/*- * See the file LICENSE for redistribution information. * * Copyright (c) 2002,2008 Oracle. All rights reserved. * * $Id: StatsConfig.java,v 12.7 2008/01/17 05:04:53 mjc Exp $ */ package com.sleepycat.db; import com.sleepycat.db.internal.DbConstants; /** Specifies the attributes of a statistics retrieval operation. */ public class StatsConfig { /* * For internal use, to allow null as a valid value for * the config parameter. */ public static final StatsConfig DEFAULT = new StatsConfig(); /* package */ static StatsConfig checkNull(StatsConfig config) { return (config == null) ? DEFAULT : config; } private boolean clear = false; private boolean fast = false; /** An instance created using the default constructor is initialized with the system's default settings. */ public StatsConfig() { } /** Configure the statistics operation to reset statistics after they are returned. The default value is false.
@param clear If set to true, configure the statistics operation to reset statistics after they are returned. */ public void setClear(boolean clear) { this.clear = clear; } /** Return if the statistics operation is configured to reset statistics after they are returned.
@return If the statistics operation is configured to reset statistics after they are returned. */ public boolean getClear() { return clear; } /** Configure the statistics operation to return only the values which do not incur some performance penalty.
The default value is false.
For example, skip stats that require a traversal of the database or in-memory tree, or which lock down the lock table for a period of time.
Among other things, this flag makes it possible for applications to request key and record counts without incurring the performance penalty of traversing the entire database. If the underlying database is of type Recno, or of type Btree and the database was configured to support retrieval by record number, the count of keys will be exact. Otherwise, the count of keys will be the value saved the last time the database was traversed, or 0 if no count of keys has ever been made. If the underlying database is of type Recno, the count of data items will be exact, otherwise, the count of data items will be the value saved the last time the database was traversed, or 0 if no count of data items has ever been done.
@param fast If set to true, configure the statistics operation to return only the values which do not incur some performance penalty. */ public void setFast(boolean fast) { this.fast = fast; } /** Return if the statistics operation is configured to return only the values which do not require expensive actions.
@return If the statistics operation is configured to return only the values which do not require expensive actions. */ public boolean getFast() { return fast; } int getFlags() { int flags = 0; if (fast) flags |= DbConstants.DB_FAST_STAT; if (clear) flags |= DbConstants.DB_STAT_CLEAR; return flags; } }