Loggers clonage

Every time you modify some information inside the Logger, a new instance will be created by cloning the old version into a new one.

This process can be expensive, depending on the size of the Logger being cloned. Because of this, it's recommended that you create all your Loggers at startup time, not on-demand.

A Logger is represented using the following struct:

// new.gotype Logger struct {    configuration *Configuration    fields        LogFields    preHooks      Hooks    postHooks     Hooks    outputs       []Output}

To clone the Logger instance, it's necessary to clone the LogFields into another map, clone the PreHooks and PostHooks into another map, and clone the Outputs into another slice.

Note that the values are not cloned, just the containers. If you have a field called pointer that is a pointer to some int, for example, the cloned LogFields will point to the same int (the same to the Hooks and Outputs methods):

myInt := 10
// Field "pointer" points to "myInt"someLogger := logger.NewDefault().    Fields(logger.LogFields{"pointer": &myInt})
// Clone "someLogger" using any methodclone := someLogger.RawPreHooks(nil)
// Now, both "someLogger" and "clone" have a field// called "pointer" that points to "myInt", but in// different mapsfmt.Println(*someLogger.Field("pointer").(*int)) // 10fmt.Println(*clone.Field("pointer").(*int))      // 10
otherLogger := someLogger.Fields(logger.LogFields{"pointer": 5})fmt.Println(otherLogger.Field("pointer").(int)) // 5fmt.Println(*clone.Field("pointer").(*int))     // 10

info

The Configuration pointer is just copied to the new Logger, without changing it, so all the following versions of some Logger will share the same Configuration. This way, you can configure your logging strategy in a more centralized way.

If you still want new Loggers to point to a different Configuration, you can just create another instance using logger.New()/logger.NewDefault()