IntersectingPattern.java

/*******************************************************************************
 * Copyright (c) 2000, 2010 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.core.search.matching;

import java.io.IOException;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.jdt.core.search.IJavaSearchScope;
import org.eclipse.jdt.core.search.SearchParticipant;
import org.eclipse.jdt.core.search.SearchPattern;
import org.eclipse.jdt.internal.compiler.util.SimpleSet;
import org.eclipse.jdt.internal.core.index.EntryResult;
import org.eclipse.jdt.internal.core.index.Index;
import org.eclipse.jdt.internal.core.search.IndexQueryRequestor;

/**
 * Query the index multiple times and do an 'and' on the results.
 */
public abstract class IntersectingPattern extends JavaSearchPattern {

	public IntersectingPattern(int patternKind, int matchRule) {
		super(patternKind, matchRule);
	}

	public void findIndexMatches(Index index, IndexQueryRequestor requestor, SearchParticipant participant, IJavaSearchScope scope, IProgressMonitor progressMonitor) throws IOException {
		if (progressMonitor != null && progressMonitor.isCanceled())
			throw new OperationCanceledException();

		resetQuery();
		SimpleSet intersectedNames= null;
		try {
			index.startQuery();
			do {
				SearchPattern pattern= currentPattern();
				EntryResult[] entries= pattern.queryIn(index);
				if (entries == null)
					return;

				SearchPattern decodedResult= pattern.getBlankPattern();
				SimpleSet newIntersectedNames= new SimpleSet(3);
				for (int i= 0, l= entries.length; i < l; i++) {
					if (progressMonitor != null && progressMonitor.isCanceled())
						throw new OperationCanceledException();

					EntryResult entry= entries[i];
					decodedResult.decodeIndexKey(entry.getWord());
					if (pattern.matchesDecodedKey(decodedResult)) {
						String[] names= entry.getDocumentNames(index);
						if (intersectedNames != null) {
							for (int j= 0, n= names.length; j < n; j++)
								if (intersectedNames.includes(names[j]))
									newIntersectedNames.add(names[j]);
						} else {
							for (int j= 0, n= names.length; j < n; j++)
								newIntersectedNames.add(names[j]);
						}
					}
				}

				if (newIntersectedNames.elementSize == 0)
					return;
				intersectedNames= newIntersectedNames;
			} while (hasNextQuery());
		} finally {
			index.stopQuery();
		}

		String containerPath= index.containerPath;
		char separator= index.separator;
		Object[] names= intersectedNames.values;
		for (int i= 0, l= names.length; i < l; i++)
			if (names[i] != null)
				acceptMatch((String)names[i], containerPath, separator, null/*no pattern*/, requestor, participant, scope, progressMonitor); // AndPatterns cannot provide the decoded result
	}

	/**
	 * Returns whether another query must be done.
	 */
	protected abstract boolean hasNextQuery();

	/**
	 * Resets the query and prepares this pattern to be queried.
	 */
	protected abstract void resetQuery();
}