| /* |
| * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code 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 General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| package sun.jvm.hotspot.oops; |
| |
| import java.io.*; |
| import java.util.*; |
| import sun.jvm.hotspot.debugger.*; |
| import sun.jvm.hotspot.runtime.*; |
| import sun.jvm.hotspot.types.*; |
| import sun.jvm.hotspot.utilities.*; |
| |
| // A Symbol is a canonicalized string. |
| // All Symbols reside in global symbolTable. |
| |
| public class Symbol extends VMObject { |
| static { |
| VM.registerVMInitializedObserver(new Observer() { |
| public void update(Observable o, Object data) { |
| initialize(VM.getVM().getTypeDataBase()); |
| } |
| }); |
| } |
| |
| private static synchronized void initialize(TypeDataBase db) throws WrongTypeException { |
| Type type = db.lookupType("Symbol"); |
| length = type.getCIntegerField("_length"); |
| baseOffset = type.getField("_body").getOffset(); |
| idHash = type.getCIntegerField("_identity_hash"); |
| } |
| |
| // Format: |
| // [header] |
| // [klass ] |
| // [length] byte size of uft8 string |
| // ..body.. |
| |
| public static Symbol create(Address addr) { |
| if (addr == null) { |
| return null; |
| } |
| return new Symbol(addr); |
| } |
| |
| Symbol(Address addr) { |
| super(addr); |
| } |
| |
| public boolean isSymbol() { return true; } |
| |
| private static long baseOffset; // tells where the array part starts |
| |
| // Fields |
| private static CIntegerField length; |
| |
| // Accessors for declared fields |
| public long getLength() { return length.getValue(this.addr); } |
| |
| public byte getByteAt(long index) { |
| return addr.getJByteAt(baseOffset + index); |
| } |
| |
| private static CIntegerField idHash; |
| |
| public int identityHash() { return (int)idHash.getValue(this.addr); } |
| |
| public boolean equals(byte[] modUTF8Chars) { |
| int l = (int) getLength(); |
| if (l != modUTF8Chars.length) return false; |
| while (l-- > 0) { |
| if (modUTF8Chars[l] != getByteAt(l)) return false; |
| } |
| if (Assert.ASSERTS_ENABLED) { |
| Assert.that(l == -1, "we should be at the beginning"); |
| } |
| return true; |
| } |
| |
| public byte[] asByteArray() { |
| int length = (int) getLength(); |
| byte [] result = new byte [length]; |
| for (int index = 0; index < length; index++) { |
| result[index] = getByteAt(index); |
| } |
| return result; |
| } |
| |
| public String asString() { |
| // Decode the byte array and return the string. |
| try { |
| return readModifiedUTF8(asByteArray()); |
| } catch(Exception e) { |
| System.err.println(addr); |
| e.printStackTrace(); |
| return null; |
| } |
| } |
| |
| public boolean startsWith(String str) { |
| return asString().startsWith(str); |
| } |
| |
| public void printValueOn(PrintStream tty) { |
| tty.print("#" + asString()); |
| } |
| |
| /** Note: this comparison is used for vtable sorting only; it |
| doesn't matter what order it defines, as long as it is a total, |
| time-invariant order Since Symbol* are in C_HEAP, their |
| relative order in memory never changes, so use address |
| comparison for speed. */ |
| public int fastCompare(Symbol other) { |
| return (int) addr.minus(other.addr); |
| } |
| |
| private static String readModifiedUTF8(byte[] buf) throws IOException { |
| final int len = buf.length; |
| byte[] tmp = new byte[len + 2]; |
| // write modified UTF-8 length as short in big endian |
| tmp[0] = (byte) ((len >>> 8) & 0xFF); |
| tmp[1] = (byte) ((len >>> 0) & 0xFF); |
| // copy the data |
| System.arraycopy(buf, 0, tmp, 2, len); |
| DataInputStream dis = new DataInputStream(new ByteArrayInputStream(tmp)); |
| return dis.readUTF(); |
| } |
| } |