| /******************************************************************************* |
| * Copyright (c) 2009 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.equinox.p2.internal.repository.comparator.java; |
| |
| public abstract class ClassFileStruct { |
| |
| protected double doubleAt(byte[] reference, int relativeOffset, int structOffset) { |
| return (Double.longBitsToDouble(i8At(reference, relativeOffset, structOffset))); |
| } |
| |
| protected float floatAt(byte[] reference, int relativeOffset, int structOffset) { |
| return (Float.intBitsToFloat(i4At(reference, relativeOffset, structOffset))); |
| } |
| |
| protected int i1At(byte[] reference, int relativeOffset, int structOffset) { |
| return reference[relativeOffset + structOffset]; |
| } |
| |
| protected int i2At(byte[] reference, int relativeOffset, int structOffset) { |
| int position = relativeOffset + structOffset; |
| return (reference[position++] << 8) + (reference[position] & 0xFF); |
| } |
| |
| protected int i4At(byte[] reference, int relativeOffset, int structOffset) { |
| int position = relativeOffset + structOffset; |
| return ((reference[position++] & 0xFF) << 24) + ((reference[position++] & 0xFF) << 16) + ((reference[position++] & 0xFF) << 8) + (reference[position] & 0xFF); |
| } |
| |
| protected long i8At(byte[] reference, int relativeOffset, int structOffset) { |
| int position = relativeOffset + structOffset; |
| return (((long) (reference[position++] & 0xFF)) << 56) + (((long) (reference[position++] & 0xFF)) << 48) + (((long) (reference[position++] & 0xFF)) << 40) + (((long) (reference[position++] & 0xFF)) << 32) + (((long) (reference[position++] & 0xFF)) << 24) + (((long) (reference[position++] & 0xFF)) << 16) + (((long) (reference[position++] & 0xFF)) << 8) + (reference[position++] & 0xFF); |
| } |
| |
| protected int u1At(byte[] reference, int relativeOffset, int structOffset) { |
| return (reference[relativeOffset + structOffset] & 0xFF); |
| } |
| |
| protected int u2At(byte[] reference, int relativeOffset, int structOffset) { |
| int position = relativeOffset + structOffset; |
| return ((reference[position++] & 0xFF) << 8) + (reference[position] & 0xFF); |
| } |
| |
| protected long u4At(byte[] reference, int relativeOffset, int structOffset) { |
| int position = relativeOffset + structOffset; |
| return (((reference[position++] & 0xFFL) << 24) + ((reference[position++] & 0xFF) << 16) + ((reference[position++] & 0xFF) << 8) + (reference[position] & 0xFF)); |
| } |
| |
| protected char[] utf8At(byte[] reference, int relativeOffset, int structOffset, int bytesAvailable) { |
| int length = bytesAvailable; |
| char outputBuf[] = new char[bytesAvailable]; |
| int outputPos = 0; |
| int readOffset = structOffset + relativeOffset; |
| |
| while (length != 0) { |
| int x = reference[readOffset++] & 0xFF; |
| length--; |
| if ((0x80 & x) != 0) { |
| if ((x & 0x20) != 0) { |
| length -= 2; |
| x = ((x & 0xF) << 12) + ((reference[readOffset++] & 0x3F) << 6) + (reference[readOffset++] & 0x3F); |
| } else { |
| length--; |
| x = ((x & 0x1F) << 6) + (reference[readOffset++] & 0x3F); |
| } |
| } |
| outputBuf[outputPos++] = (char) x; |
| } |
| |
| if (outputPos != bytesAvailable) { |
| System.arraycopy(outputBuf, 0, (outputBuf = new char[outputPos]), 0, outputPos); |
| } |
| return outputBuf; |
| } |
| } |