Quadcap Embeddable Database

com/quadcap/sql/file/Logger.java

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package com.quadcap.sql.file;

/* Copyright 1999 - 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;

import java.util.Properties;

import com.quadcap.util.collections.LongMap;

/**
 * 
 *
 * @author Stan Bailes
 */
public interface Logger {
    /**
     * Initialization
     */
    void init(Log log, boolean create, Properties props) throws IOException;
    
    /**
     * Make it so.
     */
    void sync() throws IOException;

    /**
     * Checkpoint.
     */
    void checkpoint() throws IOException;

    /**
     * Dismissed.
     */
    void close() throws IOException;

    /**
     * Reset the entire log to be empty
     */
    void reset() throws IOException;

    /**
     * Return the id of the oldest active transaction
     */
    long getOldestTransaction();

    /**
     * Return the number of active transactions
     */
    int getActiveTransactionCount();

    /**
     * Return a map containing the active transaction ids as keys
     */
    LongMap getActiveTransactions();

    /**
     * Write a single op to the buffer.
     */
    void put(LogEntry op) throws IOException;

    /**
     * Set the 'redo' value for the most recently read LogEntry
     */
    void setRedoState(LogEntry op, int state) throws IOException;

    /**
     * Return the last op in the log for the specified transaction
     */
    LogEntry getLastOp(long t) throws IOException;

    /**
     * Return the preceding op (of the same transaction)
     */
    LogEntry getPrevOp(LogEntry op) throws IOException;

    /**
     * Return the first op in the log
     */
    LogEntry getFirstOp() throws IOException;

    /**
     * Return the next op
     */
    LogEntry getNextOp() throws IOException;

    /**
     * Return the position of the last checkpoint
     */
    int getCheckpoint();

    /**
     * Return the end position of the log buffer
     */
    int getEnd();
}