Adding Functionality with Decoration

In this chapter, we'll continue to address this remark: If you like design patterns, use Java, not Go. We'll do so with the help of the decorator and strategy patterns.

Our goal in this chapter is to understand:

• Go's Reader and Writer interfaces
• Why designing using the interface composition is better than type hierarchy design
• How to design with and implement the Decorator Pattern
• Inversion of Control (IoC) by implementing an IoC framework
• How to set up a request timeout using a proxy 
• How to apply the Strategy Pattern when load balancing requests
• How to understand easy-metrics graphs
• How to implement a simple yet effective logger using standard library interfaces
• How to enrich HTTP requests with logging using dependency injection
• How to use channels to control the flow of events in a concurrent program
• A better way to extend our application's functionality