cpython/Include
Emma Smith 3b4333583f
gh-132983: Introduce _zstd bindings module (GH-133027)
* Add _zstd module for https://peps.python.org/pep-0784/

This commit introduces the `_zstd` module, with bindings to libzstd from
the pyzstd project. It also includes the unix build system configuration.
Windows build system support will be integrated independently as it
depends on integration with cpython-source-deps.

* Add _zstd to modules

* Fix path for compression.zstd module

* Ignore _zstd module like _io

* Expand module state macros to improve code quality

Also removes module state references from the classes in the _zstd
module and instead uses PyType_GetModuleState()

* Remove backticks suggested in review

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>

* Use critical sections to lock object state

This should avoid races and deadlocks.

* Remove compress/decompress and mark module as not reliant on the GIL

The `compress`/`decompress` functions will be moved to Python code for simplicity.
C implementations can always be re-added in the future.

Also, mark _zstd as not requiring the GIL.

* Lift critical section to avoid clang warning

* Respond to comments by picnixz

* Call out pyzstd explicitly in license description

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

* Use a much more robust implementation...

... for `get_zstd_state_from_type`

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

* Use PyList_GetItemRef for thread safety purposes

* Use a macro for the minimum supported version

* remove const from primivite types

* Use PyMem_New in another spot

* Simplify error handling in _get_frame_size

* Another simplification of error handling in get_frame_info

* Rename _module_state to mod_state

* Rewrite comment explaining the context of the code

* Add link to pyzstd

* Add TODO about refactoring dict training code

* Use PyModule_AddObjectRef over PyModule_AddObject

PyModule_AddObject is soft-deprecated, so we should use PyModule_AddObjectRef

* Check result of OutputBufferGrow

* Simplify return logic in `add_constant_to_type`

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

* Ignore return value of _zstd_clear()

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

* Remove redundant comments

* Remove __reduce__ from ZstdDict

We should instead document that to pickle a dictionary a user should use
the `.dict_content` attribute.

* Use PyUnicode_FromFormat instead of a buffer

* Don't use C constants/types in error messages

* Make error messages easier to understand for Python users

* Lower minimum required version 1.4.0

* Use casts and make slot function signatures correct

* Be consistent with CPython on const usage

* Make else clauses in line with PEP 7

* Fix over-indented blocks in argument clinic

* Add critical section around ZSTD_DCtx_setParameter

* Add a TODO about refactoring critical sections

* Use Py_UNREACHABLE

* Move bytes operations out of Py_BEGIN_ALLOW_THREADS

* Add TODO about ensuring a lock is held

* Remove asserts that may not be correct

* Add TODO to make ZstdDict and others GC objects

* Make objects GC tracked

* Remove unused include

* Fix some memory issues

* Fix refleaks on module and in ZstdDict

* Update configure to check for ZDICT_finalizeDictionary

* Properly check version in configure

* exit(1) if check fails

* Use AC_RUN_IFELSE

* Use a define() to re-use version check

* Actually properly set _zstd module status based on version

---------

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
2025-05-04 01:29:55 +00:00
..
cpython gh-128972: Add _Py_ALIGN_AS and revert PyASCIIObject memory layout. (GH-133085) 2025-05-02 18:30:40 +02:00
internal gh-132983: Introduce _zstd bindings module (GH-133027) 2025-05-04 01:29:55 +00:00
abstract.h gh-130947: Add again PySequence_Fast() to the limited C API (#130948) 2025-03-13 13:00:57 +01:00
audit.h gh-125604: Move _Py_AuditHookEntry, etc. Out of pycore_runtime.h (gh-125605) 2024-10-18 09:26:08 -06:00
bltinmodule.h these builtins have to be initialized 2009-05-09 18:10:51 +00:00
boolobject.h gh-115754: Add Py_GetConstant() function (#116883) 2024-03-21 16:07:00 +00:00
bytearrayobject.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
bytesobject.h gh-108765: Move standard includes to Python.h (#108769) 2023-09-01 21:03:20 +02:00
ceval.h GH-120507: Lower the BEFORE_WITH and BEFORE_ASYNC_WITH instructions. (#120640) 2024-06-18 12:17:46 +01:00
codecs.h Remove private _PyCodec_Lookup() function (#106269) 2023-06-30 09:34:01 +00:00
compile.h gh-109596: Ensure repeated rules in the grammar are not allowed and fix incorrect soft keywords (#109606) 2023-09-22 19:03:23 +01:00
complexobject.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
critical_section.h gh-119344: Make critical section API public (#119353) 2024-06-21 15:50:18 -04:00
datetime.h gh-87347: Add parenthesis around macro arguments (#93915) 2022-06-20 16:04:52 +02:00
descrobject.h gh-103509: PEP 697 -- Limited C API for Extending Opaque Types (GH-103511) 2023-05-04 09:56:53 +02:00
dictobject.h gh-106004: PyDict_GetItemRef() should only be in the limited API 3.13 (GH-107229) 2023-07-25 21:48:07 +03:00
dynamic_annotations.h gh-96959: Update HTTP links which are redirected to HTTPS (GH-96961) 2022-09-24 14:38:53 +03:00
enumobject.h Implement and apply PEP 322, reverse iteration 2003-11-06 14:06:48 +00:00
errcode.h gh-107450: Check for overflow in the tokenizer and fix overflow test (#110832) 2023-10-16 16:42:49 +02:00
exports.h gh-121040: Use __attribute__((fallthrough)) (#121044) 2024-06-27 09:58:44 +00:00
fileobject.h gh-106320: Remove _PyIsSelectable_fd() C API (#107142) 2023-07-23 19:07:12 +00:00
fileutils.h gh-108765: Move stat() fiddling from pyport.h to fileutils.h (#108854) 2023-09-03 21:32:13 +00:00
floatobject.h gh-120026: soft deprecate Py_HUGE_VAL macro (#120027) 2024-11-01 22:04:31 +00:00
frameobject.h bpo-45434: Remove useless space in includes (GH-28963) 2021-10-15 01:50:04 +02:00
genericaliasobject.h bpo-44654: Refactor and clean up the union type implementation (GH-27196) 2021-07-17 22:44:10 +03:00
import.h gh-105922: Add PyImport_AddModuleRef() function (#105923) 2023-06-20 08:48:14 +02:00
intrcheck.h gh-106320: Remove private _PyOS_IsMainThread() function (#108605) 2023-08-29 03:20:31 +00:00
iterobject.h gh-106320: Remove _PyAnextAwaitable_Type from the public C API (#108597) 2023-08-29 02:05:11 +00:00
listobject.h gh-114329: Fix PyList_GetItemRef() limited C API definition (#117520) 2024-04-03 21:02:42 +00:00
lock.h gh-117511: Make PyMutex public in the non-limited API (#117731) 2024-06-20 11:29:08 -04:00
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-125063: marshal: Add version 5, improve documentation (GH-126829) 2024-11-15 13:48:57 +01:00
memoryobject.h gh-79315: Add Include/cpython/memoryobject.h header (#99723) 2022-11-23 15:44:42 +01:00
methodobject.h gh-132097: use a macro for semantically casting function pointers (#132406) 2025-04-18 12:24:34 +02:00
modsupport.h gh-112136: Restore removed _PyArg_Parser (#121262) 2024-07-03 18:36:57 +02:00
moduleobject.h gh-116322: Rename PyModule_ExperimentalSetGIL to PyUnstable_Module_SetGIL (GH-118645) 2024-05-06 18:59:36 +02:00
monitoring.h gh-111997: C-API for signalling monitoring events (#116413) 2024-05-04 08:23:50 +00:00
object.h Revert gh-127266: avoid data races when updating type slots (gh-131174) (gh-133129) 2025-04-28 23:38:29 -07:00
objimpl.h gh-102013: Move PyUnstable_GC_VisitObjects() to Include/cpython/objimpl.h (#115560) 2024-02-16 15:49:13 +01:00
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-100239: specialize BINARY_OP/SUBSCR for list-slice (#132626) 2025-05-01 10:28:52 +00:00
osdefs.h gh-108765: Reformat Include/osdefs.h (#108766) 2023-09-01 14:35:39 +00:00
osmodule.h Issue #29058: All stable API extensions added after Python 3.2 are now 2016-12-27 14:57:39 +02:00
patchlevel.h Post 3.14.0a7 2025-04-08 17:06:51 +03:00
py_curses.h gh-123961: Add a global state to _curses (#124729) 2024-09-29 15:17:20 +00:00
pyatomic.h gh-108724: Add PyMutex and _PyParkingLot APIs (gh-109344) 2023-09-19 09:54:29 -06:00
pybuffer.h gh-102500: Implement PEP 688 (#102521) 2023-05-04 07:59:46 -07:00
pycapsule.h gh-108240: Add pycore_capsule.h internal header file (#108596) 2023-08-29 01:20:02 +00:00
pydtrace.d bpo-36842: Implement PEP 578 (GH-12613) 2019-05-23 08:45:22 -07:00
pydtrace.h Fix pydtrace.d path comment in Include/pydtrace.h (#28539) 2022-12-31 22:40:25 +05:30
pyerrors.h gh-119521: Rename IncompleteInputError to _IncompleteInputError and remove from public API/ABI (GH-119680) 2024-06-24 14:08:12 +02:00
pyexpat.h gh-115398: Revert PyExpat_CAPI_MAGIC version bump (GH-116411) 2024-03-06 09:55:07 -08:00
pyframe.h gh-93937, C API: Move PyFrame_GetBack() to Python.h (#93938) 2022-06-19 12:02:33 +02:00
pyhash.h gh-111545: Add Include/cpython/pyhash.h header file (#112063) 2023-11-15 01:19:20 +01:00
pylifecycle.h gh-117987: Restore several functions removed in Python 3.13 alpha 1 (GH-117993) 2024-04-18 15:20:38 +02:00
pymacconfig.h gh-110820: Make sure processor specific defines are correct for Universal 2 build on macOS (#112828) 2023-12-08 10:09:34 +01:00
pymacro.h gh-128972: Add _Py_ALIGN_AS and revert PyASCIIObject memory layout. (GH-133085) 2025-05-02 18:30:40 +02:00
pymath.h gh-120026: soft deprecate Py_HUGE_VAL macro (#120027) 2024-11-01 22:04:31 +00:00
pymem.h gh-85283: Add PyMem_RawMalloc() to the limited C API (#108570) 2023-10-17 02:41:51 +02:00
pyport.h gh-133256: Add _Py_NONSTRING macro (#133257) 2025-05-01 17:55:49 +02:00
pystate.h gh-108867: Add PyThreadState_GetUnchecked() function (#108870) 2023-10-03 16:53:51 +00:00
pystats.h GH-124284: Add stats for refcount operations on immortal objects (GH-124288) 2024-09-23 19:10:55 +01:00
pystrcmp.h Merged revisions 59541-59561 via svnmerge from 2007-12-19 02:07:34 +00:00
pystrtod.h gh-106320: Remove private float C API functions (#108430) 2023-08-24 19:09:49 +02:00
Python.h gh-127271: Replace use of PyCell_GET/SET (gh-127272) 2024-12-03 10:33:06 -08:00
pythonrun.h GH-124715: Move trashcan mechanism into Py_Dealloc (GH-132280) 2025-04-30 11:37:53 +01:00
pythread.h gh-87135: Hang non-main threads that attempt to acquire the GIL during finalization (GH-105805) 2024-10-02 09:17:49 -07:00
pytypedefs.h bpo-45459: Fix PyModuleDef_Slot type in the limited C API (GH-31668) 2022-03-03 23:06:55 +01:00
rangeobject.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
README.rst gh-101101: Unstable C API tier (PEP 689) (GH-101102) 2023-02-28 09:31:01 +01:00
refcount.h Revert gh-127266: avoid data races when updating type slots (gh-131174) (gh-133129) 2025-04-28 23:38:29 -07:00
setobject.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
sliceobject.h gh-115754: Add Py_GetConstant() function (#116883) 2024-03-21 16:07:00 +00:00
structmember.h Fix typos in comments (#120188) 2024-06-07 10:19:41 +02:00
structseq.h gh-106168: PyTuple_SET_ITEM() now checks the index (#106164) 2023-06-28 03:45:57 +02:00
sysmodule.h gh-125604: Move _Py_AuditHookEntry, etc. Out of pycore_runtime.h (gh-125605) 2024-10-18 09:26:08 -06:00
traceback.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
tupleobject.h gh-87347: Add parenthesis around PyXXX_Check() arguments (#92815) 2022-06-16 13:49:43 +02:00
typeslots.h gh-124153: Implement PyType_GetBaseByToken() and Py_tp_token slot (GH-124163) 2024-09-18 09:18:19 +02:00
unicodeobject.h gh-132798: Schedule removal of PyUnicode_AsDecoded/Encoded functions for 3.15 (#132799) 2025-04-25 15:07:41 +02:00
warnings.h bpo-35134: Split warnings.h and weakrefobject.h (GH-29042) 2021-10-19 01:31:57 +02:00
weakrefobject.h gh-105927: Limit PyWeakref_GetRef() to limited C API 3.13 (#117091) 2024-03-20 23:52:23 +01:00

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/