001: /* ====================================================================
002: * The Jcorporate Apache Style Software License, Version 1.2 05-07-2002
003: *
004: * Copyright (c) 1995-2002 Jcorporate Ltd. All rights reserved.
005: *
006: * Redistribution and use in source and binary forms, with or without
007: * modification, are permitted provided that the following conditions
008: * are met:
009: *
010: * 1. Redistributions of source code must retain the above copyright
011: * notice, this list of conditions and the following disclaimer.
012: *
013: * 2. Redistributions in binary form must reproduce the above copyright
014: * notice, this list of conditions and the following disclaimer in
015: * the documentation and/or other materials provided with the
016: * distribution.
017: *
018: * 3. The end-user documentation included with the redistribution,
019: * if any, must include the following acknowledgment:
020: * "This product includes software developed by Jcorporate Ltd.
021: * (http://www.jcorporate.com/)."
022: * Alternately, this acknowledgment may appear in the software itself,
023: * if and wherever such third-party acknowledgments normally appear.
024: *
025: * 4. "Jcorporate" and product names such as "Expresso" must
026: * not be used to endorse or promote products derived from this
027: * software without prior written permission. For written permission,
028: * please contact info@jcorporate.com.
029: *
030: * 5. Products derived from this software may not be called "Expresso",
031: * or other Jcorporate product names; nor may "Expresso" or other
032: * Jcorporate product names appear in their name, without prior
033: * written permission of Jcorporate Ltd.
034: *
035: * 6. No product derived from this software may compete in the same
036: * market space, i.e. framework, without prior written permission
037: * of Jcorporate Ltd. For written permission, please contact
038: * partners@jcorporate.com.
039: *
040: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
041: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
042: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
043: * DISCLAIMED. IN NO EVENT SHALL JCORPORATE LTD OR ITS CONTRIBUTORS
044: * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
045: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
046: * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
047: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
048: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
049: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
050: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
051: * SUCH DAMAGE.
052: * ====================================================================
053: *
054: * This software consists of voluntary contributions made by many
055: * individuals on behalf of the Jcorporate Ltd. Contributions back
056: * to the project(s) are encouraged when you make modifications.
057: * Please send them to support@jcorporate.com. For more information
058: * on Jcorporate Ltd. and its products, please see
059: * <http://www.jcorporate.com/>.
060: *
061: * Portions of this software are based upon other open source
062: * products and are subject to their respective licenses.
063: */
064: package com.jcorporate.expresso.core.dbobj;
065:
066: import com.jcorporate.expresso.core.misc.StringUtil;
067:
068: /**
069: * Cache Statistic Entry. Used by the DBObject system for tracking cache
070: * hit statistics
071: *
072: * @version 1.0
073: */
074: public class CacheStatEntry extends Object implements Comparable {
075:
076: private String dbobjName = null;
077: private String dbName = null;
078: private int readCount = 0;
079: private int cacheHits = 0;
080: private int cacheMisses = 0;
081:
082: /**
083: * Creates new CacheStatEntry
084: *
085: * @param newName the new dbobject name
086: * @param newDBName the data context for the name
087: */
088: public CacheStatEntry(String newName, String newDBName) {
089: dbobjName = newName;
090: dbName = StringUtil.notNull(newDBName);
091:
092: if (dbName.equals("")) {
093: dbName = "default";
094: }
095: }
096:
097: /**
098: * Retrieve the overall read count for dbobjects
099: *
100: * @return integer
101: */
102: public int getReadCount() {
103: return readCount;
104: }
105:
106: /**
107: * Retrieve the number of cache hits
108: *
109: * @return integer
110: */
111: public int getCacheHits() {
112: return cacheHits;
113: }
114:
115: /**
116: * Retrieve the number of cache misses
117: *
118: * @return integer
119: */
120: public int getCacheMisses() {
121: return cacheMisses;
122: }
123:
124: /**
125: * Retrieve the data context of the stat entry
126: *
127: * @return java.lang.String
128: */
129: public String getDataContext() {
130: return dbName;
131: }
132:
133: /**
134: * Retrieve the classname of the DBObject for this
135: * cache stat
136: *
137: * @return java.lang.String
138: */
139: public String getDBObjName() {
140: return dbobjName;
141: }
142:
143: /**
144: * Increment the counts for the particular class name. Increments
145: * the read count and either the cache hit or cache miss
146: *
147: * @param cached true if we got a cache hit, false if we got a cache
148: * miss
149: */
150: public synchronized void incCounts(boolean cached) {
151: if (cached) {
152: cacheHits++;
153: } else {
154: cacheMisses++;
155: }
156:
157: readCount++;
158: }
159:
160: /**
161: * Compares this object with the specified object for order.
162: * <p/>
163: * order by hit rate, hits/misses
164: *
165: * @param o the Object to be compared.
166: * @return a negative integer, zero, or a positive integer as this object
167: * is less than, equal to, or greater than the specified object.
168: * @throws ClassCastException if the specified object's type prevents it
169: * from being compared to this Object.
170: */
171: public int compareTo(Object o) {
172: int result = 0;
173: CacheStatEntry entry = (CacheStatEntry) o;
174:
175: // want lower hitrates first
176: Float myhitrate = new Float((float) this .getCacheHits()
177: / (float) getReadCount());
178: Float hitrate = new Float((float) entry.getCacheHits()
179: / (float) entry.getReadCount());
180: result = myhitrate.compareTo(hitrate);
181: if (result == 0) {
182: //secondary: # of reads HIGHER is first
183: result = new Integer(entry.getReadCount())
184: .compareTo(new Integer(getReadCount()));
185: }
186: return result;
187: }
188: }
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