d

domain-api/app/core/db.py

@@ -1,6 +1,9 @@
 from contextlib import contextmanager
+from functools import wraps
+import time
 
 import psycopg2
+from psycopg2 import errors
 
 from app.core.config import settings
 
@@ -18,3 +21,39 @@ def get_db():
         yield conn
     finally:
         conn.close()
+
+
+_RETRYABLE_READ_ERRORS = (
+    errors.DeadlockDetected,
+    errors.SerializationFailure,
+    errors.LockNotAvailable,
+)
+
+
+def is_retryable_read_error(exc: Exception) -> bool:
+    return isinstance(exc, _RETRYABLE_READ_ERRORS)
+
+
+def is_retryable_db_error(exc: Exception) -> bool:
+    return isinstance(exc, _RETRYABLE_READ_ERRORS)
+
+
+def db_read_retry(*, attempts: int = 3, initial_delay_seconds: float = 0.05, backoff: float = 2.0):
+    def decorator(func):
+        @wraps(func)
+        def wrapper(*args, **kwargs):
+            delay = max(0.0, float(initial_delay_seconds or 0.0))
+            for attempt in range(1, max(1, int(attempts or 1)) + 1):
+                try:
+                    return func(*args, **kwargs)
+                except Exception as exc:
+                    if not is_retryable_read_error(exc) or attempt >= max(1, int(attempts or 1)):
+                        raise
+                    if delay > 0:
+                        time.sleep(delay)
+                    delay *= max(1.0, float(backoff or 1.0))
+            return func(*args, **kwargs)
+
+        return wrapper
+
+    return decorator