substrait-prost

Generated Rust protobuf bindings for the Substrait specification, using prost.

The protobuf definitions from which the code is generated can be found here.

Versions of this crate correspond to Substrait releases. vx.y.z of substrait-prost contains code generated from vx.y.z of the substrait repository.

Usage

The generated types are available under the substrait package (crate root) and substrait.extensions (the extensions module):

use substrait_prost::{Plan, Version};
use substrait_prost::extensions::SimpleExtensionUrn;

The Rust code is generated at build time with prost-build from the vendored .proto files, so a protobuf compiler is required. By default that is protoc on the PATH; enable the protox feature to compile with a pure-Rust compiler and no external toolchain, or the protoc feature to build and vendor protoc from source.

Features

• serde — derive serde Serialize/Deserialize for the proto types via pbjson, following the Protobuf JSON Mapping.
• protoc — build and vendor protoc from source.
• protox — compile the .proto files with protox, a pure-Rust protobuf compiler (used by docs.rs).
• embed-descriptor — embed the protobuf file descriptor set (FILE_DESCRIPTOR_SET) for reflection.

Generation and Publishing

Code generation and publishing is handled in the substrait-packaging repository.

When a new version of the Substrait specification is released, automation vendors the protobuf definitions for that version and pushes them to GitHub with a tag formatted like rust/substrait-prost/vx.y.z. The automation then publishes that crate to crates.io.

Local Generation

The generate_protobuf.sh script can be executed locally to vendor the protobuf definitions. Set SUBSTRAIT_HOME to a directory containing the Substrait specification (defaults to ../../substrait).