Mercurial > hg > truffle
diff agent/src/share/classes/sun/jvm/hotspot/oops/Symbol.java @ 0:a61af66fc99e jdk7-b24
Initial load
author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | c18cbe5936b8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/agent/src/share/classes/sun/jvm/hotspot/oops/Symbol.java Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,149 @@ +/* + * Copyright 2000-2004 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.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 Oop { + 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("symbolOopDesc"); + length = new CIntField(type.getCIntegerField("_length"), 0); + baseOffset = type.getField("_body").getOffset(); + } + + // Format: + // [header] + // [klass ] + // [length] byte size of uft8 string + // ..body.. + + Symbol(OopHandle handle, ObjectHeap heap) { + super(handle, heap); + } + + public boolean isSymbol() { return true; } + + private static long baseOffset; // tells where the array part starts + + // Fields + private static CIntField length; + + // Accessors for declared fields + public long getLength() { return length.getValue(this); } + + public byte getByteAt(long index) { + return getHandle().getJByteAt(baseOffset + index); + } + + 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(IOException e) { + return null; + } + } + + public boolean startsWith(String str) { + return asString().startsWith(str); + } + + public void printValueOn(PrintStream tty) { + tty.print("#" + asString()); + } + + public long getObjectSize() { + return alignObjectSize(baseOffset + getLength()); + } + + void iterateFields(OopVisitor visitor, boolean doVMFields) { + super.iterateFields(visitor, doVMFields); + if (doVMFields) { + visitor.doCInt(length, true); + int length = (int) getLength(); + for (int index = 0; index < length; index++) { + visitor.doByte(new ByteField(new IndexableFieldIdentifier(index), baseOffset + index, false), true); + } + } + } + + /** 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 symbolOops are in permSpace, their + relative order in memory never changes, so use address + comparison for speed. */ + public int fastCompare(Symbol other) { + return (int) getHandle().minus(other.getHandle()); + } + + 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(); + } +}