Design of the iOS cache class

Using caching in a program can greatly improve the speed of a program, and designing a simple cache class does not require much complex logic.
Simply 3 interfaces are required.

1. Save Object
2. Fetch Object
3. Delete Object

Reading objects

• Read memory first when reading an object
• Memory not enrolled in file

Save Object

• The foreground is saved to the memory when the object is saved.
• Backstage Deposit into file
• There is not enough memory space to release a piece of memory first
• Delete frees all memory when receiving out-of-memory messages