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* Moved `PostgresMessageMeta` and `PostgresMessage` into their own file to make it easier to add typings later on * Re-exported `PostgresMessageMeta` and `PostgresMessage` from `asyncpg.exceptions._base` to maintain backwards compatibility * Removed `import asyncpg` statements and import within methods to prevent circular imports
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,153 @@ | ||
| # Copyright (C) 2016-present the asyncpg authors and contributors | ||
| # <see AUTHORS file> | ||
| # | ||
| # This module is part of asyncpg and is released under | ||
| # the Apache 2.0 License: http://www.apache.org/licenses/LICENSE-2.0 | ||
|
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| import sys | ||
| import textwrap | ||
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| def _is_asyncpg_class(cls): | ||
| modname = cls.__module__ | ||
| return modname == 'asyncpg' or modname.startswith('asyncpg.') | ||
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| class PostgresMessageMeta(type): | ||
|
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| _message_map = {} | ||
| _field_map = { | ||
| 'S': 'severity', | ||
| 'V': 'severity_en', | ||
| 'C': 'sqlstate', | ||
| 'M': 'message', | ||
| 'D': 'detail', | ||
| 'H': 'hint', | ||
| 'P': 'position', | ||
| 'p': 'internal_position', | ||
| 'q': 'internal_query', | ||
| 'W': 'context', | ||
| 's': 'schema_name', | ||
| 't': 'table_name', | ||
| 'c': 'column_name', | ||
| 'd': 'data_type_name', | ||
| 'n': 'constraint_name', | ||
| 'F': 'server_source_filename', | ||
| 'L': 'server_source_line', | ||
| 'R': 'server_source_function' | ||
| } | ||
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| def __new__(mcls, name, bases, dct): | ||
| cls = super().__new__(mcls, name, bases, dct) | ||
| if cls.__module__ == mcls.__module__ and name == 'PostgresMessage': | ||
| for f in mcls._field_map.values(): | ||
| setattr(cls, f, None) | ||
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| if _is_asyncpg_class(cls): | ||
| mod = sys.modules[cls.__module__] | ||
| if hasattr(mod, name): | ||
| raise RuntimeError('exception class redefinition: {}'.format( | ||
| name)) | ||
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| code = dct.get('sqlstate') | ||
| if code is not None: | ||
| existing = mcls._message_map.get(code) | ||
| if existing is not None: | ||
| raise TypeError('{} has duplicate SQLSTATE code, which is' | ||
| 'already defined by {}'.format( | ||
| name, existing.__name__)) | ||
| mcls._message_map[code] = cls | ||
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| return cls | ||
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| @classmethod | ||
| def get_message_class_for_sqlstate(mcls, code): | ||
| from ._base import UnknownPostgresError | ||
| return mcls._message_map.get(code, UnknownPostgresError) | ||
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| class PostgresMessage(metaclass=PostgresMessageMeta): | ||
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| @classmethod | ||
| def _get_error_class(cls, fields): | ||
| sqlstate = fields.get('C') | ||
| return type(cls).get_message_class_for_sqlstate(sqlstate) | ||
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| @classmethod | ||
| def _get_error_dict(cls, fields, query): | ||
| dct = { | ||
| 'query': query | ||
| } | ||
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| field_map = type(cls)._field_map | ||
| for k, v in fields.items(): | ||
| field = field_map.get(k) | ||
| if field: | ||
| dct[field] = v | ||
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| return dct | ||
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| @classmethod | ||
| def _make_constructor(cls, fields, query=None): | ||
| dct = cls._get_error_dict(fields, query) | ||
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| exccls = cls._get_error_class(fields) | ||
| message = dct.get('message', '') | ||
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| # PostgreSQL will raise an exception when it detects | ||
| # that the result type of the query has changed from | ||
| # when the statement was prepared. | ||
| # | ||
| # The original error is somewhat cryptic and unspecific, | ||
| # so we raise a custom subclass that is easier to handle | ||
| # and identify. | ||
| # | ||
| # Note that we specifically do not rely on the error | ||
| # message, as it is localizable. | ||
| is_icse = ( | ||
| exccls.__name__ == 'FeatureNotSupportedError' and | ||
| _is_asyncpg_class(exccls) and | ||
| dct.get('server_source_function') == 'RevalidateCachedQuery' | ||
| ) | ||
|
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| if is_icse: | ||
| exceptions = sys.modules[exccls.__module__] | ||
| exccls = exceptions.InvalidCachedStatementError | ||
| message = ('cached statement plan is invalid due to a database ' | ||
| 'schema or configuration change') | ||
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| is_prepared_stmt_error = ( | ||
| exccls.__name__ in ('DuplicatePreparedStatementError', | ||
| 'InvalidSQLStatementNameError') and | ||
| _is_asyncpg_class(exccls) | ||
| ) | ||
|
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| if is_prepared_stmt_error: | ||
| hint = dct.get('hint', '') | ||
| hint += textwrap.dedent("""\ | ||
| NOTE: pgbouncer with pool_mode set to "transaction" or | ||
| "statement" does not support prepared statements properly. | ||
| You have two options: | ||
| * if you are using pgbouncer for connection pooling to a | ||
| single server, switch to the connection pool functionality | ||
| provided by asyncpg, it is a much better option for this | ||
| purpose; | ||
| * if you have no option of avoiding the use of pgbouncer, | ||
| then you can set statement_cache_size to 0 when creating | ||
| the asyncpg connection object. | ||
| """) | ||
|
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| dct['hint'] = hint | ||
|
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| return exccls, message, dct | ||
|
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| def as_dict(self): | ||
| dct = {} | ||
| for f in type(self)._field_map.values(): | ||
| val = getattr(self, f) | ||
| if val is not None: | ||
| dct[f] = val | ||
| return dct |