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|
/*
* UTF8Encoding.cs - Implementation of the "System.Text.UTF8Encoding" class.
*
* Copyright (c) 2001, 2002 Southern Storm Software, Pty Ltd
* Copyright (C) 2004 Novell, Inc (http://www.novell.com)
*
* 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;
using System.Runtime.InteropServices;
[Serializable]
[MonoLimitation ("Serialization format not compatible with .NET")]
[ComVisible (true)]
public class UTF8Encoding : Encoding
{
// Magic number used by Windows for UTF-8.
internal const int UTF8_CODE_PAGE = 65001;
// Internal state.
private bool emitIdentifier;
// Constructors.
public UTF8Encoding () : this (false, false) {}
public UTF8Encoding (bool encoderShouldEmitUTF8Identifier)
: this (encoderShouldEmitUTF8Identifier, false) {}
public UTF8Encoding (bool encoderShouldEmitUTF8Identifier, bool throwOnInvalidBytes)
: base (UTF8_CODE_PAGE)
{
emitIdentifier = encoderShouldEmitUTF8Identifier;
if (throwOnInvalidBytes)
SetFallbackInternal (EncoderFallback.ExceptionFallback, DecoderFallback.ExceptionFallback);
else
SetFallbackInternal (EncoderFallback.StandardSafeFallback, DecoderFallback.StandardSafeFallback);
web_name = body_name = header_name = "utf-8";
encoding_name = "Unicode (UTF-8)";
is_browser_save = true;
is_browser_display = true;
is_mail_news_display = true;
is_mail_news_save = true;
windows_code_page = UnicodeEncoding.UNICODE_CODE_PAGE;
}
#region GetByteCount()
// Internal version of "GetByteCount" which can handle a rolling
// state between multiple calls to this method.
private static int InternalGetByteCount (char[] chars, int index, int count, EncoderFallback fallback, ref char leftOver, bool flush)
{
// Validate the parameters.
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"));
}
if (index == chars.Length) {
if (flush && leftOver != '\0') {
// Flush the left-over surrogate pair start.
leftOver = '\0';
return 3;
}
return 0;
}
unsafe {
fixed (char* cptr = chars) {
return InternalGetByteCount (cptr + index, count, fallback, ref leftOver, flush);
}
}
}
private unsafe static int InternalGetByteCount (char* chars, int count, EncoderFallback fallback, ref char leftOver, bool flush)
{
int length = 0;
char* end = chars + count;
char* start = chars;
EncoderFallbackBuffer buffer = null;
while (chars < end) {
if (leftOver == 0) {
for (; chars < end; chars++) {
if (*chars < '\x80') {
++length;
} else if (*chars < '\x800') {
length += 2;
} else if (*chars < '\uD800' || *chars > '\uDFFF') {
length += 3;
} else if (*chars <= '\uDBFF') {
// This is a surrogate start char, exit the inner loop only
// if we don't find the complete surrogate pair.
if (chars + 1 < end && chars [1] >= '\uDC00' && chars [1] <= '\uDFFF') {
length += 4;
chars++;
continue;
}
leftOver = *chars;
chars++;
break;
} else {
// We have a surrogate tail without
// leading surrogate.
char [] fallback_chars = GetFallbackChars (chars, start, fallback, ref buffer);
fixed (char *fb_chars = fallback_chars) {
char dummy = '\0';
length += InternalGetByteCount (fb_chars, fallback_chars.Length, fallback, ref dummy, true);
}
leftOver = '\0';
}
}
} else {
if (*chars >= '\uDC00' && *chars <= '\uDFFF') {
// We have a correct surrogate pair.
length += 4;
chars++;
} else {
// We have a surrogate start followed by a
// regular character. Technically, this is
// invalid, but we have to do something.
// We write out the surrogate start and then
// re-visit the current character again.
char [] fallback_chars = GetFallbackChars (chars, start, fallback, ref buffer);
fixed (char *fb_chars = fallback_chars) {
char dummy = '\0';
length += InternalGetByteCount (fb_chars, fallback_chars.Length, fallback, ref dummy, true);
}
}
leftOver = '\0';
}
}
if (flush) {
// Flush the left-over surrogate pair start.
if (leftOver != '\0') {
length += 3;
leftOver = '\0';
}
}
return length;
}
unsafe static char [] GetFallbackChars (char *chars, char *start, EncoderFallback fallback, ref EncoderFallbackBuffer buffer)
{
if (buffer == null)
buffer = fallback.CreateFallbackBuffer ();
buffer.Fallback (*chars, (int) (chars - start));
char [] fallback_chars = new char [buffer.Remaining];
for (int i = 0; i < fallback_chars.Length; i++)
fallback_chars [i] = buffer.GetNextChar ();
buffer.Reset ();
return fallback_chars;
}
// Get the number of bytes needed to encode a character buffer.
public override int GetByteCount (char[] chars, int index, int count)
{
char dummy = '\0';
return InternalGetByteCount (chars, index, count, EncoderFallback, ref dummy, true);
}
[CLSCompliant (false)]
[ComVisible (false)]
public unsafe override int GetByteCount (char* chars, int count)
{
if (chars == null)
throw new ArgumentNullException ("chars");
if (count == 0)
return 0;
char dummy = '\0';
return InternalGetByteCount (chars, count, EncoderFallback, ref dummy, true);
}
#endregion
#region GetBytes()
// Internal version of "GetBytes" which can handle a rolling
// state between multiple calls to this method.
private static int InternalGetBytes (char[] chars, int charIndex,
int charCount, byte[] bytes,
int byteIndex,
EncoderFallback fallback, ref EncoderFallbackBuffer buffer,
ref char leftOver, bool flush)
{
// Validate the parameters.
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 (charIndex == chars.Length) {
if (flush && leftOver != '\0') {
// FIXME: use EncoderFallback.
//
// By default it is empty, so I do nothing for now.
leftOver = '\0';
}
return 0;
}
unsafe {
fixed (char* cptr = chars) {
if (bytes.Length == byteIndex)
return InternalGetBytes (
cptr + charIndex, charCount,
null, 0, fallback, ref buffer, ref leftOver, flush);
fixed (byte *bptr = bytes) {
return InternalGetBytes (
cptr + charIndex, charCount,
bptr + byteIndex, bytes.Length - byteIndex,
fallback, ref buffer,
ref leftOver, flush);
}
}
}
}
private unsafe static int InternalGetBytes (char* chars, int count, byte* bytes, int bcount, EncoderFallback fallback, ref EncoderFallbackBuffer buffer, ref char leftOver, bool flush)
{
char* end = chars + count;
char* start = chars;
byte* start_bytes = bytes;
byte* end_bytes = bytes + bcount;
while (chars < end) {
if (leftOver == 0) {
for (; chars < end; chars++) {
int ch = *chars;
if (ch < '\x80') {
if (bytes >= end_bytes)
goto fail_no_space;
*bytes++ = (byte)ch;
} else if (ch < '\x800') {
if (bytes + 1 >= end_bytes)
goto fail_no_space;
bytes [0] = (byte) (0xC0 | (ch >> 6));
bytes [1] = (byte) (0x80 | (ch & 0x3F));
bytes += 2;
} else if (ch < '\uD800' || ch > '\uDFFF') {
if (bytes + 2 >= end_bytes)
goto fail_no_space;
bytes [0] = (byte) (0xE0 | (ch >> 12));
bytes [1] = (byte) (0x80 | ((ch >> 6) & 0x3F));
bytes [2] = (byte) (0x80 | (ch & 0x3F));
bytes += 3;
} else if (ch <= '\uDBFF') {
// This is a surrogate char, exit the inner loop.
leftOver = *chars;
chars++;
break;
} else {
// We have a surrogate tail without
// leading surrogate.
char [] fallback_chars = GetFallbackChars (chars, start, fallback, ref buffer);
char dummy = '\0';
if (bytes + InternalGetByteCount (fallback_chars, 0, fallback_chars.Length, fallback, ref dummy, true) > end_bytes)
goto fail_no_space;
fixed (char *fb_chars = fallback_chars) {
bytes += InternalGetBytes (fb_chars, fallback_chars.Length, bytes, bcount - (int) (bytes - start_bytes), fallback, ref buffer, ref dummy, true);
}
leftOver = '\0';
}
}
} else {
if (*chars >= '\uDC00' && *chars <= '\uDFFF') {
// We have a correct surrogate pair.
int ch = 0x10000 + (int) *chars - 0xDC00 + (((int) leftOver - 0xD800) << 10);
if (bytes + 3 >= end_bytes)
goto fail_no_space;
bytes [0] = (byte) (0xF0 | (ch >> 18));
bytes [1] = (byte) (0x80 | ((ch >> 12) & 0x3F));
bytes [2] = (byte) (0x80 | ((ch >> 6) & 0x3F));
bytes [3] = (byte) (0x80 | (ch & 0x3F));
bytes += 4;
chars++;
} else {
// We have a surrogate start followed by a
// regular character. Technically, this is
// invalid, but we have to do something.
// We write out the surrogate start and then
// re-visit the current character again.
char [] fallback_chars = GetFallbackChars (chars, start, fallback, ref buffer);
char dummy = '\0';
if (bytes + InternalGetByteCount (fallback_chars, 0, fallback_chars.Length, fallback, ref dummy, true) > end_bytes)
goto fail_no_space;
fixed (char *fb_chars = fallback_chars) {
InternalGetBytes (fb_chars, fallback_chars.Length, bytes, bcount - (int) (bytes - start_bytes), fallback, ref buffer, ref dummy, true);
}
leftOver = '\0';
}
leftOver = '\0';
}
}
if (flush) {
// Flush the left-over surrogate pair start.
if (leftOver != '\0') {
int ch = leftOver;
if (bytes + 2 < end_bytes) {
bytes [0] = (byte) (0xE0 | (ch >> 12));
bytes [1] = (byte) (0x80 | ((ch >> 6) & 0x3F));
bytes [2] = (byte) (0x80 | (ch & 0x3F));
bytes += 3;
} else {
goto fail_no_space;
}
leftOver = '\0';
}
}
return (int)(bytes - (end_bytes - bcount));
fail_no_space:
throw new ArgumentException ("Insufficient Space", "bytes");
}
// Get the bytes that result from encoding a character buffer.
public override int GetBytes (char[] chars, int charIndex, int charCount,
byte[] bytes, int byteIndex)
{
char leftOver = '\0';
EncoderFallbackBuffer buffer = null;
return InternalGetBytes (chars, charIndex, charCount, bytes, byteIndex, EncoderFallback, ref buffer, ref leftOver, true);
}
// Convenience wrappers for "GetBytes".
public override int GetBytes (String s, int charIndex, int charCount,
byte[] bytes, int byteIndex)
{
// Validate the parameters.
if (s == null) {
throw new ArgumentNullException ("s");
}
if (bytes == null) {
throw new ArgumentNullException ("bytes");
}
if (charIndex < 0 || charIndex > s.Length) {
throw new ArgumentOutOfRangeException ("charIndex", _("ArgRange_StringIndex"));
}
if (charCount < 0 || charCount > (s.Length - charIndex)) {
throw new ArgumentOutOfRangeException ("charCount", _("ArgRange_StringRange"));
}
if (byteIndex < 0 || byteIndex > bytes.Length) {
throw new ArgumentOutOfRangeException ("byteIndex", _("ArgRange_Array"));
}
if (charIndex == s.Length)
return 0;
unsafe {
fixed (char* cptr = s) {
char dummy = '\0';
EncoderFallbackBuffer buffer = null;
if (bytes.Length == byteIndex)
return InternalGetBytes (
cptr + charIndex, charCount,
null, 0, EncoderFallback, ref buffer, ref dummy, true);
fixed (byte *bptr = bytes) {
return InternalGetBytes (
cptr + charIndex, charCount,
bptr + byteIndex, bytes.Length - byteIndex,
EncoderFallback, ref buffer,
ref dummy, true);
}
}
}
}
[CLSCompliant (false)]
[ComVisible (false)]
public unsafe override int GetBytes (char* chars, int charCount, byte* bytes, int byteCount)
{
if (chars == null)
throw new ArgumentNullException ("chars");
if (charCount < 0)
throw new IndexOutOfRangeException ("charCount");
if (bytes == null)
throw new ArgumentNullException ("bytes");
if (byteCount < 0)
throw new IndexOutOfRangeException ("charCount");
if (charCount == 0)
return 0;
char dummy = '\0';
EncoderFallbackBuffer buffer = null;
if (byteCount == 0)
return InternalGetBytes (chars, charCount, null, 0, EncoderFallback, ref buffer, ref dummy, true);
else
return InternalGetBytes (chars, charCount, bytes, byteCount, EncoderFallback, ref buffer, ref dummy, true);
}
#endregion
// Internal version of "GetCharCount" which can handle a rolling
// state between multiple calls to this method.
private unsafe static int InternalGetCharCount (
byte[] bytes, int index, int count, uint leftOverBits,
uint leftOverCount, object provider,
ref DecoderFallbackBuffer fallbackBuffer, ref byte [] bufferArg, bool flush)
{
// Validate the parameters.
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 (count == 0)
return 0;
fixed (byte *bptr = bytes)
return InternalGetCharCount (bptr + index, count,
leftOverBits, leftOverCount, provider, ref fallbackBuffer, ref bufferArg, flush);
}
private unsafe static int InternalGetCharCount (
byte* bytes, int count, uint leftOverBits,
uint leftOverCount, object provider,
ref DecoderFallbackBuffer fallbackBuffer, ref byte [] bufferArg, bool flush)
{
int index = 0;
int length = 0;
if (leftOverCount == 0) {
int end = index + count;
for (; index < end; index++, count--) {
if (bytes [index] < 0x80)
length++;
else
break;
}
}
// Determine the number of characters that we have.
uint ch;
uint leftBits = leftOverBits;
uint leftSoFar = (leftOverCount & (uint)0x0F);
uint leftSize = ((leftOverCount >> 4) & (uint)0x0F);
while (count > 0) {
ch = (uint)(bytes[index++]);
--count;
if (leftSize == 0) {
// Process a UTF-8 start character.
if (ch < (uint)0x0080) {
// Single-byte UTF-8 character.
++length;
} else if ((ch & (uint)0xE0) == (uint)0xC0) {
// Double-byte UTF-8 character.
leftBits = (ch & (uint)0x1F);
leftSoFar = 1;
leftSize = 2;
} else if ((ch & (uint)0xF0) == (uint)0xE0) {
// Three-byte UTF-8 character.
leftBits = (ch & (uint)0x0F);
leftSoFar = 1;
leftSize = 3;
} else if ((ch & (uint)0xF8) == (uint)0xF0) {
// Four-byte UTF-8 character.
leftBits = (ch & (uint)0x07);
leftSoFar = 1;
leftSize = 4;
} else if ((ch & (uint)0xFC) == (uint)0xF8) {
// Five-byte UTF-8 character.
leftBits = (ch & (uint)0x03);
leftSoFar = 1;
leftSize = 5;
} else if ((ch & (uint)0xFE) == (uint)0xFC) {
// Six-byte UTF-8 character.
leftBits = (ch & (uint)0x03);
leftSoFar = 1;
leftSize = 6;
} else {
// Invalid UTF-8 start character.
length += Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, index - 1, 1);
}
} else {
// Process an extra byte in a multi-byte sequence.
if ((ch & (uint)0xC0) == (uint)0x80) {
leftBits = ((leftBits << 6) | (ch & (uint)0x3F));
if (++leftSoFar >= leftSize) {
// We have a complete character now.
if (leftBits < (uint)0x10000) {
// is it an overlong ?
bool overlong = false;
switch (leftSize) {
case 2:
overlong = (leftBits <= 0x7F);
break;
case 3:
overlong = (leftBits <= 0x07FF);
break;
case 4:
overlong = (leftBits <= 0xFFFF);
break;
case 5:
overlong = (leftBits <= 0x1FFFFF);
break;
case 6:
overlong = (leftBits <= 0x03FFFFFF);
break;
}
if (overlong) {
length += Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, index - leftSoFar, leftSoFar);
}
else if ((leftBits & 0xF800) == 0xD800) {
// UTF-8 doesn't use surrogate characters
length += Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, index - leftSoFar, leftSoFar);
}
else
++length;
} else if (leftBits < (uint)0x110000) {
length += 2;
} else {
length += Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, index - leftSoFar, leftSoFar);
}
leftSize = 0;
}
} else {
// Invalid UTF-8 sequence: clear and restart.
length += Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, index - leftSoFar, leftSoFar);
leftSize = 0;
--index;
++count;
}
}
}
if (flush && leftSize != 0) {
// We had left-over bytes that didn't make up
// a complete UTF-8 character sequence.
length += Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, index - leftSoFar, leftSoFar);
}
// Return the final length to the caller.
return length;
}
// for GetCharCount()
static unsafe int Fallback (object provider, ref DecoderFallbackBuffer buffer, ref byte [] bufferArg, byte* bytes, long index, uint size)
{
if (buffer == null) {
DecoderFallback fb = provider as DecoderFallback;
if (fb != null)
buffer = fb.CreateFallbackBuffer ();
else
buffer = ((Decoder) provider).FallbackBuffer;
}
if (bufferArg == null)
bufferArg = new byte [1];
int ret = 0;
for (int i = 0; i < size; i++) {
bufferArg [0] = bytes [(int) index + i];
buffer.Fallback (bufferArg, 0);
ret += buffer.Remaining;
buffer.Reset ();
}
return ret;
}
// for GetChars()
static unsafe void Fallback (object provider, ref DecoderFallbackBuffer buffer, ref byte [] bufferArg, byte* bytes, long byteIndex, uint size,
char* chars, ref int charIndex)
{
if (buffer == null) {
DecoderFallback fb = provider as DecoderFallback;
if (fb != null)
buffer = fb.CreateFallbackBuffer ();
else
buffer = ((Decoder) provider).FallbackBuffer;
}
if (bufferArg == null)
bufferArg = new byte [1];
for (int i = 0; i < size; i++) {
bufferArg [0] = bytes [byteIndex + i];
buffer.Fallback (bufferArg, 0);
while (buffer.Remaining > 0)
chars [charIndex++] = buffer.GetNextChar ();
buffer.Reset ();
}
}
// Get the number of characters needed to decode a byte buffer.
public override int GetCharCount (byte[] bytes, int index, int count)
{
DecoderFallbackBuffer buf = null;
byte [] bufferArg = null;
return InternalGetCharCount (bytes, index, count, 0, 0, DecoderFallback, ref buf, ref bufferArg, true);
}
[CLSCompliant (false)]
[ComVisible (false)]
public unsafe override int GetCharCount (byte* bytes, int count)
{
DecoderFallbackBuffer buf = null;
byte [] bufferArg = null;
return InternalGetCharCount (bytes, count, 0, 0, DecoderFallback, ref buf, ref bufferArg, true);
}
// Get the characters that result from decoding a byte buffer.
private unsafe static int InternalGetChars (
byte[] bytes, int byteIndex, int byteCount, char[] chars,
int charIndex, ref uint leftOverBits, ref uint leftOverCount,
object provider,
ref DecoderFallbackBuffer fallbackBuffer, ref byte [] bufferArg, bool flush)
{
// Validate the parameters.
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"));
}
if (charIndex == chars.Length)
return 0;
fixed (char* cptr = chars) {
if (byteCount == 0 || byteIndex == bytes.Length)
return InternalGetChars (null, 0, cptr + charIndex, chars.Length - charIndex, ref leftOverBits, ref leftOverCount, provider, ref fallbackBuffer, ref bufferArg, flush);
// otherwise...
fixed (byte* bptr = bytes)
return InternalGetChars (bptr + byteIndex, byteCount, cptr + charIndex, chars.Length - charIndex, ref leftOverBits, ref leftOverCount, provider, ref fallbackBuffer, ref bufferArg, flush);
}
}
private unsafe static int InternalGetChars (
byte* bytes, int byteCount, char* chars, int charCount,
ref uint leftOverBits, ref uint leftOverCount,
object provider,
ref DecoderFallbackBuffer fallbackBuffer, ref byte [] bufferArg, bool flush)
{
int charIndex = 0, byteIndex = 0;
int length = charCount;
int posn = charIndex;
if (leftOverCount == 0) {
int end = byteIndex + byteCount;
for (; byteIndex < end; posn++, byteIndex++, byteCount--) {
if (bytes [byteIndex] < 0x80)
chars [posn] = (char) bytes [byteIndex];
else
break;
}
}
// Convert the bytes into the output buffer.
uint ch;
uint leftBits = leftOverBits;
uint leftSoFar = (leftOverCount & (uint)0x0F);
uint leftSize = ((leftOverCount >> 4) & (uint)0x0F);
int byteEnd = byteIndex + byteCount;
for(; byteIndex < byteEnd; byteIndex++) {
// Fetch the next character from the byte buffer.
ch = (uint)(bytes[byteIndex]);
if (leftSize == 0) {
// Process a UTF-8 start character.
if (ch < (uint)0x0080) {
// Single-byte UTF-8 character.
if (posn >= length) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "chars");
}
chars[posn++] = (char)ch;
} else if ((ch & (uint)0xE0) == (uint)0xC0) {
// Double-byte UTF-8 character.
leftBits = (ch & (uint)0x1F);
leftSoFar = 1;
leftSize = 2;
} else if ((ch & (uint)0xF0) == (uint)0xE0) {
// Three-byte UTF-8 character.
leftBits = (ch & (uint)0x0F);
leftSoFar = 1;
leftSize = 3;
} else if ((ch & (uint)0xF8) == (uint)0xF0) {
// Four-byte UTF-8 character.
leftBits = (ch & (uint)0x07);
leftSoFar = 1;
leftSize = 4;
} else if ((ch & (uint)0xFC) == (uint)0xF8) {
// Five-byte UTF-8 character.
leftBits = (ch & (uint)0x03);
leftSoFar = 1;
leftSize = 5;
} else if ((ch & (uint)0xFE) == (uint)0xFC) {
// Six-byte UTF-8 character.
leftBits = (ch & (uint)0x03);
leftSoFar = 1;
leftSize = 6;
} else {
// Invalid UTF-8 start character.
Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, byteIndex, 1, chars, ref posn);
}
} else {
// Process an extra byte in a multi-byte sequence.
if ((ch & (uint)0xC0) == (uint)0x80) {
leftBits = ((leftBits << 6) | (ch & (uint)0x3F));
if (++leftSoFar >= leftSize) {
// We have a complete character now.
if (leftBits < (uint)0x10000) {
// is it an overlong ?
bool overlong = false;
switch (leftSize) {
case 2:
overlong = (leftBits <= 0x7F);
break;
case 3:
overlong = (leftBits <= 0x07FF);
break;
case 4:
overlong = (leftBits <= 0xFFFF);
break;
case 5:
overlong = (leftBits <= 0x1FFFFF);
break;
case 6:
overlong = (leftBits <= 0x03FFFFFF);
break;
}
if (overlong) {
Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, byteIndex - leftSoFar, leftSoFar, chars, ref posn);
}
else if ((leftBits & 0xF800) == 0xD800) {
// UTF-8 doesn't use surrogate characters
Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, byteIndex - leftSoFar, leftSoFar, chars, ref posn);
}
else {
if (posn >= length) {
throw new ArgumentException
(_("Arg_InsufficientSpace"), "chars");
}
chars[posn++] = (char)leftBits;
}
} else if (leftBits < (uint)0x110000) {
if ((posn + 2) > length) {
throw new ArgumentException
(_("Arg_InsufficientSpace"), "chars");
}
leftBits -= (uint)0x10000;
chars[posn++] = (char)((leftBits >> 10) +
(uint)0xD800);
chars[posn++] =
(char)((leftBits & (uint)0x3FF) + (uint)0xDC00);
} else {
Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, byteIndex - leftSoFar, leftSoFar, chars, ref posn);
}
leftSize = 0;
}
} else {
// Invalid UTF-8 sequence: clear and restart.
Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, byteIndex - leftSoFar, leftSoFar, chars, ref posn);
leftSize = 0;
--byteIndex;
}
}
}
if (flush && leftSize != 0) {
// We had left-over bytes that didn't make up
// a complete UTF-8 character sequence.
Fallback (provider, ref fallbackBuffer, ref bufferArg, bytes, byteIndex - leftSoFar, leftSoFar, chars, ref posn);
}
leftOverBits = leftBits;
leftOverCount = (leftSoFar | (leftSize << 4));
// Return the final length to the caller.
return posn - charIndex;
}
// Get the characters that result from decoding a byte buffer.
public override int GetChars (byte[] bytes, int byteIndex, int byteCount,
char[] chars, int charIndex)
{
uint leftOverBits = 0;
uint leftOverCount = 0;
DecoderFallbackBuffer buf = null;
byte [] bufferArg = null;
return InternalGetChars (bytes, byteIndex, byteCount, chars,
charIndex, ref leftOverBits, ref leftOverCount, DecoderFallback, ref buf, ref bufferArg, true);
}
[CLSCompliant (false)]
[ComVisible (false)]
public unsafe override int GetChars (byte* bytes, int byteCount, char* chars, int charCount)
{
DecoderFallbackBuffer buf = null;
byte [] bufferArg = null;
uint leftOverBits = 0;
uint leftOverCount = 0;
return InternalGetChars (bytes, byteCount, chars,
charCount, ref leftOverBits, ref leftOverCount, DecoderFallback, ref buf, ref bufferArg, true);
}
// 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;
}
// Get a UTF8-specific decoder that is attached to this instance.
public override Decoder GetDecoder ()
{
return new UTF8Decoder (DecoderFallback);
}
// Get a UTF8-specific encoder that is attached to this instance.
public override Encoder GetEncoder ()
{
return new UTF8Encoder (EncoderFallback, emitIdentifier);
}
// Get the UTF8 preamble.
public override byte[] GetPreamble ()
{
if (emitIdentifier)
return new byte [] { 0xEF, 0xBB, 0xBF };
return EmptyArray<byte>.Value;
}
// Determine if this object is equal to another.
public override bool Equals (Object value)
{
UTF8Encoding enc = (value as UTF8Encoding);
if (enc != null) {
return (codePage == enc.codePage &&
emitIdentifier == enc.emitIdentifier &&
DecoderFallback.Equals (enc.DecoderFallback) &&
EncoderFallback.Equals (enc.EncoderFallback));
} else {
return false;
}
}
// Get the hash code for this object.
public override int GetHashCode ()
{
return base.GetHashCode ();
}
public override int GetByteCount (string chars)
{
// hmm, does this override make any sense?
return base.GetByteCount (chars);
}
[ComVisible (false)]
public override string GetString (byte [] bytes, int index, int count)
{
// hmm, does this override make any sense?
return base.GetString (bytes, index, count);
}
// UTF-8 decoder implementation.
[Serializable]
private class UTF8Decoder : Decoder
{
private uint leftOverBits;
private uint leftOverCount;
// Constructor.
public UTF8Decoder (DecoderFallback fallback)
{
Fallback = fallback;
leftOverBits = 0;
leftOverCount = 0;
}
// Override inherited methods.
public override int GetCharCount (byte[] bytes, int index, int count)
{
DecoderFallbackBuffer buf = null;
byte [] bufferArg = null;
return InternalGetCharCount (bytes, index, count,
leftOverBits, leftOverCount, this, ref buf, ref bufferArg, false);
}
public override int GetChars (byte[] bytes, int byteIndex,
int byteCount, char[] chars, int charIndex)
{
DecoderFallbackBuffer buf = null;
byte [] bufferArg = null;
return InternalGetChars (bytes, byteIndex, byteCount,
chars, charIndex, ref leftOverBits, ref leftOverCount, this, ref buf, ref bufferArg, false);
}
} // class UTF8Decoder
// UTF-8 encoder implementation.
[Serializable]
private class UTF8Encoder : Encoder
{
// private bool emitIdentifier;
private char leftOverForCount;
private char leftOverForConv;
// Constructor.
public UTF8Encoder (EncoderFallback fallback, bool emitIdentifier)
{
Fallback = fallback;
// this.emitIdentifier = emitIdentifier;
leftOverForCount = '\0';
leftOverForConv = '\0';
}
// Override inherited methods.
public override int GetByteCount (char[] chars, int index,
int count, bool flush)
{
return InternalGetByteCount (chars, index, count, Fallback, ref leftOverForCount, flush);
}
public override int GetBytes (char[] chars, int charIndex,
int charCount, byte[] bytes, int byteIndex, bool flush)
{
int result;
EncoderFallbackBuffer buffer = null;
result = InternalGetBytes (chars, charIndex, charCount, bytes, byteIndex, Fallback, ref buffer, ref leftOverForConv, flush);
// emitIdentifier = false;
return result;
}
public unsafe override int GetByteCount (char* chars, int count, bool flush)
{
return InternalGetByteCount (chars, count, Fallback, ref leftOverForCount, flush);
}
public unsafe override int GetBytes (char* chars, int charCount,
byte* bytes, int byteCount, bool flush)
{
int result;
EncoderFallbackBuffer buffer = null;
result = InternalGetBytes (chars, charCount, bytes, byteCount, Fallback, ref buffer, ref leftOverForConv, flush);
// emitIdentifier = false;
return result;
}
} // class UTF8Encoder
}; // class UTF8Encoding
}; // namespace System.Text
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