/*
* @(#)CharToByteDoubleByte.java 1.12 06/10/10
*
* Copyright 1990-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program 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.
*
* This program 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 at /legal/license.txt).
*
* 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 Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*
*/
package sun.io;
/**
* @author Limin Shi
*/
public abstract class CharToByteDoubleByte extends CharToByteConverter {
/*
* 1st level index, provided by subclass
*/
protected short index1[];
/*
* 2nd level index, provided by subclass
*/
protected String index2[];
/*
* Size of bad input that caused conversion to stop
*/
protected int badInputLength;
protected char highHalfZoneCode;
public int flush(byte[] output, int outStart, int outEnd)
throws MalformedInputException, ConversionBufferFullException {
if (highHalfZoneCode != 0) {
highHalfZoneCode = 0;
badInputLength = 0;
throw new MalformedInputException();
}
byteOff = charOff = 0;
return 0;
}
/**
* Converts characters to sequences of bytes.
* Conversions that result in Exceptions can be restarted by calling
* convert again, with appropriately modified parameters.
* @return the characters written to output.
* @param input char array containing text in Unicode
* @param inStart offset in input array
* @param inEnd offset of last byte to be converted
* @param output byte array to receive conversion result
* @param outStart starting offset
* @param outEnd offset of last byte to be written to
* @throw UnsupportedCharacterException for any character
* that cannot be converted to the external character set.
*/
public int convert(char[] input, int inOff, int inEnd,
byte[] output, int outOff, int outEnd)
throws MalformedInputException, UnknownCharacterException,
ConversionBufferFullException {
char inputChar; // Input character to be converted
byte[] outputByte; // Output byte written to output
int inputSize = 0; // Size of input
int outputSize = 0; // Size of output
byte[] tmpbuf = new byte[2];
// Record beginning offsets
charOff = inOff;
byteOff = outOff;
if (highHalfZoneCode != 0) {
inputChar = highHalfZoneCode;
highHalfZoneCode = 0;
if (input[inOff] >= 0xdc00 && input[inOff] <= 0xdfff) {
// This is legal UTF16 sequence.
badInputLength = 1;
throw new UnknownCharacterException();
} else {
// This is illegal UTF16 sequence.
badInputLength = 0;
throw new MalformedInputException();
}
}
inputSize = 1;
// Loop until we hit the end of the input
while (charOff < inEnd) {
outputByte = tmpbuf;
inputChar = input[charOff]; // Get the input character
// Is this a high surrogate?
if (inputChar >= '\uD800' && inputChar <= '\uDBFF') {
// Is this the last character of the input?
if (charOff + 1 >= inEnd) {
highHalfZoneCode = inputChar;
break;
}
// Is there a low surrogate following?
inputChar = input[charOff + 1];
if (inputChar >= '\uDC00' && inputChar <= '\uDFFF') {
// We have a valid surrogate pair. Too bad we don't do
// surrogates. Is substitution enabled?
if (subMode) {
outputByte = subBytes;
outputSize = subBytes.length;
inputSize = 2;
} else {
badInputLength = 2;
throw new UnknownCharacterException();
}
} else {
// We have a malformed surrogate pair
badInputLength = 1;
throw new MalformedInputException();
}
} // Is this an unaccompanied low surrogate?
else if (inputChar >= '\uDC00' && inputChar <= '\uDFFF') {
badInputLength = 1;
throw new MalformedInputException();
} else {
outputSize = convSingleByte(inputChar, outputByte);
if (outputSize == 0) { // DoubleByte
int ncode = getNative(inputChar);
if (ncode != 0) {
if (ncode < 0x100) {
outputByte[0] = (byte) (ncode & 0xff);
outputSize = 1;
} else {
outputByte[0] = (byte) ((ncode & 0xff00) >> 8);
outputByte[1] = (byte) (ncode & 0xff);
outputSize = 2;
}
} else {
if (subMode) {
outputByte = subBytes;
outputSize = subBytes.length;
} else {
badInputLength = 1;
throw new UnknownCharacterException();
}
}
}
}
// If we don't have room for the output, throw an exception
if (byteOff + outputSize > outEnd)
throw new ConversionBufferFullException();
// Put the byte in the output buffer
for (int i = 0; i < outputSize; i++) {
output[byteOff++] = outputByte[i];
}
charOff += inputSize;
}
// Return the length written to the output buffer
return byteOff - outOff;
}
/**
* the maximum number of bytes needed to hold a converted char
* @returns the maximum number of bytes needed for a converted char
*/
public int getMaxBytesPerChar() {
return 2;
}
/**
* Resets the converter.
* Call this method to reset the converter to its initial state
*/
public void reset() {
byteOff = charOff = 0;
highHalfZoneCode = 0;
}
/**
* Return whether a character is mappable or not
* @return true if a character is mappable
*/
public boolean canConvert(char ch) {
byte[] outByte = new byte[2];
if ((ch == (char) 0) || (convSingleByte(ch, outByte) != 0))
return true;
if (this.getNative(ch) != 0)
return true;
return false;
}
/*
* Can be changed by subclass
*/
protected int convSingleByte(char inputChar, byte[] outputByte) {
if (inputChar < 0x80) {
outputByte[0] = (byte) (inputChar & 0x7f);
return 1;
}
return 0;
}
/*
* Can be changed by subclass
*/
protected int getNative(char ch) {
int offset = index1[((ch & 0xff00) >> 8)] << 8;
return index2[offset >> 12].charAt((offset & 0xfff) + (ch & 0xff));
}
}