/**
* Modifies current position.
*
* @param pos Current position in file
*/
private void setCurrentPosition(long pos) {
if (pos == Long.MAX_VALUE) {
pos = file.length();
}
if (!useLoadBuf) {
in.position((int) pos);
return;
}
try {
if (pos >= (channel.position() - in.limit()) && pos < channel.position()) {
in.position((int) (pos - (channel.position() - in.limit())));
} else {
channel.position(pos);
fillBuffer(bufferSize, true);
}
} catch (Exception e) {
log.error("Error setCurrentPosition", e);
}
}
@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;
}
/**
* 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;
}
