Add benchmark tests

.github/workflows/benchmark.yml

@@ -0,0 +1,104 @@
+name: Benchmark
+
+on:
+  push:
+    branches:
+      - "**"
+    paths-ignore: &paths-ignore
+      - ".github/workflows/docs.yml"
+      - ".github/workflows/wheels*"
+      - ".gitmodules"
+      - "docs/**"
+      - "wheels/**"
+  pull_request:
+    paths-ignore: *paths-ignore
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  FORCE_COLOR: 1
+  PIP_DISABLE_PIP_VERSION_CHECK: 1
+
+jobs:
+  benchmark:
+
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [
+          "ubuntu-latest",
+        ]
+        python-version: [
+          # NB: Codspeed doesn't seem to support multiple runs of the same benchmark:
+          #     > At least one benchmark was run multiple times in your benchmarking workflow.
+          #     > This could be because you used a matrix that runs your benchmarks multiple times.
+          #     Hence, this list should only ever have exactly one version.
+          "3.14",
+        ]
+
+    runs-on: ${{ matrix.os }}
+    name: Benchmark ${{ matrix.os }} Python ${{ matrix.python-version }}
+
+    steps:
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      with:
+        persist-credentials: false
+
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+      with:
+        python-version: ${{ matrix.python-version }}
+        allow-prereleases: true
+        cache: pip
+        cache-dependency-path: |
+          ".ci/*.sh"
+          "pyproject.toml"
+
+    - name: Cache libavif
+      if: startsWith(matrix.os, 'ubuntu')
+      uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+      id: cache-libavif
+      with:
+        path: ~/cache-libavif
+        key: ${{ runner.os }}-libavif-${{ hashFiles('depends/install_libavif.sh', 'depends/libavif-svt4.patch') }}
+
+    - name: Cache libimagequant
+      if: startsWith(matrix.os, 'ubuntu')
+      uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+      id: cache-libimagequant
+      with:
+        path: ~/cache-libimagequant
+        key: ${{ runner.os }}-libimagequant-${{ hashFiles('depends/install_imagequant.sh') }}
+
+    - name: Cache libwebp
+      if: startsWith(matrix.os, 'ubuntu')
+      uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+      id: cache-libwebp
+      with:
+        path: ~/cache-libwebp
+        key: ${{ runner.os }}-libwebp-${{ hashFiles('depends/install_webp.sh') }}
+
+    - name: Install Linux dependencies
+      if: startsWith(matrix.os, 'ubuntu')
+      run: |
+        .ci/install.sh
+      env:
+        GHA_PYTHON_VERSION: ${{ matrix.python-version }}
+        GHA_LIBAVIF_CACHE_HIT: ${{ steps.cache-libavif.outputs.cache-hit }}
+        GHA_LIBIMAGEQUANT_CACHE_HIT: ${{ steps.cache-libimagequant.outputs.cache-hit }}
+        GHA_LIBWEBP_CACHE_HIT: ${{ steps.cache-libwebp.outputs.cache-hit }}
+
+    - name: Run CodSpeed benchmarks
+      uses: CodSpeedHQ/action@a4a36bb07c0638b0b4ca52bf1f3dad1b4289e52f # v4.18.1
+      if: ${{ matrix.os == 'ubuntu-latest' }}
+      with:
+        mode: simulation
+        run: |
+          python3 -m pip install -e . pytest-codspeed
+          pytest -vv --codspeed Tests/benchmarks.py