org.aspectj.org.eclipse.jdt.internal.core.BufferManager Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of aspectjtools Show documentation

AspectJ tools most notably contains the AspectJ compiler (AJC). AJC applies aspects to Java classes during compilation, fully replacing Javac for plain Java classes and also compiling native AspectJ or annotation-based @AspectJ syntax. Furthermore, AJC can weave aspects into existing class files in a post-compile binary weaving step. This library is a superset of AspectJ weaver and hence also of AspectJ runtime.

There is a newer version: 1.9.22.1

Show newest version

/*******************************************************************************
 * Copyright (c) 2000, 2013 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.aspectj.org.eclipse.jdt.internal.core;

import java.text.NumberFormat;
import java.util.Enumeration;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.aspectj.org.eclipse.jdt.core.IBuffer;
import org.aspectj.org.eclipse.jdt.core.IOpenable;

/**
 * The buffer manager manages the set of open buffers.
 * It implements an LRU cache of buffers.
 */
public class BufferManager {

	protected static BufferManager DEFAULT_BUFFER_MANAGER;
	protected static boolean VERBOSE;

	/**
	 * LRU cache of buffers. The key and value for an entry
	 * in the table is the identical buffer.
	 */
	private final BufferCache openBuffers = new BufferCache<>(60);

	/**
	 * @deprecated
	 */
	protected org.aspectj.org.eclipse.jdt.core.IBufferFactory defaultBufferFactory = new org.eclipse.jdt.core.IBufferFactory() {
	    /**
	     * @deprecated
	     */
		@Override
		public IBuffer createBuffer(IOpenable owner) {
			return BufferManager.createBuffer(owner);
		}
	};

/**
 * Adds a buffer to the table of open buffers.
 */
protected void addBuffer(IBuffer buffer) {
	if (VERBOSE) {
		String owner = ((Openable)buffer.getOwner()).toStringWithAncestors();
		System.out.println("Adding buffer for " + owner); //$NON-NLS-1$
	}
	synchronized (this.openBuffers) {
		this.openBuffers.put(buffer.getOwner(), buffer);
	}
	// close buffers that were removed from the cache if space was needed
	this.openBuffers.closeBuffers();
	if (VERBOSE) {
		System.out.println("-> Buffer cache filling ratio = " + NumberFormat.getInstance().format(this.openBuffers.fillingRatio()) + "%"); //$NON-NLS-1$//$NON-NLS-2$
	}
}
public static IBuffer createBuffer(IOpenable owner) {
	JavaElement element = (JavaElement) owner;
	IResource resource = element.resource();
	return
		new Buffer(
			resource instanceof IFile ? (IFile)resource : null,
			owner,
			element.isReadOnly());
}
public static IBuffer createNullBuffer(IOpenable owner) {
	JavaElement element = (JavaElement) owner;
	IResource resource = element.resource();
	return
		new NullBuffer(
			resource instanceof IFile ? (IFile)resource : null,
			owner,
			element.isReadOnly());
}
/**
 * Returns the open buffer associated with the given owner,
 * or null if the owner does not have an open
 * buffer associated with it.
 */
public IBuffer getBuffer(IOpenable owner) {
	synchronized (this.openBuffers) {
		return this.openBuffers.get(owner);
	}
}
/**
 * Returns the default buffer manager.
 */
public synchronized static BufferManager getDefaultBufferManager() {
	if (DEFAULT_BUFFER_MANAGER == null) {
		DEFAULT_BUFFER_MANAGER = new BufferManager();
	}
	return DEFAULT_BUFFER_MANAGER;
}
/**
 * Returns the default buffer factory.
 * @deprecated
 */
public org.aspectj.org.eclipse.jdt.core.IBufferFactory getDefaultBufferFactory() {
	return this.defaultBufferFactory;
}
/**
 * Returns an enumeration of all open buffers.
 * 
 * The Enumeration answered is thread safe.
 *
 * @see OverflowingLRUCache
 * @return Enumeration of IBuffer
 */
public Enumeration getOpenBuffers() {
	Enumeration result;
	synchronized (this.openBuffers) {
		this.openBuffers.shrink();
		result = this.openBuffers.elements();
	}
	// close buffers that were removed from the cache if space was needed
	this.openBuffers.closeBuffers();
	return result;
}

/**
 * Removes a buffer from the table of open buffers.
 */
protected void removeBuffer(IBuffer buffer) {
	if (VERBOSE) {
		String owner = ((Openable)buffer.getOwner()).toStringWithAncestors();
		System.out.println("Removing buffer for " + owner); //$NON-NLS-1$
	}
	synchronized (this.openBuffers) {
		this.openBuffers.remove(buffer.getOwner());
	}
	// close buffers that were removed from the cache (should be only one)
	this.openBuffers.closeBuffers();
	if (VERBOSE) {
		System.out.println("-> Buffer cache filling ratio = " + NumberFormat.getInstance().format(this.openBuffers.fillingRatio()) + "%"); //$NON-NLS-1$//$NON-NLS-2$
	}
}
}