예제 #1
0
// LazyHandler writes all values to the wrapped handler after evaluating
// any lazy functions in the record's context. It is already wrapped
// around StreamHandler and SyslogHandler in this library, you'll only need
// it if you write your own Handler.
func LazyHandler(h Handler) Handler {
	return FuncHandler(func(r *Record) error {
		// go through the values (odd indices) and reassign
		// the values of any lazy fn to the result of its execution
		hadErr := false
		for i := 1; i < len(r.Ctx); i += 2 {
			lz, ok := r.Ctx[i].(Lazy)
			if ok {
				v, err := evaluateLazy(lz)
				if err != nil {
					hadErr = true
					r.Ctx[i] = err
				} else {
					if cs, ok := v.(stack.Trace); ok {
						v = cs.TrimBelow(stack.Call(r.CallPC[0])).
							TrimRuntime()
					}
					r.Ctx[i] = v
				}
			}
		}

		if hadErr {
			r.Ctx = append(r.Ctx, errorKey, "bad lazy")
		}

		return h.Log(r)
	})
}
예제 #2
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// CallerFileHandler returns a Handler that adds the line number and file of
// the calling function to the context with key "caller".
func CallerFileHandler(h Handler) Handler {
	return FuncHandler(func(r *Record) error {
		call := stack.Call(r.CallPC[0])
		r.Ctx = append(r.Ctx, "caller", fmt.Sprint(call))
		return h.Log(r)
	})
}
예제 #3
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// CallerStackHandler returns a Handler that adds a stack trace to the context
// with key "stack". The stack trace is formated as a space separated list of
// call sites inside matching []'s. The most recent call site is listed first.
// Each call site is formatted according to format. See the documentation of
// log15/stack.Call.Format for the list of supported formats.
func CallerStackHandler(format string, h Handler) Handler {
	return FuncHandler(func(r *Record) error {
		s := stack.Callers().
			TrimBelow(stack.Call(r.CallPC[0])).
			TrimRuntime()
		if len(s) > 0 {
			buf := &bytes.Buffer{}
			buf.WriteByte('[')
			for i, pc := range s {
				if i > 0 {
					buf.WriteByte(' ')
				}
				fmt.Fprintf(buf, format, pc)
			}
			buf.WriteByte(']')
			r.Ctx = append(r.Ctx, "stack", buf.String())
		}
		return h.Log(r)
	})
}