org.eclipse.jdt.internal.compiler.classfmt.ClassFileStruct Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2000, 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.jdt.internal.compiler.classfmt;
abstract public class ClassFileStruct {
byte[] reference;
int[] constantPoolOffsets;
int structOffset;
public ClassFileStruct(byte[] classFileBytes, int[] offsets, int offset) {
this.reference = classFileBytes;
this.constantPoolOffsets = offsets;
this.structOffset = offset;
}
public double doubleAt(int relativeOffset) {
return (Double.longBitsToDouble(i8At(relativeOffset)));
}
public float floatAt(int relativeOffset) {
return (Float.intBitsToFloat(i4At(relativeOffset)));
}
public int i4At(int relativeOffset) {
int position = relativeOffset + this.structOffset;
return ((this.reference[position++] & 0xFF) << 24) | ((this.reference[position++] & 0xFF) << 16) | ((this.reference[position++] & 0xFF) << 8) + (this.reference[position] & 0xFF);
}
public long i8At(int relativeOffset) {
int position = relativeOffset + this.structOffset;
return (((long) (this.reference[position++] & 0xFF)) << 56)
| (((long) (this.reference[position++] & 0xFF)) << 48)
| (((long) (this.reference[position++] & 0xFF)) << 40)
| (((long) (this.reference[position++] & 0xFF)) << 32)
| (((long) (this.reference[position++] & 0xFF)) << 24)
| (((long) (this.reference[position++] & 0xFF)) << 16)
| (((long) (this.reference[position++] & 0xFF)) << 8)
| (this.reference[position++] & 0xFF);
}
protected void reset() {
this.reference = null;
this.constantPoolOffsets = null;
}
public int u1At(int relativeOffset) {
return (this.reference[relativeOffset + this.structOffset] & 0xFF);
}
public int u2At(int relativeOffset) {
int position = relativeOffset + this.structOffset;
return ((this.reference[position++] & 0xFF) << 8) | (this.reference[position] & 0xFF);
}
public long u4At(int relativeOffset) {
int position = relativeOffset + this.structOffset;
return (((this.reference[position++] & 0xFFL) << 24) | ((this.reference[position++] & 0xFF) << 16) | ((this.reference[position++] & 0xFF) << 8) | (this.reference[position] & 0xFF));
}
public char[] utf8At(int relativeOffset, int bytesAvailable) {
int length = bytesAvailable;
char outputBuf[] = new char[bytesAvailable];
int outputPos = 0;
int readOffset = this.structOffset + relativeOffset;
while (length != 0) {
int x = this.reference[readOffset++] & 0xFF;
length--;
if ((0x80 & x) != 0) {
if ((x & 0x20) != 0) {
length-=2;
x = ((x & 0xF) << 12) | ((this.reference[readOffset++] & 0x3F) << 6) | (this.reference[readOffset++] & 0x3F);
} else {
length--;
x = ((x & 0x1F) << 6) | (this.reference[readOffset++] & 0x3F);
}
}
outputBuf[outputPos++] = (char) x;
}
if (outputPos != bytesAvailable) {
System.arraycopy(outputBuf, 0, (outputBuf = new char[outputPos]), 0, outputPos);
}
return outputBuf;
}
}