import java.io.*;
import java.util.zip.*;

public class CompressedInputStream extends FilterInputStream {
    Inflater inflater; // The inflater
    protected byte buf[]; //  The internal buffer where uncompressed data is stored
    protected int pos;    // The current position in the buffer.   
    protected int count; // The index one greater than the index of the last valid byte in the buffer. 

    private void ensureOpen() throws IOException {
	if (in == null)
	    throw new IOException("Stream closed");
    }

    public CompressedInputStream(InputStream in) {
	super(in);
	inflater = new Inflater();
    }

    private void fill() throws IOException {
	InflaterInputStream iis = new InflaterInputStream(in);
	DataInputStream dataIn = new DataInputStream(iis);
	int noBytes = 0;
	try {
	    noBytes = dataIn.readInt();
	    buf = new byte[noBytes];
	} catch (EOFException ee) {
	    return;
	}
	System.err.println("reading="+noBytes);
	count = dataIn.read(buf,0,noBytes);
	pos = 0;
    }

    public synchronized int read() throws IOException {
        ensureOpen();
	if (pos >= count) {
	    fill();
	    if (pos >= count)
		return -1;
	}
	return buf[pos++] & 0xff;
    }


    public synchronized int read(byte b[], int off, int len)
	throws IOException
    {
        ensureOpen();
	for (int i=0; i<len; i++) 
	    b[i+off]=(byte)read();
	return len;
    }

    public synchronized long skip(long n) throws IOException {
        ensureOpen();
	for (int i=0; i<n; i++) 
	    read();
	return n;
    }

    public synchronized int available() throws IOException {
	return (count - pos) + in.available();
    }

    public boolean markSupported() {
	return false;
    }

    public void close() throws IOException {
        if (in == null)
            return;
        in.close();
        in = null;
        buf = null;
    }
}