BoundedInputStream Class — netty Architecture

Source Code

common/src/main/java/io/netty/util/internal/BoundedInputStream.java lines 24–69

public final class BoundedInputStream extends FilterInputStream {

    private final int maxBytesRead;
    private int numRead;

    public BoundedInputStream(@NotNull InputStream in, int maxBytesRead) {
        super(in);
        this.maxBytesRead = ObjectUtil.checkPositive(maxBytesRead, "maxRead");
    }

    public BoundedInputStream(@NotNull InputStream in) {
        this(in, 8 * 1024);
    }

    @Override
    public int read() throws IOException {
        checkMaxBytesRead();

        int b = super.read();
        if (b != -1) {
            numRead++;
        }
        return b;
    }

    @Override
    public int read(byte[] buf, int off, int len) throws IOException {
        checkMaxBytesRead();

        // Calculate the maximum number of bytes that we should try to read.
        int num = Math.min(len, maxBytesRead - numRead + 1);

        int b = super.read(buf, off, num);

        if (b != -1) {
            numRead += b;
        }
        return b;
    }

    private void checkMaxBytesRead() throws IOException {
        if (numRead > maxBytesRead) {
            throw new IOException("Maximum number of bytes read: " + numRead);
        }
    }
}