1/* 2 * Copyright (c) 2001, 2005, 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 25package sun.jvm.hotspot.oops; 26 27import sun.jvm.hotspot.code.*; 28import sun.jvm.hotspot.debugger.*; 29 30public class CompressedLineNumberReadStream extends CompressedReadStream { 31 /** Equivalent to CompressedLineNumberReadStream(buffer, 0) */ 32 public CompressedLineNumberReadStream(Address buffer) { 33 this(buffer, 0); 34 } 35 36 public CompressedLineNumberReadStream(Address buffer, int position) { 37 super(buffer, position); 38 } 39 40 /** Read (bci, line number) pair from stream. Returns false at end-of-stream. */ 41 public boolean readPair() { 42 int next = readByte() & 0xFF; 43 // Check for terminator 44 if (next == 0) return false; 45 if (next == 0xFF) { 46 // Escape character, regular compression used 47 bci += readSignedInt(); 48 line += readSignedInt(); 49 } else { 50 // Single byte compression used 51 bci += next >> 3; 52 line += next & 0x7; 53 } 54 return true; 55 } 56 57 public int bci() { return bci; } 58 public int line() { return line; } 59 60 //-------------------------------------------------------------------------------- 61 // Internals only below this point 62 // 63 64 private int bci; 65 private int line; 66} 67