CODESAMPLE
Object Pool - Python
The Object Pool pattern manages a pool of reusable objects to reduce the overhead of frequent object creation and destruction. This is particularly useful for expensive-to-create objects. The pool maintains a collection of objects, and instead of creating new ones, clients request objects from the pool. When an object is no longer needed, it’s returned to the pool for reuse.
This Python implementation uses a simple list to store the available objects. PooledObject represents the type of object being pooled. ObjectPool handles object creation (up to a maximum size) and distribution. acquire_object retrieves an object, creating one if needed and available. release_object returns an object to the pool. This approach aligns with Python’s dynamic nature and avoids complex synchronization for basic use cases. More robust implementations might use threading locks for concurrent access.
class PooledObject:
def __init__(self, id):
self.id = id
self.reset()
def reset(self):
# Simulate expensive initialization/resetting
print(f"Object {self.id} resetting...")
self.value = 0
def do_something(self):
self.value += 1
print(f"Object {self.id} did something. Value: {self.value}")
class ObjectPool:
def __init__(self, obj_class, max_size):
self.obj_class = obj_class
self.max_size = max_size
self.pool = []
self._create_pool()
def _create_pool(self):
for i in range(self.max_size):
self.pool.append(self.obj_class(i))
def acquire_object(self):
if self.pool:
return self.pool.pop()
else:
return self.obj_class(len(self.pool)) # Create if pool is empty
def release_object(self, obj):
obj.reset()
self.pool.append(obj)
if __name__ == "__main__":
pool = ObjectPool(PooledObject, 3)
obj1 = pool.acquire_object()
obj1.do_something()
obj1.do_something()
obj2 = pool.acquire_object()
obj2.do_something()
pool.release_object(obj1)
obj3 = pool.acquire_object()
obj3.do_something()
pool.release_object(obj2)
pool.release_object(obj3)