wip: do most of the processing on the client side - instead of the server #2641
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sylvestre wants to merge 21 commits intomozilla:mainfrom
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wip: do most of the processing on the client side - instead of the server #2641sylvestre wants to merge 21 commits intomozilla:mainfrom
sylvestre wants to merge 21 commits intomozilla:mainfrom
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Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #2641 +/- ##
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- Coverage 73.37% 72.84% -0.53%
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Files 68 73 +5
Lines 37337 37631 +294
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+ Hits 27395 27412 +17
- Misses 9942 10219 +277 ☔ View full report in Codecov by Sentry. 🚀 New features to boost your workflow:
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moved here #2642 |
- Add CacheGet/CachePut requests and responses to protocol - Add PreprocessorCacheGet/CachePut requests for preprocessor cache - Add CacheWrite::from_bytes() to construct from serialized data - Add CacheRead::into_bytes() to extract raw bytes - Add server handlers for cache get/put operations - Wire new handlers into SccacheService request handling This lays the foundation for moving cache operations from server to client while maintaining backward compatibility.
- Add client_compiler module with cache, compile, detect, hash, and preprocess submodules - Implement CompilerCache for client-side compiler information caching - Add detect_compiler wrapper for client-side compiler detection - Add placeholder implementations for hash generation, preprocessing, and local compilation - Register module in lib.rs This establishes the foundation for moving compilation logic from server to client.
- Add SCCACHE_CLIENT_SIDE_COMPILE environment variable check - Route to do_compile_client_side when flag is set to '1' - Add stub implementation of do_compile_client_side - Maintain backward compatibility with legacy server-side path When SCCACHE_CLIENT_SIDE_COMPILE=1, the client will handle compilation logic directly and use the server only for cache storage (once fully implemented). Defaults to legacy mode (0) for backward compatibility.
- Add compiler detection in client - Add argument parsing via compiler hasher - Add fallback to direct compilation for now - Add TODO comments for cache lookup/put implementation This provides the skeleton for client-side compilation. Currently falls back to direct compilation as cache operations are not yet wired up. The structure is in place for: - Preprocessing - Hash key generation - CacheGet request to server - Local compilation on miss - CachePut request to server
Document the complete refactoring progress including: - Completed work: protocol extensions, server handlers, client module, feature flag, basic flow - Remaining work: cache lookup/storage, protocol versioning, testing, performance optimization - Migration strategy with 5 phases - Architecture benefits and trade-offs - Testing instructions and next steps This provides a comprehensive overview of the client-side compilation refactoring effort.
- Add PROTOCOL_VERSION constant (v2) and PROTOCOL_VERSION_1 (legacy) - Document backward compatibility strategy in detail - Add Request::requires_v2() to check if request needs v2 server - Add Request::is_v1_compatible() to check v1 compatibility - Document compatibility matrix for all client/server combinations Versioning strategy: - Enum variants provide natural backward compatibility - Old clients work with new servers (send v1 requests) - New clients can detect and fall back to v1 if needed - New servers handle both v1 and v2 requests This enables gradual rollout without breaking existing deployments.
- Fix PreprocessorCacheEntry::read() usage in server - Fix detect_compiler signature to match get_compiler_info - Remove unused imports - Simplify do_compile_client_side to fall back to legacy mode All tests now pass (403 passed, 0 failed).
All 9 foundational tasks are now complete: - Protocol extensions - Server handlers - Client compiler module - Feature flag - Basic compilation flow - Protocol versioning - Compilation error fixes - All tests passing (403/403) The foundation is complete and ready for the next phase of implementation.
Guide includes: - Current implementation status - Verification methods (tests, feature flag, backward compat) - Integration test scenarios - Debugging tools and logging - Performance metrics to track - Troubleshooting guide - Next steps for full implementation This provides a complete guide for verifying the refactoring works correctly.
Add test matrix entries for: - Ubuntu 22.04 with SCCACHE_CLIENT_SIDE_COMPILE=1 - macOS 14 (M1) with client-side mode - Windows 2022 with client-side mode These tests verify that: - Feature flag routing works correctly - Client-side mode falls back to legacy mode gracefully - All tests pass with the new mode enabled - No regressions across all platforms Tests run in parallel with existing tests to ensure both modes work.
Extend the check_features job with a client_side_compile matrix dimension ["0", "1"], and switch from cargo check to cargo test so the runtime env variable is actually exercised. This produces 14 jobs (7 features × 2 modes) instead of 7, verifying each storage backend works in both compilation modes.
- Replace block_in_place with pool.block_on to avoid hanging when no tokio runtime context is available during cache initialization. - Add 30s timeout to the HTTP client used for TaskCluster token fetch to prevent indefinite hangs when the endpoint is unreachable.
…jectSource serializable - Fix from_bytes: previously passed pre-built bytes into a ZipWriter, which would append zip metadata on finish(), corrupting the data. Now stores them in a `prebuilt` field and returns them unchanged. - Derive Serialize/Deserialize on FileObjectSource so it can be used in the IPC protocol for client-side compilation.
Redesign the client-side compilation protocol to avoid transferring large artifacts over IPC: - CacheGetRequest now includes output_paths so the server can extract artifacts directly to disk on a cache hit. - CacheGetResponse::Hit now carries only stdout/stderr instead of the full cache entry bytes. - CachePutRequest now includes output_paths (for the server to read from disk) plus stdout/stderr, replacing the raw entry bytes. This relies on client and server sharing the same filesystem, which is always the case since they run on the same machine. Note: this commit temporarily breaks compilation of server.rs; the next commit updates the server handlers to match.
- Remove IPC frame size limit (use usize::MAX) so large cache entries can be transferred when needed. - handle_cache_get: extract artifacts directly to client-supplied paths on disk, returning only stdout/stderr over IPC. - handle_cache_put: read output artifacts from disk, pack into a cache entry with stdout/stderr, and store to the backend. Errors are logged but don't crash the connection (best-effort caching).
Replace the stub that fell back to server-side compilation with the full client-side flow: 1. Detect the compiler locally. 2. Parse arguments and bail out for non-cacheable invocations. 3. Run the preprocessor and compute the BLAKE3 cache key using a NoopStorage (real cache I/O goes through the server). 4. Send CacheGet to the server; on a hit the server extracts artifacts to disk and returns only stdout/stderr. 5. On a miss, compile locally and send CachePut so the server can read output files from disk and store them.
- Replace flowcharts with sequence diagrams for both compilation modes - Add colored styling to mermaid diagrams - Document C/C++ vs Rust cache key generation differences - Add performance note for client-side preprocessing - Update "foundational stage" note to reflect current implementation
The per-feature cargo test matrix was failing because tests depend on features not included in the individual feature flag. Revert to cargo check which validates compilation without running tests.
Mark test_server_unsupported_compiler and test_server_compile with #[serial] and explicitly unset SCCACHE_CLIENT_SIDE_COMPILE so they exercise the server-side compilation path regardless of the environment.
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see https://github.com/sylvestre/sccache/blob/97483f6178a4253990364025705b26d74c84eaf9/docs/Architecture.md for the description of the change