--- /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();
+  }
+}