156 lines
4.7 KiB
Python
156 lines
4.7 KiB
Python
# engine/util.py
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# Copyright (C) 2005-2021 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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from .. import exc
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from .. import util
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from ..util import collections_abc
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from ..util import immutabledict
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def connection_memoize(key):
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"""Decorator, memoize a function in a connection.info stash.
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Only applicable to functions which take no arguments other than a
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connection. The memo will be stored in ``connection.info[key]``.
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"""
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@util.decorator
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def decorated(fn, self, connection):
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connection = connection.connect()
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try:
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return connection.info[key]
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except KeyError:
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connection.info[key] = val = fn(self, connection)
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return val
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return decorated
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_no_tuple = ()
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_no_kw = util.immutabledict()
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def _distill_params(connection, multiparams, params):
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r"""Given arguments from the calling form \*multiparams, \**params,
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return a list of bind parameter structures, usually a list of
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dictionaries.
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In the case of 'raw' execution which accepts positional parameters,
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it may be a list of tuples or lists.
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"""
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if not multiparams:
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if params:
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connection._warn_for_legacy_exec_format()
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return [params]
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else:
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return []
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elif len(multiparams) == 1:
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zero = multiparams[0]
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if isinstance(zero, (list, tuple)):
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if (
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not zero
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or hasattr(zero[0], "__iter__")
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and not hasattr(zero[0], "strip")
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):
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# execute(stmt, [{}, {}, {}, ...])
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# execute(stmt, [(), (), (), ...])
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return zero
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else:
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# this is used by exec_driver_sql only, so a deprecation
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# warning would already be coming from passing a plain
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# textual statement with positional parameters to
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# execute().
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# execute(stmt, ("value", "value"))
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return [zero]
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elif hasattr(zero, "keys"):
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# execute(stmt, {"key":"value"})
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return [zero]
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else:
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connection._warn_for_legacy_exec_format()
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# execute(stmt, "value")
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return [[zero]]
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else:
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connection._warn_for_legacy_exec_format()
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if hasattr(multiparams[0], "__iter__") and not hasattr(
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multiparams[0], "strip"
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):
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return multiparams
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else:
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return [multiparams]
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def _distill_cursor_params(connection, multiparams, params):
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"""_distill_params without any warnings. more appropriate for
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"cursor" params that can include tuple arguments, lists of tuples,
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etc.
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"""
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if not multiparams:
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if params:
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return [params]
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else:
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return []
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elif len(multiparams) == 1:
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zero = multiparams[0]
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if isinstance(zero, (list, tuple)):
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if (
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not zero
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or hasattr(zero[0], "__iter__")
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and not hasattr(zero[0], "strip")
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):
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# execute(stmt, [{}, {}, {}, ...])
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# execute(stmt, [(), (), (), ...])
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return zero
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else:
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# this is used by exec_driver_sql only, so a deprecation
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# warning would already be coming from passing a plain
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# textual statement with positional parameters to
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# execute().
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# execute(stmt, ("value", "value"))
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return [zero]
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elif hasattr(zero, "keys"):
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# execute(stmt, {"key":"value"})
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return [zero]
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else:
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# execute(stmt, "value")
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return [[zero]]
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else:
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if hasattr(multiparams[0], "__iter__") and not hasattr(
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multiparams[0], "strip"
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):
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return multiparams
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else:
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return [multiparams]
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def _distill_params_20(params):
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if params is None:
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return _no_tuple, _no_kw
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elif isinstance(params, list):
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# collections_abc.MutableSequence): # avoid abc.__instancecheck__
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if params and not isinstance(
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params[0], (collections_abc.Mapping, tuple)
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):
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raise exc.ArgumentError(
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"List argument must consist only of tuples or dictionaries"
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)
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return (params,), _no_kw
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elif isinstance(
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params,
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(tuple, dict, immutabledict),
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# avoid abc.__instancecheck__
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# (collections_abc.Sequence, collections_abc.Mapping),
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):
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return (params,), _no_kw
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else:
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raise exc.ArgumentError("mapping or sequence expected for parameters")
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