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yacy_search_server/source/de/anomic/kelondro/kelondroMSetTools.java

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// kelondroMSetTools.java
// -------------------------------------
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
// last major change: 28.12.2004
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.
package de.anomic.kelondro;
import java.io.File;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.io.FileInputStream;
import java.util.Comparator;
import java.util.Iterator;
import java.util.TreeMap;
import java.util.TreeSet;
public class kelondroMSetTools {
//public static Comparator fastStringComparator = fastStringComparator(true);
// ------------------------------------------------------------------------------------------------
// helper methods
private static int compare(Object a, Object b, Comparator c) {
if (c != null) return c.compare(a,b);
if ((a instanceof String) && (b instanceof String)) return ((String) a).compareTo((String) b);
throw new ClassCastException();
}
public static int log2a(int x) {
// this computes 1 + log2
// it is the number of bits in x, not the logarithmus by 2
int l = 0;
while (x > 0) {x = x >>> 1; l++;}
return l;
}
// ------------------------------------------------------------------------------------------------
// join
// We distinguish two principal solutions
// - constructive join (generate new data structure)
// - destructive join (remove non-valid elements from given data structure)
// The alogorithm to perform the join can be also of two kind:
// - join by pairvise enumeration
// - join by iterative tests (where we distinguish left-right and right-left tests)
public static TreeMap joinConstructive(TreeMap map, TreeSet set) {
// comparators must be equal
if ((map == null) || (set == null)) return null;
if (map.comparator() != set.comparator()) return null;
if ((map.size() == 0) || (set.size() == 0)) return new TreeMap(map.comparator());
// decide which method to use
int high = ((map.size() > set.size()) ? map.size() : set.size());
int low = ((map.size() > set.size()) ? set.size() : map.size());
int stepsEnum = 10 * (high + low - 1);
int stepsTest = 12 * log2a(high) * low;
// start most efficient method
if (stepsEnum > stepsTest) {
if (map.size() < set.size()) return joinConstructiveByTestSetInMap(map, set);
return joinConstructiveByTestMapInSet(map, set);
}
return joinConstructiveByEnumeration(map, set);
}
private static TreeMap joinConstructiveByTestSetInMap(TreeMap map, TreeSet set) {
Iterator si = set.iterator();
TreeMap result = new TreeMap(map.comparator());
Object o;
while (si.hasNext()) {
o = si.next();
if (map.containsKey(o)) result.put(o, map.get(o));
}
return result;
}
private static TreeMap joinConstructiveByTestMapInSet(TreeMap map, TreeSet set) {
Iterator mi = map.keySet().iterator();
TreeMap result = new TreeMap(map.comparator());
Object o;
while (mi.hasNext()) {
o = mi.next();
if (set.contains(o)) result.put(o, map.get(o));
}
return result;
}
private static TreeMap joinConstructiveByEnumeration(TreeMap map, TreeSet set) {
// implement pairvise enumeration
Comparator comp = map.comparator();
Iterator mi = map.keySet().iterator();
Iterator si = set.iterator();
TreeMap result = new TreeMap(map.comparator());
int c;
if ((mi.hasNext()) && (si.hasNext())) {
Object mobj = mi.next();
Object sobj = si.next();
while (true) {
c = compare(mobj, sobj, comp);
if (c < 0) {
if (mi.hasNext()) mobj = mi.next(); else break;
} else if (c > 0) {
if (si.hasNext()) sobj = si.next(); else break;
} else {
result.put(mobj, map.get(mobj));
if (mi.hasNext()) mobj = mi.next(); else break;
if (si.hasNext()) sobj = si.next(); else break;
}
}
}
return result;
}
// now the same for set-set
public static TreeSet joinConstructive(TreeSet set1, TreeSet set2) {
// comparators must be equal
if ((set1 == null) || (set2 == null)) return null;
if (set1.comparator() != set2.comparator()) return null;
if ((set1.size() == 0) || (set2.size() == 0)) return new TreeSet(set1.comparator());
// decide which method to use
int high = ((set1.size() > set2.size()) ? set1.size() : set2.size());
int low = ((set1.size() > set2.size()) ? set2.size() : set1.size());
int stepsEnum = 10 * (high + low - 1);
int stepsTest = 12 * log2a(high) * low;
// start most efficient method
if (stepsEnum > stepsTest) {
if (set1.size() < set2.size()) return joinConstructiveByTest(set1, set2);
return joinConstructiveByTest(set2, set1);
}
return joinConstructiveByEnumeration(set1, set2);
}
private static TreeSet joinConstructiveByTest(TreeSet small, TreeSet large) {
Iterator mi = small.iterator();
TreeSet result = new TreeSet(small.comparator());
Object o;
while (mi.hasNext()) {
o = mi.next();
if (large.contains(o)) result.add(o);
}
return result;
}
private static TreeSet joinConstructiveByEnumeration(TreeSet set1, TreeSet set2) {
// implement pairvise enumeration
Comparator comp = set1.comparator();
Iterator mi = set1.iterator();
Iterator si = set2.iterator();
TreeSet result = new TreeSet(set1.comparator());
int c;
if ((mi.hasNext()) && (si.hasNext())) {
Object mobj = mi.next();
Object sobj = si.next();
while (true) {
c = compare(mobj, sobj, comp);
if (c < 0) {
if (mi.hasNext()) mobj = mi.next(); else break;
} else if (c > 0) {
if (si.hasNext()) sobj = si.next(); else break;
} else {
result.add(mobj);
if (mi.hasNext()) mobj = mi.next(); else break;
if (si.hasNext()) sobj = si.next(); else break;
}
}
}
return result;
}
// ------------------------------------------------------------------------------------------------
// exclude
public static TreeMap excludeConstructive(TreeMap map, TreeSet set) {
// comparators must be equal
if (map == null) return null;
if (set == null) return map;
if ((map.size() == 0) || (set.size() == 0)) return map;
if (map.comparator() != set.comparator()) return excludeConstructiveByTestMapInSet(map, set);
return excludeConstructiveByTestMapInSet(map, set);
// return excludeConstructiveByEnumeration(map, set);
}
private static TreeMap excludeConstructiveByTestMapInSet(TreeMap map, TreeSet set) {
Iterator mi = map.keySet().iterator();
TreeMap result = new TreeMap(map.comparator());
Object o;
while (mi.hasNext()) {
o = mi.next();
if (!(set.contains(o))) result.put(o, map.get(o));
}
return result;
}
private static TreeMap excludeConstructiveByEnumeration(TreeMap map, TreeSet set) {
// returns map without the elements in set
// enumerates objects
Comparator comp = map.comparator();
Iterator mi = map.keySet().iterator();
Iterator si = set.iterator();
TreeMap result = new TreeMap(map.comparator());
int c;
if ((mi.hasNext()) && (si.hasNext())) {
Object mobj = mi.next();
Object sobj = si.next();
while (true) {
c = compare(mobj, sobj, comp);
if (c < 0) {
result.put(mobj, map.get(mobj));
if (mi.hasNext()) mobj = mi.next();
else break;
} else if (c > 0) {
if (si.hasNext()) sobj = si.next();
else break;
} else {
if (mi.hasNext()) mobj = mi.next();
else break;
if (si.hasNext()) sobj = si.next();
else {
// final flush
result.put(mobj, map.get(mobj));
while (mi.hasNext()) {
mobj = mi.next();
result.put(mobj, map.get(mobj));
}
break;
}
}
}
}
return result;
}
public static void excludeDestructive(TreeMap map, TreeSet set) {
// comparators must be equal
if (map == null) return;
if (set == null) return;
if (map.comparator() != set.comparator()) return;
if ((map.size() == 0) || (set.size() == 0)) return;
if (map.size() < set.size())
excludeDestructiveByTestMapInSet(map, set);
else
excludeDestructiveByTestSetInMap(map, set);
}
private static void excludeDestructiveByTestMapInSet(TreeMap map, TreeSet set) {
Iterator mi = map.keySet().iterator();
while (mi.hasNext()) if (set.contains(mi.next())) mi.remove();
}
private static void excludeDestructiveByTestSetInMap(TreeMap map, TreeSet set) {
Iterator si = set.iterator();
while (si.hasNext()) map.remove(si.next());
}
// and the same again with set-set
public static void excludeDestructive(TreeSet set1, TreeSet set2) {
// comparators must be equal
if (set1 == null) return;
if (set2 == null) return;
if (set1.comparator() != set2.comparator()) return;
if ((set1.size() == 0) || (set2.size() == 0)) return;
if (set1.size() < set2.size())
excludeDestructiveByTestSmallInLarge(set1, set2);
else
excludeDestructiveByTestLargeInSmall(set1, set2);
}
private static void excludeDestructiveByTestSmallInLarge(TreeSet small, TreeSet large) {
Iterator mi = small.iterator();
while (mi.hasNext()) if (large.contains(mi.next())) mi.remove();
}
private static void excludeDestructiveByTestLargeInSmall(TreeSet large, TreeSet small) {
Iterator si = small.iterator();
while (si.hasNext()) large.remove(si.next());
}
// ------------------------------------------------------------------------------------------------
public static TreeMap loadMap(String filename, String sep) {
TreeMap map = new TreeMap();
BufferedReader br = null;
try {
br = new BufferedReader(new InputStreamReader(new FileInputStream(filename)));
String line;
int pos;
while ((line = br.readLine()) != null) {
line = line.trim();
if ((line.length() > 0) && (!(line.startsWith("#"))) && ((pos = line.indexOf(sep)) > 0))
map.put(line.substring(0, pos).trim().toLowerCase(), line.substring(pos + sep.length()).trim());
}
} catch (IOException e) {
} finally {
if (br != null) try { br.close(); } catch (Exception e) {}
}
return map;
}
public static TreeSet loadList(File file, Comparator c) {
TreeSet list = new TreeSet(c);
if (!(file.exists())) return list;
BufferedReader br = null;
try {
br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
String line;
while ((line = br.readLine()) != null) {
line = line.trim();
if ((line.length() > 0) && (!(line.startsWith("#")))) list.add(line.trim().toLowerCase());
}
br.close();
} catch (IOException e) {
} finally {
if (br != null) try{br.close();}catch(Exception e){}
}
return list;
}
// ------------------------------------------------------------------------------------------------
public static void main(String[] args) {
TreeMap m = new TreeMap();
TreeSet s = new TreeSet();
m.put("a", "a");
m.put("x", "x");
m.put("f", "f");
m.put("h", "h");
m.put("w", "w");
m.put("7", "7");
m.put("t", "t");
m.put("k", "k");
m.put("y", "y");
m.put("z", "z");
s.add("a");
s.add("b");
s.add("c");
s.add("k");
s.add("l");
s.add("m");
s.add("n");
s.add("o");
s.add("p");
s.add("q");
s.add("r");
s.add("s");
s.add("t");
s.add("x");
System.out.println("Compare " + m.toString() + " with " + s.toString());
System.out.println("Join=" + joinConstructiveByEnumeration(m, s));
System.out.println("Join=" + joinConstructiveByTestMapInSet(m, s));
System.out.println("Join=" + joinConstructiveByTestSetInMap(m, s));
System.out.println("Join=" + joinConstructive(m, s));
System.out.println("Exclude=" + excludeConstructiveByEnumeration(m, s));
/*
for (int low = 0; low < 10; low++)
for (int high = 0; high < 100; high=high + 10) {
int stepsEnum = 10 * high;
int stepsTest = 12 * log2(high) * low;
System.out.println("low=" + low + ", high=" + high + ", stepsEnum=" + stepsEnum + ", stepsTest=" + stepsTest + "; best method is " + ((stepsEnum < stepsTest) ? "joinByEnumeration" : "joinByTest"));
}
*/
}
}