Added Connect encoder part

netty_parser/src/main/java/org/dna/mqtt/moquette/parser/netty/MQTTEncoder.java

@@ -0,0 +1,77 @@
+package org.dna.mqtt.moquette.parser.netty;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.MessageToByteEncoder;
+import org.dna.mqtt.moquette.proto.messages.AbstractMessage;
+import org.dna.mqtt.moquette.proto.messages.ConnectMessage;
+
+/**
+ *
+ * @author andrea
+ */
+public class MQTTEncoder extends MessageToByteEncoder<AbstractMessage> {
+
+    @Override
+    protected void encode(ChannelHandlerContext chc, AbstractMessage msg, ByteBuf bb) throws Exception {
+        if (msg.getMessageType() == AbstractMessage.CONNECT) {
+            encodeConnect(chc, (ConnectMessage)msg, bb);
+        }
+    }
+
+    private void encodeConnect(ChannelHandlerContext chc, ConnectMessage message, ByteBuf out) {
+        ByteBuf staticHeaderBuff = chc.alloc().buffer(12);
+        staticHeaderBuff.writeBytes(Utils.encodeString("MQIsdp"));
+        
+        //version 
+        staticHeaderBuff.writeByte(0x03);
+        
+        //connection flags and Strings
+        byte connectionFlags = 0;
+        if (message.isCleanSession()) {
+            connectionFlags |= 0x02;
+        }
+        if (message.isWillFlag()) {
+            connectionFlags |= 0x04;
+        }
+        connectionFlags |= ((message.getWillQos() & 0x03) << 3);
+        if (message.isWillRetain()) {
+            connectionFlags |= 0x020;
+        }
+        if (message.isPasswordFlag()) {
+            connectionFlags |= 0x040;
+        }
+        if (message.isUserFlag()) {
+            connectionFlags |= 0x080;
+        }
+        staticHeaderBuff.writeByte(connectionFlags);
+        
+        //Keep alive timer
+        staticHeaderBuff.writeShort(message.getKeepAlive());
+        
+        //Variable part
+        ByteBuf variableHeaderBuff = chc.alloc().buffer(12);
+        if (message.getClientID() != null) {
+            variableHeaderBuff.writeBytes(Utils.encodeString(message.getClientID()));
+            if (message.isWillFlag()) {
+                variableHeaderBuff.writeBytes(Utils.encodeString(message.getWillTopic()));
+                variableHeaderBuff.writeBytes(Utils.encodeString(message.getWillMessage()));
+            }
+            if (message.isUserFlag() && message.getUsername() != null) {
+                variableHeaderBuff.writeBytes(Utils.encodeString(message.getUsername()));
+                if (message.isPasswordFlag() && message.getPassword() != null) {
+                    variableHeaderBuff.writeBytes(Utils.encodeString(message.getPassword()));
+                }
+            }
+        }
+
+        int variableHeaderSize = variableHeaderBuff.readableBytes();
+        ByteBuf buff = chc.alloc().buffer();
+        buff.writeByte(AbstractMessage.CONNECT << 4);
+        buff.writeBytes(Utils.encodeRemainingLength(12 + variableHeaderSize));
+        buff.writeBytes(staticHeaderBuff).writeBytes(variableHeaderBuff);
+
+        out.writeBytes(buff);
+    }
+    
+}

netty_parser/src/main/java/org/dna/mqtt/moquette/parser/netty/Utils.java

@@ -2,6 +2,7 @@ package org.dna.mqtt.moquette.parser.netty;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
+import io.netty.handler.codec.CorruptedFrameException;
 import java.io.UnsupportedEncodingException;
 import org.slf4j.LoggerFactory;
 
@@ -11,6 +12,8 @@ import org.slf4j.LoggerFactory;
  */
 public class Utils {
     
+    public static final int MAX_LENGTH_LIMIT = 268435455;
+    
     static byte readMessageType(ByteBuf in) {
         byte h1 = in.readByte();
         byte messageType = (byte) ((h1 & 0x00F0) >> 4);
@@ -60,6 +63,32 @@ public class Utils {
         return value;
     }
     
+    /**
+     * Encode the value in the format defined in specification as variable length
+     * array.
+     * 
+     * @throws IllegalArgumentException if the value is not in the specification bounds
+     *  [0..268435455].
+     */
+    static ByteBuf encodeRemainingLength(int value) throws CorruptedFrameException {
+        if (value > MAX_LENGTH_LIMIT || value < 0) {
+            throw new CorruptedFrameException("Value should in range 0.." + MAX_LENGTH_LIMIT + " found " + value);
+        }
+
+        ByteBuf encoded = Unpooled.buffer(4);
+        byte digit;
+        do {
+            digit = (byte) (value % 128);
+            value = value / 128;
+            // if there are more digits to encode, set the top bit of this digit
+            if (value > 0) {
+                digit = (byte) (digit | 0x80);
+            }
+            encoded.writeByte(digit);
+        } while (value > 0);
+        return encoded;
+    }
+    
     /**
      * Load a string from the given buffer, reading first the two bytes of len
      * and then the UTF-8 bytes of the string.