// Create a safe duplicate of the message to write it to a channel but not affect other writes.
// See https://github.com/netty/netty/issues/1461
private static Object safeDuplicate(Object message) {
if (message instanceof ByteBuf) {
return ((ByteBuf) message).duplicate().retain();
} else if (message instanceof ByteBufHolder) {
return ((ByteBufHolder) message).duplicate().retain();
} else {
return ReferenceCountUtil.retain(message);
}
}
@Override
public ChannelGroupFuture writeAndFlush(Object message, ChannelMatcher matcher) {
if (message == null) {
throw new NullPointerException("message");
}
Map<Channel, ChannelFuture> futures = new LinkedHashMap<Channel, ChannelFuture>(size());
for (Channel c : nonServerChannels) {
if (matcher.matches(c)) {
futures.put(c, c.writeAndFlush(safeDuplicate(message)));
}
}
ReferenceCountUtil.release(message);
return new DefaultChannelGroupFuture(this, futures, executor);
}