| /* |
| * Copyright (c) 2000, 2005, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| package sun.jvm.hotspot.code; |
| |
| import sun.jvm.hotspot.debugger.*; |
| |
| public class CompressedReadStream extends CompressedStream { |
| /** Equivalent to CompressedReadStream(buffer, 0) */ |
| public CompressedReadStream(Address buffer) { |
| this(buffer, 0); |
| } |
| |
| public CompressedReadStream(Address buffer, int position) { |
| super(buffer, position); |
| } |
| |
| public boolean readBoolean() { |
| return (read() != 0); |
| } |
| |
| public byte readByte() { |
| return (byte) read(); |
| } |
| |
| public char readChar() { |
| return (char) readInt(); |
| } |
| |
| public short readShort() { |
| return (short) readSignedInt(); |
| } |
| |
| public int readSignedInt() { |
| return decodeSign(readInt()); |
| } |
| |
| public int readInt() { |
| int b0 = read(); |
| if (b0 < L) { |
| return b0; |
| } else { |
| return readIntMb(b0); |
| } |
| } |
| |
| |
| public float readFloat() { |
| return Float.intBitsToFloat(reverseInt(readInt())); |
| } |
| |
| public double readDouble() { |
| int rh = readInt(); |
| int rl = readInt(); |
| int h = reverseInt(rh); |
| int l = reverseInt(rl); |
| return Double.longBitsToDouble((h << 32) | ((long)l & 0x00000000FFFFFFFFL)); |
| } |
| |
| public long readLong() { |
| long low = readSignedInt() & 0x00000000FFFFFFFFL; |
| long high = readSignedInt(); |
| return (high << 32) | low; |
| } |
| |
| //-------------------------------------------------------------------------------- |
| // Internals only below this point |
| // |
| |
| |
| // This encoding, called UNSIGNED5, is taken from J2SE Pack200. |
| // It assumes that most values have lots of leading zeroes. |
| // Very small values, in the range [0..191], code in one byte. |
| // Any 32-bit value (including negatives) can be coded, in |
| // up to five bytes. The grammar is: |
| // low_byte = [0..191] |
| // high_byte = [192..255] |
| // any_byte = low_byte | high_byte |
| // coding = low_byte |
| // | high_byte low_byte |
| // | high_byte high_byte low_byte |
| // | high_byte high_byte high_byte low_byte |
| // | high_byte high_byte high_byte high_byte any_byte |
| // Each high_byte contributes six bits of payload. |
| // The encoding is one-to-one (except for integer overflow) |
| // and easy to parse and unparse. |
| |
| private int readIntMb(int b0) { |
| int pos = position - 1; |
| int sum = b0; |
| // must collect more bytes: b[1]...b[4] |
| int lg_H_i = lg_H; |
| for (int i = 0; ;) { |
| int b_i = read(pos + (++i)); |
| sum += b_i << lg_H_i; // sum += b[i]*(64**i) |
| if (b_i < L || i == MAX_i) { |
| setPosition(pos+i+1); |
| return sum; |
| } |
| lg_H_i += lg_H; |
| } |
| } |
| |
| private short read(int index) { |
| return (short) buffer.getCIntegerAt(index, 1, true); |
| } |
| |
| /** Reads an unsigned byte, but returns it as a short */ |
| private short read() { |
| short retval = (short) buffer.getCIntegerAt(position, 1, true); |
| ++position; |
| return retval; |
| } |
| } |