Copyright (c) 2000, 2009 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2009 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core.index;

import org.eclipse.jdt.core.search.*;
import org.eclipse.jdt.internal.core.util.*;
import org.eclipse.jdt.internal.compiler.util.HashtableOfObject;
import org.eclipse.jdt.internal.compiler.util.SimpleLookupTable;
import org.eclipse.jdt.internal.compiler.util.SimpleSet;

public class MemoryIndex {

public int NUM_CHANGES = 100; // number of separate document changes... used to decide when to merge

SimpleLookupTable docsToReferences; // document paths -> HashtableOfObject(category names -> set of words)
SimpleWordSet allWords; // save space by locally interning the referenced words, since an indexer can generate numerous duplicates
String lastDocumentName;
HashtableOfObject lastReferenceTable;

MemoryIndex() {
	this.docsToReferences = new SimpleLookupTable(7);
	this.allWords = new SimpleWordSet(7);
}
void addDocumentNames(String substring, SimpleSet results) {
	// assumed the disk index already skipped over documents which have been added/changed/deleted
	Object[] paths = this.docsToReferences.keyTable;
	Object[] referenceTables = this.docsToReferences.valueTable;
	if (substring == null) { // add all new/changed documents
		for (int i = 0, l = referenceTables.length; i < l; i++)
			if (referenceTables[i] != null)
				results.add(paths[i]);
	} else {
		for (int i = 0, l = referenceTables.length; i < l; i++)
			if (referenceTables[i] != null && ((String) paths[i]).startsWith(substring, 0))
				results.add(paths[i]);
	}
}
void addIndexEntry(char[] category, char[] key, String documentName) {
	HashtableOfObject referenceTable;
	if (documentName.equals(this.lastDocumentName))
		referenceTable = this.lastReferenceTable;
	else {
		// assumed a document was removed before its reindexed
		referenceTable = (HashtableOfObject) this.docsToReferences.get(documentName);
		if (referenceTable == null)
			this.docsToReferences.put(documentName, referenceTable = new HashtableOfObject(3));
		this.lastDocumentName = documentName;
		this.lastReferenceTable = referenceTable;
	}

	SimpleWordSet existingWords = (SimpleWordSet) referenceTable.get(category);
	if (existingWords == null)
		referenceTable.put(category, existingWords = new SimpleWordSet(1));

	existingWords.add(this.allWords.add(key));
}
HashtableOfObject addQueryResults(char[][] categories, char[] key, int matchRule, HashtableOfObject results) {
	// assumed the disk index already skipped over documents which have been added/changed/deleted
	// results maps a word -> EntryResult
	Object[] paths = this.docsToReferences.keyTable;
	Object[] referenceTables = this.docsToReferences.valueTable;
	if (matchRule == (SearchPattern.R_EXACT_MATCH | SearchPattern.R_CASE_SENSITIVE) && key != null) {
		nextPath : for (int i = 0, l = referenceTables.length; i < l; i++) {
			HashtableOfObject categoryToWords = (HashtableOfObject) referenceTables[i];
			if (categoryToWords != null) {
				for (int j = 0, m = categories.length; j < m; j++) {
					SimpleWordSet wordSet = (SimpleWordSet) categoryToWords.get(categories[j]);
					if (wordSet != null && wordSet.includes(key)) {
						if (results == null)
							results = new HashtableOfObject(13);
						EntryResult result = (EntryResult) results.get(key);
						if (result == null)
							results.put(key, result = new EntryResult(key, null));
						result.addDocumentName((String) paths[i]);
						continue nextPath;
					}
				}
			}
		}
	} else {
		for (int i = 0, l = referenceTables.length; i < l; i++) {
			HashtableOfObject categoryToWords = (HashtableOfObject) referenceTables[i];
			if (categoryToWords != null) {
				for (int j = 0, m = categories.length; j < m; j++) {
					SimpleWordSet wordSet = (SimpleWordSet) categoryToWords.get(categories[j]);
					if (wordSet != null) {
						char[][] words = wordSet.words;
						for (int k = 0, n = words.length; k < n; k++) {
							char[] word = words[k];
							if (word != null && Index.isMatch(key, word, matchRule)) {
								if (results == null)
									results = new HashtableOfObject(13);
								EntryResult result = (EntryResult) results.get(word);
								if (result == null)
									results.put(word, result = new EntryResult(word, null));
								result.addDocumentName((String) paths[i]);
							}
						}
					}
				}
			}
		}
	}
	return results;
}
boolean hasChanged() {
	return this.docsToReferences.elementSize > 0;
}
void remove(String documentName) {
	if (documentName.equals(this.lastDocumentName)) {
		this.lastDocumentName = null;
		this.lastReferenceTable = null;
	}
	this.docsToReferences.put(documentName, null);
}
boolean shouldMerge() {
	return this.docsToReferences.elementSize >= this.NUM_CHANGES;
}
}