/*******************************************************************************
* Copyright (c) 2000, 2003 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Common Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/cpl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
* MetaMatrix, Inc - repackaging and updates for use as a metadata store
*******************************************************************************/
package org.teiid.designer.core.index;
import java.util.Arrays;
import org.teiid.core.designer.util.StringUtilities;
/**
* @since 8.0
*/
public class WordEntry implements Comparable<WordEntry> {
protected char[] fWord;
protected int fNumRefs;
protected int[] fRefs;
public WordEntry() {
this(new char[0]);
}
public WordEntry(char[] word) {
fWord= word;
fNumRefs= 0;
fRefs= new int[1];
}
/**
* Adds a reference and records the change in footprint.
*/
public int addRef(int fileNum) {
if (fNumRefs > 0 && fRefs[fNumRefs - 1] == fileNum) {
return 0;
}
if (fNumRefs < fRefs.length) {
fRefs[fNumRefs++]= fileNum;
return 0;
}
// For rt.jar, 73265 word entries are created. 51997 have 1 ref, then 9438, 3738, 1980, 1214, 779, 547, 429, 371 etc.
int newSize= fNumRefs < 4 ? 4 : fNumRefs * 2; // so will start @ 1, grow to 4, 8, 16, 32, 64 etc.
System.arraycopy(fRefs, 0, fRefs= new int[newSize], 0, fNumRefs);
fRefs[fNumRefs++]= fileNum;
return (newSize - fNumRefs + 1) * 4;
}
/**
* Adds a set of references and records the change in footprint.
*/
public void addRefs(int[] refs) {
int[] newRefs= new int[fNumRefs + refs.length];
int pos1= 0;
int pos2= 0;
int posNew= 0;
int compare;
int r1= 0;
int r2= 0;
while (pos1 < fNumRefs || pos2 < refs.length) {
if (pos1 >= fNumRefs) {
r2= refs[pos2];
compare= -1;
} else if (pos2 >= refs.length) {
compare= 1;
r1= fRefs[pos1];
} else {
r1= fRefs[pos1];
r2= refs[pos2];
compare= r2 - r1;
}
if (compare > 0) {
newRefs[posNew]= r1;
posNew++;
pos1++;
} else {
if (r2 != 0) {
newRefs[posNew]= r2;
posNew++;
}
pos2++;
}
}
fRefs= newRefs;
fNumRefs= posNew;
/*for (int i = 0; i < refs.length; i++)
addRef(refs[i]);
int[] newRefs = new int[fNumRefs];
System.arraycopy(fRefs, 0, newRefs, 0, fNumRefs);
fRefs = newRefs;
Util.sort(fRefs);*/
}
/**
* Returns the size of the wordEntry
*/
public int footprint() {
return 8 + (3 * 4) + (8 + fWord.length * 2) + (8 + fRefs.length * 4);
}
/**
* Returns the number of references, e.g. the number of files this word appears in.
*/
public int getNumRefs() {
return fNumRefs;
}
/**
* returns the file number in the i position in the list of references.
*/
public int getRef(int i) {
if (i < fNumRefs) return fRefs[i];
throw new IndexOutOfBoundsException();
}
/**
* Returns the references of the wordEntry (the number of the files it appears in).
*/
public int[] getRefs() {
int[] result= new int[fNumRefs];
System.arraycopy(fRefs, 0, result, 0, fNumRefs);
return result;
}
/**
* returns the word of the wordEntry.
*/
public char[] getWord() {
return fWord;
}
/**
* Changes the references of the wordEntry to match the mapping. For example,<br>
* if the current references are [1 3 4]<br>
* and mapping is [1 2 3 4 5]<br>
* in references 1 becomes mapping[1] = 2, 3->4, and 4->5<br>
* => references = [2 4 5].<br>
*/
public void mapRefs(int[] mappings) {
int position= 0;
for (int i= 0; i < fNumRefs; i++) {
int map= mappings[fRefs[i]];
if (map != -1 && map != 0)
fRefs[position++]= map;
}
fNumRefs= position;
//to be changed!
System.arraycopy(fRefs, 0, (fRefs= new int[fNumRefs]), 0, fNumRefs);
Arrays.sort(fRefs);
}
/**
* Clears the wordEntry.
*/
public void reset(char[] word) {
for (int i= fNumRefs; i-- > 0;) {
fRefs[i]= 0;
}
fNumRefs= 0;
fWord= word;
}
@Override
public String toString() {
return new String(fWord);
}
@Override
public int compareTo(WordEntry other) {
return StringUtilities.compare(this.fWord, other.fWord);
}
}