Implement an end-to-end reliability, aka Scalable Data Sync (SDS) library in Nim according to the API specification that provides reliability primitives for further integration to status-go.

Tasks:

Core Library Implementation

• Implement core types:

  • Message, MessageID, UnacknowledgedMessage
  • ReliabilityManager
  • ReliabilityConfig with customizable parameters
  • Results and Error types

• Implement reliability primitives:

  • wrapOutgoingMessage: Add reliability metadata before encryption
  • unwrapReceivedMessage: Extract reliability metadata and track dependencies
  • markDependenciesMet: Handle dependency resolution
  • setCallbacks: Allow application to handle events

Message Tracking & Ordering

• Implement Lamport Clock mechanisms
  • Initialize and update timestamps
  • Maintain causal ordering
• Implement message history tracking
  • Short-term message ID logging
  • Causal history management
  • Handle message dependencies

Message State Management

• Buffer management
  • Unacknowledged outgoing messages
  • Messages with unmet dependencies
  • Buffer maintenance and cleanup
• ACK tracking
  • Track message acknowledgments via bloom filters
  • Track acknowledgments via causal history
  • Clean expired entries

Periodic Tasks

• Implement periodic maintenance tasks
  • Buffer sweeping
  • Bloom filter cleaning
  • Sync message scheduling

Testing

• Unit tests for major components
• Integration tests for:
  • Message ordering
  • Dependency tracking
  • ACK/resend mechanisms
  • Edge cases

Acceptance Criteria:

• Library provides all the required methods and callbacks as per the specification
• Causal dependencies are properly tracked and resolved
• Message acknowledgment works via bloom filter and causal history
• Thread-safe operations with proper locking
• Test coverage & error handling