Replace c extension with cython versions.workflow_test_cython

Re-implement c version immutabledict / processors / resultproxy / utils with cython.
Performance is in general in par or better than the c version
Added a collection module that has cython version of OrderedSet and IdentitySet

Added a new test/perf file to compare the implementations.
Run ``python test/perf/compiled_extensions.py all`` to execute the comparison test.

See results here: https://docs.google.com/document/d/1nOcDGojHRtXEkuy4vNXcW_XOJd9gqKhSeALGG3kYr6A/edit?usp=sharing

Fixes: #7256
Change-Id: I2930ef1894b5048210384728118e586e813f6a76
Signed-off-by: Federico Caselli <cfederico87@gmail.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/lib/sqlalchemy/engine/processors.py b/lib/sqlalchemy/engine/processors.py
new file mode 100644
index 000000000..023444d10
--- /dev/null
+++ b/lib/sqlalchemy/engine/processors.py
@@ -0,0 +1,44 @@
+# sqlalchemy/processors.py
+# Copyright (C) 2010-2021 the SQLAlchemy authors and contributors
+# <see AUTHORS file>
+# Copyright (C) 2010 Gaetan de Menten gdementen@gmail.com
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: https://www.opensource.org/licenses/mit-license.php
+
+"""defines generic type conversion functions, as used in bind and result
+processors.
+
+They all share one common characteristic: None is passed through unchanged.
+
+"""
+from ._py_processors import str_to_datetime_processor_factory  # noqa
+
+try:
+    from sqlalchemy.cyextension.processors import (
+        DecimalResultProcessor,
+    )  # noqa
+    from sqlalchemy.cyextension.processors import int_to_boolean  # noqa
+    from sqlalchemy.cyextension.processors import str_to_date  # noqa
+    from sqlalchemy.cyextension.processors import str_to_datetime  # noqa
+    from sqlalchemy.cyextension.processors import str_to_time  # noqa
+    from sqlalchemy.cyextension.processors import to_float  # noqa
+    from sqlalchemy.cyextension.processors import to_str  # noqa
+
+    def to_decimal_processor_factory(target_class, scale):
+        # Note that the scale argument is not taken into account for integer
+        # values in the C implementation while it is in the Python one.
+        # For example, the Python implementation might return
+        # Decimal('5.00000') whereas the C implementation will
+        # return Decimal('5'). These are equivalent of course.
+        return DecimalResultProcessor(target_class, "%%.%df" % scale).process
+
+
+except ImportError:
+    from ._py_processors import int_to_boolean  # noqa
+    from ._py_processors import str_to_date  # noqa
+    from ._py_processors import str_to_datetime  # noqa
+    from ._py_processors import str_to_time  # noqa
+    from ._py_processors import to_decimal_processor_factory  # noqa
+    from ._py_processors import to_float  # noqa
+    from ._py_processors import to_str  # noqa