v0.5.0 - Fine-grained Rate Limiting & Request Deduplication

Added

• Fine-grained rate limiting: Per-second and per-minute rate limits for domain-specific throttling
  • Configure max_requests_per_second and max_requests_per_minute in domain mappings
  • Automatic request throttling with configurable delay tolerance
  • Multi-window priority system (second → minute → hour)
  • Sliding window implementation for accurate rate limiting
  • Backward compatible with existing hour-level throttling
• Request deduplication: Automatic coalescing of concurrent requests to the same resource
  • InFlightTracker class for tracking in-flight upstream requests
  • Thread-safe coordination using threading events
  • Prevents duplicate upstream API calls during request bursts
  • Error propagation and timeout handling for waiting requests
  • Automatic cleanup of completed requests
  • Statistics reporting via get_stats()
• Comprehensive test coverage with 8 new tests for request deduplication and 9 tests for rate limiting
• Configuration validation for new rate limiting parameters

Changed

• ThrottleManager now accepts domain_mappings parameter to extract per-minute/per-second limits
• ThrottleManager extends ThrottleState to track minute and second-level request windows
• Request handler flow modified to use get_required_delay() instead of should_throttle()
• Proxy now sleeps automatically to stay within rate limits rather than rejecting requests with 429
• Only returns 429 when required delay exceeds progressive_max_delay (default 300 seconds)
• Request handler wraps upstream forwarding with deduplication logic
• Updated existing tests to work with new get_required_delay() method

Fixed

• Prevents burst requests to upstream APIs when multiple clients request the same resource simultaneously
• Eliminates race conditions during concurrent cache misses for identical resources

Performance

• Significant reduction in duplicate upstream API calls during request bursts
• Faster response times for waiting requests (share result instead of making duplicate calls)
• Better upstream API utilization with automatic rate smoothing
• Deduplicated requests do NOT count against rate limits - only the first upstream request is rate-limited

Release v0.4.3

Bug fix for gzip handling for some wikidata requests

Release v0.4.2

Initial public release