ccipocr3

CCIP OCR3 Provider gRPC Implementation

This package implements the gRPC-based adapter for the CCIPProvider interface, following the pattern established by the median provider implementation.

Overview

The CCIPProvider interface requires three main components:

1. ChainAccessor - For all direct chain access operations
2. ContractTransmitter - For OCR3 contract transmission (reuses existing OCR3 implementation)
3. Codec - For encoding/decoding various types of CCIP data

Files

• ccip_provider.go - Main CCIPProvider client/server implementation
• chainaccessor.go - ChainAccessor gRPC client/server
• codec.go - Codec interfaces gRPC client/server implementations
• helpers.go - Helper functions and type conversions
• chainaccessor.proto - Protocol buffer definitions for ChainAccessor
• codec.proto - Protocol buffer definitions for Codec interfaces

Architecture

The implementation follows the established gRPC adapter pattern:

1. Client Side: Wraps gRPC clients to implement Go interfaces
2. Server Side: Wraps Go interface implementations to serve gRPC requests
3. Protocol Buffers: Define the wire format for all method calls
4. Type Conversion: Convert between Go types and protobuf types

Components

ChainAccessor

Implements the complete ChainAccessor interface with methods for:

• AllAccessors: Common functionality (GetContractAddress, GetAllConfigsLegacy, etc.)
• DestinationAccessor: Destination chain operations (CommitReports, ExecutedMessages, etc.)
• SourceAccessor: Source chain operations (MsgsBetweenSeqNums, TokenPriceUSD, etc.)

Codec

Implements all codec interfaces:

• ChainSpecificAddressCodec: Address encoding/decoding
• CommitPluginCodec: Commit plugin report encoding/decoding (reuses existing)
• ExecutePluginCodec: Execute plugin report encoding/decoding
• TokenDataEncoder: Token data encoding (USDC/CCTP)
• SourceChainExtraDataCodec: Source chain extra data decoding

ContractTransmitter

Reuses the existing OCR3 ContractTransmitter gRPC implementation from pkg/loop/internal/relayer/pluginprovider/ocr3/.

Usage

// Server side - register all services
func RegisterProviderServices(s *grpc.Server, provider types.CCIPProvider) {
    ccipocr3.RegisterProviderServices(s, provider)
}

// Client side - create provider client
func ConnToProvider(conn grpc.ClientConnInterface, broker net.Broker, brokerCfg net.BrokerConfig) types.CCIPProvider {
    be := &net.BrokerExt{Broker: broker, BrokerConfig: brokerCfg}
    return ccipocr3.NewProviderClient(be, conn)
}

Development Notes

• Type conversions between Go and protobuf types are handled in helper functions
• Complex types like maps and nested structures require careful conversion
• Error handling follows gRPC best practices
• The implementation is designed to be compatible with the existing LOOP infrastructure