feat(backend): added support of message size

backend/pkg/messages/batch.go

@@ -1,35 +1,138 @@
 package messages
 
 import (
+	"bytes"
 	"fmt"
 	"github.com/pkg/errors"
 	"io"
+	"log"
 	"strings"
 )
 
+// RawMessage is a not decoded message
+type RawMessage struct {
+	tp   uint64
+	size uint64
+	data []byte
+	meta *message
+}
+
+func (m *RawMessage) Encode() []byte {
+	return m.data
+}
+
+func (m *RawMessage) TypeID() int {
+	return int(m.tp)
+}
+
+func (m *RawMessage) Meta() *message {
+	return m.meta
+}
+
+func WriteSize(size uint64, buf []byte, p int) {
+	var m uint64 = 255
+	for i := 0; i < 3; i++ {
+		buf[p+i] = byte(size & m)
+		size = size >> 8
+	}
+	fmt.Println(buf)
+}
+
+func ReadSize(reader io.Reader) (uint64, error) {
+	buf := make([]byte, 3)
+	n, err := io.ReadFull(reader, buf)
+	if err != nil {
+		return 0, err
+	}
+	if n != 3 {
+		return 0, fmt.Errorf("read only %d of 3 size bytes", n)
+	}
+	var size uint64
+	for i, b := range buf {
+		size += uint64(b) << (8 * i)
+	}
+	return size, nil
+}
+
+func messageHasSize(msgType uint64) bool {
+	return !(msgType == 80 || msgType == 81 || msgType == 82)
+}
+
 func ReadBatchReader(reader io.Reader, messageHandler func(Message)) error {
-	var index uint64
-	var timestamp int64
+	var (
+		index     uint64
+		timestamp int64
+		version   uint64
+	)
+	log.Println("new batch")
 
 	for {
-		msg, err := ReadMessage(reader)
-		if err == io.EOF {
-			return nil
-		} else if err != nil {
-			if strings.HasPrefix(err.Error(), "Unknown message code:") {
-				code := strings.TrimPrefix(err.Error(), "Unknown message code: ")
-				msg, err = DecodeExtraMessage(code, reader)
-				if err != nil {
-					return fmt.Errorf("can't decode msg: %s", err)
-				}
-			} else {
-				return errors.Wrapf(err, "Batch Message decoding error on message with index %v", index)
+		// Read message type
+		msgType, err := ReadUint(reader)
+		if err != nil {
+			if err == io.EOF {
+				return nil
 			}
+			return fmt.Errorf("can't read message type: %s", err)
+		}
+		log.Printf("message type: %d", msgType)
+
+		var msg Message
+		if version > 0 && messageHasSize(msgType) {
+			// Read message size if it's new protocol version
+			msgSize, err := ReadSize(reader)
+			if err != nil {
+				return fmt.Errorf("can't read message size: %s", err)
+			}
+			// Read raw message (bytes)
+			log.Println("size:", msgSize)
+			buf := make([]byte, msgSize)
+			_, err = io.ReadFull(reader, buf)
+			if err != nil {
+				return fmt.Errorf("can't read raw body: %s", err)
+			}
+			// Create message object
+			msg = &RawMessage{
+				tp:   msgType,
+				size: msgSize,
+				data: buf,
+				meta: &message{},
+			}
+			// Temp code
+			msg, err = ReadMessage(msgType, bytes.NewReader(buf))
+			if err != nil {
+				return err
+			}
+		} else {
+			msg, err = ReadMessage(msgType, reader)
+			if err == io.EOF {
+				return nil
+			} else if err != nil {
+				if strings.HasPrefix(err.Error(), "Unknown message code:") {
+					code := strings.TrimPrefix(err.Error(), "Unknown message code: ")
+					msg, err = DecodeExtraMessage(code, reader)
+					if err != nil {
+						return fmt.Errorf("can't decode msg: %s", err)
+					}
+				} else {
+					return errors.Wrapf(err, "Batch Message decoding error on message with index %v", index)
+				}
+			}
+			msg = transformDeprecated(msg)
 		}
-		msg = transformDeprecated(msg)
 
 		isBatchMeta := false
 		switch m := msg.(type) {
+		case *BatchMetadata:
+			if index != 0 { // Might be several 0-0 BatchMeta in a row without a error though
+				return errors.New("Batch Meta found at the end of the batch")
+			}
+			index = m.PageNo<<32 + m.FirstIndex // 2^32  is the maximum count of messages per page (ha-ha)
+			timestamp = m.Timestamp
+			version = m.Version
+			isBatchMeta = true
+			log.Printf("new batch version: %d", version)
+
 		case *BatchMeta: // Is not required to be present in batch since IOS doesn't have it (though we might change it)
 			if index != 0 { // Might be several 0-0 BatchMeta in a row without a error though
 				return errors.New("Batch Meta found at the end of the batch")

backend/pkg/messages/messages.go

@@ -1498,22 +1498,6 @@ func (msg *CustomIssue) TypeID() int {
 	return 64
 }
 
-type PageClose struct {
-	message
-}
-
-func (msg *PageClose) Encode() []byte {
-	buf := make([]byte, 1)
-	buf[0] = 65
-	p := 1
-
-	return buf[:p]
-}
-
-func (msg *PageClose) TypeID() int {
-	return 65
-}
-
 type AssetCache struct {
 	message
 	URL string