chore: simple traffic logger (#2378)

* feat: simple traffic logger

Controls: 
```
DEBUG TRAFFIC <base_path> | [STOP]
```
---------

Signed-off-by: Vladislav Oleshko <vlad@dragonflydb.io>
Signed-off-by: Roman Gershman <roman@dragonflydb.io>
Co-authored-by: Roman Gershman <roman@dragonflydb.io>

tools/replay/parsing.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"bufio"
+	"encoding/binary"
+	"io"
+	"os"
+)
+
+var kBigEmptyBytes = make([]byte, 100_000)
+
+func parseStrings(file io.Reader) (out []interface{}, err error) {
+	var num, strLen uint32
+	err = binary.Read(file, binary.LittleEndian, &num)
+	if err != nil {
+		return nil, err
+	}
+
+	out = make([]interface{}, num)
+	for i := range out {
+		err = binary.Read(file, binary.LittleEndian, &strLen)
+		if err != nil {
+			return nil, err
+		}
+		out[i] = strLen
+	}
+
+	for i := range out {
+		strLen = out[i].(uint32)
+
+		if strLen == 0 {
+			err = binary.Read(file, binary.LittleEndian, &strLen)
+			if err != nil {
+				return nil, err
+			}
+			out[i] = kBigEmptyBytes[:strLen]
+			continue
+		}
+
+		buf := make([]byte, strLen)
+		_, err := io.ReadFull(file, buf)
+		if err != nil {
+			return nil, err
+		}
+
+		out[i] = string(buf)
+	}
+	return
+}
+
+func parseRecords(filename string, cb func(Record) bool) error {
+	file, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	reader := bufio.NewReader(file)
+	for {
+		var rec Record
+		err := binary.Read(reader, binary.LittleEndian, &rec.RecordHeader)
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return err
+		}
+
+		rec.values, err = parseStrings(reader)
+		if err != nil {
+			return err
+		}
+
+		if !cb(rec) {
+			return nil
+		}
+	}
+
+	return nil
+}