logging

type Level uint32

type LeveledLogger struct {
	// Level is the minimum logging level that will be emitted by this logger.
	//
	// For example, a Level set to LevelWarn will emit warnings and errors, but
	// not informational or debug messages.
	//
	// Always set this with a constant like LevelWarn because the individual
	// values are not guaranteed to be stable.
	Level Level

	// Whether to add a timestamp or not.
	Timestamp bool

	// Tag to prefix message with.
	Tag string

	// Internal testing use only.
	ClockOverride  clock
	StderrOverride io.Writer
	StdoutOverride io.Writer
}

type LeveledLoggerInterface interface {
	// Debugf logs a debug message using Printf conventions.
	Debugf(format string, v ...interface{})

	// Errorf logs a warning message using Printf conventions.
	Errorf(format string, v ...interface{})

	// Infof logs an informational message using Printf conventions.
	Infof(format string, v ...interface{})

	// Warnf logs a warning message using Printf conventions.
	Warnf(format string, v ...interface{})

	// WithTag returns a new LeveledLogger based on the current one but with given tag.
	WithTag(tag string) *LeveledLogger
}

type SimpleLogger interface {
	// Log inserts a log entry.  Arguments may be handled in the manner
	// of fmt.Print, but the underlying logger may also decide to handle
	// them differently.
	Log(v ...interface{})
	// Logf insets a log entry.  Arguments are handled in the manner of
	// fmt.Printf.
	Logf(format string, v ...interface{})
}