Mercurial > hg > truffle
annotate agent/src/share/classes/sun/jvm/hotspot/code/CompressedReadStream.java @ 17524:89152779163c
Merge with jdk8-b132
| author | Gilles Duboscq <duboscq@ssw.jku.at> |
|---|---|
| date | Wed, 15 Oct 2014 11:59:32 +0200 |
| parents | c18cbe5936b8 |
| children |
| rev | line source |
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| 0 | 1 /* |
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2 * Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
|
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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6941466: Oracle rebranding changes for Hotspot repositories
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 25 package sun.jvm.hotspot.code; | |
| 26 | |
| 27 import sun.jvm.hotspot.debugger.*; | |
| 28 | |
| 29 public class CompressedReadStream extends CompressedStream { | |
| 30 /** Equivalent to CompressedReadStream(buffer, 0) */ | |
| 31 public CompressedReadStream(Address buffer) { | |
| 32 this(buffer, 0); | |
| 33 } | |
| 34 | |
| 35 public CompressedReadStream(Address buffer, int position) { | |
| 36 super(buffer, position); | |
| 37 } | |
| 38 | |
| 39 public boolean readBoolean() { | |
| 40 return (read() != 0); | |
| 41 } | |
| 42 | |
| 43 public byte readByte() { | |
| 44 return (byte) read(); | |
| 45 } | |
| 46 | |
| 47 public char readChar() { | |
| 48 return (char) readInt(); | |
| 49 } | |
| 50 | |
| 51 public short readShort() { | |
| 52 return (short) readSignedInt(); | |
| 53 } | |
| 54 | |
| 55 public int readSignedInt() { | |
| 56 return decodeSign(readInt()); | |
| 57 } | |
| 58 | |
| 59 public int readInt() { | |
| 60 int b0 = read(); | |
| 61 if (b0 < L) { | |
| 62 return b0; | |
| 63 } else { | |
| 64 return readIntMb(b0); | |
| 65 } | |
| 66 } | |
| 67 | |
| 68 | |
| 69 public float readFloat() { | |
| 70 return Float.intBitsToFloat(reverseInt(readInt())); | |
| 71 } | |
| 72 | |
| 73 public double readDouble() { | |
| 74 int rh = readInt(); | |
| 75 int rl = readInt(); | |
| 76 int h = reverseInt(rh); | |
| 77 int l = reverseInt(rl); | |
| 78 return Double.longBitsToDouble((h << 32) | ((long)l & 0x00000000FFFFFFFFL)); | |
| 79 } | |
| 80 | |
| 81 public long readLong() { | |
| 82 long low = readSignedInt() & 0x00000000FFFFFFFFL; | |
| 83 long high = readSignedInt(); | |
| 84 return (high << 32) | low; | |
| 85 } | |
| 86 | |
| 87 //-------------------------------------------------------------------------------- | |
| 88 // Internals only below this point | |
| 89 // | |
| 90 | |
| 91 | |
| 92 // This encoding, called UNSIGNED5, is taken from J2SE Pack200. | |
| 93 // It assumes that most values have lots of leading zeroes. | |
| 94 // Very small values, in the range [0..191], code in one byte. | |
| 95 // Any 32-bit value (including negatives) can be coded, in | |
| 96 // up to five bytes. The grammar is: | |
| 97 // low_byte = [0..191] | |
| 98 // high_byte = [192..255] | |
| 99 // any_byte = low_byte | high_byte | |
| 100 // coding = low_byte | |
| 101 // | high_byte low_byte | |
| 102 // | high_byte high_byte low_byte | |
| 103 // | high_byte high_byte high_byte low_byte | |
| 104 // | high_byte high_byte high_byte high_byte any_byte | |
| 105 // Each high_byte contributes six bits of payload. | |
| 106 // The encoding is one-to-one (except for integer overflow) | |
| 107 // and easy to parse and unparse. | |
| 108 | |
| 109 private int readIntMb(int b0) { | |
| 110 int pos = position - 1; | |
| 111 int sum = b0; | |
| 112 // must collect more bytes: b[1]...b[4] | |
| 113 int lg_H_i = lg_H; | |
| 114 for (int i = 0; ;) { | |
| 115 int b_i = read(pos + (++i)); | |
| 116 sum += b_i << lg_H_i; // sum += b[i]*(64**i) | |
| 117 if (b_i < L || i == MAX_i) { | |
| 118 setPosition(pos+i+1); | |
| 119 return sum; | |
| 120 } | |
| 121 lg_H_i += lg_H; | |
| 122 } | |
| 123 } | |
| 124 | |
| 125 private short read(int index) { | |
| 126 return (short) buffer.getCIntegerAt(index, 1, true); | |
| 127 } | |
| 128 | |
| 129 /** Reads an unsigned byte, but returns it as a short */ | |
| 130 private short read() { | |
| 131 short retval = (short) buffer.getCIntegerAt(position, 1, true); | |
| 132 ++position; | |
| 133 return retval; | |
| 134 } | |
| 135 } |