Adapter mode

The hardware adapter pattern provides a way , Make the existing hardware interface suitable for application expectation . It can be said that it is based on the hardware proxy mode , In order to be able to adapt to the underlying different hardware devices , Add a layer of adapter in the middle . For example, communication exists in hardware RS232,RS485, Programs need to be used in different situations 232 Communication or 485 Communications , The adapter can provide a unified interface to the client layer , Point to the desired communication through a pointer , Then you can achieve . The most important feature is the selection of , You need to generate a different executable than using a macro definition , Can be implemented in the program adaptive function .

1.2.1 Pattern structure

1.2.2  role

1.2.2.1 Hardware adapter （HardwareAdapter）

Hardware matching is performed between the client and the hardware agent . The customer said the hardware required for the adapter , The adapter performs the client's request .

1.2.2.2 Customer hardware interface （HardwareInterfaceToClient）

The customer's hardware interface represents a set of services and parameter lists that the customer expects the hardware agent to provide . Just as an interface , It didn't happen , The hardware implementation is provided through the adapter .

1.2.2.3 Hardware device （HardwareDevice）

It is consistent with the description in hardware proxy mode .

1.2.2.4 Hardware agent （HardwareProxy）

It is consistent with the description in hardware proxy mode .

1.2.3 effect

This mode allows the use of various hardware agents , And use the hardware devices associated with them in different applications , At the same time, some applications do not need to change when using different hardware devices . My personal understanding is somewhat similar to the concept of polymorphism in object-oriented languages .

1.2.4 Realization

The same as linux System driven , Create an interface proxy for the structure , The hardware device uses these interfaces to realize , Then use a pointer to the struct interface , Register the hardware device you need to use with the pointer , The client code just calls this pointer , You can operate specific hardware devices , And can dynamically modify the pointer to , So as to achieve dynamic load switching .