Copyright (c) 2006, 2018 IBM Corp. 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/
or the Apache License, Version 2.0 which accompanies this distribution and
is available at https://www.apache.org/licenses/LICENSE-2.0.
This Source Code may also be made available under the following
Secondary Licenses when the conditions for such availability set
forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
General Public License, version 2 with the GNU Classpath
Exception [1] and GNU General Public License, version 2 with the
OpenJDK Assembly Exception [2].
[1] https://www.gnu.org/software/classpath/license.html
[2] http://openjdk.java.net/legal/assembly-exception.html
SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
/*******************************************************************************
 * Copyright (c) 2006, 2018 IBM Corp. 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/
 * or the Apache License, Version 2.0 which accompanies this distribution and
 * is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following
 * Secondary Licenses when the conditions for such availability set
 * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
 * General Public License, version 2 with the GNU Classpath
 * Exception [1] and GNU General Public License, version 2 with the
 * OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] http://openjdk.java.net/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
 *******************************************************************************/

package org.eclipse.osgi.internal.cds;

import com.ibm.oti.shared.SharedClassURLHelper;
import java.net.MalformedURLException;
import java.net.URL;
import org.eclipse.osgi.storage.bundlefile.BundleEntry;
import org.eclipse.osgi.storage.bundlefile.BundleFile;
import org.eclipse.osgi.storage.bundlefile.BundleFileWrapper;

Wraps an actual BundleFile object for purposes of loading classes from the
shared classes cache. 
/**
 * Wraps an actual BundleFile object for purposes of loading classes from the
 * shared classes cache. 
 */
public class CDSBundleFile extends BundleFileWrapper {
	private final static String classFileExt = ".class"; //$NON-NLS-1$
	private final URL url; // the URL to the content of the real bundle file
	private SharedClassURLHelper urlHelper; // the url helper set by the classloader
	private boolean primed = false;

	
The constructor
Params:
wrapped – the real bundle file/**
	 * The constructor
	 * @param wrapped the real bundle file
	 */
	public CDSBundleFile(BundleFile wrapped) {
		super(wrapped);
		// get the url to the content of the real bundle file
		URL content = null;
		try {
			content = new URL("file", "", wrapped.getBaseFile().getAbsolutePath()); //$NON-NLS-1$ //$NON-NLS-2$
		} catch (MalformedURLException e) {
			// do nothing
		}
		this.url = content;
	}

	public CDSBundleFile(BundleFile bundleFile, SharedClassURLHelper urlHelper) {
		this(bundleFile);
		this.urlHelper = urlHelper;
	}

	/*
	 * (non-Javadoc)
	 * @see org.eclipse.osgi.storage.bundlefile.BundleFile#getEntry(java.lang.String)
	 * 
	 * If path is not for a class then just use the wrapped bundle file to answer the call. 
	 * If the path is for a class, it returns a CDSBundleEntry object.
	 * If the path is for a class, it will look for the magic cookie in the 
	 * shared classes cache. If found, the bytes representing the magic cookie are stored in CDSBundleEntry object.
	 */
	@Override
	public BundleEntry getEntry(String path) {
		if (!primed || !path.endsWith(classFileExt)) {
			return super.getEntry(path);
		}
		byte[] classbytes = getClassBytes(path.substring(0, path.length() - classFileExt.length()));
		if (classbytes == null) {
			return super.getEntry(path);
		}

		BundleEntry be = new CDSBundleEntry(path, classbytes, this);
		return be;
	}

	BundleEntry getWrappedEntry(String path) {
		return super.getEntry(path);
	}

	
Returns the file url to the content of the actual bundle file 
Returns:
the file url to the content of the actual bundle file/**
	 * Returns the file url to the content of the actual bundle file 
	 * @return the file url to the content of the actual bundle file
	 */
	URL getURL() {
		return url;
	}

	
Returns the url helper for this bundle file.  This is set by the 
class loading hook
Returns:
the url helper for this bundle file/**
	 * Returns the url helper for this bundle file.  This is set by the 
	 * class loading hook
	 * @return the url helper for this bundle file
	 */
	SharedClassURLHelper getURLHelper() {
		return urlHelper;
	}

	
Sets the url helper for this bundle file.  This is called by the 
class loading hook.
Params:
urlHelper – the url helper/**
	 * Sets the url helper for this bundle file.  This is called by the 
	 * class loading hook.
	 * @param urlHelper the url helper
	 */
	void setURLHelper(SharedClassURLHelper urlHelper) {
		this.urlHelper = urlHelper;
		this.primed = false; // always unprime when a new urlHelper is set
	}

	
Sets the primed flag for the bundle file.  This is called by the 
class loading hook after the first class has been loaded from disk for 
this bundle file.
Params:
primed – the primed flag/**
	 * Sets the primed flag for the bundle file.  This is called by the 
	 * class loading hook after the first class has been loaded from disk for 
	 * this bundle file.
	 * @param primed the primed flag
	 */
	void setPrimed(boolean primed) {
		this.primed = primed;
	}

	
Searches in the shared classes cache for the specified class name.
Params:
name – the name of the class
Returns:
the magic cookie to the shared class or null if the class is not in the cache./**
	 * Searches in the shared classes cache for the specified class name.
	 * @param name the name of the class
	 * @return the magic cookie to the shared class or null if the class is not in the cache.
	 */
	private byte[] getClassBytes(String name) {
		if (urlHelper == null || url == null)
			return null;
		return urlHelper.findSharedClass(null, url, name);
	}

	
Returns the primed flag for this bundle file.
Returns:
the primed flag/**
	 * Returns the primed flag for this bundle file.
	 * @return the primed flag
	 */
	public boolean getPrimed() {
		return this.primed;
	}
}