001/* 002 * The contents of this file are subject to the terms of the Common Development and 003 * Distribution License (the License). You may not use this file except in compliance with the 004 * License. 005 * 006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the 007 * specific language governing permission and limitations under the License. 008 * 009 * When distributing Covered Software, include this CDDL Header Notice in each file and include 010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL 011 * Header, with the fields enclosed by brackets [] replaced by your own identifying 012 * information: "Portions Copyright [year] [name of copyright owner]". 013 * 014 * Copyright 2014-2015 ForgeRock AS. 015 */ 016package org.opends.server.backends.pluggable.spi; 017 018import org.forgerock.opendj.ldap.ByteSequence; 019import org.forgerock.opendj.ldap.ByteString; 020 021/** 022 * Represents a readable transaction on a storage engine. 023 */ 024public interface ReadableTransaction 025{ 026 /** 027 * Reads the record's value associated to the provided key, in the tree whose name is provided. 028 * 029 * @param treeName 030 * the tree name 031 * @param key 032 * the record's key 033 * @return the record's value, or {@code null} if none exists 034 */ 035 ByteString read(TreeName treeName, ByteSequence key); 036 037 /** 038 * Opens a cursor on the tree whose name is provided. 039 * 040 * @param treeName 041 * the tree name 042 * @return a new cursor 043 */ 044 Cursor<ByteString, ByteString> openCursor(TreeName treeName); 045 046 /** 047 * Returns the number of key/value pairs in the provided tree. 048 * 049 * @param treeName 050 * the tree name 051 * @return the number of key/value pairs in the provided tree. 052 */ 053 long getRecordCount(TreeName treeName); 054}