/*
* UTF32Encoding.cs - Implementation of the
* "System.Text.UTF32Encoding" class.
*
* Author: Atsushi Enomoto <atsushi@ximian.com>
*
* Copyright (C) 2005 Novell, Inc. http://www.novell.com
*
* The basic part (now almost nothing) is copied from UnicodeEncoding.cs.
* Original copyrights goes here:
*
* Copyright (c) 2001, 2002 Southern Storm Software, Pty Ltd
* Copyright (C) 2003, 2004 Novell, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
namespace System.Text{
using System;
[Serializable]
public sealed class UTF32Encoding : Encoding
{
// Magic numbers used by Windows for UTF32.
internal const int UTF32_CODE_PAGE = 12000;
internal const int BIG_UTF32_CODE_PAGE = 12001;
// Internal state.
private bool bigEndian;
private bool byteOrderMark;
// Constructors.
public UTF32Encoding () : this (false, true, false)
{
}
public UTF32Encoding (bool bigEndian, bool byteOrderMark)
: this (bigEndian, byteOrderMark, false)
{
}
public UTF32Encoding (bool bigEndian, bool byteOrderMark, bool throwOnInvalidCharacters)
: base ((bigEndian ? BIG_UTF32_CODE_PAGE : UTF32_CODE_PAGE))
{
this.bigEndian = bigEndian;
this.byteOrderMark = byteOrderMark;
if (throwOnInvalidCharacters)
SetFallbackInternal (EncoderFallback.ExceptionFallback,
DecoderFallback.ExceptionFallback);
else
SetFallbackInternal (new EncoderReplacementFallback ("\uFFFD"),
new DecoderReplacementFallback ("\uFFFD"));
if (bigEndian){
body_name = "utf-32BE";
encoding_name = "UTF-32 (Big-Endian)";
header_name = "utf-32BE";
web_name = "utf-32BE";
} else {
body_name = "utf-32";
encoding_name = "UTF-32";
header_name = "utf-32";
web_name = "utf-32";
}
// Windows reports the same code page number for
// both the little-endian and big-endian forms.
windows_code_page = UTF32_CODE_PAGE;
}
// Get the number of bytes needed to encode a character buffer.
[MonoTODO ("handle fallback")]
public override int GetByteCount (char[] chars, int index, int count)
{
if (chars == null) {
throw new ArgumentNullException ("chars");
}
if (index < 0 || index > chars.Length) {
throw new ArgumentOutOfRangeException ("index", _("ArgRange_Array"));
}
if (count < 0 || count > (chars.Length - index)) {
throw new ArgumentOutOfRangeException ("count", _("ArgRange_Array"));
}
int ret = 0;
for (int i = index; i < index + count; i++) {
if (Char.IsSurrogate (chars [i])) {
if (i + 1 < chars.Length && Char.IsSurrogate (chars [i + 1]))
ret += 4;
else
// FIXME: handle fallback
// ret += DecoderFallback.MaxCharCount;
ret += 4;
}
else
ret += 4;
}
return ret;
}
// Get the bytes that result from encoding a character buffer.
[MonoTODO ("handle fallback")]
public override int GetBytes (char[] chars, int charIndex, int charCount,
byte[] bytes, int byteIndex)
{
if (chars == null) {
throw new ArgumentNullException ("chars");
}
if (bytes == null) {
throw new ArgumentNullException ("bytes");
}
if (charIndex < 0 || charIndex > chars.Length) {
throw new ArgumentOutOfRangeException ("charIndex", _("ArgRange_Array"));
}
if (charCount < 0 || charCount > (chars.Length - charIndex)) {
throw new ArgumentOutOfRangeException ("charCount", _("ArgRange_Array"));
}
if (byteIndex < 0 || byteIndex > bytes.Length) {
throw new ArgumentOutOfRangeException ("byteIndex", _("ArgRange_Array"));
}
if ((bytes.Length - byteIndex) < (charCount * 4)) {
throw new ArgumentException (_("Arg_InsufficientSpace"));
}
int posn = byteIndex;
char ch;
while (charCount-- > 0) {
ch = chars[charIndex++];
if (Char.IsSurrogate (ch)) {
if (charCount-- > 0) {
int value = 0x400 * (ch - 0xD800) + 0x10000 + chars [charIndex++] - 0xDC00;
if (bigEndian) {
for (int i = 0; i < 4; i++) {
bytes [posn + 3 - i] = (byte) (value % 0x100);
value >>= 8;
}
posn += 4;
} else {
for (int i = 0; i < 4; i++) {
bytes [posn++] = (byte) (value % 0x100);
value >>= 8;
}
}
} else {
// Illegal surrogate
// FIXME: use fallback
if (bigEndian) {
bytes[posn++] = 0;
bytes[posn++] = 0;
bytes[posn++] = 0;
bytes[posn++] = (byte) '?';
} else {
bytes[posn++] = (byte) '?';
bytes[posn++] = 0;
bytes[posn++] = 0;
bytes[posn++] = 0;
}
}
} else {
if (bigEndian) {
bytes[posn++] = 0;
bytes[posn++] = 0;
bytes[posn++] = (byte)(ch >> 8);
bytes[posn++] = (byte)ch;
} else {
bytes[posn++] = (byte)ch;
bytes[posn++] = (byte)(ch >> 8);
bytes[posn++] = 0;
bytes[posn++] = 0;
}
}
}
return posn - byteIndex;
}
// Get the number of characters needed to decode a byte buffer.
public override int GetCharCount (byte[] bytes, int index, int count)
{
if (bytes == null) {
throw new ArgumentNullException ("bytes");
}
if (index < 0 || index > bytes.Length) {
throw new ArgumentOutOfRangeException ("index", _("ArgRange_Array"));
}
if (count < 0 || count > (bytes.Length - index)) {
throw new ArgumentOutOfRangeException ("count", _("ArgRange_Array"));
}
return count / 4;
}
// Get the characters that result from decoding a byte buffer.
public override int GetChars (byte[] bytes, int byteIndex, int byteCount,
char[] chars, int charIndex)
{
if (bytes == null) {
throw new ArgumentNullException ("bytes");
}
if (chars == null) {
throw new ArgumentNullException ("chars");
}
if (byteIndex < 0 || byteIndex > bytes.Length) {
throw new ArgumentOutOfRangeException ("byteIndex", _("ArgRange_Array"));
}
if (byteCount < 0 || byteCount > (bytes.Length - byteIndex)) {
throw new ArgumentOutOfRangeException ("byteCount", _("ArgRange_Array"));
}
if (charIndex < 0 || charIndex > chars.Length) {
throw new ArgumentOutOfRangeException ("charIndex", _("ArgRange_Array"));
}
/*
// Determine the byte order in the incoming buffer.
bool isBigEndian;
if (byteCount >= 2) {
if (bytes[byteIndex] == (byte)0xFE && bytes[byteIndex + 1] == (byte)0xFF) {
isBigEndian = true;
} else if (bytes[byteIndex] == (byte)0xFF && bytes[byteIndex + 1] == (byte)0xFE) {
isBigEndian = false;
} else {
isBigEndian = bigEndian;
}
} else {
isBigEndian = bigEndian;
}
*/
// Validate that we have sufficient space in "chars".
if ((chars.Length - charIndex) < (byteCount / 4)) {
throw new ArgumentException (_("Arg_InsufficientSpace"));
}
// Convert the characters.
int posn = charIndex;
if (bigEndian) {
while (byteCount >= 4) {
chars[posn++] = (char) (
bytes[byteIndex] << 24 |
bytes[byteIndex + 1] << 16 |
bytes[byteIndex + 2] << 8 |
bytes[byteIndex + 3]);
byteIndex += 4;
byteCount -= 4;
}
} else {
while (byteCount >= 4) {
chars[posn++] = (char) (
bytes[byteIndex] |
bytes[byteIndex + 1] << 8 |
bytes[byteIndex + 2] << 16 |
bytes[byteIndex + 3] << 24);
byteIndex += 4;
byteCount -= 4;
}
}
return posn - charIndex;
}
// Get the maximum number of bytes needed to encode a
// specified number of characters.
public override int GetMaxByteCount (int charCount)
{
if (charCount < 0) {
throw new ArgumentOutOfRangeException ("charCount", _("ArgRange_NonNegative"));
}
return charCount * 4;
}
// Get the maximum number of characters needed to decode a
// specified number of bytes.
public override int GetMaxCharCount (int byteCount)
{
if (byteCount < 0) {
throw new ArgumentOutOfRangeException
("byteCount", _("ArgRange_NonNegative"));
}
return byteCount / 4;
}
// Get a UTF32-specific decoder that is attached to this instance.
public override Decoder GetDecoder ()
{
return new UTF32Decoder (bigEndian);
}
// Get the UTF32 preamble.
public override byte[] GetPreamble ()
{
if (byteOrderMark) {
byte[] preamble = new byte[4];
if (bigEndian) {
preamble[2] = (byte)0xFE;
preamble[3] = (byte)0xFF;
} else {
preamble[0] = (byte)0xFF;
preamble[1] = (byte)0xFE;
}
return preamble;
} else {
return new byte [0];
}
}
// Determine if this object is equal to another.
public override bool Equals (Object value)
{
UTF32Encoding enc = (value as UTF32Encoding);
if (enc != null) {
return (codePage == enc.codePage &&
bigEndian == enc.bigEndian &&
byteOrderMark == enc.byteOrderMark &&
base.Equals (value));
} else {
return false;
}
}
// Get the hash code for this object.
public override int GetHashCode ()
{
int basis = base.GetHashCode ();
if (bigEndian)
basis ^= 0x1F;
if (byteOrderMark)
basis ^= 0x3F;
return basis;
}
// UTF32 decoder implementation.
private sealed class UTF32Decoder : Decoder
{
private bool bigEndian;
private int leftOverByte;
private int leftOverLength;
// Constructor.
public UTF32Decoder (bool bigEndian)
{
this.bigEndian = bigEndian;
leftOverByte = -1;
}
// Override inherited methods.
public override int GetCharCount (byte[] bytes, int index, int count)
{
if (bytes == null) {
throw new ArgumentNullException ("bytes");
}
if (index < 0 || index > bytes.Length) {
throw new ArgumentOutOfRangeException ("index", _("ArgRange_Array"));
}
if (count < 0 || count > (bytes.Length - index)) {
throw new ArgumentOutOfRangeException ("count", _("ArgRange_Array"));
}
if (leftOverByte != -1) {
return (count + 1) / 4;
} else {
return count / 4;
}
}
public override int GetChars (byte[] bytes, int byteIndex,
int byteCount, char[] chars,
int charIndex)
{
if (bytes == null) {
throw new ArgumentNullException ("bytes");
}
if (chars == null) {
throw new ArgumentNullException ("chars");
}
if (byteIndex < 0 || byteIndex > bytes.Length) {
throw new ArgumentOutOfRangeException ("byteIndex", _("ArgRange_Array"));
}
if (byteCount < 0 || byteCount > (bytes.Length - byteIndex)) {
throw new ArgumentOutOfRangeException ("byteCount", _("ArgRange_Array"));
}
if (charIndex < 0 || charIndex > chars.Length) {
throw new ArgumentOutOfRangeException ("charIndex", _("ArgRange_Array"));
}
// Convert the characters.
int posn = charIndex;
int leftOver = leftOverByte;
int length = chars.Length;
char ch;
int remain = 4 - leftOverLength;
if (leftOverLength > 0 && byteCount > remain) {
if (bigEndian) {
for (int i = 0; i < remain; i++)
leftOver += bytes [byteIndex++] << (4 - byteCount--);
} else {
for (int i = 0; i < remain; i++)
leftOver += bytes [byteIndex++] << byteCount--;
}
if (leftOver > char.MaxValue && posn + 1 < length
|| posn < length)
throw new ArgumentException (_("Arg_InsufficientSpace"));
if (leftOver > char.MaxValue) {
chars [posn++] = (char) ((leftOver - 10000) / 0x400 + 0xD800);
chars [posn++] = (char) ((leftOver - 10000) % 0x400 + 0xDC00);
}
else
chars [posn++] = (char) leftOver;
leftOver = -1;
leftOverLength = 0;
}
while (byteCount > 3) {
if (bigEndian) {
ch = (char) (
bytes[byteIndex++] << 24 |
bytes[byteIndex++] << 16 |
bytes[byteIndex++] << 8 |
bytes[byteIndex++]);
} else {
ch = (char) (
bytes[byteIndex++] |
bytes[byteIndex++] << 8 |
bytes[byteIndex++] << 16 |
bytes[byteIndex++] << 24);
}
byteCount -= 4;
if (posn < length) {
chars[posn++] = ch;
} else {
throw new ArgumentException (_("Arg_InsufficientSpace"));
}
}
if (byteCount > 0) {
leftOverLength = byteCount;
leftOver = 0;
if (bigEndian) {
for (int i = 0; i < byteCount; i++)
leftOver += bytes [byteIndex++] << (4 - byteCount--);
} else {
for (int i = 0; i < byteCount; i++)
leftOver += bytes [byteIndex++] << byteCount--;
}
leftOverByte = leftOver;
}
// Finished - return the converted length.
return posn - charIndex;
}
} // class UTF32Decoder
[CLSCompliantAttribute(false)]
public unsafe override int GetByteCount (char *chars, int count)
{
if (chars == null)
throw new ArgumentNullException ("chars");
return count * 4;
}
// a bunch of practically missing implementations (but should just work)
public override int GetByteCount (string s)
{
return base.GetByteCount (s);
}
[CLSCompliantAttribute (false)]
public override unsafe int GetBytes (char *chars, int charCount, byte *bytes, int byteCount)
{
return base.GetBytes (chars, charCount, bytes, byteCount);
}
public override int GetBytes (string s, int charIndex, int charCount, byte [] bytes, int byteIndex)
{
return base.GetBytes (s, charIndex, charCount, bytes, byteIndex);
}
[CLSCompliantAttribute (false)]
public override unsafe int GetCharCount (byte *bytes, int count)
{
return base.GetCharCount (bytes, count);
}
[CLSCompliantAttribute (false)]
public override unsafe int GetChars (byte *bytes, int byteCount, char* chars, int charCount)
{
return base.GetChars (bytes, byteCount, chars, charCount);
}
public override string GetString (byte [] bytes, int index, int count)
{
return base.GetString (bytes, index, count);
}
public override Encoder GetEncoder ()
{
return base.GetEncoder ();
}
}; // class UTF32Encoding
}; // namespace System.Text
|