)) self._rowbuffer = collections.deque(new_rows) def __aiter__(self): return self async def __anext__(self): if not self._rowbuffer: self._buffer_rows() while True: while self._rowbuffer: yield self._rowbuffer.popleft() self._buffer_rows() if not self._rowbuffer: break def fetchone(self): if not self._rowbuffer: self._buffer_rows() if not self._rowbuffer: return None return self._rowbuffer.popleft() def fetchmany(self, size=None): if size is None: return self.fetchall() if not self._rowbuffer: self._buffer_rows() buf = list(self._rowbuffer) lb = len(buf) if size > lb: buf.extend( self._adapt_connection.await_(self._cursor.fetch(size - lb)) ) result = buf[0:size] self._rowbuffer = collections.deque(buf[size:]) return result def fetchall(self): ret = list(self._rowbuffer) + list( self._adapt_connection.await_(self._all()) ) self._rowbuffer.clear() return ret async def _all(self): rows = [] # TODO: looks like we have to hand-roll some kind of batching here. # hardcoding for the moment but this should be improved. while True: batch = await self._cursor.fetch(1000) if batch: rows.extend(batch) continue else: break return rows def executemany(self, operation, seq_of_parameters): raise NotImplementedError( "server side cursor doesn't support executemany yet" ) class AsyncAdapt_asyncpg_connection(AdaptedConnection): __slots__ = ( "dbapi", "_connection", "isolation_level", "_isolation_setting", "readonly", "deferrable", "_transaction", "_started", "_prepared_statement_cache", "_invalidate_schema_cache_asof", "_execute_mutex", ) await_ = staticmethod(await_only) def __init__(self, dbapi, connection, prepared_statement_cache_size=100): self.dbapi = dbapi self._connection = connection self.isolation_level = self._isolation_setting = "read_committed" self.readonly = False self.deferrable = False self._transaction = None self._started = False self._invalidate_schema_cache_asof = time.time() self._execute_mutex = asyncio.Lock() if prepared_statement_cache_size: self._prepared_statement_cache = util.LRUCache( prepared_statement_cache_size ) else: self._prepared_statement_cache = None async def _check_type_cache_invalidation(self, invalidate_timestamp): if invalidate_timestamp > self._invalidate_schema_cache_asof: await self._connection.reload_schema_state() self._invalidate_schema_cache_asof = invalidate_timestamp async def _prepare(self, operation, invalidate_timestamp): await self._check_type_cache_invalidation(invalidate_timestamp) cache = self._prepared_statement_cache if cache is None: prepared_stmt = await self._connection.prepare(operation) attributes = prepared_stmt.get_attributes() return prepared_stmt, attributes # asyncpg uses a type cache for the "attributes" which seems to go # stale independently of the PreparedStatement itself, so place that # collection in the cache as well. if operation in cache: prepared_stmt, attributes, cached_timestamp = cache[operation] # preparedstatements themselves also go stale for certain DDL # changes such as size of a VARCHAR changing, so there is also # a cross-connection invalidation timestamp if cached_timestamp > invalidate_timestamp: return prepared_stmt, attributes prepared_stmt = await self._connection.prepare(operation) attributes = prepared_stmt.get_attributes() cache[operation] = (prepared_stmt, attributes, time.time()) return prepared_stmt, attributes def _handle_exception(self, error): if self._connection.is_closed(): self._transaction = None self._started = False if not isinstance(error, AsyncAdapt_asyncpg_dbapi.Error): exception_mapping = self.dbapi._asyncpg_error_translate for super_ in type(error).__mro__: if super_ in exception_mapping: translated_error = exception_mapping[super_]( "%s: %s" % (type(error), error) ) translated_error.pgcode = ( translated_error.sqlstate ) = getattr(error, "sqlstate", None) raise translated_error from error else: raise error else: raise error @property def autocommit(self): return self.isolation_level == "autocommit" @autocommit.setter def autocommit(self, value): if value: self.isolation_level = "autocommit" else: self.isolation_level = self._isolation_setting def set_isolation_level(self, level): if self._started: self.rollback() self.isolation_level = self._isolation_setting = level async def _start_transaction(self): if self.isolation_level == "autocommit": return try: self._transaction = self._connection.transaction( isolation=self.isolation_level, readonly=self.readonly, deferrable=self.deferrable, ) await self._transaction.start() except Exception as error: self._handle_exception(error) else: self._started = True def cursor(self, server_side=False): if server_side: return AsyncAdapt_asyncpg_ss_cursor(self) else: return AsyncAdapt_asyncpg_cursor(self) def rollback(self): if self._started: try: self.await_(self._transaction.rollback()) except Exception as error: self._handle_exception(error) finally: self._transaction = None self._started = False def commit(self): if self._started: try: self.await_(self._transaction.commit()) except Exception as error: self._handle_exception(error) finally: self._transaction = None self._started = False def close(self): self.rollback() self.await_(self._connection.close()) def terminate(self): self._connection.terminate() class AsyncAdaptFallback_asyncpg_connection(AsyncAdapt_asyncpg_connection): __slots__ = () await_ = staticmethod(await_fallback) class AsyncAdapt_asyncpg_dbapi: def __init__(self, asyncpg): self.asyncpg = asyncpg self.paramstyle = "format" def connect(self, *arg, **kw): async_fallback = kw.pop("async_fallback", False) prepared_statement_cache_size = kw.pop( "prepared_statement_cache_size", 100 ) if util.asbool(async_fallback): return AsyncAdaptFallback_asyncpg_connection( self, await_fallback(self.asyncpg.connect(*arg, **kw)), prepared_statement_cache_size=prepared_statement_cache_size, ) else: return AsyncAdapt_asyncpg_connection( self, await_only(self.asyncpg.connect(*arg, **kw)), prepared_statement_cache_size=prepared_statement_cache_size, ) class Error(Exception): pass class Warning(Exception): # noqa pass class InterfaceError(Error): pass class DatabaseError(Error): pass class InternalError(DatabaseError): pass class OperationalError(DatabaseError): pass class ProgrammingError(DatabaseError): pass class IntegrityError(DatabaseError): pass class DataError(DatabaseError): pass class NotSupportedError(DatabaseError): pass class InternalServerError(InternalError): pass class InvalidCachedStatementError(NotSupportedError): def __init__(self, message): super( AsyncAdapt_asyncpg_dbapi.InvalidCachedStatementError, self ).__init__( message + " (SQLAlchemy asyncpg dialect will now invalidate " "all prepared caches in response to this exception)", ) @util.memoized_property def _asyncpg_error_translate(self): import asyncpg return { asyncpg.exceptions.IntegrityConstraintViolationError: self.IntegrityError, # noqa: E501 asyncpg.exceptions.PostgresError: self.Error, asyncpg.exceptions.SyntaxOrAccessError: self.ProgrammingError, asyncpg.exceptions.InterfaceError: self.InterfaceError, asyncpg.exceptions.InvalidCachedStatementError: self.InvalidCachedStatementError, # noqa: E501 asyncpg.exceptions.InternalServerError: self.InternalServerError, } def Binary(self, value): return value STRING = util.symbol("STRING") TIMESTAMP = util.symbol("TIMESTAMP") TIMESTAMP_W_TZ = util.symbol("TIMESTAMP_W_TZ") TIME = util.symbol("TIME") TIME_W_TZ = util.symbol("TIME_W_TZ") DATE = util.symbol("DATE") INTERVAL = util.symbol("INTERVAL") NUMBER = util.symbol("NUMBER") FLOAT = util.symbol("FLOAT") BOOLEAN = util.symbol("BOOLEAN") INTEGER = util.symbol("INTEGER") BIGINTEGER = util.symbol("BIGINTEGER") BYTES = util.symbol("BYTES") DECIMAL = util.symbol("DECIMAL") JSON = util.symbol("JSON") JSONB = util.symbol("JSONB") ENUM = util.symbol("ENUM") UUID = util.symbol("UUID") BYTEA = util.symbol("BYTEA") DATETIME = TIMESTAMP BINARY = BYTEA _pg_types = { AsyncAdapt_asyncpg_dbapi.STRING: "varchar", AsyncAdapt_asyncpg_dbapi.TIMESTAMP: "timestamp", AsyncAdapt_asyncpg_dbapi.TIMESTAMP_W_TZ: "timestamp with time zone", AsyncAdapt_asyncpg_dbapi.DATE: "date", AsyncAdapt_asyncpg_dbapi.TIME: "time", AsyncAdapt_asyncpg_dbapi.TIME_W_TZ: "time with time zone", AsyncAdapt_asyncpg_dbapi.INTERVAL: "interval", AsyncAdapt_asyncpg_dbapi.NUMBER: "numeric", AsyncAdapt_asyncpg_dbapi.FLOAT: "float", AsyncAdapt_asyncpg_dbapi.BOOLEAN: "bool", AsyncAdapt_asyncpg_dbapi.INTEGER: "integer", AsyncAdapt_asyncpg_dbapi.BIGINTEGER: "bigint", AsyncAdapt_asyncpg_dbapi.BYTES: "bytes", AsyncAdapt_asyncpg_dbapi.DECIMAL: "decimal", AsyncAdapt_asyncpg_dbapi.JSON: "json", AsyncAdapt_asyncpg_dbapi.JSONB: "jsonb", AsyncAdapt_asyncpg_dbapi.ENUM: "enum", AsyncAdapt_asyncpg_dbapi.UUID: "uuid", AsyncAdapt_asyncpg_dbapi.BYTEA: "bytea", } class PGDialect_asyncpg(PGDialect): driver = "asyncpg" supports_statement_cache = True supports_unicode_statements = True supports_server_side_cursors = True supports_unicode_binds = True has_terminate = True default_paramstyle = "format" supports_sane_multi_rowcount = False execution_ctx_cls = PGExecutionContext_asyncpg statement_compiler = PGCompiler_asyncpg preparer = PGIdentifierPreparer_asyncpg use_setinputsizes = True use_native_uuid = True colspecs = util.update_copy( PGDialect.colspecs, { sqltypes.Time: AsyncpgTime, sqltypes.Date: AsyncpgDate, sqltypes.DateTime: AsyncpgDateTime, sqltypes.Interval: AsyncPgInterval, INTERVAL: AsyncPgInterval, UUID: AsyncpgUUID, sqltypes.Boolean: AsyncpgBoolean, sqltypes.Integer: AsyncpgInteger, sqltypes.BigInteger: AsyncpgBigInteger, sqltypes.Numeric: AsyncpgNumeric, sqltypes.Float: AsyncpgFloat, sqltypes.JSON: AsyncpgJSON, json.JSONB: AsyncpgJSONB, sqltypes.JSON.JSONPathType: AsyncpgJSONPathType, sqltypes.JSON.JSONIndexType: AsyncpgJSONIndexType, sqltypes.JSON.JSONIntIndexType: AsyncpgJSONIntIndexType, sqltypes.JSON.JSONStrIndexType: AsyncpgJSONStrIndexType, sqltypes.Enum: AsyncPgEnum, OID: AsyncpgOID, REGCLASS: AsyncpgREGCLASS, }, ) is_async = True _invalidate_schema_cache_asof = 0 def _invalidate_schema_cache(self): self._invalidate_schema_cache_asof = time.time() @util.memoized_property def _dbapi_version(self): if self.dbapi and hasattr(self.dbapi, "__version__"): return tuple( [ int(x) for x in re.findall( r"(\d+)(?:[-\.]?|$)", self.dbapi.__version__ ) ] ) else: return (99, 99, 99) @classmethod def dbapi(cls): return AsyncAdapt_asyncpg_dbapi(__import__("asyncpg")) @util.memoized_property def _isolation_lookup(self): return { "AUTOCOMMIT": "autocommit", "READ COMMITTED": "read_committed", "REPEATABLE READ": "repeatable_read", "SERIALIZABLE": "serializable", } def set_isolation_level(self, connection, level): try: level = self._isolation_lookup[level.replace("_", " ")] except KeyError as err: util.raise_( exc.ArgumentError( "Invalid value '%s' for isolation_level. " "Valid isolation levels for %s are %s" % (level, self.name, ", ".join(self._isolation_lookup)) ), replace_context=err, ) connection.set_isolation_level(level) def set_readonly(self, connection, value): connection.readonly = value def get_readonly(self, connection): return connection.readonly def set_deferrable(self, connection, value): connection.deferrable = value def get_deferrable(self, connection): return connection.deferrable def do_terminate(self, dbapi_connection) -> None: dbapi_connection.terminate() def create_connect_args(self, url): opts = url.translate_connect_args(username="user") opts.update(url.query) util.coerce_kw_type(opts, "prepared_statement_cache_size", int) util.coerce_kw_type(opts, "port", int) return ([], opts) @classmethod def get_pool_class(cls, url): async_fallback = url.query.get("async_fallback", False) if util.asbool(async_fallback): return pool.FallbackAsyncAdaptedQueuePool else: return pool.AsyncAdaptedQueuePool def is_disconnect(self, e, connection, cursor): if connection: return connection._connection.is_closed() else: return isinstance( e, self.dbapi.InterfaceError ) and "connection is closed" in str(e) def do_set_input_sizes(self, cursor, list_of_tuples, context): if self.positional: cursor.setinputsizes( *[dbtype for key, dbtype, sqltype in list_of_tuples] ) else: cursor.setinputsizes( **{ key: dbtype for key, dbtype, sqltype in list_of_tuples if dbtype } ) async def setup_asyncpg_json_codec(self, conn): """set up JSON codec for asyncpg. This occurs for all new connections and can be overridden by third party dialects. .. versionadded:: 1.4.27 """ asyncpg_connection = conn._connection deserializer = self._json_deserializer or _py_json.loads def _json_decoder(bin_value): return deserializer(bin_value.decode()) await asyncpg_connection.set_type_codec( "json", encoder=str.encode, decoder=_json_decoder, schema="pg_catalog", format="binary", ) async def setup_asyncpg_jsonb_codec(self, conn): """set up JSONB codec for asyncpg. This occurs for all new connections and can be overridden by third party dialects. .. versionadded:: 1.4.27 """ asyncpg_connection = conn._connection deserializer = self._json_deserializer or _py_json.loads def _jsonb_encoder(str_value): # \x01 is the prefix for jsonb used by PostgreSQL. # asyncpg requires it when format='binary' return b"\x01" + str_value.encode() deserializer = self._json_deserializer or _py_json.loads def _jsonb_decoder(bin_value): # the byte is the \x01 prefix for jsonb used by PostgreSQL. # asyncpg returns it when format='binary' return deserializer(bin_value[1:].decode()) await asyncpg_connection.set_type_codec( "jsonb", encoder=_jsonb_encoder, decoder=_jsonb_decoder, schema="pg_catalog", format="binary", ) def on_connect(self): """on_connect for asyncpg A major component of this for asyncpg is to set up type decoders at the asyncpg level. See https://github.com/MagicStack/asyncpg/issues/623 for notes on JSON/JSONB implementation. """ super_connect = super(PGDialect_asyncpg, self).on_connect() def connect(conn): conn.await_(self.setup_asyncpg_json_codec(conn)) conn.await_(self.setup_asyncpg_jsonb_codec(conn)) if super_connect is not None: super_connect(conn) return connect def get_driver_connection(self, connection): return connection._connection dialect = PGDialect_asyncpg