refactoring

siteCache to prevent nil map access
comments enhancements

log/format.go

@@ -30,70 +30,42 @@ type TerminalStringer interface {
 	TerminalString() string
 }
 
+// format formats the log record for terminal output
 func (h *TerminalHandler) format(buf []byte, r slog.Record, usecolor bool) []byte {
 	msg := escapeMessage(r.Message)
-	var color = ""
-	if usecolor {
-		switch r.Level {
-		case LevelCrit:
-			color = "\x1b[35m"
-		case slog.LevelError:
-			color = "\x1b[31m"
-		case slog.LevelWarn:
-			color = "\x1b[33m"
-		case slog.LevelInfo:
-			color = "\x1b[32m"
-		case slog.LevelDebug:
-			color = "\x1b[36m"
-		case LevelTrace:
-			color = "\x1b[34m"
-		}
-	}
+	color := determineColor(usecolor, r.Level)
+
 	if buf == nil {
 		buf = make([]byte, 0, 30+termMsgJust)
 	}
 	b := bytes.NewBuffer(buf)
 
-	if color != "" { // Start color
-		b.WriteString(color)
-		b.WriteString(LevelAlignedString(r.Level))
-		b.WriteString("\x1b[0m")
-	} else {
-		b.WriteString(LevelAlignedString(r.Level))
-	}
+	b.WriteString(color)
+	b.WriteString(LevelAlignedString(r.Level))
+	b.WriteString("\x1b[0m")
 	b.WriteString("[")
 	writeTimeTermFormat(b, r.Time)
 	b.WriteString("] ")
 	b.WriteString(msg)
 
-	// try to justify the log output for short messages
-	//length := utf8.RuneCountInString(msg)
 	length := len(msg)
 	if (r.NumAttrs()+len(h.attrs)) > 0 && length < termMsgJust {
 		b.Write(spaces[:termMsgJust-length])
 	}
-	// print the attributes
 	h.formatAttributes(b, r, color)
 
 	return b.Bytes()
 }
 
+// formatAttributes formats the attributes of the log record
 func (h *TerminalHandler) formatAttributes(buf *bytes.Buffer, r slog.Record, color string) {
 	writeAttr := func(attr slog.Attr, first, last bool) {
 		buf.WriteByte(' ')
-
-		if color != "" {
-			buf.WriteString(color)
-			buf.Write(appendEscapeString(buf.AvailableBuffer(), attr.Key))
-			buf.WriteString("\x1b[0m=")
-		} else {
-			buf.Write(appendEscapeString(buf.AvailableBuffer(), attr.Key))
-			buf.WriteByte('=')
-		}
+		buf.WriteString(color)
+		buf.Write(appendEscapeString(buf.AvailableBuffer(), attr.Key))
+		buf.WriteString("\x1b[0m=")
 		val := FormatSlogValue(attr.Value, buf.AvailableBuffer())
-
 		padding := h.fieldPadding[attr.Key]
-
 		length := utf8.RuneCount(val)
 		if padding < length && length <= termCtxMaxPadding {
 			padding = length
@@ -104,6 +76,7 @@ func (h *TerminalHandler) formatAttributes(buf *bytes.Buffer, r slog.Record, col
 			buf.Write(spaces[:padding-length])
 		}
 	}
+
 	var n = 0
 	var nAttrs = len(h.attrs) + r.NumAttrs()
 	for _, attr := range h.attrs {
@@ -118,6 +91,29 @@ func (h *TerminalHandler) formatAttributes(buf *bytes.Buffer, r slog.Record, col
 	buf.WriteByte('\n')
 }
 
+// determineColor determines the color code for the log level
+func determineColor(usecolor bool, level slog.Level) string {
+	if !usecolor {
+		return ""
+	}
+	switch level {
+	case LevelCrit:
+		return "\x1b[35m"
+	case slog.LevelError:
+		return "\x1b[31m"
+	case slog.LevelWarn:
+		return "\x1b[33m"
+	case slog.LevelInfo:
+		return "\x1b[32m"
+	case slog.LevelDebug:
+		return "\x1b[36m"
+	case LevelTrace:
+		return "\x1b[34m"
+	default:
+		return ""
+	}
+}
+
 // FormatSlogValue formats a slog.Value for serialization to terminal.
 func FormatSlogValue(v slog.Value, tmp []byte) (result []byte) {
 	var value any
@@ -188,9 +184,8 @@ func appendUint64(dst []byte, n uint64, neg bool) []byte {
 	if n < 100000 {
 		if neg {
 			return strconv.AppendInt(dst, -int64(n), 10)
-		} else {
-			return strconv.AppendInt(dst, int64(n), 10)
 		}
+		return strconv.AppendInt(dst, int64(n), 10)
 	}
 	// Large numbers should be split
 	const maxLength = 26
@@ -268,8 +263,7 @@ func appendU256(dst []byte, n *uint256.Int) []byte {
 // appendEscapeString writes the string s to the given writer, with
 // escaping/quoting if needed.
 func appendEscapeString(dst []byte, s string) []byte {
-	needsQuoting := false
-	needsEscaping := false
+	needsQuoting, needsEscaping := false, false
 	for _, r := range s {
 		// If it contains spaces or equal-sign, we need to quote it.
 		if r == ' ' || r == '=' {
@@ -357,7 +351,6 @@ func writePosIntWidth(b *bytes.Buffer, i, width int) {
 		bp--
 		i = q
 	}
-	// i < 10
 	bb[bp] = byte('0' + i)
 	b.Write(bb[bp:])
 }

log/format_test.go

@@ -7,6 +7,7 @@ import (
 
 var sink []byte
 
+// Benchmark for formatting int64 using logfmt
 func BenchmarkPrettyInt64Logfmt(b *testing.B) {
 	buf := make([]byte, 100)
 	b.ReportAllocs()
@@ -15,6 +16,7 @@ func BenchmarkPrettyInt64Logfmt(b *testing.B) {
 	}
 }
 
+// Benchmark for formatting uint64 using logfmt
 func BenchmarkPrettyUint64Logfmt(b *testing.B) {
 	buf := make([]byte, 100)
 	b.ReportAllocs()

log/handler_glog.go

@@ -37,22 +37,21 @@ var errVmoduleSyntax = errors.New("expect comma-separated list of filename=N")
 // glog logger: setting global log levels; overriding with callsite pattern
 // matches; and requesting backtraces at certain positions.
 type GlogHandler struct {
-	origin slog.Handler // The origin handler this wraps
-
-	level    atomic.Int32 // Current log level, atomically accessible
-	override atomic.Bool  // Flag whether overrides are used, atomically accessible
-
-	patterns  []pattern              // Current list of patterns to override with
+	origin    slog.Handler     // The origin handler this wraps
+	level     atomic.Int32     // Current log level, atomically accessible
+	override  atomic.Bool      // Flag whether overrides are used, atomically accessible
+	patterns  []pattern        // Current list of patterns to override with
 	siteCache map[uintptr]slog.Level // Cache of callsite pattern evaluations
-	location  string                 // file:line location where to do a stackdump at
-	lock      sync.RWMutex           // Lock protecting the override pattern list
+	location  string           // file:line location where to do a stackdump at
+	lock      sync.RWMutex     // Lock protecting the override pattern list
 }
 
 // NewGlogHandler creates a new log handler with filtering functionality similar
 // to Google's glog logger. The returned handler implements Handler.
 func NewGlogHandler(h slog.Handler) *GlogHandler {
 	return &GlogHandler{
-		origin: h,
+		origin:    h,
+		siteCache: make(map[uintptr]slog.Level),
 	}
 }
 
@@ -96,13 +95,13 @@ func (h *GlogHandler) Vmodule(ruleset string) error {
 		if len(parts) != 2 {
 			return errVmoduleSyntax
 		}
-		parts[0] = strings.TrimSpace(parts[0])
-		parts[1] = strings.TrimSpace(parts[1])
-		if len(parts[0]) == 0 || len(parts[1]) == 0 {
+		pattern := strings.TrimSpace(parts[0])
+		levelStr := strings.TrimSpace(parts[1])
+		if len(pattern) == 0 || len(levelStr) == 0 {
 			return errVmoduleSyntax
 		}
 		// Parse the level and if correct, assemble the filter rule
-		l, err := strconv.Atoi(parts[1])
+		l, err := strconv.Atoi(levelStr)
 		if err != nil {
 			return errVmoduleSyntax
 		}
@@ -112,19 +111,7 @@ func (h *GlogHandler) Vmodule(ruleset string) error {
 			continue // Ignore. It's harmless but no point in paying the overhead.
 		}
 		// Compile the rule pattern into a regular expression
-		matcher := ".*"
-		for _, comp := range strings.Split(parts[0], "/") {
-			if comp == "*" {
-				matcher += "(/.*)?"
-			} else if comp != "" {
-				matcher += "/" + regexp.QuoteMeta(comp)
-			}
-		}
-		if !strings.HasSuffix(parts[0], ".go") {
-			matcher += "/[^/]+\\.go"
-		}
-		matcher = matcher + "$"
-
+		matcher := compilePattern(pattern)
 		re, _ := regexp.Compile(matcher)
 		filter = append(filter, pattern{re, level})
 	}
@@ -139,8 +126,24 @@ func (h *GlogHandler) Vmodule(ruleset string) error {
 	return nil
 }
 
+// compilePattern converts a vmodule pattern to a regular expression string.
+func compilePattern(pattern string) string {
+	matcher := ".*"
+	for _, comp := range strings.Split(pattern, "/") {
+		if comp == "*" {
+			matcher += "(/.*)?"
+		} else if comp != "" {
+			matcher += "/" + regexp.QuoteMeta(comp)
+		}
+	}
+	if !strings.HasSuffix(pattern, ".go") {
+		matcher += "/[^/]+\\.go"
+	}
+	return matcher + "$"
+}
+
 func (h *GlogHandler) Enabled(ctx context.Context, lvl slog.Level) bool {
-	// fast-track skipping logging if override not enabled and the provided verbosity is above configured
+	// Fast-track skipping logging if override not enabled and the provided verbosity is above configured
 	return h.override.Load() || slog.Level(h.level.Load()) <= lvl
 }
 
@@ -149,8 +152,7 @@ func (h *GlogHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
 	siteCache := maps.Clone(h.siteCache)
 	h.lock.RUnlock()
 
-	patterns := []pattern{}
-	patterns = append(patterns, h.patterns...)
+	patterns := append([]pattern{}, h.patterns...)
 
 	res := GlogHandler{
 		origin:    h.origin.WithAttrs(attrs),
@@ -168,7 +170,7 @@ func (h *GlogHandler) WithGroup(name string) slog.Handler {
 	panic("not implemented")
 }
 
-// Log implements Handler.Log, filtering a log record through the global, local
+// Handle implements Handler.Handle, filtering a log record through the global, local
 // and backtrace filters, finally emitting it if either allow it through.
 func (h *GlogHandler) Handle(_ context.Context, r slog.Record) error {
 	// If the global log level allows, fast track logging
@@ -184,6 +186,7 @@ func (h *GlogHandler) Handle(_ context.Context, r slog.Record) error {
 	// If we didn't cache the callsite yet, calculate it
 	if !ok {
 		h.lock.Lock()
+		defer h.lock.Unlock()
 
 		fs := runtime.CallersFrames([]uintptr{r.PC})
 		frame, _ := fs.Next()
@@ -191,13 +194,13 @@ func (h *GlogHandler) Handle(_ context.Context, r slog.Record) error {
 		for _, rule := range h.patterns {
 			if rule.pattern.MatchString(fmt.Sprintf("+%s", frame.File)) {
 				h.siteCache[r.PC], lvl, ok = rule.level, rule.level, true
+				break
 			}
 		}
 		// If no rule matched, remember to drop log the next time
 		if !ok {
 			h.siteCache[r.PC] = 0
 		}
-		h.lock.Unlock()
 	}
 	if lvl <= r.Level {
 		return h.origin.Handle(context.Background(), r)