6 "github.com/pkg/errors"
9 // NewTracingLogger enables tracing by wrapping all errors (if they
10 // implement stackTracer interface) in tracedError.
12 // All errors returned by https://github.com/pkg/errors implement stackTracer
15 // For debugging purposes only as it doubles the amount of allocations.
16 func NewTracingLogger(next Logger) Logger {
17 return &tracingLogger{
22 type stackTracer interface {
24 StackTrace() errors.StackTrace
27 type tracingLogger struct {
31 func (l *tracingLogger) Info(msg string, keyvals ...interface{}) {
32 l.next.Info(msg, formatErrors(keyvals)...)
35 func (l *tracingLogger) Debug(msg string, keyvals ...interface{}) {
36 l.next.Debug(msg, formatErrors(keyvals)...)
39 func (l *tracingLogger) Error(msg string, keyvals ...interface{}) {
40 l.next.Error(msg, formatErrors(keyvals)...)
43 func (l *tracingLogger) With(keyvals ...interface{}) Logger {
44 return &tracingLogger{next: l.next.With(formatErrors(keyvals)...)}
47 func formatErrors(keyvals []interface{}) []interface{} {
48 newKeyvals := make([]interface{}, len(keyvals))
49 copy(newKeyvals, keyvals)
50 for i := 0; i < len(newKeyvals)-1; i += 2 {
51 if err, ok := newKeyvals[i+1].(stackTracer); ok {
52 newKeyvals[i+1] = tracedError{err}
58 // tracedError wraps a stackTracer and just makes the Error() result
59 // always return a full stack trace.
60 type tracedError struct {
64 var _ stackTracer = tracedError{}
66 func (t tracedError) StackTrace() errors.StackTrace {
67 return t.wrapped.StackTrace()
70 func (t tracedError) Cause() error {
74 func (t tracedError) Error() string {
75 return fmt.Sprintf("%+v", t.wrapped)