remove holder key

Author: sanderegg

packages/service-library/src/servicelib/redis/_constants.py

@@ -11,7 +11,6 @@
 
 DEFAULT_SEMAPHORE_TTL: Final[datetime.timedelta] = datetime.timedelta(seconds=10)
 SEMAPHORE_KEY_PREFIX: Final[str] = "semaphores:"
-SEMAPHORE_HOLDER_KEY_PREFIX: Final[str] = "semaphores:holders:"
 
 DEFAULT_DECODE_RESPONSES: Final[bool] = True
 DEFAULT_HEALTH_CHECK_INTERVAL: Final[datetime.timedelta] = datetime.timedelta(seconds=5)

packages/service-library/src/servicelib/redis/_semaphore.py

@@ -176,6 +176,17 @@ def validate_timeout(
             raise ValueError(msg)
         return v
 
+    async def _initialize_semaphore(self) -> None:
+        """Initializes the semaphore in Redis if not already done."""
+        ttl_seconds = int(self.ttl.total_seconds())
+        cls = type(self)
+        assert cls.register_semaphore is not None  # nosec
+        await cls.register_semaphore(  # pylint: disable=not-callable
+            keys=[self.tokens_key, self.holders_key],
+            args=[self.capacity, ttl_seconds],
+            client=self.redis_client.redis,
+        )
+
     async def acquire(self) -> bool:
         """
         Acquire the semaphore.
@@ -202,14 +213,7 @@ async def acquire(self) -> bool:
                 self.blocking_timeout.total_seconds() if self.blocking_timeout else 0
             )
 
-        # Execute the Lua scripts atomically
-        cls = type(self)
-        assert cls.register_semaphore is not None  # nosec
-        await cls.register_semaphore(  # pylint: disable=not-callable
-            keys=[self.tokens_key, self.holders_key],
-            args=[self.capacity, ttl_seconds],
-            client=self.redis_client.redis,
-        )
+        await self._initialize_semaphore()
 
         try:
             # this is blocking pop with timeout
@@ -234,6 +238,7 @@ async def acquire(self) -> bool:
         assert tokens_key_token[0] == self.tokens_key  # nosec
         token = tokens_key_token[1]
 
+        cls = type(self)
         assert cls.acquire_script is not None  # nosec
         result = await cls.acquire_script(  # pylint: disable=not-callable
             keys=[self.holders_key, self.holder_key],
@@ -387,6 +392,7 @@ async def get_current_count(self) -> int:
 
     async def get_available_count(self) -> int:
         """Get the number of available semaphore slots"""
+        await self._initialize_semaphore()
         return await handle_redis_returns_union_types(
             self.redis_client.redis.llen(self.tokens_key)
         )

packages/service-library/tests/redis/test_semaphore.py

@@ -14,7 +14,6 @@
 from servicelib.redis import RedisClientSDK
 from servicelib.redis._constants import (
     DEFAULT_SEMAPHORE_TTL,
-    SEMAPHORE_HOLDER_KEY_PREFIX,
     SEMAPHORE_KEY_PREFIX,
 )
 from servicelib.redis._errors import SemaphoreLostError
@@ -60,7 +59,7 @@ async def test_semaphore_initialization(
     assert semaphore.instance_id is not None
     assert semaphore.semaphore_key == f"{SEMAPHORE_KEY_PREFIX}{semaphore_name}"
     assert semaphore.holder_key.startswith(
-        f"{SEMAPHORE_HOLDER_KEY_PREFIX}{semaphore_name}:"
+        f"{SEMAPHORE_KEY_PREFIX}{semaphore_name}:holders_:"
     )
 
 
@@ -109,6 +108,9 @@ async def test_semaphore_acquire_release_single(
     )
 
     # Initially not acquired
+    assert await semaphore.get_current_count() == 0
+    assert await semaphore.get_available_count() == semaphore_capacity
+    assert await semaphore.is_acquired() is False
 
     # Acquire successfully
     result = await semaphore.acquire()
@@ -117,6 +119,7 @@ async def test_semaphore_acquire_release_single(
     # Check Redis state
     assert await semaphore.get_current_count() == 1
     assert await semaphore.get_available_count() == semaphore_capacity - 1
+    assert await semaphore.is_acquired() is True
 
     # Acquire again on same instance should return True immediately and keep the same count (reentrant)
     result = await semaphore.acquire()