Substrait Packaging

Machinery for releasing Substrait code artifacts based on specification releases across multiple languages. This includes things like:

• Generated Protobuf Bindings
• Generated ANTLR Bindings
• Generated YAML Bindings

How It Works

Artifacts are generated and published using a hierarchy of GitHub Actions:

• publish_artifacts.yml: For releasing artifacts across all languages
  • java_publish.yml: For releasing Java specific artifacts
    • java_antlr.yml
    • java_protobuf.yml
    • java_extensions.yml
  • python_publish.yml: For releasing Python specific artifacts
    • python_antlr.yml
    • python_protobuf.yml
    • python_extensions.yml
  • rust_publish.yml: For releasing Rust specific artifacts
    • rust_antlr.yml
    • rust_protobuf.yml
    • rust_extensions.yml
  • cpp_publish.yml: For releasing C++ specific artifacts
    • cpp_antlr.yml
    • cpp_protobuf.yml
    • cpp_extensions.yml

Each of these workflows consumes a required substrait_version input. They are intended to be invoked by their parent workflow, but can be also be invoked directly to release specific artifacts.

The spec_released.yml workflow is a thin-wrapper around publish_artifacts.yml which is designed to be invoked whenever a new version of substrait specification is released.

The ci_java.yml, ci_python.yml, ci_rust.yml and ci_cpp.yml workflows run on pull requests and pushes to main. They validate the packaging machinery against the most recent substrait spec release by running the same generate + build + test steps as the publish workflows, but without versioning, committing, tagging or publishing. This catches changes that would break a real release before they are merged. Each only runs when its language's relevant paths change (via a paths filter), and a specific spec version can be validated on demand via the workflow_dispatch substrait_version input.

Re-usable scripts for use across these workflows can be found in /scripts.

Development

Pixi is used to manage codegen tooling, both locally and in CI. Install it via the official instructions.

# Install dependencies and update pixi.lock
pixi install

Python Code Generation

# Generate substrait-antlr Python Package
pixi run python-generate-antlr

# Generate substrait-protobuf Python Package
pixi run python-generate-protobuf

# Generate substrait-extensions Python Package
pixi run python-generate-extensions

Java Code Generation

Java artifacts are built with Gradle; code is generated at build time. See java/README.md for details.

# Generate antlr Java parsers
pixi run java-generate-antlr

# Generate protobuf Java code
pixi run java-generate-protobuf

# Build and test all Java artifacts
pixi run java-build

Rust Code Generation

# Generate substrait-antlr Rust crate (requires java; downloads a forked ANTLR JAR)
pixi run rust-generate-antlr

# Vendor protobuf definitions for the substrait-prost Rust crate
pixi run rust-generate-prost

# Package Substrait extensions files for the substrait-extensions Rust crate
pixi run rust-generate-extensions

The protobuf and extensions crates generate their Rust code at build time (with prost-build and typify respectively), so the generation scripts only vendor the spec inputs into the crate; building substrait-prost requires protoc. The ANTLR parsers cannot be generated at build time (the Rust target needs a forked ANTLR build and Java), so they are committed by the generation script.

C++ Code Generation

# Vendor protobuf definitions for the substrait-protobuf C++ package
pixi run cpp-generate-protobuf

# Generate substrait-antlr C++ parsers (requires java for the ANTLR tool)
pixi run cpp-generate-antlr

# Package Substrait extensions files for the substrait-extensions C++ package
pixi run cpp-generate-extensions

The C++ packages are distributed as CMake source packages on git tags (cpp/<package>/vx.y.z); consumers pull them with CMake FetchContent. There is no registry upload — pushing the tag publishes the package.

The protobuf package vendors the .proto files and generates C++ at build time with the consumer's own protoc (C++ protobuf code is ABI-coupled to a protobuf runtime, so committing generated sources would pin every consumer to one protobuf version). The ANTLR parsers are committed (stock ANTLR C++ target, no fork) and the substrait-antlr CMakeLists.txt builds the ANTLR C++ runtime hermetically via FetchContent. The extensions package is data-only — C++ has no canonical YAML/JSON schema code generation (unlike Rust's typify or Python's datamodel-code-generator), so it ships the raw spec data and the typed parsing lives downstream in the consumer.