core/src/core/org/jnode/vm/VmAccessControlContext.java - new-gc-algorithms in JNode

/*
 * $Id$
 *
 * Copyright (C) 2003-2009 JNode.org
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; If not, write to the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
package org.jnode.vm;

import java.security.AccessControlException;
import java.security.Permission;
import java.security.ProtectionDomain;
import java.util.ArrayList;
import java.util.List;

/**
 * Representation of the current access control context.
 *
 * @author Ewout Prangsma (epr@users.sourceforge.net)
 */
public final class VmAccessControlContext {

    private final ProtectionDomain domains[];

    /**
     * Initialize this instance.
     *
     * @param context
     * @param inheritedContext
     */
    public VmAccessControlContext(ProtectionDomain[] context,
                                  VmAccessControlContext inheritedContext) {
        final ArrayList<ProtectionDomain> ctxList = new ArrayList<ProtectionDomain>();
        if (context != null) {
            addUniqueToList(ctxList, context);
        }
        if ((inheritedContext != null) && (inheritedContext.domains != null)) {
            addUniqueToList(ctxList, inheritedContext.domains);
        }
        if (ctxList.isEmpty()) {
            this.domains = null;
        } else {
            this.domains = (ProtectionDomain[]) ctxList
                .toArray(new ProtectionDomain[ctxList.size()]);
        }
    }

    /**
     * Determines whether or not the specific permission is granted depending
     * on the context it is within.
     *
     * @param perm a permission to check
     * @throws AccessControlException if the permssion is not permitted
     */
    public final void checkPermission(Permission perm)
        throws AccessControlException {
        if (domains != null) {
            final int count = domains.length;
            for (int i = 0; i < count; i++) {
                if (!domains[i].implies(perm)) {
                    throw new AccessControlException(
                        "Permission \"" + perm + "\" not granted");
                }
            }
        }
    }

    /**
     * Checks if two AccessControlContexts are equal.
     * <p/>
     * It first checks if obj is an AccessControlContext class, and then checks
     * if each ProtectionDomain matches.
     *
     * @param obj The object to compare this class to
     * @return true if equal, false otherwise
     */
    public final boolean equals(Object obj) {
        if (obj instanceof VmAccessControlContext) {
            final VmAccessControlContext acc = (VmAccessControlContext) obj;
            final int count = (domains == null) ? 0 : domains.length;

            if (acc.domains.length != count) {
                return false;
            }

            for (int i = 0; i < count; i++) {
                if (acc.domains[i] != domains[i]) {
                    return false;
                }
            }
            return true;
        }
        return false;
    }

    /**
     * Computes a hash code of this class
     *
     * @return a hash code representing this class
     */
    public final int hashCode() {
        int h = 0;
        final int count = (domains == null) ? 0 : domains.length;
        for (int i = 0; i < count; i++) {
            h ^= domains[i].hashCode();
        }
        return h;
    }

    private final void addUniqueToList(List<ProtectionDomain> ctxList,
                                       ProtectionDomain[] context) {
        final int count = context.length;
        for (int i = 0; i < count; i++) {
            final ProtectionDomain pd = context[i];
            if (pd != null) {
                if (!ctxList.contains(pd)) {
                    ctxList.add(pd);
                }
            }
        }
    }
}

1	/*
2	* $Id$
3	*
4	* Copyright (C) 2003-2009 JNode.org
5	*
6	* This library is free software; you can redistribute it and/or modify it
7	* under the terms of the GNU Lesser General Public License as published
8	* by the Free Software Foundation; either version 2.1 of the License, or
9	* (at your option) any later version.
10	*
11	* This library is distributed in the hope that it will be useful, but
12	* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13	* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
14	* License for more details.
15	*
16	* You should have received a copy of the GNU Lesser General Public License
17	* along with this library; If not, write to the Free Software Foundation, Inc.,
18	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19	*/
20
21	package org.jnode.vm;
22
23	import java.security.AccessControlException;
24	import java.security.Permission;
25	import java.security.ProtectionDomain;
26	import java.util.ArrayList;
27	import java.util.List;
28
29	/**
30	* Representation of the current access control context.
31	*
32	* @author Ewout Prangsma (epr@users.sourceforge.net)
33	*/
34	public final class VmAccessControlContext {
35
36	private final ProtectionDomain domains[];
37
38	/**
39	* Initialize this instance.
40	*
41	* @param context
42	* @param inheritedContext
43	*/
44	public VmAccessControlContext(ProtectionDomain[] context,
45	VmAccessControlContext inheritedContext) {
46	final ArrayList<ProtectionDomain> ctxList = new ArrayList<ProtectionDomain>();
47	if (context != null) {
48	addUniqueToList(ctxList, context);
49	}
50	if ((inheritedContext != null) && (inheritedContext.domains != null)) {
51	addUniqueToList(ctxList, inheritedContext.domains);
52	}
53	if (ctxList.isEmpty()) {
54	this.domains = null;
55	} else {
56	this.domains = (ProtectionDomain[]) ctxList
57	.toArray(new ProtectionDomain[ctxList.size()]);
58	}
59	}
60
61	/**
62	* Determines whether or not the specific permission is granted depending
63	* on the context it is within.
64	*
65	* @param perm a permission to check
66	* @throws AccessControlException if the permssion is not permitted
67	*/
68	public final void checkPermission(Permission perm)
69	throws AccessControlException {
70	if (domains != null) {
71	final int count = domains.length;
72	for (int i = 0; i < count; i++) {
73	if (!domains[i].implies(perm)) {
74	throw new AccessControlException(
75	"Permission \"" + perm + "\" not granted");
76	}
77	}
78	}
79	}
80
81	/**
82	* Checks if two AccessControlContexts are equal.
83	* <p/>
84	* It first checks if obj is an AccessControlContext class, and then checks
85	* if each ProtectionDomain matches.
86	*
87	* @param obj The object to compare this class to
88	* @return true if equal, false otherwise
89	*/
90	public final boolean equals(Object obj) {
91	if (obj instanceof VmAccessControlContext) {
92	final VmAccessControlContext acc = (VmAccessControlContext) obj;
93	final int count = (domains == null) ? 0 : domains.length;
94
95	if (acc.domains.length != count) {
96	return false;
97	}
98
99	for (int i = 0; i < count; i++) {
100	if (acc.domains[i] != domains[i]) {
101	return false;
102	}
103	}
104	return true;
105	}
106	return false;
107	}
108
109	/**
110	* Computes a hash code of this class
111	*
112	* @return a hash code representing this class
113	*/
114	public final int hashCode() {
115	int h = 0;
116	final int count = (domains == null) ? 0 : domains.length;
117	for (int i = 0; i < count; i++) {
118	h ^= domains[i].hashCode();
119	}
120	return h;
121	}
122
123	private final void addUniqueToList(List<ProtectionDomain> ctxList,
124	ProtectionDomain[] context) {
125	final int count = context.length;
126	for (int i = 0; i < count; i++) {
127	final ProtectionDomain pd = context[i];
128	if (pd != null) {
129	if (!ctxList.contains(pd)) {
130	ctxList.add(pd);
131	}
132	}
133	}
134	}
135	}

Gitorious