1 /*
   2  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.lang;
  27 
  28 import java.io.DataInputStream;
  29 import java.io.InputStream;
  30 import java.lang.ref.SoftReference;
  31 import java.util.Arrays;
  32 import java.util.zip.InflaterInputStream;
  33 import java.security.AccessController;
  34 import java.security.PrivilegedAction;
  35 
  36 class CharacterName {
  37 
  38     private static SoftReference<byte[]> refStrPool;
  39     private static int[][] lookup;
  40 
  41     private static synchronized byte[] initNamePool() {
  42         byte[] strPool = null;
  43         if (refStrPool != null && (strPool = refStrPool.get()) != null)
  44             return strPool;
  45         DataInputStream dis = null;
  46         try {
  47             dis = new DataInputStream(new InflaterInputStream(
  48                 AccessController.doPrivileged(new PrivilegedAction<InputStream>()
  49                 {
  50                     public InputStream run() {
  51                         return getClass().getResourceAsStream("uniName.dat");
  52                     }
  53                 })));
  54 
  55             lookup = new int[(Character.MAX_CODE_POINT + 1) >> 8][];
  56             int total = dis.readInt();
  57             int cpEnd = dis.readInt();
  58             byte ba[] = new byte[cpEnd];
  59             dis.readFully(ba);
  60 
  61             int nameOff = 0;
  62             int cpOff = 0;
  63             int cp = 0;
  64             do {
  65                 int len = ba[cpOff++] & 0xff;
  66                 if (len == 0) {
  67                     len = ba[cpOff++] & 0xff;
  68                     // always big-endian
  69                     cp = ((ba[cpOff++] & 0xff) << 16) |
  70                          ((ba[cpOff++] & 0xff) <<  8) |
  71                          ((ba[cpOff++] & 0xff));
  72                 }  else {
  73                     cp++;
  74                 }
  75                 int hi = cp >> 8;
  76                 if (lookup[hi] == null) {
  77                     lookup[hi] = new int[0x100];
  78                 }
  79                 lookup[hi][cp&0xff] = (nameOff << 8) | len;
  80                 nameOff += len;
  81             } while (cpOff < cpEnd);
  82             strPool = new byte[total - cpEnd];
  83             dis.readFully(strPool);
  84             refStrPool = new SoftReference<byte[]>(strPool);
  85         } catch (Exception x) {
  86             throw new InternalError(x.getMessage());
  87         } finally {
  88             try {
  89                 if (dis != null)
  90                     dis.close();
  91             } catch (Exception xx) {}
  92         }
  93         return strPool;
  94     }
  95 
  96     public static String get(int cp) {
  97         byte[] strPool = null;
  98         if (refStrPool == null || (strPool = refStrPool.get()) == null)
  99             strPool = initNamePool();
 100         int off = 0;
 101         if (lookup[cp>>8] == null ||
 102             (off = lookup[cp>>8][cp&0xff]) == 0)
 103             return null;
 104         return new String(strPool, 0, off >>> 8, off & 0xff);  // ASCII
 105     }
 106 }