zarrs bindings [do not merge]

.github/workflows/zarrs.yml

@@ -0,0 +1,34 @@
+name: Zarrs bindings
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        with:
+          fetch-depth: 0  # hatch-vcs needs tags to compute zarr's version
+          persist-credentials: false
+      - name: Install uv
+        uses: astral-sh/setup-uv@fac544c07dec837d0ccb6301d7b5580bf5edae39 # v8.2.0
+        with:
+          python-version: '3.12'
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 # stable
+      - name: Run zarrs bindings tests
+        # the ubuntu runner image ships a Rust toolchain; the maturin build
+        # backend is fetched by uv on demand
+        run: uv run --group zarrs pytest tests/crud tests/zarrs -v

.gitignore

@@ -94,3 +94,6 @@ zarr.egg-info/
 
 # zarr-metadata package lockfile (a library, not an app)
 packages/zarr-metadata/uv.lock
+
+# zarrs-bindings Rust build artifacts
+packages/zarrs-bindings/target/

changes/+zarrs-bindings.feature.md

@@ -0,0 +1,9 @@
+Added `zarr.crud`, an experimental backend-agnostic low-level functional API for
+zarr hierarchy CRUD (`create_*`, `read_chunk`, `read_region`, `read_encoded_chunk`,
+`write_chunk`, `delete_chunk`, `read_metadata`, `delete_node`, `list_children`).
+Array routines take an explicit metadata document, enabling read-only views.
+Operations delegate to a pluggable `CrudBackend`: a pure-Python reference backend
+(the default) or the zarrs-accelerated backend in `zarr.zarrs`, backed by the Rust
+[zarrs](https://zarrs.dev) crate via the in-repo `zarrs-bindings` PyO3 crate.
+Select a backend with the `crud.backend` config key or a per-call `backend=`
+argument. Build the zarrs backend for development with `uv sync --group zarrs`.