001: /*
002: * $Id: PatternCacheFIFO2.java,v 1.7 2003/11/07 20:16:24 dfs Exp $
003: *
004: * ====================================================================
005: * The Apache Software License, Version 1.1
006: *
007: * Copyright (c) 2000 The Apache Software Foundation. All rights
008: * reserved.
009: *
010: * Redistribution and use in source and binary forms, with or without
011: * modification, are permitted provided that the following conditions
012: * are met:
013: *
014: * 1. Redistributions of source code must retain the above copyright
015: * notice, this list of conditions and the following disclaimer.
016: *
017: * 2. Redistributions in binary form must reproduce the above copyright
018: * notice, this list of conditions and the following disclaimer in
019: * the documentation and/or other materials provided with the
020: * distribution.
021: *
022: * 3. The end-user documentation included with the redistribution,
023: * if any, must include the following acknowledgment:
024: * "This product includes software developed by the
025: * Apache Software Foundation (http://www.apache.org/)."
026: * Alternately, this acknowledgment may appear in the software itself,
027: * if and wherever such third-party acknowledgments normally appear.
028: *
029: * 4. The names "Apache" and "Apache Software Foundation", "Jakarta-Oro"
030: * must not be used to endorse or promote products derived from this
031: * software without prior written permission. For written
032: * permission, please contact apache@apache.org.
033: *
034: * 5. Products derived from this software may not be called "Apache"
035: * or "Jakarta-Oro", nor may "Apache" or "Jakarta-Oro" appear in their
036: * name, without prior written permission of the Apache Software Foundation.
037: *
038: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
039: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
040: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
041: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
042: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
043: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
044: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
045: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
046: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
047: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
048: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
049: * SUCH DAMAGE.
050: * ====================================================================
051: *
052: * This software consists of voluntary contributions made by many
053: * individuals on behalf of the Apache Software Foundation. For more
054: * information on the Apache Software Foundation, please see
055: * <http://www.apache.org/>.
056: */
057:
058: package org.apache.oro.text;
059:
060: import java.util.*;
061:
062: import org.apache.oro.text.regex.*;
063: import org.apache.oro.util.*;
064:
065: /**
066: * This class is a GenericPatternCache subclass implementing a second
067: * chance FIFO (First In First Out) cache replacement policy. In other
068: * words, patterns are added to the cache until the cache becomes full.
069: * Once the cache is full, when a new pattern is added to the cache, it
070: * replaces the first of the current patterns in the cache to have been
071: * added, unless that pattern has been used recently (generally
072: * between the last cache replacement and now).
073: * If the pattern to be replaced has been used, it is given
074: * a second chance, and the next pattern in the cache is tested for
075: * replacement in the same manner. If all the patterns are given a
076: * second chance, then the original pattern selected for replacement is
077: * replaced.
078: *
079: * @version @version@
080: * @since 1.0
081: * @see GenericPatternCache
082: */
083: public final class PatternCacheFIFO2 extends GenericPatternCache {
084:
085: /**
086: * Creates a PatternCacheFIFO2 instance with a given cache capacity,
087: * initialized to use a given PatternCompiler instance as a pattern compiler.
088: * <p>
089: * @param capacity The capacity of the cache.
090: * @param compiler The PatternCompiler to use to compile patterns.
091: */
092: public PatternCacheFIFO2(int capacity, PatternCompiler compiler) {
093: super (new CacheFIFO2(capacity), compiler);
094: }
095:
096: /**
097: * Same as:
098: * <blockquote><pre>
099: * PatternCacheFIFO2(GenericPatternCache.DEFAULT_CAPACITY, compiler);
100: * </pre></blockquote>
101: */
102: public PatternCacheFIFO2(PatternCompiler compiler) {
103: this (GenericPatternCache.DEFAULT_CAPACITY, compiler);
104: }
105:
106: /**
107: * Same as:
108: * <blockquote><pre>
109: * PatternCacheFIFO2(capacity, new Perl5Compiler());
110: * </pre></blockquote>
111: */
112: public PatternCacheFIFO2(int capacity) {
113: this (capacity, new Perl5Compiler());
114: }
115:
116: /**
117: * Same as:
118: * <blockquote><pre>
119: * PatternCacheFIFO2(GenericPatternCache.DEFAULT_CAPACITY);
120: * </pre></blockquote>
121: */
122: public PatternCacheFIFO2() {
123: this(GenericPatternCache.DEFAULT_CAPACITY);
124: }
125:
126: }
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