Ethexe Blob Loader

Fetches Gear program code blobs posted to Ethereum as EIP-4844 blob transactions, decoding them from the beacon chain into raw WASM bytes. Emits unverified bytes only; code validation and instrumentation happen later in ethexe-processor.

Role in the Stack

ethexe-service constructs a [BlobLoader] at startup, stores it as Box<dyn BlobLoaderService>, and drives it inside the main event loop, calling [BlobLoaderService::load_codes] whenever the compute service emits RequestLoadCodes. The loader reads code locations from the local database (via the [Database] bound) and fetches blob data from the execution-layer JSON-RPC and beacon node.

Public API

• [BlobLoaderService] — Trait stored by ethexe-service; a fused stream of fetched code blobs driven via load_codes
• [BlobLoader] — Concrete implementation; constructed with BlobLoader::new(db, cfg).await
• [ConsensusLayerConfig] — RPC endpoints (ethereum_rpc, ethereum_beacon_rpc), beacon_block_time, retry attempts
• [BlobLoaderEvent] — Output event; the only variant is BlobLoaded(CodeAndIdUnchecked)
• [BlobLoaderError] — Public error: Transport or CodeBlobInfoNotFound(CodeId)
• [Database] — Blanket-implemented marker bound: CodesStorageRO + OnChainStorageRO + Unpin + Send + Clone + 'static

Invariants

• Calling [BlobLoaderService::load_codes] with an already-pending [CodeId] is a no-op.
• The stream never terminates; a failed fetch is logged and silently dropped (no error item).