1 /* 2 * Copyright (c) 2001, 2013, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 package sun.jvm.hotspot.memory; 26 27 import java.io.*; 28 import java.util.*; 29 import sun.jvm.hotspot.debugger.*; 30 import sun.jvm.hotspot.oops.*; 31 import sun.jvm.hotspot.types.*; 32 import sun.jvm.hotspot.runtime.*; 33 import sun.jvm.hotspot.utilities.*; 34 35 public class SymbolTable extends sun.jvm.hotspot.utilities.Hashtable { 36 static { 37 VM.registerVMInitializedObserver(new Observer() { 38 public void update(Observable o, Object data) { 39 initialize(VM.getVM().getTypeDataBase()); 40 } 41 }); 42 } 43 44 private static synchronized void initialize(TypeDataBase db) { 45 Type type = db.lookupType("SymbolTable"); 46 theTableField = type.getAddressField("_the_table"); 47 } 48 49 // Fields 50 private static AddressField theTableField; 51 52 // Accessors 53 public static SymbolTable getTheTable() { 54 Address tmp = theTableField.getValue(); 55 return (SymbolTable) VMObjectFactory.newObject(SymbolTable.class, tmp); 56 } 57 58 public SymbolTable(Address addr) { 59 super(addr); 60 } 61 62 /** Clone of VM's "temporary" probe routine, as the SA currently 63 does not support mutation so lookup() would have no effect 64 anyway. Returns null if the given string is not in the symbol 65 table. */ 66 public Symbol probe(String name) { 67 try { 68 return probe(toModifiedUTF8Bytes(name)); 69 } catch (IOException e) { 70 return null; 71 } 72 } 73 74 /** Clone of VM's "temporary" probe routine, as the SA currently 75 does not support mutation so lookup() would have no effect 76 anyway. Returns null if the given string is not in the symbol 77 table. */ 78 public Symbol probe(byte[] name) { 79 long hashValue = hashSymbol(name); 80 for (HashtableEntry e = (HashtableEntry) bucket(hashToIndex(hashValue)); e != null; e = (HashtableEntry) e.next()) { 81 if (e.hash() == hashValue) { 82 Symbol sym = Symbol.create(e.literalValue()); 83 if (sym.equals(name)) { 84 return sym; 85 } 86 } 87 } 88 return null; 89 } 90 91 public interface SymbolVisitor { 92 public void visit(Symbol sym); 93 } 94 95 public void symbolsDo(SymbolVisitor visitor) { 96 int numBuckets = tableSize(); 97 for (int i = 0; i < numBuckets; i++) { 98 for (HashtableEntry e = (HashtableEntry) bucket(i); e != null; 99 e = (HashtableEntry) e.next()) { 100 visitor.visit(Symbol.create(e.literalValue())); 101 } 102 } 103 } 104 105 private static byte[] toModifiedUTF8Bytes(String name) throws IOException { 106 ByteArrayOutputStream baos = new ByteArrayOutputStream(); 107 DataOutputStream dos = new DataOutputStream(baos); 108 dos.writeUTF(name); 109 dos.flush(); 110 byte[] buf = baos.toByteArray(); 111 byte[] res = new byte[buf.length - 2]; 112 // skip the length part 113 System.arraycopy(buf, 2, res, 0, res.length); 114 return res; 115 } 116 }