1 files changed, 239 insertions, 0 deletions
diff --git a/modules/log/logger_impl.go b/modules/log/logger_impl.go
new file mode 100644
index 0000000000..c7e8fde3c0
--- /dev/null
+++ b/modules/log/logger_impl.go
@@ -0,0 +1,239 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package log
+
+import (
+	"context"
+	"runtime"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"code.gitea.io/gitea/modules/json"
+	"code.gitea.io/gitea/modules/util"
+)
+
+type LoggerImpl struct {
+	LevelLogger
+
+	ctx       context.Context
+	ctxCancel context.CancelFunc
+
+	level           atomic.Int32
+	stacktraceLevel atomic.Int32
+
+	eventWriterMu sync.RWMutex
+	eventWriters  map[string]EventWriter
+}
+
+var (
+	_ BaseLogger  = (*LoggerImpl)(nil)
+	_ LevelLogger = (*LoggerImpl)(nil)
+)
+
+// SendLogEvent sends a log event to all writers
+func (l *LoggerImpl) SendLogEvent(event *Event) {
+	l.eventWriterMu.RLock()
+	defer l.eventWriterMu.RUnlock()
+
+	if len(l.eventWriters) == 0 {
+		FallbackErrorf("[no logger writer]: %s", event.MsgSimpleText)
+		return
+	}
+
+	// the writers have their own goroutines, the message arguments (with Stringer) shouldn't be used in other goroutines
+	// so the event message must be formatted here
+	msgFormat, msgArgs := event.msgFormat, event.msgArgs
+	event.msgFormat, event.msgArgs = "(already processed by formatters)", nil
+
+	for _, w := range l.eventWriters {
+		if event.Level < w.GetLevel() {
+			continue
+		}
+		formatted := &EventFormatted{
+			Origin: event,
+			Msg:    w.Base().FormatMessage(w.Base().Mode, event, msgFormat, msgArgs...),
+		}
+		select {
+		case w.Base().Queue <- formatted:
+		default:
+			bs, _ := json.Marshal(event)
+			FallbackErrorf("log writer %q queue is full, event: %v", w.GetWriterName(), string(bs))
+		}
+	}
+}
+
+// syncLevelInternal syncs the level of the logger with the levels of the writers
+func (l *LoggerImpl) syncLevelInternal() {
+	lowestLevel := NONE
+	for _, w := range l.eventWriters {
+		if w.GetLevel() < lowestLevel {
+			lowestLevel = w.GetLevel()
+		}
+	}
+	l.level.Store(int32(lowestLevel))
+
+	lowestLevel = NONE
+	for _, w := range l.eventWriters {
+		if w.Base().Mode.StacktraceLevel < lowestLevel {
+			lowestLevel = w.GetLevel()
+		}
+	}
+	l.stacktraceLevel.Store(int32(lowestLevel))
+}
+
+// removeWriterInternal removes a writer from the logger, and stops it if it's not shared
+func (l *LoggerImpl) removeWriterInternal(w EventWriter) {
+	if !w.Base().shared {
+		eventWriterStopWait(w) // only stop non-shared writers, shared writers are managed by the manager
+	}
+	delete(l.eventWriters, w.GetWriterName())
+}
+
+// AddWriters adds writers to the logger, and starts them. Existing writers will be replaced by new ones.
+func (l *LoggerImpl) AddWriters(writer ...EventWriter) {
+	l.eventWriterMu.Lock()
+	defer l.eventWriterMu.Unlock()
+
+	for _, w := range writer {
+		if old, ok := l.eventWriters[w.GetWriterName()]; ok {
+			l.removeWriterInternal(old)
+		}
+	}
+
+	for _, w := range writer {
+		l.eventWriters[w.GetWriterName()] = w
+		eventWriterStartGo(l.ctx, w, false)
+	}
+
+	l.syncLevelInternal()
+}
+
+// RemoveWriter removes a writer from the logger, and the writer is closed and flushed if it is not shared
+func (l *LoggerImpl) RemoveWriter(modeName string) error {
+	l.eventWriterMu.Lock()
+	defer l.eventWriterMu.Unlock()
+
+	w, ok := l.eventWriters[modeName]
+	if !ok {
+		return util.ErrNotExist
+	}
+
+	l.removeWriterInternal(w)
+	l.syncLevelInternal()
+	return nil
+}
+
+// RemoveAllWriters removes all writers from the logger, non-shared writers are closed and flushed
+func (l *LoggerImpl) RemoveAllWriters() *LoggerImpl {
+	l.eventWriterMu.Lock()
+	defer l.eventWriterMu.Unlock()
+
+	for _, w := range l.eventWriters {
+		l.removeWriterInternal(w)
+	}
+	l.eventWriters = map[string]EventWriter{}
+	l.syncLevelInternal()
+	return l
+}
+
+// DumpWriters dumps the writers as a JSON map, it's used for debugging and display purposes.
+func (l *LoggerImpl) DumpWriters() map[string]any {
+	l.eventWriterMu.RLock()
+	defer l.eventWriterMu.RUnlock()
+
+	writers := make(map[string]any, len(l.eventWriters))
+	for k, w := range l.eventWriters {
+		bs, err := json.Marshal(w.Base().Mode)
+		if err != nil {
+			FallbackErrorf("marshal writer %q to dump failed: %v", k, err)
+			continue
+		}
+		m := map[string]any{}
+		_ = json.Unmarshal(bs, &m)
+		m["WriterType"] = w.GetWriterType()
+		writers[k] = m
+	}
+	return writers
+}
+
+// Close closes the logger, non-shared writers are closed and flushed
+func (l *LoggerImpl) Close() {
+	l.RemoveAllWriters()
+	l.ctxCancel()
+}
+
+// IsEnabled returns true if the logger is enabled: it has a working level and has writers
+// Fatal is not considered as enabled, because it's a special case and the process just exits
+func (l *LoggerImpl) IsEnabled() bool {
+	l.eventWriterMu.RLock()
+	defer l.eventWriterMu.RUnlock()
+	return l.level.Load() < int32(FATAL) && len(l.eventWriters) > 0
+}
+
+// Log prepares the log event, if the level matches, the event will be sent to the writers
+func (l *LoggerImpl) Log(skip int, level Level, format string, logArgs ...any) {
+	if Level(l.level.Load()) > level {
+		return
+	}
+
+	event := &Event{
+		Time:   time.Now(),
+		Level:  level,
+		Caller: "?()",
+	}
+
+	pc, filename, line, ok := runtime.Caller(skip + 1)
+	if ok {
+		fn := runtime.FuncForPC(pc)
+		if fn != nil {
+			event.Caller = fn.Name() + "()"
+		}
+	}
+	event.Filename, event.Line = strings.TrimPrefix(filename, projectPackagePrefix), line
+
+	if l.stacktraceLevel.Load() <= int32(level) {
+		event.Stacktrace = Stack(skip + 1)
+	}
+
+	labels := getGoroutineLabels()
+	if labels != nil {
+		event.GoroutinePid = labels["pid"]
+	}
+
+	// get a simple text message without color
+	msgArgs := make([]any, len(logArgs))
+	copy(msgArgs, logArgs)
+
+	// handle LogStringer values
+	for i, v := range msgArgs {
+		if cv, ok := v.(*ColoredValue); ok {
+			if s, ok := cv.v.(LogStringer); ok {
+				cv.v = logStringFormatter{v: s}
+			}
+		} else if s, ok := v.(LogStringer); ok {
+			msgArgs[i] = logStringFormatter{v: s}
+		}
+	}
+
+	event.MsgSimpleText = colorSprintf(false, format, msgArgs...)
+	event.msgFormat = format
+	event.msgArgs = msgArgs
+	l.SendLogEvent(event)
+}
+
+func (l *LoggerImpl) GetLevel() Level {
+	return Level(l.level.Load())
+}
+
+func NewLoggerWithWriters(ctx context.Context, writer ...EventWriter) *LoggerImpl {
+	l := &LoggerImpl{}
+	l.ctx, l.ctxCancel = context.WithCancel(ctx)
+	l.LevelLogger = BaseLoggerToGeneralLogger(l)
+	l.eventWriters = map[string]EventWriter{}
+	l.syncLevelInternal()
+	l.AddWriters(writer...)
+	return l
+}