Batman

1 files changed, 61 insertions, 0 deletions

diff --git a/internal/logging/trace.go b/internal/logging/trace.go
new file mode 100644
index 0000000..8900727
--- /dev/null
+++ b/internal/logging/trace.go
@@ -0,0 +1,61 @@
+package logging
+
+import (
+	"context"
+	"log/slog"
+	"runtime"
+	"strconv"
+	"strings"
+)
+
+const (
+	prgCount = 20
+	defSkip  = 6
+)
+
+type stackTracer struct {
+	h     slog.Handler
+	nSkip int
+}
+
+func (h stackTracer) Enabled(ctx context.Context, lvl slog.Level) bool {
+	return h.h.Enabled(ctx, lvl)
+}
+
+func (h stackTracer) WithAttrs(attrs []slog.Attr) slog.Handler {
+	return h.h.WithAttrs(attrs)
+}
+
+func (h stackTracer) WithGroup(name string) slog.Handler {
+	return h.h.WithGroup(name)
+}
+
+func (h stackTracer) Handle(ctx context.Context, r slog.Record) error {
+	if r.Level < slog.LevelError {
+		return h.h.Handle(ctx, r)
+	}
+
+	trace := h.GetTrace()
+	r.AddAttrs(slog.String("trace", trace))
+
+	return h.h.Handle(ctx, r)
+}
+
+func (h stackTracer) GetTrace() string {
+	var b strings.Builder
+	pc := make([]uintptr, prgCount)
+	n := runtime.Callers(h.nSkip, pc)
+	frames := runtime.CallersFrames(pc[:n])
+
+	for frame, more := frames.Next(); more; frame, more = frames.Next() {
+		b.WriteString(frame.Function + "\n    " + frame.File + ":" + strconv.Itoa(frame.Line) + "\n")
+	}
+	return b.String()
+}
+
+func withStackTrace(h slog.Handler) slog.Handler {
+	return stackTracer{
+		h:     h,
+		nSkip: defSkip,
+	}
+}