package jp.ac.u_ryukyu.ie.cr.jungle.persistent;

import jp.ac.u_ryukyu.ie.cr.jungle.store.operations.TreeOperation;

import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.util.Iterator;
import java.util.LinkedList;

// not thread safe
public class DefaultChangeListReader implements ChangeListReader {
    private long pos;
    private ByteBuffer buf;
    private FileChannel ch;

    DefaultChangeListReader(FileChannel ch, ByteBuffer buf, long pos) {
        this.pos = pos;
        this.buf = buf;
        this.ch = ch;
    }

    @Override
    public ChangeListReader newReader() {
        ByteBuffer readByteBuffer = buf.asReadOnlyBuffer();
        return new DefaultChangeListReader(ch, readByteBuffer, pos);
    }

    @Override
    public ChangeList read() {
        LinkedList<TreeOperation> list = new LinkedList<TreeOperation>();

        int size = buf.getInt();
        if (size == 0) {

        }

        return null;
    }

    @Override
    public Iterator<ChangeList> iterator() {
        return null;
    }


}