/*
* $Id$
*
* Copyright (C) 2003-2015 JNode.org
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; If not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package org.jnode.vm;
import org.jnode.system.resource.MemoryScanner;
import org.jnode.annotation.MagicPermission;
import org.vmmagic.unboxed.Address;
import org.vmmagic.unboxed.Offset;
/**
* @author Ewout Prangsma (epr@users.sourceforge.net)
*/
@MagicPermission
final class MemoryScannerImpl implements MemoryScanner {
/**
* @see org.jnode.system.resource.MemoryScanner#findInt16(org.jnode.vm.Address, int, int, int)
*/
public Address findInt16(Address start, int size, int match, int stepSize) {
int offset = 0;
match &= 0xFFFF;
size -= 1;
while (offset < size) {
if ((start.loadShort(Offset.fromIntSignExtend(offset)) & 0xFFFF) == match) {
return start.add(offset);
} else {
offset += stepSize;
}
}
return null;
}
/**
* @see org.jnode.system.resource.MemoryScanner#findInt32(org.jnode.vm.Address, int, int, int)
*/
public Address findInt32(Address start, int size, int match, int stepSize) {
int offset = 0;
size -= 3;
while (offset < size) {
if (start.loadInt(Offset.fromIntSignExtend(offset)) == match) {
return start.add(offset);
} else {
offset += stepSize;
}
}
return null;
}
/**
* @see org.jnode.system.resource.MemoryScanner#findInt64(org.jnode.vm.Address, int, long, int)
*/
public Address findInt64(Address start, int size, long match, int stepSize) {
int offset = 0;
size -= 7;
while (offset < size) {
if (start.loadLong(Offset.fromIntSignExtend(offset)) == match) {
return start.add(offset);
} else {
offset += stepSize;
}
}
return null;
}
/**
* @see org.jnode.system.resource.MemoryScanner#findInt8(org.jnode.vm.Address, int, int, int)
*/
public Address findInt8(Address start, int size, int match, int stepSize) {
int offset = 0;
match &= 0xFF;
while (offset < size) {
if ((start.loadByte(Offset.fromIntSignExtend(offset)) & 0xFF) == match) {
return start.add(offset);
} else {
offset += stepSize;
}
}
return null;
}
/**
* @see org.jnode.system.resource.MemoryScanner#findInt8Array(org.jnode.vm.Address, int, byte[], int, int, int)
*/
public Address findInt8Array(Address start, int size, byte[] match,
int matchOffset, int matchLength, int stepSize) {
int offset = 0;
size -= (matchLength - 1);
final int match0 = match[matchOffset] & 0xFF;
while (offset < size) {
if ((start.loadByte(Offset.fromIntSignExtend(offset)) & 0xFF) == match0) {
if (isMatch(start, offset, match, matchOffset, matchLength)) {
return start.add(offset);
}
}
offset += stepSize;
}
return null;
}
/**
* @see org.jnode.system.resource.MemoryScanner#findInt16Array(org.jnode.vm.Address, int, char[], int, int, int)
*/
public Address findInt16Array(Address start, int size, char[] match,
int matchOffset, int matchLength, int stepSize) {
int offset = 0;
size -= ((matchLength * 2) - 1);
final int match0 = match[matchOffset] & 0xFFFF;
while (offset < size) {
if ((start.loadChar(Offset.fromIntSignExtend(offset)) & 0xFFFF) == match0) {
if (isMatch(start, offset, match, matchOffset, matchLength)) {
return start.add(offset);
}
}
offset += stepSize;
}
return null;
}
/**
* @see org.jnode.system.resource.MemoryScanner#findInt16Array(org.jnode.vm.Address, int, short[], int, int, int)
*/
public Address findInt16Array(Address start, int size, short[] match,
int matchOffset, int matchLength, int stepSize) {
int offset = 0;
size -= ((matchLength * 2) - 1);
final int match0 = match[matchOffset] & 0xFFFF;
while (offset < size) {
if ((start.loadShort(Offset.fromIntSignExtend(offset)) & 0xFFFF) == match0) {
if (isMatch(start, offset, match, matchOffset, matchLength)) {
return start.add(offset);
}
}
offset += stepSize;
}
return null;
}
/**
* @see org.jnode.system.resource.MemoryScanner#findInt32Array(org.jnode.vm.Address, int, int[], int, int, int)
*/
public Address findInt32Array(Address start, int size, int[] match,
int matchOffset, int matchLength, int stepSize) {
int offset = 0;
size -= ((matchLength * 4) - 1);
final int match0 = match[matchOffset];
while (offset < size) {
if (start.loadInt(Offset.fromIntSignExtend(offset)) == match0) {
if (isMatch(start, offset, match, matchOffset, matchLength)) {
return start.add(offset);
}
}
offset += stepSize;
}
return null;
}
/**
* @see org.jnode.system.resource.MemoryScanner#findInt64Array(org.jnode.vm.Address, int, long[], int, int, int)
*/
public Address findInt64Array(Address start, int size, long[] match,
int matchOffset, int matchLength, int stepSize) {
int offset = 0;
size -= ((matchLength * 8) - 1);
final long match0 = match[matchOffset];
while (offset < size) {
if (start.loadLong(Offset.fromIntSignExtend(offset)) == match0) {
if (isMatch(start, offset, match, matchOffset, matchLength)) {
return start.add(offset);
}
}
offset += stepSize;
}
return null;
}
private final boolean isMatch(Address start, int offset, byte[] match,
int matchOffset, int matchLength) {
for (int i = 0; i < matchLength; i++) {
if ((start.loadByte(Offset.fromIntSignExtend(offset + i)) & 0xFF) != (match[matchOffset + i] & 0xFF)) {
return false;
}
}
return true;
}
private final boolean isMatch(Address start, int offset, char[] match,
int matchOffset, int matchLength) {
for (int i = 0; i < matchLength; i++) {
if ((start.loadChar(Offset.fromIntSignExtend(offset + (i * 2))) & 0xFFFF) !=
(match[matchOffset + i] & 0xFFFF)) {
return false;
}
}
return true;
}
private final boolean isMatch(Address start, int offset, short[] match,
int matchOffset, int matchLength) {
for (int i = 0; i < matchLength; i++) {
if ((start.loadShort(Offset.fromIntSignExtend(offset + (i * 2))) & 0xFFFF) !=
(match[matchOffset + i] & 0xFFFF)) {
return false;
}
}
return true;
}
private final boolean isMatch(Address start, int offset, int[] match,
int matchOffset, int matchLength) {
for (int i = 0; i < matchLength; i++) {
if (start.loadInt(Offset.fromIntSignExtend(offset + (i * 4))) != match[matchOffset + i]) {
return false;
}
}
return true;
}
private final boolean isMatch(Address start, int offset, long[] match,
int matchOffset, int matchLength) {
for (int i = 0; i < matchLength; i++) {
if (start.loadLong(Offset.fromIntSignExtend(offset + (i * 8))) != match[matchOffset + i]) {
return false;
}
}
return true;
}
}