Copyright (c) 2003, 2016 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) 2003, 2016 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.osgi.storage;

import java.io.*;
import java.util.*;

Permission Storage interface for managing a persistent storage of
bundle permissions.
This class is used to provide methods to manage
persistent storage of bundle permissions.
/**
 * Permission Storage interface for managing a persistent storage of
 * bundle permissions.
 *
 * <p>This class is used to provide methods to manage
 * persistent storage of bundle permissions.
 */
public class PermissionData {
	private static final int PERMDATA_VERSION = 1;
	private final Map<String, String[]> locations = new HashMap<>();
	private String[] defaultInfos;
	private String[] condPermInfos;
	private boolean dirty;

	
Returns the locations that have permission data assigned to them,
that is, locations for which permission data
exists in persistent storage.
Returns:
The locations that have permission data in
persistent storage, or null if there is no permission data
in persistent storage./**
	 * Returns the locations that have permission data assigned to them,
	 * that is, locations for which permission data
	 * exists in persistent storage.
	 *
	 * @return The locations that have permission data in
	 * persistent storage, or <tt>null</tt> if there is no permission data
	 * in persistent storage.
	 */
	public String[] getLocations() {
		synchronized (locations) {
			String[] result = new String[locations.size()];
			int i = 0;
			for (Iterator<String> iLocs = locations.keySet().iterator(); iLocs.hasNext(); i++)
				result[i] = iLocs.next();
			return result;
		}
	}

	
Gets the permission data assigned to the specified
location.
Params:
location – The location whose permission data is to
be returned.
The location can be null for the default permission data.
Returns:
The permission data assigned to the specified
location, or null if that location has not been assigned any
permission data./**
	 * Gets the permission data assigned to the specified
	 * location.
	 *
	 * @param location The location whose permission data is to
	 * be returned.
	 * The location can be <tt>null</tt> for the default permission data.
	 *
	 * @return The permission data assigned to the specified
	 * location, or <tt>null</tt> if that location has not been assigned any
	 * permission data.
	 */
	public String[] getPermissionData(String location) {
		if (location == null)
			return defaultInfos;
		synchronized (locations) {
			if (locations.size() == 0)
				return null;
			return locations.get(location);
		}
	}

	
Assigns the specified permission data to the specified
location.
Params:
location – The location that will be assigned the
permissions.
The location can be null for the default permission data.
data – The permission data to be assigned, or null
if the specified location is to be removed from persistent storaqe./**
	 * Assigns the specified permission data to the specified
	 * location.
	 *
	 * @param location The location that will be assigned the
	 * permissions.
	 * The location can be <tt>null</tt> for the default permission data.
	 * @param data The permission data to be assigned, or <tt>null</tt>
	 * if the specified location is to be removed from persistent storaqe.
	 */
	public void setPermissionData(String location, String[] data) {
		if (location == null) {
			defaultInfos = data;
			return;
		}
		synchronized (locations) {
			if (data == null)
				locations.remove(location);
			else
				locations.put(location, data);
		}
		setDirty(true);
	}

	
Persists the array of encoded ConditionalPermissionInfo strings
Params:
infos – an array of encoded ConditionalPermissionInfo strings/**
	 * Persists the array of encoded ConditionalPermissionInfo strings
	 * @param infos an array of encoded ConditionalPermissionInfo strings
	 */
	public void saveConditionalPermissionInfos(String[] infos) {
		condPermInfos = infos;
		setDirty(true);
	}

	
Returns the persistent array of encoded ConditionalPermissionInfo strings
Returns:
an array of encoded ConditionalPermissionInfo strings or null 
if none exist in persistent storage./**
	 * Returns the persistent array of encoded ConditionalPermissionInfo strings
	 * @return an array of encoded ConditionalPermissionInfo strings or null 
	 * if none exist in persistent storage.
	 */
	public String[] getConditionalPermissionInfos() {
		return condPermInfos;
	}

	boolean isDirty() {
		return dirty;
	}

	private void setDirty(boolean dirty) {
		this.dirty = dirty;
	}

	void readPermissionData(DataInputStream in) throws IOException {
		int version = in.readInt();
		int dataSize = in.readInt();
		byte[] bytes = new byte[dataSize];
		in.readFully(bytes);
		if (PERMDATA_VERSION == version) {
			DataInputStream temp = new DataInputStream(new ByteArrayInputStream(bytes));
			try {
				// read the default permissions first
				int numPerms = temp.readInt();
				if (numPerms > 0) {
					String[] perms = new String[numPerms];
					for (int i = 0; i < numPerms; i++)
						perms[i] = temp.readUTF();
					setPermissionData(null, perms);
				}
				int numLocs = temp.readInt();
				if (numLocs > 0) {
					for (int i = 0; i < numLocs; i++) {
						String loc = temp.readUTF();
						numPerms = temp.readInt();
						String[] perms = new String[numPerms];
						for (int j = 0; j < numPerms; j++)
							perms[j] = temp.readUTF();
						setPermissionData(loc, perms);
					}
				}
				int numCondPerms = temp.readInt();
				if (numCondPerms > 0) {
					String[] condPerms = new String[numCondPerms];
					for (int i = 0; i < numCondPerms; i++) {
						condPerms[i] = temp.readUTF();
					}
					saveConditionalPermissionInfos(condPerms);
				}

			} finally {
				setDirty(false);
				temp.close();
			}
		}
	}

	void savePermissionData(DataOutputStream out) throws IOException {
		out.writeInt(PERMDATA_VERSION);
		// create a temporary in memory stream so we can figure out the length
		ByteArrayOutputStream tempBytes = new ByteArrayOutputStream();
		DataOutputStream temp = new DataOutputStream(tempBytes);
		// always write the default permissions first
		String[] defaultPerms = getPermissionData(null);
		temp.writeInt(defaultPerms == null ? 0 : defaultPerms.length);
		if (defaultPerms != null)
			for (String defaultPerm : defaultPerms) {
				temp.writeUTF(defaultPerm);
			}
		String[] locs = getLocations();
		temp.writeInt(locs == null ? 0 : locs.length);
		if (locs != null)
			for (String loc : locs) {
				temp.writeUTF(loc);
				String[] perms = getPermissionData(loc);
				temp.writeInt(perms == null ? 0 : perms.length);
				if (perms != null) {
					for (String perm : perms) {
						temp.writeUTF(perm);
					}
				}
			}
		String[] condPerms = getConditionalPermissionInfos();
		temp.writeInt(condPerms == null ? 0 : condPerms.length);
		if (condPerms != null)
			for (String condPerm : condPerms) {
				temp.writeUTF(condPerm);
			}
		temp.close();

		out.writeInt(tempBytes.size());
		out.write(tempBytes.toByteArray());
		setDirty(false);
	}
}