LimitingByteInput Class — netty Architecture

Source Code

codec-marshalling/src/main/java/io/netty/handler/codec/marshalling/LimitingByteInput.java lines 28–104

class LimitingByteInput implements ByteInput {

    // Use a static instance here to remove the overhead of fillStacktrace
    private static final TooBigObjectException EXCEPTION = new TooBigObjectException();

    private final ByteInput input;
    private final long limit;
    private long read;

    LimitingByteInput(ByteInput input, long limit) {
        this.input = input;
        this.limit = checkPositive(limit, "limit");
    }

    @Override
    public void close() throws IOException {
        // Nothing to do
    }

    @Override
    public int available() throws IOException {
        return readable(input.available());
    }

    @Override
    public int read() throws IOException {
        int readable = readable(1);
        if (readable > 0) {
            int b = input.read();
            read++;
            return b;
        } else {
            throw EXCEPTION;
        }
    }

    @Override
    public int read(byte[] array) throws IOException {
        return read(array, 0, array.length);
    }

    @Override
    public int read(byte[] array, int offset, int length) throws IOException {
        int readable = readable(length);
        if (readable > 0) {
            int i = input.read(array, offset, readable);
            read += i;
            return i;
        } else {
            throw EXCEPTION;
        }
    }

    @Override
    public long skip(long bytes) throws IOException {
        int readable = readable((int) bytes);
        if (readable > 0) {
            long i = input.skip(readable);
            read += i;
            return i;
        } else {
            throw EXCEPTION;
        }
    }

    private int readable(int length) {
        return (int) Math.min(length, limit - read);
    }

    /**
     * Exception that will get thrown if the {@link Object} is too big to unmarshall
     *
     */
    static final class TooBigObjectException extends IOException {
        private static final long serialVersionUID = 1L;
    }
}