01: /*
02: * @(#)CVMpkg.java 1.10 06/10/10
03: *
04: * Copyright 1990-2006 Sun Microsystems, Inc. All Rights Reserved.
05: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
06: *
07: * This program is free software; you can redistribute it and/or
08: * modify it under the terms of the GNU General Public License version
09: * 2 only, as published by the Free Software Foundation.
10: *
11: * This program is distributed in the hope that it will be useful, but
12: * WITHOUT ANY WARRANTY; without even the implied warranty of
13: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14: * General Public License version 2 for more details (a copy is
15: * included at /legal/license.txt).
16: *
17: * You should have received a copy of the GNU General Public License
18: * version 2 along with this work; if not, write to the Free Software
19: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20: * 02110-1301 USA
21: *
22: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
23: * Clara, CA 95054 or visit www.sun.com if you need additional
24: * information or have any questions.
25: *
26: */
27: package vm;
28:
29: import java.util.Vector;
30:
31: /*
32: * Package name in CVM type system.
33: */
34:
35: public class CVMpkg {
36: public String pkgName;
37: public CVMpkg next;
38: public CVMDataType typeData[];
39: public int entryNo;
40:
41: public final static int NCLASSHASH = 11;
42: public final static int NPACKAGEHASH = 17;
43:
44: public static Vector pkgVector = new Vector(); // must come before nullPackage!
45:
46: public static CVMpkg packages[] = new CVMpkg[NPACKAGEHASH];
47: static int nextPkgNo = 0;
48:
49: synchronized static void enlist(CVMpkg x) {
50: x.entryNo = nextPkgNo++;
51: pkgVector.addElement(x);
52: }
53:
54: CVMpkg(String pname) {
55: pkgName = pname;
56: next = null;
57: typeData = new CVMDataType[NCLASSHASH];
58: enlist(this );
59: }
60:
61: /*
62: * order matters. In order to invoke the usual constructor,
63: * this seems to have to follow it!!
64: */
65:
66: public static CVMpkg nullPackage = new CVMpkg("");
67:
68: public static CVMpkg lookup(String pkgname) {
69: if (pkgname.length() == 0)
70: return nullPackage;
71: pkgname = pkgname.intern();
72: long nameHash = CVMDataType.computeHash(pkgname);
73: /* make sure % is unsigned! */
74: int bucket = (int) ((nameHash & 0xffffffffL) % (long) NPACKAGEHASH);
75: /*DEBUG System.out.println("hash package "+pkgname+" to "+bucket); */
76:
77: for (CVMpkg this Pkg = packages[bucket]; this Pkg != null; this Pkg = this Pkg.next) {
78: if (pkgname == this Pkg.pkgName)
79: return this Pkg;
80: }
81: // not there, must add.
82: CVMpkg p = new CVMpkg(pkgname);
83: p.next = packages[bucket];
84: packages[bucket] = p;
85: return p;
86: }
87: }
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