/*
* Copyright (c) 2014, 2016, 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* 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 jdk.internal.jimage;
import java.io.UTFDataFormatException;
import java.nio.ByteBuffer;
import java.util.Objects;
/**
* @implNote This class needs to maintain JDK 8 source compatibility.
*
* It is used internally in the JDK to implement jimage/jrtfs access,
* but also compiled and delivered as part of the jrtfs.jar to support access
* to the jimage file provided by the shipped JDK by tools running on JDK 8.
*/
public class ImageStringsReader implements ImageStrings {
public static final int HASH_MULTIPLIER = 0x01000193;
private final BasicImageReader reader;
ImageStringsReader(BasicImageReader reader) {
this.reader = Objects.requireNonNull(reader);
}
@Override
public String get(int offset) {
return reader.getString(offset);
}
@Override
public int add(final String string) {
throw new InternalError("Can not add strings at runtime");
}
private static int hashCode(byte[] bytes, int offset, int count, int seed) {
Objects.requireNonNull(bytes);
if (offset < 0 || count < 0 || offset > bytes.length - count) {
throw new IndexOutOfBoundsException("offset=" + offset + ", count=" + count);
}
int limit = offset + count;
if (limit < 0 || limit > bytes.length) {
throw new IndexOutOfBoundsException("limit=" + limit);
}
for (int i = offset; i < limit; i++) {
seed = (seed * HASH_MULTIPLIER) ^ (bytes[i] & 0xFF);
}
return seed & 0x7FFFFFFF;
}
public static int hashCode(byte[] bytes, int seed) {
return hashCode(bytes, 0, bytes.length, seed);
}
public static int hashCode(byte[] bytes) {
return hashCode(bytes, 0, bytes.length, HASH_MULTIPLIER);
}
public static int hashCode(String string, int seed) {
return hashCode(mutf8FromString(string), seed);
}
public static int hashCode(String string) {
return hashCode(mutf8FromString(string), HASH_MULTIPLIER);
}
static int charsFromMUTF8Length(byte[] bytes, int offset, int count) {
int length = 0;
for (int i = offset; i < offset + count; i++) {
byte ch = bytes[i];
if (ch == 0) {
break;
}
if ((ch & 0xC0) != 0x80) {
length++;
}
}
return length;
}
static void charsFromMUTF8(char[] chars, byte[] bytes, int offset, int count) throws UTFDataFormatException {
int j = 0;
for (int i = offset; i < offset + count; i++) {
byte ch = bytes[i];
if (ch == 0) {
break;
}
boolean is_unicode = (ch & 0x80) != 0;
int uch = ch & 0x7F;
if (is_unicode) {
int mask = 0x40;
while ((uch & mask) != 0) {
ch = bytes[++i];
if ((ch & 0xC0) != 0x80) {
throw new UTFDataFormatException("bad continuation 0x" + Integer.toHexString(ch));
}
uch = ((uch & ~mask) << 6) | (ch & 0x3F);
mask <<= 6 - 1;
}
if ((uch & 0xFFFF) != uch) {
throw new UTFDataFormatException("character out of range \\u" + Integer.toHexString(uch));
}
}
chars[j++] = (char)uch;
}
}
public static String stringFromMUTF8(byte[] bytes, int offset, int count) {
int length = charsFromMUTF8Length(bytes, offset, count);
char[] chars = new char[length];
try {
charsFromMUTF8(chars, bytes, offset, count);
} catch (UTFDataFormatException ex) {
throw new InternalError("Attempt to convert non modified UTF-8 byte sequence", ex);
}
return new String(chars);
}
public static String stringFromMUTF8(byte[] bytes) {
return stringFromMUTF8(bytes, 0, bytes.length);
}
static int charsFromByteBufferLength(ByteBuffer buffer) {
int length = 0;
while(buffer.hasRemaining()) {
byte ch = buffer.get();
if (ch == 0) {
return length;
}
if ((ch & 0xC0) != 0x80) {
length++;
}
}
throw new InternalError("No terminating zero byte for modified UTF-8 byte sequence");
}
static void charsFromByteBuffer(char chars[], ByteBuffer buffer) {
int j = 0;
while(buffer.hasRemaining()) {
byte ch = buffer.get();
if (ch == 0) {
return;
}
boolean is_unicode = (ch & 0x80) != 0;
int uch = ch & 0x7F;
if (is_unicode) {
int mask = 0x40;
while ((uch & mask) != 0) {
ch = buffer.get();
if ((ch & 0xC0) != 0x80) {
throw new InternalError("Bad continuation in " +
"modified UTF-8 byte sequence: " + ch);
}
uch = ((uch & ~mask) << 6) | (ch & 0x3F);
mask <<= 6 - 1;
}
}
if ((uch & 0xFFFF) != uch) {
throw new InternalError("UTF-32 char in modified UTF-8 " +
"byte sequence: " + uch);
}
chars[j++] = (char)uch;
}
throw new InternalError("No terminating zero byte for modified UTF-8 byte sequence");
}
public static String stringFromByteBuffer(ByteBuffer buffer) {
int length = charsFromByteBufferLength(buffer);
buffer.rewind();
char[] chars = new char[length];
charsFromByteBuffer(chars, buffer);
return new String(chars);
}
static int mutf8FromCharsLength(char chars[]) {
int length = 0;
for (char ch : chars) {
int uch = ch & 0xFFFF;
if ((uch & ~0x7F) != 0) {
int mask = ~0x3F;
int n = 0;
do {
n++;
uch >>= 6;
mask >>= 1;
} while ((uch & mask) != 0);
length += n + 1;
} else if (uch == 0) {
length += 2;
} else {
length++;
}
}
return length;
}
static void mutf8FromChars(byte[] bytes, int offset, char chars[]) {
int j = offset;
byte[] buffer = new byte[8];
for (char ch : chars) {
int uch = ch & 0xFFFF;
if ((uch & ~0x7F) != 0) {
int mask = ~0x3F;
int n = 0;
do {
buffer[n++] = (byte)(0x80 | (uch & 0x3F));
uch >>= 6;
mask >>= 1;
} while ((uch & mask) != 0);
buffer[n] = (byte)((mask << 1) | uch);
do {
bytes[j++] = buffer[n--];
} while (0 <= n);
} else if (uch == 0) {
bytes[j++] = (byte)0xC0;
bytes[j++] = (byte)0x80;
} else {
bytes[j++] = (byte)uch;
}
}
}
public static byte[] mutf8FromString(String string) {
char[] chars = string.toCharArray();
int length = mutf8FromCharsLength(chars);
byte[] bytes = new byte[length];
mutf8FromChars(bytes, 0, chars);
return bytes;
}
}