Build regular CPython wheels against the Python 3.11 stable ABI

.github/workflows/ci.yml

@@ -48,6 +48,80 @@ jobs:
       - name: Run tox -e ${{ matrix.tox_env }}
         run: tox -e ${{ matrix.tox_env }}
 
+  build-abi3-test-wheel:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: ["ubuntu-latest", "macos-15-intel", "macos-latest", "windows-latest",
+             "windows-11-arm"]
+    defaults:
+      run:
+        shell: bash
+    steps:
+      - uses: actions/checkout@v7
+        with:
+          submodules: recursive
+          fetch-depth: 0
+      - uses: actions/setup-python@v7
+        with:
+          python-version: "3.11"
+      - name: Install build dependencies (macOS)
+        if: runner.os == 'macOS'
+        run: brew install make
+      - uses: ilammy/msvc-dev-cmd@v1
+        if: runner.os == 'Windows'
+        with:
+          arch: ${{ matrix.os == 'windows-11-arm' && 'arm64' || 'x64' }}
+      - name: Build and audit the stable ABI wheel
+        run: |
+          python -m pip install build abi3audit
+          python -m build --wheel --outdir wheelhouse
+          python -m abi3audit --strict wheelhouse/*-cp311-abi3-*.whl
+      - uses: actions/upload-artifact@v4
+        with:
+          name: abi3-test-${{ matrix.os }}
+          path: wheelhouse/*.whl
+
+  test-abi3-wheel:
+    needs: build-abi3-test-wheel
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: ["ubuntu-latest", "macos-15-intel", "macos-latest", "windows-latest",
+             "windows-11-arm"]
+        python-version: ["3.11", "3.12", "3.13", "3.14", "3.15"]
+    defaults:
+      run:
+        shell: bash
+    env:
+      PYTHONDEVMODE: "1"
+    steps:
+      - uses: actions/checkout@v7
+      - uses: actions/setup-python@v7
+        with:
+          python-version: ${{ matrix.python-version }}
+          allow-prereleases: true
+      - uses: actions/download-artifact@v4
+        with:
+          name: abi3-test-${{ matrix.os }}
+          path: wheelhouse
+      - name: Install the same wheel on each Python version
+        run: |
+          python -m pip install pytest pytest-timeout
+          python -m pip install --no-index --find-links wheelhouse zlib-ng
+      - name: Run the tests available in this interpreter
+        run: |
+          python - <<'PYTEST'
+          import importlib.util
+          import subprocess
+          import sys
+          command = [sys.executable, "-m", "pytest", "tests"]
+          if importlib.util.find_spec("test") is None:
+              command += ["--ignore=tests/test_zlib_compliance.py",
+                          "--ignore=tests/test_gzip_compliance.py"]
+          raise SystemExit(subprocess.call(command))
+          PYTEST
+
   test-static:
     runs-on: ${{ matrix.os }}
     strategy:
@@ -70,6 +144,8 @@ jobs:
             python-version: "3.11"
           - os: "windows-latest"
             python-version: "3.11"
+          - os: "windows-latest"
+            python-version: "3.14t"
           - os: "windows-11-arm"
             python-version: "3.11"
     steps:
@@ -179,15 +255,15 @@ jobs:
           submodules: recursive
       - name: Install build dependencies
         run: apt-get update && apt-get install -y cmake
-      - name: Install python-isal with ${{ matrix.sanitizer }} sanitizer
+      - name: Install python-zlib-ng with ${{ matrix.sanitizer }} sanitizer
         # setuptools-scm needs git, and the container user does not own the
         # repository.
         run: |
           git config --global --add safe.directory "$GITHUB_WORKSPACE"
           python -m pip install . pytest pytest-timeout
         env:
           # The extension modules get -fsanitize from CPython. CFLAGS adds it
-          # to the C code of ISA-L.
+          # to the C code of zlib-ng.
           CFLAGS: -fsanitize=${{ matrix.sanitizer }} -fno-omit-frame-pointer -g
       - name: Run tests
         # Do not set PYTHONDEVMODE. Its debug allocator pads each allocation,
@@ -205,6 +281,7 @@ jobs:
       - lint
       - package-checks
       - test-static
+      - test-abi3-wheel
       - test-dynamic
       - test-arch
       - test-sanitizers
@@ -231,6 +308,7 @@ jobs:
       - lint
       - package-checks
       - test-static
+      - test-abi3-wheel
       - test-dynamic
       - test-arch
       - test-sanitizers
@@ -273,24 +351,27 @@ jobs:
         run: cibuildwheel --output-dir dist
         env:
           CIBW_ENABLE: "pypy"
-          # Skip 32 bit, macosx_arm64 causes issues on cpython 3.9
-          CIBW_SKIP: "*-win32 *-manylinux_i686 cp38-macosx_arm64 cp39-win_arm64 cp310-win_arm64"
+          # Skip 32 bit
+          CIBW_SKIP: "*-win32 *-manylinux_i686"
           CIBW_ARCHS_LINUX: ${{ matrix.cibw_archs_linux }}
           CIBW_TEST_REQUIRES: "pytest"
           # Simple tests that requires the project to be build correctly
           CIBW_TEST_COMMAND_LINUX: >-
             pytest {project}/tests/test_zlib_compliance.py 
             {project}/tests/test_gzip_compliance.py
             {project}/tests/test_gzip_ng.py
+            {project}/tests/test_stable_abi.py
           CIBW_TEST_COMMAND_MACOS: >-
             pytest {project}/tests/test_zlib_compliance.py 
             {project}/tests/test_gzip_compliance.py
             {project}/tests/test_gzip_ng.py
+            {project}/tests/test_stable_abi.py
           # Windows does not have the test module in the included python.
           # Run compatibility tests instead.
           CIBW_TEST_COMMAND_WINDOWS: >-
             pytest {project}/tests/test_compat.py
             {project}/tests/test_gzip_ng.py
+            {project}/tests/test_stable_abi.py
           CIBW_ENVIRONMENT_LINUX: >-
             PYTHON_ZLIB_NG_BUILD_CACHE=True
             PYTHON_ZLIB_NG_BUILD_CACHE_FILE=/tmp/build_cache
@@ -302,6 +383,12 @@ jobs:
             PYTHON_ZLIB_NG_BUILD_CACHE=True
             PYTHON_ZLIB_NG_BUILD_CACHE_FILE=${{ runner.temp }}/build_cache
             CFLAGS="-O3 -DNDEBUG"
+      - name: Audit the stable ABI wheels
+        # bash expands the wheel glob on Windows too.
+        shell: bash
+        run: |
+          python -m pip install abi3audit
+          python -m abi3audit --strict dist/*-cp311-abi3-*.whl
       - uses: actions/upload-artifact@v7
         with:
           name: "cibw-${{ runner.os }}-${{ runner.arch }}-${{ matrix.cibw_archs_linux }}"

CHANGELOG.rst

@@ -7,6 +7,50 @@ Changelog
 .. This document is user facing. Please word the changes in such a way
 .. that users understand how the changes affect the new version.
 
+version 1.1.1-dev
+-----------------
++ Regular CPython 3.11 and newer share one stable ABI wheel per platform, so
+  new CPython releases no longer need new wheels. PyPy and free-threaded
+  CPython keep their interpreter-specific wheels.
++ On the stable ABI wheels, calls whose output size is not known in advance
+  copy their result once more and briefly hold that extra copy in memory:
+  ``zlib_ng.compress()``, ``zlib_ng.decompress()``, ``compressobj()`` output,
+  and ``decompressobj().decompress()`` and ``_ZlibDecompressor.decompress()``
+  without ``max_length``. In the project's benchmark, decompressing 16 MiB took
+  up to 19% longer, and the worst case, 1 MiB of zeros, took 2.74 times as
+  long; compression times did not change measurably. ``gzip_ng`` file reads
+  avoid the copy, and so does ``_ZlibDecompressor.decompress(data,
+  max_length)`` when the output fills a ``max_length`` of at most 16 MiB. A
+  bounded call that returns less than its limit copies the shorter result
+  while still holding the full allocation. With a larger limit, the copy is
+  also made by ``_ZlibDecompressor.decompress(data, max_length)`` above 16 MiB
+  and by ``decompressobj().decompress(data, max_length)`` above 16 KiB, which
+  briefly holds up to twice ``max_length``. PyPy and free-threaded CPython are
+  not affected.
++ Compression or decompression whose output ends exactly at the size of its
+  current output buffer no longer grows that buffer once more before
+  returning.
++ ``crc32_combine()`` and the internal ``_GzipReader.read()`` and
+  ``_GzipReader.seek()`` raise ``TypeError`` instead of ``SystemError`` for
+  arguments of the wrong type.
++ ``_ZlibDecompressor`` uses the ``zdict`` it was given for a stream that
+  needs a preset dictionary, and otherwise raises ``zlib_ng.error``, instead
+  of raising ``SystemError`` in both cases.
++ ``_ZlibDecompressor.decompress()`` no longer loses input when given more than
+  4 GiB of data and a ``max_length`` that stops it early; the bytes are kept
+  for the next call or in ``unused_data``.
++ ``decompressobj().decompress()`` no longer loses unread input beyond the
+  first 4 GiB of one call when the output limit or the end of the stream is
+  reached; it is kept in ``unconsumed_tail`` or ``unused_data``.
++ The internal ``_GzipReader.readinto()`` raises ``TypeError`` for a read-only
+  buffer instead of writing into it, which crashed on a read-only ``mmap``.
++ Reading with ``gzip_ng.open()`` from a file object whose ``read`` attribute
+  lookup raises an error other than ``AttributeError`` now raises that error
+  instead of an unrelated ``TypeError``.
++ A failure while importing ``zlib_ng``, such as running out of memory, is
+  reported as that error instead of ``SystemError`` and no longer leaks the
+  partially created module.
+
 version 1.1.0
 -----------------
 + Python 3.10 and PyPy 3.10 are no longer supported. Added support for PyPy