All Downloads are FREE. Search and download functionalities are using the official Maven repository.
Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $
You can buy this project and download/modify it how often you want.
io.netty.handler.codec.mqtt.MqttEncoder Maven / Gradle / Ivy
/*
* Copyright 2014 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.handler.codec.mqtt;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageEncoder;
import io.netty.util.CharsetUtil;
import java.util.List;
import static io.netty.handler.codec.mqtt.MqttCodecUtil.*;
/**
* Encodes Mqtt messages into bytes following the protocl specification v3.1
* as described here MQTTV3.1
*/
public class MqttEncoder extends MessageToMessageEncoder {
public static final MqttEncoder DEFAUL_ENCODER = new MqttEncoder();
private static final byte[] EMPTY = new byte[0];
@Override
protected void encode(ChannelHandlerContext ctx, MqttMessage msg, List out) throws Exception {
out.add(doEncode(ctx.alloc(), msg));
}
/**
* This is the main encoding method.
* It's only visible for testing.
*
* @param byteBufAllocator Allocates ByteBuf
* @param message MQTT message to encode
* @return ByteBuf with encoded bytes
*/
static ByteBuf doEncode(ByteBufAllocator byteBufAllocator, MqttMessage message) {
switch (message.fixedHeader().messageType()) {
case CONNECT:
return encodeConnectMessage(byteBufAllocator, (MqttConnectMessage) message);
case CONNACK:
return encodeConnAckMessage(byteBufAllocator, (MqttConnAckMessage) message);
case PUBLISH:
return encodePublishMessage(byteBufAllocator, (MqttPublishMessage) message);
case SUBSCRIBE:
return encodeSubscribeMessage(byteBufAllocator, (MqttSubscribeMessage) message);
case UNSUBSCRIBE:
return encodeUnsubscribeMessage(byteBufAllocator, (MqttUnsubscribeMessage) message);
case SUBACK:
return encodeSubAckMessage(byteBufAllocator, (MqttSubAckMessage) message);
case UNSUBACK:
case PUBACK:
case PUBREC:
case PUBREL:
case PUBCOMP:
return encodeMessageWithOnlySingleByteFixedHeaderAndMessageId(byteBufAllocator, message);
case PINGREQ:
case PINGRESP:
case DISCONNECT:
return encodeMessageWithOnlySingleByteFixedHeader(byteBufAllocator, message);
default:
throw new IllegalArgumentException(
"Unknown message type: " + message.fixedHeader().messageType().value());
}
}
private static ByteBuf encodeConnectMessage(
ByteBufAllocator byteBufAllocator,
MqttConnectMessage message) {
int payloadBufferSize = 0;
MqttFixedHeader mqttFixedHeader = message.fixedHeader();
MqttConnectVariableHeader variableHeader = message.variableHeader();
MqttConnectPayload payload = message.payload();
MqttVersion mqttVersion = MqttVersion.fromProtocolNameAndLevel(variableHeader.name(),
(byte) variableHeader.version());
// Client id
String clientIdentifier = payload.clientIdentifier();
if (!isValidClientId(mqttVersion, clientIdentifier)) {
throw new MqttIdentifierRejectedException("invalid clientIdentifier: " + clientIdentifier);
}
byte[] clientIdentifierBytes = encodeStringUtf8(clientIdentifier);
payloadBufferSize += 2 + clientIdentifierBytes.length;
// Will topic and message
String willTopic = payload.willTopic();
byte[] willTopicBytes = willTopic != null ? encodeStringUtf8(willTopic) : EMPTY;
String willMessage = payload.willMessage();
byte[] willMessageBytes = willMessage != null ? encodeStringUtf8(willMessage) : EMPTY;
if (variableHeader.isWillFlag()) {
payloadBufferSize += 2 + willTopicBytes.length;
payloadBufferSize += 2 + willMessageBytes.length;
}
String userName = payload.userName();
byte[] userNameBytes = userName != null ? encodeStringUtf8(userName) : EMPTY;
if (variableHeader.hasUserName()) {
payloadBufferSize += 2 + userNameBytes.length;
}
String password = payload.password();
byte[] passwordBytes = password != null ? encodeStringUtf8(password) : EMPTY;
if (variableHeader.hasPassword()) {
payloadBufferSize += 2 + passwordBytes.length;
}
// Fixed header
byte[] protocolNameBytes = mqttVersion.protocolNameBytes();
int variableHeaderBufferSize = 2 + protocolNameBytes.length + 4;
int variablePartSize = variableHeaderBufferSize + payloadBufferSize;
int fixedHeaderBufferSize = 1 + getVariableLengthInt(variablePartSize);
ByteBuf buf = byteBufAllocator.buffer(fixedHeaderBufferSize + variablePartSize);
buf.writeByte(getFixedHeaderByte1(mqttFixedHeader));
writeVariableLengthInt(buf, variablePartSize);
buf.writeShort(protocolNameBytes.length);
buf.writeBytes(protocolNameBytes);
buf.writeByte(variableHeader.version());
buf.writeByte(getConnVariableHeaderFlag(variableHeader));
buf.writeShort(variableHeader.keepAliveTimeSeconds());
// Payload
buf.writeShort(clientIdentifierBytes.length);
buf.writeBytes(clientIdentifierBytes, 0, clientIdentifierBytes.length);
if (variableHeader.isWillFlag()) {
buf.writeShort(willTopicBytes.length);
buf.writeBytes(willTopicBytes, 0, willTopicBytes.length);
buf.writeShort(willMessageBytes.length);
buf.writeBytes(willMessageBytes, 0, willMessageBytes.length);
}
if (variableHeader.hasUserName()) {
buf.writeShort(userNameBytes.length);
buf.writeBytes(userNameBytes, 0, userNameBytes.length);
}
if (variableHeader.hasPassword()) {
buf.writeShort(passwordBytes.length);
buf.writeBytes(passwordBytes, 0, passwordBytes.length);
}
return buf;
}
private static int getConnVariableHeaderFlag(MqttConnectVariableHeader variableHeader) {
int flagByte = 0;
if (variableHeader.hasUserName()) {
flagByte |= 0x80;
}
if (variableHeader.hasPassword()) {
flagByte |= 0x40;
}
if (variableHeader.isWillRetain()) {
flagByte |= 0x20;
}
flagByte |= (variableHeader.willQos() & 0x03) << 3;
if (variableHeader.isWillFlag()) {
flagByte |= 0x04;
}
if (variableHeader.isCleanSession()) {
flagByte |= 0x02;
}
return flagByte;
}
private static ByteBuf encodeConnAckMessage(
ByteBufAllocator byteBufAllocator,
MqttConnAckMessage message) {
ByteBuf buf = byteBufAllocator.buffer(4);
buf.writeByte(getFixedHeaderByte1(message.fixedHeader()));
buf.writeByte(2);
buf.writeByte(message.variableHeader().isSessionPresent() ? 0x01 : 0x00);
buf.writeByte(message.variableHeader().connectReturnCode().byteValue());
return buf;
}
private static ByteBuf encodeSubscribeMessage(
ByteBufAllocator byteBufAllocator,
MqttSubscribeMessage message) {
int variableHeaderBufferSize = 2;
int payloadBufferSize = 0;
MqttFixedHeader mqttFixedHeader = message.fixedHeader();
MqttMessageIdVariableHeader variableHeader = message.variableHeader();
MqttSubscribePayload payload = message.payload();
for (MqttTopicSubscription topic : payload.topicSubscriptions()) {
String topicName = topic.topicName();
byte[] topicNameBytes = encodeStringUtf8(topicName);
payloadBufferSize += 2 + topicNameBytes.length;
payloadBufferSize += 1;
}
int variablePartSize = variableHeaderBufferSize + payloadBufferSize;
int fixedHeaderBufferSize = 1 + getVariableLengthInt(variablePartSize);
ByteBuf buf = byteBufAllocator.buffer(fixedHeaderBufferSize + variablePartSize);
buf.writeByte(getFixedHeaderByte1(mqttFixedHeader));
writeVariableLengthInt(buf, variablePartSize);
// Variable Header
int messageId = variableHeader.messageId();
buf.writeShort(messageId);
// Payload
for (MqttTopicSubscription topic : payload.topicSubscriptions()) {
String topicName = topic.topicName();
byte[] topicNameBytes = encodeStringUtf8(topicName);
buf.writeShort(topicNameBytes.length);
buf.writeBytes(topicNameBytes, 0, topicNameBytes.length);
buf.writeByte(topic.qualityOfService().value());
}
return buf;
}
private static ByteBuf encodeUnsubscribeMessage(
ByteBufAllocator byteBufAllocator,
MqttUnsubscribeMessage message) {
int variableHeaderBufferSize = 2;
int payloadBufferSize = 0;
MqttFixedHeader mqttFixedHeader = message.fixedHeader();
MqttMessageIdVariableHeader variableHeader = message.variableHeader();
MqttUnsubscribePayload payload = message.payload();
for (String topicName : payload.topics()) {
byte[] topicNameBytes = encodeStringUtf8(topicName);
payloadBufferSize += 2 + topicNameBytes.length;
}
int variablePartSize = variableHeaderBufferSize + payloadBufferSize;
int fixedHeaderBufferSize = 1 + getVariableLengthInt(variablePartSize);
ByteBuf buf = byteBufAllocator.buffer(fixedHeaderBufferSize + variablePartSize);
buf.writeByte(getFixedHeaderByte1(mqttFixedHeader));
writeVariableLengthInt(buf, variablePartSize);
// Variable Header
int messageId = variableHeader.messageId();
buf.writeShort(messageId);
// Payload
for (String topicName : payload.topics()) {
byte[] topicNameBytes = encodeStringUtf8(topicName);
buf.writeShort(topicNameBytes.length);
buf.writeBytes(topicNameBytes, 0, topicNameBytes.length);
}
return buf;
}
private static ByteBuf encodeSubAckMessage(
ByteBufAllocator byteBufAllocator,
MqttSubAckMessage message) {
int variableHeaderBufferSize = 2;
int payloadBufferSize = message.payload().grantedQoSLevels().size();
int variablePartSize = variableHeaderBufferSize + payloadBufferSize;
int fixedHeaderBufferSize = 1 + getVariableLengthInt(variablePartSize);
ByteBuf buf = byteBufAllocator.buffer(fixedHeaderBufferSize + variablePartSize);
buf.writeByte(getFixedHeaderByte1(message.fixedHeader()));
writeVariableLengthInt(buf, variablePartSize);
buf.writeShort(message.variableHeader().messageId());
for (int qos : message.payload().grantedQoSLevels()) {
buf.writeByte(qos);
}
return buf;
}
private static ByteBuf encodePublishMessage(
ByteBufAllocator byteBufAllocator,
MqttPublishMessage message) {
MqttFixedHeader mqttFixedHeader = message.fixedHeader();
MqttPublishVariableHeader variableHeader = message.variableHeader();
ByteBuf payload = message.payload().duplicate();
String topicName = variableHeader.topicName();
byte[] topicNameBytes = encodeStringUtf8(topicName);
int variableHeaderBufferSize = 2 + topicNameBytes.length +
(mqttFixedHeader.qosLevel().value() > 0 ? 2 : 0);
int payloadBufferSize = payload.readableBytes();
int variablePartSize = variableHeaderBufferSize + payloadBufferSize;
int fixedHeaderBufferSize = 1 + getVariableLengthInt(variablePartSize);
ByteBuf buf = byteBufAllocator.buffer(fixedHeaderBufferSize + variablePartSize);
buf.writeByte(getFixedHeaderByte1(mqttFixedHeader));
writeVariableLengthInt(buf, variablePartSize);
buf.writeShort(topicNameBytes.length);
buf.writeBytes(topicNameBytes);
if (mqttFixedHeader.qosLevel().value() > 0) {
buf.writeShort(variableHeader.messageId());
}
buf.writeBytes(payload);
return buf;
}
private static ByteBuf encodeMessageWithOnlySingleByteFixedHeaderAndMessageId(
ByteBufAllocator byteBufAllocator,
MqttMessage message) {
MqttFixedHeader mqttFixedHeader = message.fixedHeader();
MqttMessageIdVariableHeader variableHeader = (MqttMessageIdVariableHeader) message.variableHeader();
int msgId = variableHeader.messageId();
int variableHeaderBufferSize = 2; // variable part only has a message id
int fixedHeaderBufferSize = 1 + getVariableLengthInt(variableHeaderBufferSize);
ByteBuf buf = byteBufAllocator.buffer(fixedHeaderBufferSize + variableHeaderBufferSize);
buf.writeByte(getFixedHeaderByte1(mqttFixedHeader));
writeVariableLengthInt(buf, variableHeaderBufferSize);
buf.writeShort(msgId);
return buf;
}
private static ByteBuf encodeMessageWithOnlySingleByteFixedHeader(
ByteBufAllocator byteBufAllocator,
MqttMessage message) {
MqttFixedHeader mqttFixedHeader = message.fixedHeader();
ByteBuf buf = byteBufAllocator.buffer(2);
buf.writeByte(getFixedHeaderByte1(mqttFixedHeader));
buf.writeByte(0);
return buf;
}
private static int getFixedHeaderByte1(MqttFixedHeader header) {
int ret = 0;
ret |= header.messageType().value() << 4;
if (header.isDup()) {
ret |= 0x08;
}
ret |= header.qosLevel().value() << 1;
if (header.isRetain()) {
ret |= 0x01;
}
return ret;
}
private static void writeVariableLengthInt(ByteBuf buf, int num) {
do {
int digit = num % 128;
num /= 128;
if (num > 0) {
digit |= 0x80;
}
buf.writeByte(digit);
} while (num > 0);
}
private static int getVariableLengthInt(int num) {
int count = 0;
do {
num /= 128;
count++;
} while (num > 0);
return count;
}
private static byte[] encodeStringUtf8(String s) {
return s.getBytes(CharsetUtil.UTF_8);
}
}
