Mesa Description

This PR introduces a new gRPC-based data plane for performing fine-grained, stateful Version Control System (VCS) operations. The existing REST-like API is not well-suited for high-frequency operations like building a commit from multiple file changes. This new gRPC service provides a high-performance, low-latency alternative, enabling a more efficient workflow for creating and modifying changes before they are committed.

Key Changes:

• gRPC API Definition (vcs.proto):

  • A new Protobuf schema defines three core services:
    • ControlService: For mutations (e.g., creating changes, applying file operations).
    • DataService: For read-only access (e.g., fetching commits, listing trees).
    • BlobTransferService: For efficient large object I/O.

• New ChangeClient:

  • Introduced a new high-level Rust client for interacting with the ControlService.
  • It provides methods to create a "change" from a branch, perform file operations (create, modify, delete, move) on it, and finally snapshot the result into a new commit.

• Build & Integration:

  • The build.rs script now automatically compiles the .proto file into Rust client code using tonic_prost_build.
  • Core gRPC dependencies (tonic, prost, tokio) have been added to the project.

• Client Configuration Refactor:

  • To integrate the new client configuration, many existing API clients were refactored to access configuration via a standardized path (&self.repo.org.client.config). This accounts for the large number of modified files.

• Testing:

  • A new suite of high-level integration tests has been added to validate the core functionality of the ChangeClient.
  • The test setup is now configured to initialize the MesaClient with a gRPC endpoint, configurable via the MESA_TEST_GRPC_ENDPOINT environment variable.

^{Description generated by Mesa. Update settings}