latest updates

src/openrouter/utils/retries.py

@@ -3,7 +3,9 @@
 import asyncio
 import random
 import time
-from typing import List
+from datetime import datetime
+from email.utils import parsedate_to_datetime
+from typing import List, Optional
 
 import httpx
 
@@ -51,9 +53,11 @@ class Retries:
 
 class TemporaryError(Exception):
     response: httpx.Response
+    retry_after: Optional[int]
 
     def __init__(self, response: httpx.Response):
         self.response = response
+        self.retry_after = _parse_retry_after_header(response)
 
 
 class PermanentError(Exception):
@@ -63,6 +67,62 @@ class PermanentError(Exception):
         self.inner = inner
 
 
+def _parse_retry_after_header(response: httpx.Response) -> Optional[int]:
+    """Parse Retry-After header from response.
+
+    Returns:
+        Retry interval in milliseconds, or None if header is missing or invalid.
+    """
+    retry_after_header = response.headers.get("retry-after")
+    if not retry_after_header:
+        return None
+
+    try:
+        seconds = float(retry_after_header)
+        return round(seconds * 1000)
+    except ValueError:
+        pass
+
+    try:
+        retry_date = parsedate_to_datetime(retry_after_header)
+        delta = (retry_date - datetime.now(retry_date.tzinfo)).total_seconds()
+        return round(max(0, delta) * 1000)
+    except (ValueError, TypeError):
+        pass
+
+    return None
+
+
+def _get_sleep_interval(
+    exception: Exception,
+    initial_interval: int,
+    max_interval: int,
+    exponent: float,
+    retries: int,
+) -> float:
+    """Get sleep interval for retry with exponential backoff.
+
+    Args:
+        exception: The exception that triggered the retry.
+        initial_interval: Initial retry interval in milliseconds.
+        max_interval: Maximum retry interval in milliseconds.
+        exponent: Base for exponential backoff calculation.
+        retries: Current retry attempt count.
+
+    Returns:
+        Sleep interval in seconds.
+    """
+    if (
+        isinstance(exception, TemporaryError)
+        and exception.retry_after is not None
+        and exception.retry_after > 0
+    ):
+        return exception.retry_after / 1000
+
+    sleep = (initial_interval / 1000) * exponent**retries + random.uniform(0, 1)
+    return min(sleep, max_interval / 1000)
+
+
 def retry(func, retries: Retries):
     if retries.config.strategy == "backoff":
 
@@ -183,8 +243,10 @@ def retry_with_backoff(
                     return exception.response
 
                 raise
-            sleep = (initial_interval / 1000) * exponent**retries + random.uniform(0, 1)
-            sleep = min(sleep, max_interval / 1000)
+
+            sleep = _get_sleep_interval(
+                exception, initial_interval, max_interval, exponent, retries
+            )
             time.sleep(sleep)
             retries += 1
 
@@ -211,7 +273,9 @@ async def retry_with_backoff_async(
                     return exception.response
 
                 raise
-            sleep = (initial_interval / 1000) * exponent**retries + random.uniform(0, 1)
-            sleep = min(sleep, max_interval / 1000)
+
+            sleep = _get_sleep_interval(
+                exception, initial_interval, max_interval, exponent, retries
+            )
             await asyncio.sleep(sleep)
             retries += 1