Copyright (c) 2005, 2017 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) 2005, 2017 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.compiler;

import java.util.Arrays;

import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
import org.eclipse.jdt.internal.compiler.lookup.ModuleBinding;
import org.eclipse.jdt.internal.compiler.lookup.SourceTypeBinding;

public class ClassFilePool {
	public static final int POOL_SIZE = 25; // need to have enough for 2 units
	ClassFile[] classFiles;

private ClassFilePool() {
	// prevent instantiation
	this.classFiles = new ClassFile[POOL_SIZE];
}

public static ClassFilePool newInstance() {
	return new ClassFilePool();
}

public synchronized ClassFile acquire(SourceTypeBinding typeBinding) {
	for (int i = 0; i < POOL_SIZE; i++) {
		ClassFile classFile = this.classFiles[i];
		if (classFile == null) {
			ClassFile newClassFile = new ClassFile(typeBinding);
			this.classFiles[i] = newClassFile;
			newClassFile.isShared = true;
			return newClassFile;
		}
		if (!classFile.isShared) {
			classFile.reset(typeBinding, typeBinding.scope.compilerOptions());
			classFile.isShared = true;
			return classFile;
		}
	}
	return new ClassFile(typeBinding);
}
public synchronized ClassFile acquireForModule(ModuleBinding moduleBinding, CompilerOptions options) {
	for (int i = 0; i < POOL_SIZE; i++) {
		ClassFile classFile = this.classFiles[i];
		if (classFile == null) {
			ClassFile newClassFile = new ClassFile(moduleBinding, options);
			this.classFiles[i] = newClassFile;
			newClassFile.isShared = true;
			return newClassFile;
		}
		if (!classFile.isShared) {
			classFile.reset(null, options);
			classFile.isShared = true;
			return classFile;
		}
	}
	return new ClassFile(moduleBinding, options);
}
public synchronized void release(ClassFile classFile) {
	classFile.isShared = false;
}
public void reset() {
	Arrays.fill(this.classFiles, null);
}
}