--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/agent/src/share/classes/sun/jvm/hotspot/code/CompressedStream.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,91 @@
+/*
+ * Copyright 2000-2005 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.code;
+
+import sun.jvm.hotspot.debugger.*;
+
+/** NOTE that this class takes the address of a buffer. This means
+    that it can read previously-generated debug information directly
+    from the target VM. However, it also means that you can't create a
+    "wrapper" object for a CompressedStream down in the VM. It looks
+    like these are only kept persistently in OopMaps, and the code has
+    been special-cased in OopMap.java to handle this. */
+
+public class CompressedStream {
+  protected Address buffer;
+  protected int     position;
+
+  /** Equivalent to CompressedStream(buffer, 0) */
+  public CompressedStream(Address buffer) {
+    this(buffer, 0);
+  }
+
+  public CompressedStream(Address buffer, int position) {
+    this.buffer   = buffer;
+    this.position = position;
+  }
+
+  public Address getBuffer() {
+    return buffer;
+  }
+
+  public static final int LogBitsPerByte = 3;
+  public static final int BitsPerByte = 1 << 3;
+
+  // Constants for UNSIGNED5 coding of Pack200
+  public static final int lg_H = 6;
+  public static final int H = 1<<lg_H;  // number of high codes (64)
+  public static final int L = (1<<BitsPerByte) - H; // number of low codes (192)
+  public static final int MAX_i = 4;      // bytes are numbered in (0..4)
+
+  // Positioning
+  public int getPosition() {
+    return position;
+  }
+  public void setPosition(int position) {
+    this.position = position;
+  }
+
+  // 32-bit one-to-one sign encoding taken from Pack200
+  // converts leading sign bits into leading zeros with trailing sign bit
+  public int encodeSign(int value) {
+    return (value << 1) ^ (value >> 31);
+  }
+
+  public int decodeSign(int value) {
+    return (value >>> 1) ^ -(value & 1);
+  }
+
+  // 32-bit self-inverse encoding of float bits
+  // converts trailing zeros (common in floats) to leading zeros
+  public int reverseInt(int i) {
+    // Hacker's Delight, Figure 7-1
+    i = (i & 0x55555555) << 1 | (i >>> 1) & 0x55555555;
+    i = (i & 0x33333333) << 3 | (i >>> 2) & 0x33333333;
+    i = (i & 0x0f0f0f0f) << 4 | (i >>> 4) & 0x0f0f0f0f;
+    i = (i << 24) | ((i & 0xff00) << 8) | ((i >>> 8) & 0xff00) | (i >>> 24);
+    return i;
+  }
+}