Author: Armin Rigo <ar...@tunes.org> Branch: Changeset: r2073:2393be9537f9 Date: 2015-05-21 10:00 +0200 http://bitbucket.org/cffi/cffi/changeset/2393be9537f9/
Log: Add an example purely for performance diff --git a/doc/source/overview.rst b/doc/source/overview.rst --- a/doc/source/overview.rst +++ b/doc/source/overview.rst @@ -198,6 +198,53 @@ .. _array: http://docs.python.org/library/array.html +.. _performance: + +Purely for performance (API level, out-of-line) +----------------------------------------------- + +A variant of the `section above`__ where the goal is not to call an +existing C library, but to compile and call some C function written +directly in the build script: + +.. __: real-example_ + +.. code-block:: python + + # file "example_build.py" + + from cffi import FFI + ffi = FFI() + + ffi.cdef("int foo(int *, int *, int);") + + ffi.set_source("_example", + """ + static int foo(int *buffer_in, int *buffer_out, int x) + { + /* some algorithm that is seriously faster in C than in Python */ + } + """) + + if __name__ == "__main__": + ffi.compile() + +.. code-block:: python + + # file "example.py" + + from _example import ffi, lib + + buffer_in = ffi.new("int[]", 1000) + # initialize buffer_in here... + + # easier to do all buffer allocations in Python and pass them to C, + # even for output-only arguments + buffer_out = ffi.new("int[]", 1000) + + result = lib.foo(buffer_in, buffer_out, 1000) + + What actually happened? ----------------------- _______________________________________________ pypy-commit mailing list pypy-commit@python.org https://mail.python.org/mailman/listinfo/pypy-commit
