/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.marshalling;
import java.io.IOException;
import java.io.UTFDataFormatException;
import java.io.EOFException;
/**
* Handy utility methods for dealing with strings in the modified UTF-8 format.
* @apiviz.exclude
*/
public final class UTFUtils {
private static final String INVALID_BYTE = "Invalid byte";
private static final String MALFORMED = "Malformed UTF-8 sequence";
private UTFUtils() {
}
private static final int UTF_BUFS_CHAR_CNT = 256;
private static final int UTF_BUFS_BYTE_CNT = UTF_BUFS_CHAR_CNT * 3;
private static final class BytesHolder extends ThreadLocal<byte[]> {
protected byte[] initialValue() {
return new byte[UTF_BUFS_BYTE_CNT];
}
}
private static final BytesHolder BYTES_HOLDER = new BytesHolder();
/**
* Get the number of bytes used by the modified UTF-8 encoded form of the given string. If the length is
* greater than {@code 65536}, an exception is thrown.
*
* @param s the string
* @return the length
* @throws UTFDataFormatException if the string is longer than {@code 65536} characters
* @see java.io.DataInput#readUTF()
*/
public static int getShortUTFLength(final String s) throws UTFDataFormatException {
final int length = s.length();
int l = 0;
for (int i = 0; i < length; i ++) {
final char c = s.charAt(i);
if (c > 0 && c <= 0x7f) {
l ++;
} else if (c <= 0x07ff) {
l += 2;
} else {
l += 3;
}
if (l > 65535) {
throw new UTFDataFormatException("String is too long for writeUTF");
}
}
return l;
}
/**
* Get the number of bytes used by the modified UTF-8 encoded form of the given string.
*
* @param s the string
* @return the length
* @see java.io.DataInput#readUTF()
*/
public static long getLongUTFLength(final String s) {
final int length = s.length();
long l = 0;
for (int i = 0; i < length; i ++) {
final char c = s.charAt(i);
if (c > 0 && c <= 0x7f) {
l ++;
} else if (c <= 0x07ff) {
l += 2L;
} else {
l += 3L;
}
}
return l;
}
/**
* Write the modified UTF-8 form of the given string to the given output.
*
* @param output the output to write to
* @param s the string
* @throws IOException if an I/O error occurs
* @see java.io.DataOutput#writeUTF(String)
*/
public static void writeUTFBytes(final ByteOutput output, final String s) throws IOException {
final byte[] byteBuf = BYTES_HOLDER.get();
final int length = s.length();
int strIdx = 0;
int byteIdx = 0;
while (strIdx < length) {
final char c = s.charAt(strIdx ++);
if (c > 0 && c <= 0x7f) {
byteBuf[byteIdx ++] = (byte) c;
} else if (c <= 0x07ff) {
byteBuf[byteIdx ++] = (byte)(0xc0 | 0x1f & c >> 6);
byteBuf[byteIdx ++] = (byte)(0x80 | 0x3f & c);
} else {
byteBuf[byteIdx ++] = (byte)(0xe0 | 0x0f & c >> 12);
byteBuf[byteIdx ++] = (byte)(0x80 | 0x3f & c >> 6);
byteBuf[byteIdx ++] = (byte)(0x80 | 0x3f & c);
}
if (byteIdx > UTF_BUFS_BYTE_CNT - 4) {
output.write(byteBuf, 0, byteIdx);
byteIdx = 0;
}
}
if (byteIdx > 0) {
output.write(byteBuf, 0, byteIdx);
}
}
/**
* Read the given number of characters from the given byte input. The length given is in characters,
* <b>NOT</b> in bytes.
*
* @param input the byte source
* @param len the number of characters to read
* @return the string
* @throws IOException if an I/O error occurs
* @see java.io.DataInput#readUTF()
*/
public static String readUTFBytes(final ByteInput input, final int len) throws IOException {
final byte[] byteBuf = BYTES_HOLDER.get();
final char[] chars = new char[len];
int i = 0, cnt = 0, charIdx = 0;
while (charIdx < len) {
if (i == cnt) {
cnt = input.read(byteBuf, 0, Math.min(UTF_BUFS_BYTE_CNT, len - charIdx));
if (cnt < 0) {
throw new EOFException();
}
i = 0;
}
final int a = byteBuf[i++] & 0xff;
if (a < 0x80) {
// low bit clear
chars[charIdx ++] = (char) a;
} else if (a < 0xc0) {
throw new UTFDataFormatException(INVALID_BYTE);
} else if (a < 0xe0) {
if (i == cnt) {
cnt = input.read(byteBuf, 0, Math.min(UTF_BUFS_BYTE_CNT, len - charIdx));
if (cnt < 0) {
throw new EOFException();
}
i = 0;
}
final int b = byteBuf[i ++] & 0xff;
if ((b & 0xc0) != 0x80) {
throw new UTFDataFormatException(INVALID_BYTE);
}
chars[charIdx ++] = (char) ((a & 0x1f) << 6 | b & 0x3f);
} else if (a < 0xf0) {
if (i == cnt) {
cnt = input.read(byteBuf, 0, Math.min(UTF_BUFS_BYTE_CNT, len - charIdx));
if (cnt < 0) {
throw new EOFException();
}
i = 0;
}
final int b = byteBuf[i ++] & 0xff;
if ((b & 0xc0) != 0x80) {
throw new UTFDataFormatException(INVALID_BYTE);
}
if (i == cnt) {
cnt = input.read(byteBuf, 0, Math.min(UTF_BUFS_BYTE_CNT, len - charIdx));
if (cnt < 0) {
throw new EOFException();
}
i = 0;
}
final int c = byteBuf[i ++] & 0xff;
if ((c & 0xc0) != 0x80) {
throw new UTFDataFormatException(INVALID_BYTE);
}
chars[charIdx ++] = (char) ((a & 0x0f) << 12 | (b & 0x3f) << 6 | c & 0x3f);
} else {
throw new UTFDataFormatException(INVALID_BYTE);
}
}
return String.valueOf(chars);
}
/**
* Read the given number of characters from the given byte input. The length given is in bytes.
*
* @param input the byte source
* @param len the number of bytes to read
* @return the string
* @throws IOException if an I/O error occurs
* @see java.io.DataInput#readUTF()
*/
public static String readUTFBytesByByteCount(final ByteInput input, final long len) throws IOException {
final StringBuilder builder = new StringBuilder();
for (long i = 0; i < len; i ++) {
final int a = input.read();
if (a < 0) {
throw new EOFException("Expected " + (len - i) + " more bytes");
} else if (a == 0) {
builder.append('\0');
} else if (a < 0x80) {
builder.append((char) a);
} else if (a < 0xc0) {
throw new UTFDataFormatException(INVALID_BYTE);
} else if (a < 0xe0) {
if (++i < len) {
final int b = input.read();
if (b == -1) {
throw new EOFException("Expected " + (len - i) + " more bytes");
} else if ((b & 0xc0) != 0x80) {
throw new UTFDataFormatException(INVALID_BYTE);
}
builder.append((char) ((a & 0x1f) << 6 | b & 0x3f));
} else {
throw new UTFDataFormatException(MALFORMED);
}
} else if (a < 0xf0) {
if (++i < len) {
final int b = input.read();
if (b == -1) {
throw new EOFException("Expected " + (len - i) + " more bytes");
} else if ((b & 0xc0) != 0x80) {
throw new UTFDataFormatException(INVALID_BYTE);
}
if (++i < len) {
final int c1 = input.read();
if (c1 == -1) {
throw new EOFException("Expected " + (len - i) + " more bytes");
} else if ((c1 & 0xc0) != 0x80) {
throw new UTFDataFormatException(INVALID_BYTE);
}
builder.append((char) ((a & 0x0f) << 12 | (b & 0x3f) << 6 | c1 & 0x3f));
} else {
throw new UTFDataFormatException(MALFORMED);
}
} else {
throw new UTFDataFormatException(MALFORMED);
}
} else {
throw new UTFDataFormatException(INVALID_BYTE);
}
}
return builder.toString();
}
/**
* Read a null-terminated modified UTF-8 string from the given byte input. Bytes are read until a 0 is found or
* until the end of the stream, whichever comes first.
*
* @param input the input
* @return the string
* @throws IOException if an I/O error occurs
* @see java.io.DataInput#readUTF()
*/
public static String readUTFZBytes(final ByteInput input) throws IOException {
final StringBuilder builder = new StringBuilder();
for (;;) {
final int c = readUTFChar(input);
if (c == -1) {
return builder.toString();
}
builder.append((char) c);
}
}
private static int readUTFChar(final ByteInput input) throws IOException {
final int a = input.read();
if (a < 0) {
throw new EOFException();
} else if (a == 0) {
return -1;
} else if (a < 0x80) {
return (char)a;
} else if (a < 0xc0) {
throw new UTFDataFormatException(INVALID_BYTE);
} else if (a < 0xe0) {
final int b = input.read();
if (b == -1) {
throw new EOFException();
} else if ((b & 0xc0) != 0x80) {
throw new UTFDataFormatException(INVALID_BYTE);
}
return (a & 0x1f) << 6 | b & 0x3f;
} else if (a < 0xf0) {
final int b = input.read();
if (b == -1) {
throw new EOFException();
} else if ((b & 0xc0) != 0x80) {
throw new UTFDataFormatException(INVALID_BYTE);
}
final int c = input.read();
if (c == -1) {
throw new EOFException();
} else if ((c & 0xc0) != 0x80) {
throw new UTFDataFormatException(INVALID_BYTE);
}
return (a & 0x0f) << 12 | (b & 0x3f) << 6 | c & 0x3f;
} else {
throw new UTFDataFormatException(INVALID_BYTE);
}
}
}