Related: #4333#4421#5128
Motivation:
slice(), duplicate() and readSlice() currently create a non-recyclable
derived buffer instance. Under heavy load, an application that creates a
lot of derived buffers can put the garbage collector under pressure.
Modifications:
- Add the following methods which creates a non-recyclable derived buffer
- retainedSlice()
- retainedDuplicate()
- readRetainedSlice()
- Add the new recyclable derived buffer implementations, which has its
own reference count value
- Add ByteBufHolder.retainedDuplicate()
- Add ByteBufHolder.replace(ByteBuf) so that..
- a user can replace the content of the holder in a consistent way
- copy/duplicate/retainedDuplicate() can delegate the holder
construction to replace(ByteBuf)
- Use retainedDuplicate() and retainedSlice() wherever possible
- Miscellaneous:
- Rename DuplicateByteBufTest to DuplicatedByteBufTest (missing 'D')
- Make ReplayingDecoderByteBuf.reject() return an exception instead of
throwing it so that its callers don't need to add dummy return
statement
Result:
Derived buffers are now recycled when created via retainedSlice() and
retainedDuplicate() and derived from a pooled buffer
Motivation:
We use ByteBuf.readBytes(int) in various places where we could either remove it completely or use readSlice(int).retain().
Modifications:
- Remove ByteBuf.readBytes(int) when possible or replace by readSlice(int).retain().
Result:
Faster code.
Motivation:
Commit 2696778 changed MqttEncoder to be a singelton but missed to add @Sharable annotation. This broke the encoder as it can not be added to multiple pipelines.
Modifications:
Add @Sharable annotation
Result:
MqttEncoder can be used in multiple pipelines again.
Motivation:
codec-mqtt had some typos and was not restrict enough in terms of making things final and private constructors.
Modifications:
- Fix typos
- Make most pojos final
- Remove redundant else blocks.
Result:
Cleaner and more restrict code.
Motivation:
According to the MQTT 3.1.1 Protocol Specification: The Server MUST validate that the reserved flag in the CONNECT Control Packet is set to zero and disconnect the Client if it is not zero. (http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc385349230)
Resolves#4182
Modifications:
Check the CONNECT reserved flag for MQTT 3.1.1. If it's not 0, throw an exception.
Result:
If the CONNECT reserved flag, a decode failure will be emitted.
Motivation:
The MqttEncoder was failing to build because it was using a method that doesn't exist.
Modifications:
Change sessionPresent() to isSessionPresent().
Result:
MqttEnccoder is now able to build.
Motivation:
Found performance issues via FindBugs and PMD.
Modifications:
- Removed unnecessary boxing/unboxing operations in DefaultTextHeaders.convertToInt(CharSequence) and DefaultTextHeaders.convertToLong(CharSequence). A boxed primitive is created from a string, just to extract the unboxed primitive value.
- Added a static modifier for DefaultHttp2Connection.ParentChangedEvent class. This class is an inner class, but does not use its embedded reference to the object which created it. This reference makes the instances of the class larger, and may keep the reference to the creator object alive longer than necessary.
- Added a static compiled Pattern to avoid compile it each time it is used when we need to replace some part of authority.
- Improved using of StringBuilders.
Result:
Performance improvements.
Motivation:
MQTT 3.1.1 became an OASIS Standard at 13 Nov 2014.
http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/mqtt-v3.1.1.html
MQTT 3.1.1 is a minor update of 3.1. But, previous codec-mqtt supported only MQTT 3.1.
Modifications:
- Add protocol name `MQTT` with previous `MQIsdp` for `CONNECT`’s variable header.
- Update client identifier validation for 3.1 with 3.1.1.
- Add `FAILURE (0x80)` for `SUBACK`’s new error code.
- Add a test for encode/decode `CONNECT` of 3.1.1.
Result:
MqttEncoder/MqttDecoder can encode/decode frames of 3.1 or 3.1.1.
Motivation:
http://public.dhe.ibm.com/software/dw/webservices/ws-mqtt/mqtt-v3r1.html#connack
In MQTT 3.1, MQTT server must send a CONNACK with return code if CONNECT
request contains an invalid client identifier or an unacceptable protocol
version. The return code is one of MqttConnectReturnCode.
But, MqttDecoder throws DecoderException when CONNECT request contains
invalid value without distinguish situations. This makes it difficult
for codec-mqtt users to send a response with return code to clients.
Modifications:
Added exceptions for client identifier rejected and unacceptable
protocol version. MqttDecoder will throw those exceptions instead of
DecoderException.
Result:
Users of codec-mqtt can distinguish which is invalid when CONNECT
contains invalid client identifier or invalid protocol version. And, users can
send CONNACK with return code to clients.
Motivation:
In MQTT 3.1 specification, "The Client Identifier (Client ID) is between
1 and 23 characters long, and uniquely identifies the client to the
server". But, current client id validation length is 0~23. It must be
1~23. The empty string is invalid client id in MQTT 3.1
Modifications:
Change isValidClientId method. Add MIN_CLIENT_ID_LENGTH.
Result:
The validation check for client id length is between 1 and 23.
Motivation:
Now Netty has a few problems with null values.
Modifications:
- Check HAProxyProxiedProtocol in HAProxyMessage constructor and throw NPE if it is null.
If HAProxyProxiedProtocol is null we will set AddressFamily as null. So we will get NPE inside checkAddress(String, AddressFamily) and it won't be easy to understand why addrFamily is null.
- Check File in DiskFileUpload.toString().
If File is null we will get NPE when calling toString() method.
- Check Result<String> in MqttDecoder.decodeConnectionPayload(...).
If !mqttConnectVariableHeader.isWillFlag() || !mqttConnectVariableHeader.hasUserName() || !mqttConnectVariableHeader.hasPassword() we will get NPE when we will try to create new instance of MqttConnectPayload.
- Check Unsafe before calling unsafe.getClass() in PlatformDependent0 static block.
- Removed unnecessary null check in WebSocket08FrameEncoder.encode(...).
Because msg.content() can not return null.
- Removed unnecessary null check in DefaultStompFrame(StompCommand) constructor.
Because we have this check in the super class.
- Removed unnecessary null checks in ConcurrentHashMapV8.removeTreeNode(TreeNode<K,V>).
- Removed unnecessary null check in OioDatagramChannel.doReadMessages(List<Object>).
Because tmpPacket.getSocketAddress() always returns new SocketAddress instance.
- Removed unnecessary null check in OioServerSocketChannel.doReadMessages(List<Object>).
Because socket.accept() always returns new Socket instance.
- Pass Unpooled.buffer(0) instead of null inside CloseWebSocketFrame(boolean, int) constructor.
If we will pass null we will get NPE in super class constructor.
- Added throw new IllegalStateException in GlobalEventExecutor.awaitInactivity(long, TimeUnit) if it will be called before GlobalEventExecutor.execute(Runnable).
Because now we will get NPE. IllegalStateException will be better in this case.
- Fixed null check in OpenSslServerContext.setTicketKeys(byte[]).
Now we throw new NPE if byte[] is not null.
Result:
Added new null checks when it is necessary, removed unnecessary null checks and fixed some NPE problems.
- Use simple string concatenation instead of String.format()
- Rewrite exception messages so that it follows our style
- Merge MqttCommonUtil and MqttValidationUtil into MqttCodecUtil
- Hide MqttCodecUtil from users
- Rename MqttConnectReturnCode.value to byteValue
- Rename MqttMessageFactory.create*() to new*()
- Rename QoS to MqttQoS
- Make MqttSubAckPayload.grantedQoSLevels immutable and add more useful
constructor
MQTT is a open source protocol on top of TCP which is widely used in
mobile communication and also for IoT (Internet of Things) today. This
will add an open source implementation of MQTT so that it becomes easier
for Netty users to implement an MQTT application.
For more information about the MQTT protocol, read this:
http://public.dhe.ibm.com/software/dw/webservices/ws-mqtt/mqtt-v3r1.html
