DefaultMaxMessagesRecvByteBufAllocator Class — netty Architecture

Source Code

transport/src/main/java/io/netty/channel/DefaultMaxMessagesRecvByteBufAllocator.java lines 28–171

public abstract class DefaultMaxMessagesRecvByteBufAllocator implements MaxMessagesRecvByteBufAllocator {
    private final boolean ignoreBytesRead;
    private volatile int maxMessagesPerRead;
    private volatile boolean respectMaybeMoreData = true;

    public DefaultMaxMessagesRecvByteBufAllocator() {
        this(1);
    }

    public DefaultMaxMessagesRecvByteBufAllocator(int maxMessagesPerRead) {
        this(maxMessagesPerRead, false);
    }

    DefaultMaxMessagesRecvByteBufAllocator(int maxMessagesPerRead, boolean ignoreBytesRead) {
        this.ignoreBytesRead = ignoreBytesRead;
        maxMessagesPerRead(maxMessagesPerRead);
    }

    @Override
    public int maxMessagesPerRead() {
        return maxMessagesPerRead;
    }

    @Override
    public MaxMessagesRecvByteBufAllocator maxMessagesPerRead(int maxMessagesPerRead) {
        checkPositive(maxMessagesPerRead, "maxMessagesPerRead");
        this.maxMessagesPerRead = maxMessagesPerRead;
        return this;
    }

    /**
     * Determine if future instances of {@link #newHandle()} will stop reading if we think there is no more data.
     * @param respectMaybeMoreData
     * <ul>
     *     <li>{@code true} to stop reading if we think there is no more data. This may save a system call to read from
     *          the socket, but if data has arrived in a racy fashion we may give up our {@link #maxMessagesPerRead()}
     *          quantum and have to wait for the selector to notify us of more data.</li>
     *     <li>{@code false} to keep reading (up to {@link #maxMessagesPerRead()}) or until there is no data when we
     *          attempt to read.</li>
     * </ul>
     * @return {@code this}.
     */
    public DefaultMaxMessagesRecvByteBufAllocator respectMaybeMoreData(boolean respectMaybeMoreData) {
        this.respectMaybeMoreData = respectMaybeMoreData;
        return this;
    }

    /**
     * Get if future instances of {@link #newHandle()} will stop reading if we think there is no more data.
     * @return
     * <ul>
     *     <li>{@code true} to stop reading if we think there is no more data. This may save a system call to read from
     *          the socket, but if data has arrived in a racy fashion we may give up our {@link #maxMessagesPerRead()}
     *          quantum and have to wait for the selector to notify us of more data.</li>
     *     <li>{@code false} to keep reading (up to {@link #maxMessagesPerRead()}) or until there is no data when we
     *          attempt to read.</li>
     * </ul>
     */
    public final boolean respectMaybeMoreData() {
        return respectMaybeMoreData;
    }

    /**
     * Focuses on enforcing the maximum messages per read condition for {@link #continueReading()}.
     */
    public abstract class MaxMessageHandle implements ExtendedHandle {
        private ChannelConfig config;
        private int maxMessagePerRead;
        private int totalMessages;
        private int totalBytesRead;
        private int attemptedBytesRead;
        private int lastBytesRead;
        private final boolean respectMaybeMoreData = DefaultMaxMessagesRecvByteBufAllocator.this.respectMaybeMoreData;
        private final UncheckedBooleanSupplier defaultMaybeMoreSupplier = new UncheckedBooleanSupplier() {
            @Override
            public boolean get() {
                return attemptedBytesRead == lastBytesRead;
            }
        };

        /**