/
logger.go
80 lines (61 loc) · 1.98 KB
/
logger.go
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package model
//
// Logger
//
// DebugLogger is a logger emitting only debug messages.
type DebugLogger interface {
// Debug emits a debug message.
Debug(msg string)
// Debugf formats and emits a debug message.
Debugf(format string, v ...interface{})
}
// InfoLogger is a logger emitting debug and infor messages.
type InfoLogger interface {
// An InfoLogger is also a DebugLogger.
DebugLogger
// Info emits an informational message.
Info(msg string)
// Infof formats and emits an informational message.
Infof(format string, v ...interface{})
}
// Logger defines the common interface that a logger should have. It is
// out of the box compatible with `log.Log` in `apex/log`.
type Logger interface {
// A Logger is also an InfoLogger.
InfoLogger
// Warn emits a warning message.
Warn(msg string)
// Warnf formats and emits a warning message.
Warnf(format string, v ...interface{})
}
// DiscardLogger is the default logger that discards its input
var DiscardLogger Logger = logDiscarder{}
// logDiscarder is a logger that discards its input
type logDiscarder struct{}
// Debug implements DebugLogger.Debug
func (logDiscarder) Debug(msg string) {}
// Debugf implements DebugLogger.Debugf
func (logDiscarder) Debugf(format string, v ...interface{}) {}
// Info implements InfoLogger.Info
func (logDiscarder) Info(msg string) {}
// Infov implements InfoLogger.Infov
func (logDiscarder) Infof(format string, v ...interface{}) {}
// Warn implements Logger.Warn
func (logDiscarder) Warn(msg string) {}
// Warnf implements Logger.Warnf
func (logDiscarder) Warnf(format string, v ...interface{}) {}
// ErrorToStringOrOK emits "ok" on "<nil>"" values for success.
func ErrorToStringOrOK(err error) string {
if err != nil {
return err.Error()
}
return "ok"
}
// ValidLoggerOrDefault is a factory that either returns the logger
// provided as argument, if not nil, or DiscardLogger.
func ValidLoggerOrDefault(logger Logger) Logger {
if logger != nil {
return logger
}
return DiscardLogger
}