internal logging library

internal/logging/logger.go

@@ -0,0 +1,180 @@
+package logging
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"runtime"
+	"time"
+)
+
+// Logger creates a *slog.Logger wrap with a few more methods wrapped on top.
+// It recreates a number of methods to allow replacing a *slog.Logger functionally.
+// It also implements a number of methods to support formatted messages and
+// tracing.
+type Logger struct {
+	*slog.Logger
+}
+
+func New(h slog.Handler) *Logger {
+	return &Logger{
+		Logger: slog.New(h),
+	}
+}
+
+func From(l *slog.Logger) *Logger {
+	return &Logger{
+		Logger: l,
+	}
+}
+
+func (l *Logger) With(args ...any) *Logger {
+	return From(l.Logger.With(args...))
+}
+
+func (l *Logger) WithGroup(name string) *Logger {
+	return From(l.Logger.WithGroup(name))
+}
+
+func (l *Logger) Debugf(format string, args ...any) {
+	l.logContextf(context.Background(), slog.LevelDebug, format, args...)
+}
+
+func (l *Logger) DebugContextf(ctx context.Context, format string, args ...any) {
+	l.logContextf(ctx, slog.LevelDebug, format, args...)
+}
+
+func (l *Logger) DebugDeferf(format string, args ...any) func(func() (string, []any)) {
+	return l.logContextDeferf(context.Background(), slog.LevelDebug, format, args...)
+}
+
+func (l *Logger) DebugContextDeferf(ctx context.Context, format string, args ...any) func(func() (string, []any)) {
+	return l.logContextDeferf(ctx, slog.LevelDebug, format, args...)
+}
+
+func (l *Logger) DebugCallf(method string) func() {
+	return l.logContextCallf(context.Background(), slog.LevelDebug, method)
+}
+
+func (l *Logger) DebugContextCallf(ctx context.Context, method string) func() {
+	return l.logContextCallf(ctx, slog.LevelDebug, method)
+}
+
+func (l *Logger) Errorf(format string, args ...any) {
+	l.logContextf(context.Background(), slog.LevelError, format, args...)
+}
+
+func (l *Logger) ErrorContextf(ctx context.Context, format string, args ...any) {
+	l.logContextf(ctx, slog.LevelError, format, args...)
+}
+
+func (l *Logger) ErrorDeferf(format string, args ...any) func(func() (string, []any)) {
+	return l.logContextDeferf(context.Background(), slog.LevelError, format, args...)
+}
+
+func (l *Logger) ErrorContextDeferf(ctx context.Context, format string, args ...any) func(func() (string, []any)) {
+	return l.logContextDeferf(ctx, slog.LevelError, format, args...)
+}
+
+func (l *Logger) ErrorCallf(method string) func() {
+	return l.logContextCallf(context.Background(), slog.LevelError, method)
+}
+
+func (l *Logger) ErrorContextCallf(ctx context.Context, method string) func() {
+	return l.logContextCallf(ctx, slog.LevelError, method)
+}
+
+func (l *Logger) Infof(format string, args ...any) {
+	l.logContextf(context.Background(), slog.LevelInfo, format, args...)
+}
+
+func (l *Logger) InfoContextf(ctx context.Context, format string, args ...any) {
+	l.logContextf(ctx, slog.LevelInfo, format, args...)
+}
+
+func (l *Logger) InfoDeferf(format string, args ...any) func(func() (string, []any)) {
+	return l.logContextDeferf(context.Background(), slog.LevelInfo, format, args...)
+}
+
+func (l *Logger) InfoContextDeferf(ctx context.Context, format string, args ...any) func(func() (string, []any)) {
+	return l.logContextDeferf(ctx, slog.LevelInfo, format, args...)
+}
+
+func (l *Logger) InfoCallf(method string) func() {
+	return l.logContextCallf(context.Background(), slog.LevelInfo, method)
+}
+
+func (l *Logger) InfoContextCallf(ctx context.Context, method string) func() {
+	return l.logContextCallf(ctx, slog.LevelInfo, method)
+}
+
+func (l *Logger) Warnf(format string, args ...any) {
+	l.logContextf(context.Background(), slog.LevelWarn, format, args...)
+}
+
+func (l *Logger) WarnContextf(ctx context.Context, format string, args ...any) {
+	l.logContextf(ctx, slog.LevelWarn, format, args...)
+}
+
+func (l *Logger) WarnDeferf(format string, args ...any) func(func() (string, []any)) {
+	return l.logContextDeferf(context.Background(), slog.LevelWarn, format, args...)
+}
+
+func (l *Logger) WarnContextDeferf(ctx context.Context, format string, args ...any) func(func() (string, []any)) {
+	return l.logContextDeferf(ctx, slog.LevelWarn, format, args...)
+}
+
+func (l *Logger) WarnCallf(method string) func() {
+	return l.logContextCallf(context.Background(), slog.LevelWarn, method)
+}
+
+func (l *Logger) WarnContextCallf(ctx context.Context, method string) func() {
+	return l.logContextCallf(ctx, slog.LevelWarn, method)
+}
+
+func (l *Logger) logContextf(ctx context.Context, lvl slog.Level, format string, args ...any) {
+	if !l.Enabled(ctx, slog.LevelInfo) {
+		return
+	}
+
+	var pcs [1]uintptr
+	runtime.Callers(3, pcs[:]) // skip [Callers, Infof]
+
+	_ = l.Handler().Handle(
+		ctx,
+		slog.NewRecord(time.Now(), lvl, fmt.Sprintf(format, args...), pcs[0]),
+	)
+}
+
+func (l *Logger) logContextCallf(ctx context.Context, lvl slog.Level, method string) func() {
+	fn := l.With("method", method).logContextDeferf(ctx, lvl, "%s called", method)
+	return func() {
+		fn(func() (string, []any) {
+			return "%s returned", []any{method}
+		})
+	}
+}
+
+func (l *Logger) logContextDeferf(ctx context.Context, lvl slog.Level, format string, args ...any) func(func() (msg string, args []any)) {
+	if !l.Enabled(ctx, slog.LevelInfo) {
+		return func(func() (string, []any)) {
+		}
+	}
+
+	var pcs [1]uintptr
+	runtime.Callers(3, pcs[:]) // skip [Callers, Infof]
+	pc := pcs[0]
+
+	_ = l.Handler().Handle(ctx, slog.NewRecord(time.Now(), lvl, fmt.Sprintf(format, args...), pc))
+	return func(deferred func() (newFormat string, moreArgs []any)) {
+		if !l.Enabled(ctx, slog.LevelInfo) {
+			return
+		}
+
+		if deferred != nil {
+			format, args = deferred()
+		}
+
+		_ = l.Handler().Handle(ctx, slog.NewRecord(time.Now(), lvl, fmt.Sprintf(format, args...), pc))
+	}
+}