org.anhonesteffort.p25.chnlzr.SamplesSourceHandler.java Source code

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Here is the source code for org.anhonesteffort.p25.chnlzr.SamplesSourceHandler.java

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/*
 * Copyright (C) 2015 An Honest Effort LLC, coping.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.anhonesteffort.p25.chnlzr;

import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import org.anhonesteffort.chnlzr.ProtocolErrorException;
import org.anhonesteffort.dsp.ComplexNumber;
import org.anhonesteffort.dsp.DynamicSink;
import org.anhonesteffort.dsp.sample.Samples;

import javax.annotation.Nonnull;
import java.nio.FloatBuffer;
import java.util.concurrent.atomic.AtomicReference;

import static org.anhonesteffort.chnlzr.capnp.Proto.BaseMessage;
import static org.anhonesteffort.chnlzr.capnp.Proto.Capabilities;
import static org.anhonesteffort.chnlzr.capnp.Proto.ChannelState;

public class SamplesSourceHandler extends ChannelHandlerAdapter {

    private final SettableFuture<Void> closePromise;
    private final Capabilities.Reader capabilities;
    private final AtomicReference<DynamicSink<Samples>> sink = new AtomicReference<>(null);

    private ChannelState.Reader state;

    public SamplesSourceHandler(ChannelHandlerContext context, Capabilities.Reader capabilities,
            ChannelState.Reader state) {
        this.capabilities = capabilities;
        this.state = state;
        closePromise = SettableFuture.create();

        context.channel().closeFuture().addListener(close -> {
            if (close.isSuccess()) {
                closePromise.set(null);
            } else {
                closePromise.setException(close.cause());
            }
        });

        Futures.addCallback(closePromise, new FutureCallback<Void>() {
            @Override
            public void onSuccess(Void aVoid) {
                context.close();
            }

            @Override
            public void onFailure(@Nonnull Throwable error) {
                context.close();
            }
        });
    }

    public Capabilities.Reader getCapabilities() {
        return capabilities;
    }

    public ListenableFuture<Void> getCloseFuture() {
        return closePromise;
    }

    public void setSink(DynamicSink<Samples> sink) {
        sink.onSourceStateChange(state.getSampleRate(), state.getCenterFrequency());
        this.sink.set(sink);
    }

    public void close() {
        sink.set(null);
        closePromise.set(null);
    }

    @Override
    public void channelRead(ChannelHandlerContext context, Object msg)
            throws ProtocolErrorException, IllegalStateException {
        BaseMessage.Reader message = (BaseMessage.Reader) msg;
        DynamicSink<Samples> sink = this.sink.get();

        switch (message.getType()) {
        case CHANNEL_STATE:
            state = message.getChannelState();
            if (sink != null) {
                sink.onSourceStateChange(state.getSampleRate(), state.getCenterFrequency());
            }
            break;

        case SAMPLES:
            if (sink != null) {
                FloatBuffer floats = message.getSamples().getSamples().asByteBuffer().asFloatBuffer();
                ComplexNumber[] samples = new ComplexNumber[floats.limit() / 2];

                for (int i = 0; i < samples.length; i++) {
                    samples[i] = new ComplexNumber(floats.get(i * 2), floats.get((i * 2) + 1));
                }

                sink.consume(new Samples(samples));
            }
            break;

        case ERROR:
            ProtocolErrorException error = new ProtocolErrorException("chnlzr sent error while streaming",
                    message.getError().getCode());
            if (!closePromise.setException(error)) {
                throw error;
            }
            break;

        default:
            IllegalStateException ex = new IllegalStateException(
                    "chnlzr sent unexpected while streaming " + message.getType().name());
            if (!closePromise.setException(ex)) {
                throw ex;
            }
            break;
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext context, Throwable cause) {
        context.close();
        closePromise.setException(cause);
    }

    @Override
    public void channelInactive(ChannelHandlerContext context) {
        sink.set(null);
    }

}