BsdSocket Class — netty Architecture

Source Code

transport-classes-kqueue/src/main/java/io/netty/channel/kqueue/BsdSocket.java lines 40–270

final class BsdSocket extends Socket {

    // These limits are just based on observations. I couldn't find anything in header files which formally
    // define these limits.
    private static final int APPLE_SND_LOW_AT_MAX = 1 << 17;
    private static final int FREEBSD_SND_LOW_AT_MAX = 1 << 15;
    static final int BSD_SND_LOW_AT_MAX = Math.min(APPLE_SND_LOW_AT_MAX, FREEBSD_SND_LOW_AT_MAX);
    /**
     * The `endpoints` structure passed to `connectx(2)` has an optional "source interface" field,
     * which is the index of the network interface to use.
     * According to `if_nametoindex(3)`, the value 0 is used when no interface is specified.
     */
    private static final int UNSPECIFIED_SOURCE_INTERFACE = 0;

    BsdSocket(int fd) {
        super(fd);
    }

    void setAcceptFilter(AcceptFilter acceptFilter) throws IOException {
        setAcceptFilter(intValue(), acceptFilter.filterName(), acceptFilter.filterArgs());
    }

    void setTcpNoPush(boolean tcpNoPush) throws IOException {
        setTcpNoPush(intValue(), tcpNoPush ? 1 : 0);
    }

    void setSndLowAt(int lowAt) throws IOException {
        setSndLowAt(intValue(), lowAt);
    }

    public void setTcpFastOpen(boolean enableTcpFastOpen) throws IOException {
        setTcpFastOpen(intValue(), enableTcpFastOpen ? 1 : 0);
    }

    boolean isTcpNoPush() throws IOException {
        return getTcpNoPush(intValue()) != 0;
    }

    int getSndLowAt() throws IOException {
        return getSndLowAt(intValue());
    }

    AcceptFilter getAcceptFilter() throws IOException {
        String[] result = getAcceptFilter(intValue());
        return result == null ? PLATFORM_UNSUPPORTED : new AcceptFilter(result[0], result[1]);
    }

    public boolean isTcpFastOpen() throws IOException {
        return isTcpFastOpen(intValue()) != 0;
    }

    PeerCredentials getPeerCredentials() throws IOException {
        return getPeerCredentials(intValue());
    }

    long sendFile(DefaultFileRegion src, long baseOffset, long offset, long length) throws IOException {
        // Open the file-region as it may be created via the lazy constructor. This is needed as we directly access
        // the FileChannel field via JNI.
        src.open();

        long res = sendFile(intValue(), src, baseOffset, offset, length);
        if (res >= 0) {
            return res;
        }
        return ioResult("sendfile", (int) res);
    }

    /**
     * Establish a connection to the given destination address, and send the given data to it.
     *
     * <strong>Note:</strong> This method relies on the {@code connectx(2)} system call, which is MacOS specific.
     *
     * @param source      the source address we are connecting from.
     * @param destination the destination address we are connecting to.
     * @param data        the data to copy to the kernel-side socket buffer.
     * @param tcpFastOpen if {@code true}, set the flags needed to enable TCP FastOpen connecting.
     * @return The number of bytes copied to the kernel-side socket buffer, or the number of bytes sent to the
     * destination. This number is <em>negative</em> if connecting is left in an in-progress state,
     * or <em>positive</em> if the connection was immediately established.
     * @throws IOException if an IO error occurs, if the {@code data} is too big to send in one go,
     * or if the system call is not supported on your platform.