rate limiter 0.2 sec

LichessWebServices/rate_limiter.py

@@ -0,0 +1,53 @@
+"""
+Rate limiter for Lichess API requests
+Ensures minimum delay between requests
+"""
+import asyncio
+import time
+import logging
+from typing import Optional
+
+logger = logging.getLogger(__name__)
+
+class RateLimiter:
+    """
+    Rate limiter that ensures minimum delay between requests.
+    Thread-safe and async-safe.
+    """
+    
+    def __init__(self, min_delay: float = 0.2):
+        """
+        Initialize rate limiter.
+        
+        Args:
+            min_delay: Minimum delay in seconds between requests (default: 0.2)
+        """
+        self.min_delay = min_delay
+        self.last_request_time: Optional[float] = None
+        self.lock = asyncio.Lock()
+    
+    async def wait_if_needed(self):
+        """
+        Wait if necessary to maintain minimum delay between requests.
+        Should be called before each API request.
+        """
+        async with self.lock:
+            now = time.time()
+            
+            if self.last_request_time is not None:
+                elapsed = now - self.last_request_time
+                if elapsed < self.min_delay:
+                    wait_time = self.min_delay - elapsed
+                    logger.debug(f"Rate limiter: waiting {wait_time:.3f} seconds")
+                    await asyncio.sleep(wait_time)
+                    now = time.time()
+            
+            self.last_request_time = now
+
+# Global rate limiter instance
+_rate_limiter = RateLimiter(min_delay=0.2)
+
+def get_rate_limiter() -> RateLimiter:
+    """Get the global rate limiter instance"""
+    return _rate_limiter
+