improve: provide opts to set the truncate size in text mode to reduce memory cost

Makefile

@@ -228,3 +228,7 @@ format:
 	@clang-format -i -style=$(STYLE) kern/openssl_masterkey_3.2.h
 	@clang-format -i -style=$(STYLE) kern/boringssl_masterkey.h
 	@clang-format -i -style=$(STYLE) utils/*.c
+
+.PHONY: test
+test:
+	go test -v -race ./...

cli/cmd/root.go

@@ -50,8 +50,9 @@ var (
 )
 
 const (
-	defaultPid uint64 = 0
-	defaultUid uint64 = 0
+	defaultPid          uint64 = 0
+	defaultUid          uint64 = 0
+	defaultTruncateSize uint64 = 0
 )
 
 const (
@@ -134,6 +135,7 @@ func init() {
 	rootCmd.PersistentFlags().StringVarP(&globalConf.LoggerAddr, "logaddr", "l", "", "send logs to this server. -l /tmp/ecapture.log or -l tcp://127.0.0.1:8080")
 	rootCmd.PersistentFlags().StringVar(&globalConf.EventCollectorAddr, "eventaddr", "", "the server address that receives the captured event. --eventaddr tcp://127.0.0.1:8090, default: same as logaddr")
 	rootCmd.PersistentFlags().StringVar(&globalConf.Listen, "listen", eCaptureListenAddr, "listen on this address for http server, default: 127.0.0.1:28256")
+	rootCmd.PersistentFlags().Uint64VarP(&globalConf.TruncateSize, "tsize", "t", defaultTruncateSize, "the truncate size in text mode, default: 0 (B), no truncate")
 
 	rootCmd.SilenceUsage = true
 }
@@ -156,6 +158,7 @@ func setModConfig(globalConf config.BaseConfig, modConf config.IConfig) {
 	modConf.SetBTF(globalConf.BtfMode)
 	modConf.SetPerCpuMapSize(globalConf.PerCpuMapSize)
 	modConf.SetAddrType(loggerTypeStdout)
+	modConf.SetTruncateSize(globalConf.TruncateSize)
 
 	switch ByteCodeFiles {
 	case "core":

pkg/event_processor/iworker.go

@@ -141,6 +141,11 @@ func (ew *eventWorker) writeEvent(e event.IEventStruct) {
 // 解析类型，输出
 func (ew *eventWorker) parserEvents() []byte {
 	ew.status = ProcessStateProcessing
+	tsize := int(ew.processor.truncateSize)
+	if tsize > 0 && ew.payload.Len() > tsize {
+		ew.payload.Truncate(tsize)
+		_ = ew.writeToChan(fmt.Sprintf("Events truncated, size: %d bytes\n", tsize))
+	}
 	parser := NewParser(ew.payload.Bytes())
 	ew.parser = parser
 	n, e := ew.parser.Write(ew.payload.Bytes())

pkg/event_processor/processor.go

@@ -42,7 +42,8 @@ type EventProcessor struct {
 	errChan   chan error
 
 	// output model
-	isHex bool
+	isHex        bool
+	truncateSize uint64
 }
 
 func (ep *EventProcessor) GetLogger() io.Writer {
@@ -161,11 +162,13 @@ func (ep *EventProcessor) Close() error {
 func (ep *EventProcessor) ErrorChan() chan error {
 	return ep.errChan
 }
-func NewEventProcessor(logger io.Writer, isHex bool) *EventProcessor {
+
+func NewEventProcessor(logger io.Writer, isHex bool, truncateSize uint64) *EventProcessor {
 	var ep *EventProcessor
 	ep = &EventProcessor{}
 	ep.logger = logger
 	ep.isHex = isHex
+	ep.truncateSize = truncateSize
 	ep.isClosed = false
 	ep.init()
 	return ep

pkg/event_processor/processor_test.go

@@ -39,7 +39,8 @@ func TestEventProcessor_Serve(t *testing.T) {
 		t.Fatal(e)
 	}
 	logger.SetOutput(f)
-	ep := NewEventProcessor(f, true)
+	// no truncate
+	ep := NewEventProcessor(f, true, 0)
 	go func() {
 		var err error
 		err = ep.Serve()
@@ -108,3 +109,83 @@ func TestEventProcessor_Serve(t *testing.T) {
 	//t.Log(string(bufString))
 	t.Log("done")
 }
+
+func Test_Truncated_EventProcessor_Serve(t *testing.T) {
+
+	logger := log.Default()
+	//var buf bytes.Buffer
+	//logger.SetOutput(&buf)
+	var output = "./output_truncated.log"
+	f, e := os.Create(output)
+	if e != nil {
+		t.Fatal(e)
+	}
+	logger.SetOutput(f)
+
+	// truncate 1000 bytes
+	ep := NewEventProcessor(f, true, 1000)
+	go func() {
+		var err error
+		err = ep.Serve()
+		if err != nil {
+			//log.Fatalf(err.Error())
+			t.Error(err)
+			return
+		}
+	}()
+
+	lines := []string{
+		// short, no truncated
+		`{"DataType":0,"Timestamp":952253597324253,"Pid":469929,"Tid":469929,"DataLen":308,"Comm":[119,103,101,116,0,0,0,0,0,0,0,0,0,0,0,0],"Fd":3,"Version":771}`,
+		// long, should truncated
+		`{"DataType":0,"Timestamp":952282712204824,"Pid":469953,"Tid":469953,"DataLen":4096,"Comm":[99,117,114,108,0,0,0,0,0,0,0,0,0,0,0,0],"Fd":5,"Version":771}`,
+	}
+
+	for _, line := range lines {
+		if line == "" {
+			continue
+		}
+		var eventSSL SSLDataEventTmp
+		err := json.Unmarshal([]byte(line), &eventSSL)
+		if err != nil {
+			t.Fatalf("json unmarshal error: %s, body:%v", err.Error(), line)
+		}
+		payloadFile := fmt.Sprintf("testdata/%d.bin", eventSSL.Timestamp)
+		b, e := os.ReadFile(payloadFile)
+		if e != nil {
+			t.Fatalf("read payload file error: %s, file:%s", e.Error(), payloadFile)
+		}
+		copy(eventSSL.Data[:], b)
+		ep.Write(&BaseEvent{DataLen: eventSSL.DataLen, Data: eventSSL.Data, DataType: eventSSL.DataType, Timestamp: eventSSL.Timestamp, Pid: eventSSL.Pid, Tid: eventSSL.Tid, Comm: eventSSL.Comm, Fd: eventSSL.Fd, Version: eventSSL.Version})
+	}
+
+	tick := time.NewTicker(time.Second * 10)
+	<-tick.C
+
+	err := ep.Close()
+	logger.SetOutput(io.Discard)
+	bufString, e := os.ReadFile(output)
+	if e != nil {
+		t.Fatal(e)
+	}
+
+	lines = strings.Split(string(bufString), "\n")
+	ok := true
+	for _, line := range lines {
+		// truncated once
+		if strings.Contains(line, "Events truncated, size:") {
+			t.Log(line)
+		}
+	}
+
+	if err != nil {
+		t.Fatalf("close error: %s", err.Error())
+	}
+
+	if !ok {
+		t.Fatalf("some errors occurred")
+	}
+	//t.Log(string(bufString))
+	t.Log("done")
+}
+

user/config/iconfig.go

@@ -63,6 +63,9 @@ type IConfig interface {
 	EnableGlobalVar() bool
 	// Bytes serializes the configuration to JSON bytes
 	Bytes() []byte
+	// Set/Get TruncateSize
+	SetTruncateSize(uint64)
+	GetTruncateSize() uint64
 }
 
 // TLS capture mode constants defining different output formats
@@ -90,9 +93,10 @@ const (
 
 // BaseConfig implements the IConfig interface and holds the basic configuration settings
 type BaseConfig struct {
-	Pid    uint64 `json:"pid"`    // Process ID to monitor
-	Uid    uint64 `json:"uid"`    // User ID to monitor
-	Listen string `json:"listen"` // Listen address for the server (default: 127.0.0.1:28256)
+	Pid          uint64 `json:"pid"`           // Process ID to monitor
+	Uid          uint64 `json:"uid"`           // User ID to monitor
+	Listen       string `json:"listen"`        // Listen address for the server (default: 127.0.0.1:28256)
+	TruncateSize uint64 `json:"truncate_size"` // truncate size in text mode
 
 	// eBPF map configuration
 	PerCpuMapSize      int    `json:"per_cpu_map_size"`     // Size of eBPF map per CPU core
@@ -173,6 +177,14 @@ func (c *BaseConfig) SetPerCpuMapSize(size int) {
 	c.PerCpuMapSize = size * os.Getpagesize()
 }
 
+func (c *BaseConfig) SetTruncateSize(TruncateSize uint64) {
+	c.TruncateSize = TruncateSize
+}
+
+func (c *BaseConfig) GetTruncateSize() uint64 {
+	return c.TruncateSize
+}
+
 func (c *BaseConfig) EnableGlobalVar() bool {
 	kv, err := kernel.HostVersion()
 	if err != nil {

user/module/imodule.go

@@ -104,7 +104,8 @@ func (m *Module) Init(ctx context.Context, logger *zerolog.Logger, conf config.I
 	m.isKernelLess5_2 = false //set false default
 	m.eventCollector = eventCollector
 	//var epl = epLogger{logger: logger}
-	m.processor = event_processor.NewEventProcessor(eventCollector, conf.GetHex())
+	tsize := conf.GetTruncateSize()
+	m.processor = event_processor.NewEventProcessor(eventCollector, conf.GetHex(), tsize)
 
 	go func() {
 		// 读取错误信息
@@ -129,6 +130,7 @@ func (m *Module) Init(ctx context.Context, logger *zerolog.Logger, conf config.I
 	}
 
 	logger.Info().Int("Pid", os.Getpid()).Str("Kernel Info", kv.String()).Send()
+	logger.Info().Int("TruncateSize", int(tsize)).Str("Unit", "bytes").Send()
 
 	if conf.GetBTF() == config.BTFModeAutoDetect {
 		// 如果是自动检测模式