@Override
public IMessage recognize(ByteBuffer buf) throws MessageParseException {
// 长度尚不足，确保可读长度超过4字节
if (buf.remaining() < IMessage.MIN_MESSAGE_LENGTH) {
return null;
}
// 读取前4字节
int len = buf.getShort(); // 预期长度
short type = buf.getShort();
if (type == MessageType.FLASH_POLICY) {
// Policy请求
boolean finished = false;
// 找到结束的'\0'标志
while (buf.remaining() > 0) {
byte b = buf.get();
if (b == 0) {
finished = true;
break;
}
}
if (finished) {
// Policy请求全部接收完毕
} else {
// 不足，下次继续
return null;
}
} else {
// 普通消息，检查长度是否满足
if (buf.remaining() < len - IMessage.HEADER_SIZE) {
return null;
}
}
return createMessage(type);
}
/**
* Get the remaining bytes that could be read from a file or ByteBuffer.
*
* @return Number of remaining bytes
*/
private long getRemainingBytes() {
if (!useLoadBuf) {
return in.remaining();
}
try {
return channelSize - channel.position() + in.remaining();
} catch (Exception e) {
log.error("Error getRemainingBytes", e);
return 0;
}
}
void check() throws JMSException, AMQFrameDecodingException {
for (Object m : received) {
ByteBuffer buffer = ((JMSBytesMessage) m).getData();
FieldTable actual = FieldTableFactory.newFieldTable(buffer, buffer.remaining());
for (String key : _expected.keys()) {
assertEquals(
"Values for " + key + " did not match",
_expected.getObject(key),
actual.getObject(key));
}
}
}
@Override
protected boolean doDecode(IoSession session, ByteBuffer in, ProtocolDecoderOutput out)
throws Exception {
final int origonPos = in.position();
if (in.remaining() < 16) {
in.position(origonPos);
return false;
}
int magic = in.getInt();
if (magic != Const.MAGIC)
throw new IOException("flag error, except: " + Const.MAGIC + ", but get " + magic);
int request = in.getInt();
int pcode = in.getInt();
int len = in.getInt();
if (in.remaining() < len) {
in.position(origonPos);
return false;
}
byte[] data = new byte[len];
in.get(data);
BaseResponsePacket packet = PacketCode.createPacket(pcode, request, data);
out.write(packet);
return true;
}
/**
* Load enough bytes from channel to buffer. After the loading process, the caller can make sure
* the amount in buffer is of size 'amount' if we haven't reached the end of channel.
*
* @param amount The amount of bytes in buffer after returning, no larger than bufferSize
* @param reload Whether to reload or append
*/
private void fillBuffer(long amount, boolean reload) {
try {
if (amount > bufferSize) {
amount = bufferSize;
}
// Read all remaining bytes if the requested amount reach the end
// of channel.
if (channelSize - channel.position() < amount) {
amount = channelSize - channel.position();
}
if (in == null) {
switch (bufferType) {
case HEAP:
in = ByteBuffer.allocate(bufferSize, false);
break;
case DIRECT:
in = ByteBuffer.allocate(bufferSize, true);
break;
case AUTO:
in = ByteBuffer.allocate(bufferSize);
break;
default:
in = ByteBuffer.allocate(bufferSize);
}
channel.read(in.buf());
in.flip();
useLoadBuf = true;
}
if (!useLoadBuf) {
return;
}
if (reload || in.remaining() < amount) {
if (!reload) {
in.compact();
} else {
in.clear();
}
channel.read(in.buf());
in.flip();
}
} catch (Exception e) {
log.error("Error fillBuffer", e);
}
}
/**
* Get the current position in a file or ByteBuffer.
*
* @return Current position in a file
*/
private long getCurrentPosition() {
long pos;
if (!useLoadBuf) {
return in.position();
}
try {
if (in != null) {
pos = (channel.position() - in.remaining());
} else {
pos = channel.position();
}
return pos;
} catch (Exception e) {
log.error("Error getCurrentPosition", e);
return 0;
}
}
/** {@inheritDoc} */
public synchronized ITag readTag() {
long oldPos = getCurrentPosition();
ITag tag = readTagHeader();
if (tagPosition == 0 && tag.getDataType() != TYPE_METADATA && generateMetadata) {
// Generate initial metadata automatically
setCurrentPosition(oldPos);
KeyFrameMeta meta = analyzeKeyFrames();
tagPosition++;
if (meta != null) {
return createFileMeta();
}
}
ByteBuffer body = ByteBuffer.allocate(tag.getBodySize(), false);
// XXX Paul: this assists in 'properly' handling damaged FLV files
long newPosition = getCurrentPosition() + tag.getBodySize();
if (newPosition <= getTotalBytes()) {
int limit;
while (getCurrentPosition() < newPosition) {
fillBuffer(newPosition - getCurrentPosition());
if (getCurrentPosition() + in.remaining() > newPosition) {
limit = in.limit();
in.limit((int) (newPosition - getCurrentPosition()) + in.position());
body.put(in);
in.limit(limit);
} else {
body.put(in);
}
}
body.flip();
tag.setBody(body);
tagPosition++;
}
return tag;
}
/** Tests that the send filter correctly prepends the message length. */
public void testSend() {
int len = 1000;
byte[] sendData = getByteSequence(len);
ByteBuffer buf = ByteBuffer.allocate(len + 4, false);
buf.putInt(len);
buf.put(sendData);
buf = buf.asReadOnlyBuffer();
buf.flip();
byte[] expected = new byte[buf.remaining()];
buf.get(expected);
assertEquals(0, sentMessages.size());
assertEquals(0, receivedMessages.size());
harness.send(sendData);
assertEquals(1, sentMessages.size());
assertEquals(0, receivedMessages.size());
byte[] actual = sentMessages.get(0);
assertTrue("Incorrect send!", Arrays.equals(actual, expected));
}
private void addToList(List<byte[]> list, ByteBuffer buf) {
byte[] bytes = new byte[buf.remaining()];
buf.get(bytes);
list.add(bytes);
}