"Design Mode Design Pattern" Reading Notes
PROXY mode
structure
purpose
When accessing an object is relatively large, you can generate an agent (Proxy).
application
Remote Proxy Remote Agent, with a local object agent remote object
Virtual Proxy virtual agent, only a cost-to-expensive object only when you need it (On Demand)
Protection Proxy Protection Agent, controls access to objects
Smart Reference Function Pointer
Differences with other modes
1. Difference to Adapter: Adapter generates a different interface for the target object to meet the needs of the user; Of course, in the protection agent, Proxy's interface can be a subset of the interface of its target object, thereby reacting those interfaces that have no right access.
2. Difference to Decorator: Although proxy and decorator are very similar, their purpose is different; the purpose of Decorator is to increase functionality for an object, and the purpose of Proxy is to control access to objects.
Reference
"Design Pattern" Gang-Of-4 1997
