001: // kelondroObjectSpace.java
002: // ------------------------
003: // part of The Kelondro Database
004: // (C) by Michael Peter Christen; mc@anomic.de
005: // first published on http://www.anomic.de
006: // Frankfurt, Germany, 2005
007: // created: 12.12.2004
008: //
009: // This program is free software; you can redistribute it and/or modify
010: // it under the terms of the GNU General Public License as published by
011: // the Free Software Foundation; either version 2 of the License, or
012: // (at your option) any later version.
013: //
014: // This program is distributed in the hope that it will be useful,
015: // but WITHOUT ANY WARRANTY; without even the implied warranty of
016: // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
017: // GNU General Public License for more details.
018: //
019: // You should have received a copy of the GNU General Public License
020: // along with this program; if not, write to the Free Software
021: // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
022: //
023: // Using this software in any meaning (reading, learning, copying, compiling,
024: // running) means that you agree that the Author(s) is (are) not responsible
025: // for cost, loss of data or any harm that may be caused directly or indirectly
026: // by usage of this softare or this documentation. The usage of this software
027: // is on your own risk. The installation and usage (starting/running) of this
028: // software may allow other people or application to access your computer and
029: // any attached devices and is highly dependent on the configuration of the
030: // software which must be done by the user of the software; the author(s) is
031: // (are) also not responsible for proper configuration and usage of the
032: // software, even if provoked by documentation provided together with
033: // the software.
034: //
035: // Any changes to this file according to the GPL as documented in the file
036: // gpl.txt aside this file in the shipment you received can be done to the
037: // lines that follows this copyright notice here, but changes must not be
038: // done inside the copyright notive above. A re-distribution must contain
039: // the intact and unchanged copyright notice.
040: // Contributions and changes to the program code must be marked as such.
041:
042: package de.anomic.kelondro;
043:
044: import java.util.ArrayList;
045: import java.util.HashMap;
046: import java.util.Iterator;
047: import java.util.Map;
048: import java.util.TreeMap;
049:
050: public class kelondroObjectSpace {
051:
052: private static final int minSize = 10;
053: private static final int maxSize = 256;
054:
055: private static HashMap<Integer, ArrayList<byte[]>> objHeap = new HashMap<Integer, ArrayList<byte[]>>();
056: private static TreeMap<Integer, Integer> aliveNow = new TreeMap<Integer, Integer>();
057:
058: //private static TreeMap aliveMax = new TreeMap();
059:
060: private static void incAlive(int size) {
061: final Integer s = new Integer(size);
062: synchronized (aliveNow) {
063: final Integer x = (Integer) aliveNow.get(s);
064: if (x == null)
065: aliveNow.put(s, new Integer(1));
066: else
067: aliveNow.put(s, new Integer(x.intValue() + 1));
068: }
069: }
070:
071: private static void decAlive(int size) {
072: final Integer s = new Integer(size);
073: synchronized (aliveNow) {
074: final Integer x = aliveNow.get(s);
075: if (x == null)
076: aliveNow.put(s, new Integer(-1));
077: else
078: aliveNow.put(s, new Integer(x.intValue() - 1));
079: }
080: }
081:
082: public static byte[] alloc(int len) {
083: if ((len < minSize) || (len > maxSize))
084: return new byte[len];
085: incAlive(len);
086: synchronized (objHeap) {
087: ArrayList<byte[]> buf = objHeap.get(new Integer(len));
088: if ((buf == null) || (buf.size() == 0))
089: return new byte[len];
090: return buf.remove(buf.size() - 1);
091: }
092: }
093:
094: public static void recycle(byte[] b) {
095: if ((b.length < minSize) || (b.length > maxSize)) {
096: b = null;
097: return;
098: }
099: decAlive(b.length);
100: synchronized (objHeap) {
101: final Integer i = new Integer(b.length);
102: ArrayList<byte[]> buf = objHeap.get(i);
103: if (buf == null) {
104: buf = new ArrayList<byte[]>();
105: buf.add(b);
106: objHeap.put(i, buf);
107: } else {
108: buf.add(b);
109: }
110: }
111: b = null;
112: }
113:
114: public static TreeMap<Integer, Integer> statAlive() {
115: return aliveNow;
116: }
117:
118: public static TreeMap<Integer, Integer> statHeap() {
119: // creates a statistic output of this object space
120: // the result is a mapping from Integer (chunk size) to Integer (number of counts)
121: // and shows how many Objects are held in this space for usage
122: TreeMap<Integer, Integer> result = new TreeMap<Integer, Integer>();
123: synchronized (objHeap) {
124: Iterator<Map.Entry<Integer, ArrayList<byte[]>>> i = objHeap
125: .entrySet().iterator();
126: Map.Entry<Integer, ArrayList<byte[]>> entry;
127: while (i.hasNext()) {
128: entry = i.next();
129: result.put(entry.getKey(), new Integer(entry.getValue()
130: .size()));
131: }
132: }
133: return result;
134: }
135:
136: }
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