container

// Author: Daniel TAN // Date: 2021-12-18 00:22:22 // LastEditors: Daniel TAN // LastEditTime: 2021-12-18 00:23:29 // FilePath: /trinity-micro/core/ioc/container/README.go // Description:

container

the container package provide the dependency injection

Overview

NewContainer

new a container instance

// new container with default config 
s := NewContainer()

// new container with customize config 
s := NewContainer(Config{
	// the default value of autowired 
    // default true
	AutoWire        bool
    // replace the log
    // default logrus.New()  
	Log              : logrus.New(),
    // replace the container keyword
    // default container  
	ContainerKeyword : Keyword("container"),  
    // replace the autowire keyword
    // default autowire  
	AutowireKeyword  : Keyword("autowire"),  
    // replace the resource keyword
    // default resource 
	ResourceKeyword  : Keyword("resource"),   
})

RegisterInstance (Singleton)

register a singleton instance.

Only can register one kinds of instance, singleton or multi-instance

instance1:= UserService{}
s := NewContainer()
s.RegisterInstance("instance1", &instance1)

RegisterInstance (Multi-instance)

register a multi-instance instance.

Only can register one kinds of instance, singleton or multi-instance

instancePool1:= Sync.Pool{
    New: func() interface{}{
        return new(UserService)
    }
}
s := NewContainer()
s.RegisterInstancePool("instance1", instancePool1)

InstanceDISelfCheck

do the di self check

if the registered instance's param with autoware not be injected, will return error

• success case

type UserService struct {
    UserRepo UserRepo `container:"autowire:true;resource:UserRepo"`
}

UserServicePool:= Sync.Pool{
    New: func() interface{}{
        return new(UserService)
    }
}
UserRepoPool:= Sync.Pool{
    New: func() interface{}{
        return new(UserRepo)
    }
}
s := NewContainer()
s.RegisterInstancePool("UserService", UserServicePool)
s.RegisterInstancePool("UserRepo", UserRepoPool)
err := s.InstanceDISelfCheck() // err is nil 

• failed case

type UserService struct {
    UserRepo UserRepo `container:"autowire:true;resource:UserRepo"`
}

UserServicePool:= Sync.Pool{
    New: func() interface{}{
        return new(UserService)
    }
}
s := NewContainer()
s.RegisterInstancePool("UserService", UserServicePool)
err := s.InstanceDISelfCheck() // err is not nil
// cause autowire is true, but there is no instance "UserRepo" registered in container

GetInstance

get an instance from container

• normal case

UserServicePool:= Sync.Pool{
    New: func() interface{}{
        return new(UserService)
    }
}
s := NewContainer()
s.RegisterInstancePool("UserService", UserServicePool)
UserService := s.GetInstance("UserService")

• inject with existing instance

UserServicePool:= Sync.Pool{
    New: func() interface{}{
        return new(UserService)
    }
}
s := NewContainer()
s.RegisterInstancePool("UserService", UserServicePool)
// used to handle the Circular References.
// always inject with the existing instance as priority
UserService := s.GetInstance("UserService", map[string]interface{}{
    "UserRepo":&UserRepo{},
})

Release (multi instance)

release the instance to the pool and clean all the param which has been injected only effective in multi-instance

type UserService struct {
    UserRepo UserRepo `container:"autowire:true;resource:UserRepo"`
}

UserServicePool:= Sync.Pool{
    New: func() interface{}{
        return new(UserService)
    }
}
UserRepoPool:= Sync.Pool{
    New: func() interface{}{
        return new(UserRepo)
    }
}
s := NewContainer()
s.RegisterInstancePool("UserService", UserServicePool)
s.RegisterInstancePool("UserRepo", UserRepoPool)
UserService := s.GetInstance("UserService")
s.Release("UserService",UserService)
// s.Release("UserRepo",UserService.UserRepo ) 
// s.Release("UserService",UserService ) 

Release (multi instance)

Getting Started

• How to use Container pkg

s := NewContainer()
s.RegisterInstancePool("UserService", UserServicePool)
s.RegisterInstancePool("UserRepo", UserRepoPool)
if err := s.InstanceDISelfCheck; err != nil {
    log.Fatal("di self check failed")
}
instance := s.GetInstance("instance")
defer s.Release("instance", instance)
// service logic 
instance.XXX 

Contributing

Feel free to create the Issue and PR . We need your help !