cpython/Include
Emma Smith f262297d52
gh-139877: Use PyBytesWriter in pycore_blocks_output_buffer.h (#139976)
Previously, the _BlocksOutputBuffer code creates a list of bytes objects to handle the output data from compression libraries. This ends up being slow due to the output buffer code needing to copy each bytes element of the list into the final bytes object buffer at the end of compression.

The new PyBytesWriter API introduced in PEP 782 is an ergonomic and fast method of writing data into a buffer that will later turn into a bytes object. Benchmarks show that using the PyBytesWriter API is 10-30% faster for decompression across a variety of settings. The performance gains are greatest when the decompressor is very performant, such as for Zstandard (and likely zlib-ng). Otherwise the decompressor can bottleneck decompression and the gains are more modest, but still sizable (e.g. 10% faster for zlib)!

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
2025-10-14 10:03:55 -07:00
..
cpython gh-139640: Fix swallowing syntax warnings in different modules (GH-139755) 2025-10-14 17:48:09 +03:00
internal gh-139877: Use PyBytesWriter in pycore_blocks_output_buffer.h (#139976) 2025-10-14 10:03:55 -07:00
abstract.h gh-134989: Implement PyObject_DelAttr() as a macro in the limited C API (GH-135021) 2025-06-04 15:07:52 +02:00
audit.h gh-135755: Use private names (_Py*) for header file guards new in 3.14 (GH-135921) 2025-06-26 13:05:01 +02:00
bltinmodule.h
boolobject.h gh-134989: Fix Py_RETURN_NONE in the limited C API (GH-135165) 2025-06-05 14:43:47 +02:00
bytearrayobject.h
bytesobject.h
ceval.h gh-135755: Move SPECIAL_ constants to a private header (GH-135922) 2025-06-25 13:03:05 +02:00
codecs.h
compile.h
complexobject.h
critical_section.h
datetime.h
descrobject.h
dictobject.h
dynamic_annotations.h
enumobject.h
errcode.h
exports.h
fileobject.h
fileutils.h gh-67341: fix a typo in Include/fileutils.h (#136049) 2025-07-14 08:02:05 +00:00
floatobject.h gh-120026: soft deprecate Py_HUGE_VAL macro (#120027) 2024-11-01 22:04:31 +00:00
frameobject.h
genericaliasobject.h
import.h gh-133644: remove deprecated PyImport_ImportModuleNoBlock (#133655) 2025-05-08 13:08:43 +00:00
intrcheck.h
iterobject.h
listobject.h
longobject.h gh-132639: Adds PyLong_AsNativeBytes, PyLong_FromNativeBytes and PyLong_FromUnsignedNativeBytes to the limited API (GH-132640) 2025-04-21 15:59:03 +01:00
marshal.h gh-79315: Add Include/cpython/marshal.h header (#139725) 2025-10-07 23:49:08 +02:00
memoryobject.h
methodobject.h gh-132097: use a macro for semantically casting function pointers (#132406) 2025-04-18 12:24:34 +02:00
modsupport.h gh-137210: Move PYTHON_API_VERSION & PYTHON_ABI_VERSION to patchlevel.h (GH-138545) 2025-09-08 12:02:13 +02:00
moduleobject.h gh-137210: Add a struct, slot & function for checking an extension's ABI (GH-137212) 2025-09-05 16:23:18 +02:00
object.h gh-137956: Guard against non-free-threaded extensions in free-threaded builds (GH-137957) 2025-09-15 11:24:16 +00:00
objimpl.h
opcode.h gh-100239: replace BINARY_SUBSCR & family by BINARY_OP with oparg NB_SUBSCR (#129700) 2025-02-07 22:39:54 +00:00
opcode_ids.h GH-134282: Always borrow references LOAD_CONST (GH-134284) 2025-05-20 11:24:11 -04:00
osdefs.h
osmodule.h
patchlevel.h Post 3.15.0a1 2025-10-14 17:36:01 +03:00
py_curses.h gh-125843: indicate which C function caused a curses.error (#125844) 2025-05-19 15:53:39 +02:00
pyatomic.h
pybuffer.h
pycapsule.h
pydtrace.d
pydtrace.h
pyerrors.h
pyexpat.h gh-90949: expose Expat API to tune exponential expansion protections (#139368) 2025-09-28 08:27:04 +00:00
pyframe.h
pyhash.h
pylifecycle.h gh-133644: Remove deprecated Python initialization getter functions (#133661) 2025-05-09 11:39:23 +00:00
pymacconfig.h
pymacro.h gh-138143: Allow anonymous unions in public headers, using _Py_ANONYMOUS (GH-137283) 2025-08-26 11:14:35 +02:00
pymath.h gh-136006: fix Py_NAN expansion on Solaris systems (#136575) 2025-09-10 11:11:04 +02:00
pymem.h
pyport.h gh-137058: Update C23 standard version check in pyport.h (#137127) 2025-07-27 09:47:21 +02:00
pystate.h
pystats.h GH-124284: Add stats for refcount operations on immortal objects (GH-124288) 2024-09-23 19:10:55 +01:00
pystrcmp.h
pystrtod.h
Python.h gh-79315: Remove Include/pylock.h and Include/monitoring.h (#139731) 2025-10-08 00:49:24 +02:00
pythonrun.h gh-130396: Move PYOS_LOG2_STACK_MARGIN to internal headers (#135928) 2025-07-01 15:18:17 +02:00
pythread.h gh-137884: Added threading.get_native_id() on Illumos/Solaris (GH-137927) 2025-08-20 17:10:44 +00:00
pytypedefs.h
rangeobject.h
README.rst
refcount.h gh-111506: Add _Py_OPAQUE_PYOBJECT to hide PyObject layout & related API (GH-136505) 2025-07-12 09:55:12 +02:00
setobject.h
sliceobject.h gh-79315: Add Include/cpython/sliceobject.h header (#139729) 2025-10-08 00:48:18 +02:00
structmember.h
structseq.h gh-79315: Add Include/cpython/structseq.h header (#139730) 2025-10-08 01:19:50 +02:00
sysmodule.h gh-138886: Remove deprecated PySys_ResetWarnOptions C-API function (#138887) 2025-09-15 12:01:33 +03:00
traceback.h
tupleobject.h
typeslots.h Revert "gh-133395: add option for extension modules to specialize BINARY_OP/SUBSCR, apply to arrays (#133396)" (#133498) 2025-05-06 13:12:26 +03:00
unicodeobject.h gh-133610: Remove PyUnicode_AsDecoded/Encoded functions (#133612) 2025-05-09 17:31:24 +02:00
warnings.h
weakrefobject.h gh-133644: remove PyWeakref_GetObject and PyWeakref_GET_OBJECT (GH-133657) 2025-09-24 11:25:56 +02:00

The Python C API
================

The C API is divided into these sections:

1. ``Include/``: Limited API
2. ``Include/cpython/``: CPython implementation details
3. ``Include/cpython/``, names with the ``PyUnstable_`` prefix: API that can
   change between minor releases
4. ``Include/internal/``, and any name with ``_`` prefix: The internal API

Information on changing the C API is available `in the developer guide`_

.. _in the developer guide: https://devguide.python.org/c-api/