/**
* Pools the specified <tt>RawPacket</tt> in order to avoid future allocations and to reduce the
* effects of garbage collection.
*
* @param pkt the <tt>RawPacket</tt> to be offered to {@link #rawPacketPool}
*/
private void poolRawPacket(RawPacket pkt) {
pkt.setBuffer(null);
pkt.setFlags(0);
pkt.setLength(0);
pkt.setOffset(0);
rawPacketPool.offer(pkt);
}
/**
* Creates a new <tt>RawPacket</tt> from a specific <tt>DatagramPacket</tt> in order to have this
* instance receive its packet data through its {@link #read(byte[], int, int)} method. Returns an
* array of <tt>RawPacket</tt> with the created packet as its first element (and <tt>null</tt> for
* the other elements).
*
* <p>Allows extenders to intercept the packet data and possibly filter and/or modify it.
*
* @param datagramPacket the <tt>DatagramPacket</tt> containing the packet data
* @return an array of <tt>RawPacket</tt> containing the <tt>RawPacket</tt> which contains the
* packet data of the specified <tt>DatagramPacket</tt> as its first element.
*/
protected RawPacket[] createRawPacket(DatagramPacket datagramPacket) {
RawPacket[] pkts = rawPacketArrayPool.poll();
if (pkts == null) pkts = new RawPacket[1];
RawPacket pkt = rawPacketPool.poll();
if (pkt == null) pkt = new RawPacket();
pkt.setBuffer(datagramPacket.getData());
pkt.setFlags(0);
pkt.setLength(datagramPacket.getLength());
pkt.setOffset(datagramPacket.getOffset());
pkts[0] = pkt;
return pkts;
}
/**
* Copies the content of the most recently received packet into <tt>data</tt>.
*
* @param buffer an optional <tt>Buffer</tt> instance associated with the specified <tt>data</tt>,
* <tt>offset</tt> and <tt>length</tt> and provided to the method in case the implementation
* would like to provide additional <tt>Buffer</tt> properties such as <tt>flags</tt>
* @param data the <tt>byte[]</tt> that we'd like to copy the content of the packet to.
* @param offset the position where we are supposed to start writing in <tt>data</tt>.
* @param length the number of <tt>byte</tt>s available for writing in <tt>data</tt>.
* @return the number of bytes read
* @throws IOException if <tt>length</tt> is less than the size of the packet.
*/
protected int read(Buffer buffer, byte[] data, int offset, int length) throws IOException {
if (data == null) throw new NullPointerException("data");
if (ioError) return -1;
RawPacket pkt;
synchronized (pktSyncRoot) {
pkt = this.pkt;
this.pkt = null;
}
int pktLength;
if (pkt == null) {
pktLength = 0;
} else {
// By default, pkt will be returned to the pool after it was read.
boolean poolPkt = true;
try {
pktLength = pkt.getLength();
if (length < pktLength) {
/*
* If pkt is still the latest RawPacket made available to
* reading, reinstate it for the next invocation of read;
* otherwise, return it to the pool.
*/
poolPkt = false;
throw new IOException("Input buffer not big enough for " + pktLength);
} else {
byte[] pktBuffer = pkt.getBuffer();
if (pktBuffer == null) {
throw new NullPointerException(
"pkt.buffer null, pkt.length " + pktLength + ", pkt.offset " + pkt.getOffset());
} else {
System.arraycopy(pkt.getBuffer(), pkt.getOffset(), data, offset, pktLength);
if (buffer != null) buffer.setFlags(pkt.getFlags());
}
}
} finally {
if (!poolPkt) {
synchronized (pktSyncRoot) {
if (this.pkt == null) this.pkt = pkt;
else poolPkt = true;
}
}
if (poolPkt) {
// Return pkt to the pool because it was successfully read.
poolRawPacket(pkt);
}
}
}
return pktLength;
}
/**
* Listens for incoming datagrams, stores them for reading by the <tt>read</tt> method and
* notifies the local <tt>transferHandler</tt> that there's data to be read.
*/
public void run() {
DatagramPacket p = new DatagramPacket(buffer, 0, PACKET_RECEIVE_BUFFER_LENGTH);
while (!closed) {
try {
// http://code.google.com/p/android/issues/detail?id=24765
if (OSUtils.IS_ANDROID) p.setLength(PACKET_RECEIVE_BUFFER_LENGTH);
receivePacket(p);
} catch (IOException e) {
ioError = true;
break;
}
/*
* Do the DatagramPacketFilters accept the received DatagramPacket?
*/
DatagramPacketFilter[] datagramPacketFilters = getDatagramPacketFilters();
boolean accept;
if (!enabled) accept = false;
else if (datagramPacketFilters == null) accept = true;
else {
accept = true;
for (int i = 0; i < datagramPacketFilters.length; i++) {
try {
if (!datagramPacketFilters[i].accept(p)) {
accept = false;
break;
}
} catch (Throwable t) {
if (t instanceof ThreadDeath) throw (ThreadDeath) t;
}
}
}
if (accept) {
RawPacket pkts[] = createRawPacket(p);
for (int i = 0; i < pkts.length; i++) {
RawPacket pkt = pkts[i];
pkts[i] = null;
if (pkt != null) {
if (pkt.isInvalid()) {
/*
* Return pkt to the pool because it is invalid and,
* consequently, will not be made available to
* reading.
*/
poolRawPacket(pkt);
} else {
RawPacket oldPkt;
synchronized (pktSyncRoot) {
oldPkt = this.pkt;
this.pkt = pkt;
}
if (oldPkt != null) {
/*
* Return oldPkt to the pool because it was made
* available to reading and it was not read.
*/
poolRawPacket(oldPkt);
}
if (videoRecorder != null) videoRecorder.recordData(pkt);
if ((transferHandler != null) && !closed) {
try {
transferHandler.transferData(this);
} catch (Throwable t) {
/*
* XXX We cannot allow transferHandler to
* kill us.
*/
if (t instanceof ThreadDeath) {
throw (ThreadDeath) t;
} else {
logger.warn("An RTP packet may have not been" + " fully handled.", t);
}
}
}
}
}
}
rawPacketArrayPool.offer(pkts);
}
}
}
