Quadcap Embeddable Database

com/quadcap/sql/index/BCursor.java

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package com.quadcap.sql.index;

/* Copyright 1997 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

import java.io.IOException;

/**
 * BCursor
 *
 * @author Stan Bailes
 */
public interface BCursor {
    // Cursor positioning

    /**
     * Seek to (before) the specified key
     */
    boolean seek(byte[] key, int len) throws IOException;

    /**
     * Seek to (before) the specified key
     */
    boolean seek(byte[] buf) throws IOException;

    /**
     * Position cursor before the first record
     */
    void beforeFirst() throws IOException;

    /**
     * Position the cursor after the last record
     */
    void afterLast() throws IOException;

    /**
     * Move to the specified record; one-based.
     * -1 means last record, -2 means next to last, etc.
     * @return <b>true</b> if the specified record exists.     
     */
    boolean absolute(int x) throws IOException;

    /**
     * Move past the next record and return true the cursor is
     * now pointed at a valid record.
     */
    boolean next() throws IOException;

    /**
     * Move before the previous record and return true the cursor is
     * now pointed at a valid record.
     */
    boolean prev() throws IOException;

    int getKey(byte[] buf) throws IOException;
    byte[] getKeyBuf();
    void setKeyBuf(byte[] buf);
    int getKeyLen();
    byte[] getKey();                    // XXX a crutch.
    
    int getVal(byte[] buf) throws IOException;
    byte[] getValBuf();
    void setValBuf(byte[] buf);
    int getValLen();
    byte[] getVal();                    // XXX a crutch.
    
    long getValAsLong() throws IOException;

    long size() throws IOException;
    long position() throws IOException;

    /**
     * Release this cursor back to the pool
     */
    void release();

    /**
     * Release any resources held by this cursor (but maintain ownership of
     * it -- it can be resurrected by another positioning call.
     */
    void close() throws IOException;

    /**
     * Delete the currently positioned record
     */
    boolean delete() throws IOException;

    /**
     * Insert a new key/data pair.  We are presumably positioned just before
     * the spot where the new record should go, but we will check, anyway.
     */
    boolean insert(byte[] key, int klen,
                   byte[] data, int doff, int dlen) throws IOException;
    boolean insert(byte[] key, byte[] data) throws IOException;

    /**
     * Replace the data portion of the current item with the specified data
     */
    boolean replace(byte[] data, int doff, int dlen) throws IOException;
    boolean replace(byte[] data) throws IOException;

}