internal unsafe EncodingCharBuffer(EncodingNLS enc, DecoderNLS?decoder, char *charStart, int charCount, byte *byteStart, int byteCount)
{
_enc = enc;
_decoder = decoder;
_chars = charStart;
_charStart = charStart;
_charEnd = charStart + charCount;
_byteStart = byteStart;
_bytes = byteStart;
_byteEnd = byteStart + byteCount;
if (_decoder == null)
{
_fallbackBuffer = enc.DecoderFallback.CreateFallbackBuffer();
}
else
{
_fallbackBuffer = _decoder.FallbackBuffer;
}
// If we're getting chars or getting char count we don't expect to have
// to remember fallbacks between calls (so it should be empty)
Debug.Assert(_fallbackBuffer.Remaining == 0,
"[Encoding.EncodingCharBuffer.EncodingCharBuffer]Expected empty fallback buffer for getchars/charcount");
_fallbackBufferHelper = new DecoderFallbackBufferHelper(_fallbackBuffer);
_fallbackBufferHelper.InternalInitialize(_bytes, _charEnd);
}
[System.Security.SecurityCritical] // auto-generated
internal unsafe EncodingCharBuffer(EncodingNLS enc, DecoderNLS decoder, char* charStart, int charCount, byte* byteStart, int byteCount)
{
_enc = enc;
_decoder = decoder;
_chars = charStart;
_charStart = charStart;
_charEnd = charStart + charCount;
_byteStart = byteStart;
_bytes = byteStart;
_byteEnd = byteStart + byteCount;
if (_decoder == null)
_fallbackBuffer = enc.DecoderFallback.CreateFallbackBuffer();
else
_fallbackBuffer = _decoder.FallbackBuffer;
// If we're getting chars or getting char count we don't expect to have
// to remember fallbacks between calls (so it should be empty)
Debug.Assert(_fallbackBuffer.Remaining == 0,
"[Encoding.EncodingCharBuffer.EncodingCharBuffer]Expected empty fallback buffer for getchars/charcount");
_fallbackBufferHelper = new DecoderFallbackBufferHelper(_fallbackBuffer);
_fallbackBufferHelper.InternalInitialize(_bytes, _charEnd);
}
[System.Security.SecurityCritical] // auto-generated
public override unsafe int GetChars(byte* bytes, int byteCount,
char* chars, int charCount, DecoderNLS baseDecoder)
{
// Just need to ASSERT, this is called by something else internal that checked parameters already
Debug.Assert(bytes != null, "[DBCSCodePageEncoding.GetChars]bytes is null");
Debug.Assert(byteCount >= 0, "[DBCSCodePageEncoding.GetChars]byteCount is negative");
Debug.Assert(chars != null, "[DBCSCodePageEncoding.GetChars]chars is null");
Debug.Assert(charCount >= 0, "[DBCSCodePageEncoding.GetChars]charCount is negative");
CheckMemorySection();
// Fix our decoder
DBCSDecoder decoder = (DBCSDecoder)baseDecoder;
// We'll need to know where the end is
byte* byteStart = bytes;
byte* byteEnd = bytes + byteCount;
char* charStart = chars;
char* charEnd = chars + charCount;
bool bUsedDecoder = false;
// Get our fallback
DecoderFallbackBuffer fallbackBuffer = null;
// Shouldn't have anything in fallback buffer for GetChars
Debug.Assert(decoder == null || !decoder.m_throwOnOverflow ||
!decoder.InternalHasFallbackBuffer || decoder.FallbackBuffer.Remaining == 0,
"[DBCSCodePageEncoding.GetChars]Expected empty fallback buffer at start");
DecoderFallbackBufferHelper fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
// If we have a left over byte, use it
if (decoder != null && decoder.bLeftOver > 0)
{
// We have a left over byte?
if (byteCount == 0)
{
// No input though
if (!decoder.MustFlush)
{
// Don't have to flush
return 0;
}
// Well, we're flushing, so use '?' or fallback
// fallback leftover byte
Debug.Assert(fallbackBuffer == null,
"[DBCSCodePageEncoding.GetChars]Expected empty fallback");
fallbackBuffer = decoder.FallbackBuffer;
fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
fallbackHelper.InternalInitialize(bytes, charEnd);
// If no room, it's hopeless, this was 1st fallback
byte[] byteBuffer = new byte[] { unchecked((byte)decoder.bLeftOver) };
if (!fallbackHelper.InternalFallback(byteBuffer, bytes, ref chars))
ThrowCharsOverflow(decoder, true);
decoder.bLeftOver = 0;
// Done, return it
return (int)(chars - charStart);
}
// Get our full info
int iBytes = decoder.bLeftOver << 8;
iBytes |= (*bytes);
bytes++;
// Look up our bytes
char cDecoder = mapBytesToUnicode[iBytes];
if (cDecoder == UNKNOWN_CHAR_FLAG && iBytes != 0)
{
Debug.Assert(fallbackBuffer == null,
"[DBCSCodePageEncoding.GetChars]Expected empty fallback for two bytes");
fallbackBuffer = decoder.FallbackBuffer;
fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
fallbackHelper.InternalInitialize(byteEnd - byteCount, charEnd);
byte[] byteBuffer = new byte[] { unchecked((byte)(iBytes >> 8)), unchecked((byte)iBytes) };
if (!fallbackHelper.InternalFallback(byteBuffer, bytes, ref chars))
ThrowCharsOverflow(decoder, true);
}
else
{
// Do we have output room?, hopeless if not, this is first char
if (chars >= charEnd)
ThrowCharsOverflow(decoder, true);
*(chars++) = cDecoder;
}
}
// Loop, paying attention to our fallbacks.
while (bytes < byteEnd)
{
// Faster if don't use *bytes++;
int iBytes = *bytes;
bytes++;
char c = mapBytesToUnicode[iBytes];
// See if it was a double byte character
if (c == LEAD_BYTE_CHAR)
{
// Its a lead byte
if (bytes < byteEnd)
{
// Have another to use, so use it
iBytes <<= 8;
iBytes |= *bytes;
bytes++;
c = mapBytesToUnicode[iBytes];
}
else
{
// No input left
if (decoder == null || decoder.MustFlush)
{
// have to flush anyway, set to unknown so we use fallback
c = UNKNOWN_CHAR_FLAG;
}
else
{
// Stick it in decoder
bUsedDecoder = true;
decoder.bLeftOver = (byte)iBytes;
break;
}
}
}
// See if it was unknown
if (c == UNKNOWN_CHAR_FLAG && iBytes != 0)
{
if (fallbackBuffer == null)
{
if (decoder == null)
fallbackBuffer = DecoderFallback.CreateFallbackBuffer();
else
fallbackBuffer = decoder.FallbackBuffer;
fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
fallbackHelper.InternalInitialize(byteEnd - byteCount, charEnd);
}
// Do fallback
byte[] byteBuffer = null;
if (iBytes < 0x100)
byteBuffer = new byte[] { unchecked((byte)iBytes) };
else
byteBuffer = new byte[] { unchecked((byte)(iBytes >> 8)), unchecked((byte)iBytes) };
if (!fallbackHelper.InternalFallback(byteBuffer, bytes, ref chars))
{
// May or may not throw, but we didn't get these byte(s)
Debug.Assert(bytes >= byteStart + byteBuffer.Length,
"[DBCSCodePageEncoding.GetChars]Expected bytes to have advanced for fallback");
bytes -= byteBuffer.Length; // didn't use these byte(s)
fallbackHelper.InternalReset(); // Didn't fall this back
ThrowCharsOverflow(decoder, bytes == byteStart); // throw?
break; // don't throw, but stop loop
}
}
else
{
// Do we have buffer room?
if (chars >= charEnd)
{
// May or may not throw, but we didn't get these byte(s)
Debug.Assert(bytes > byteStart,
"[DBCSCodePageEncoding.GetChars]Expected bytes to have advanced for lead byte");
bytes--; // unused byte
if (iBytes >= 0x100)
{
Debug.Assert(bytes > byteStart,
"[DBCSCodePageEncoding.GetChars]Expected bytes to have advanced for trail byte");
bytes--; // 2nd unused byte
}
ThrowCharsOverflow(decoder, bytes == byteStart); // throw?
break; // don't throw, but stop loop
}
*(chars++) = c;
}
}
// We already stuck it in encoder if necessary, but we have to clear cases where nothing new got into decoder
if (decoder != null)
{
// Clear it in case of MustFlush
if (bUsedDecoder == false)
{
decoder.bLeftOver = 0;
}
// Remember our count
decoder.m_bytesUsed = (int)(bytes - byteStart);
}
// Shouldn't have anything in fallback buffer for GetChars
Debug.Assert(decoder == null || !decoder.m_throwOnOverflow ||
!decoder.InternalHasFallbackBuffer || decoder.FallbackBuffer.Remaining == 0,
"[DBCSCodePageEncoding.GetChars]Expected empty fallback buffer at end");
// Return length of our output
return (int)(chars - charStart);
}
[System.Security.SecurityCritical] // auto-generated
public override unsafe int GetCharCount(byte* bytes, int count, DecoderNLS baseDecoder)
{
// Just assert, we're called internally so these should be safe, checked already
Debug.Assert(bytes != null, "[DBCSCodePageEncoding.GetCharCount]bytes is null");
Debug.Assert(count >= 0, "[DBCSCodePageEncoding.GetCharCount]byteCount is negative");
CheckMemorySection();
// Fix our decoder
DBCSDecoder decoder = (DBCSDecoder)baseDecoder;
// Get our fallback
DecoderFallbackBuffer fallbackBuffer = null;
// We'll need to know where the end is
byte* byteEnd = bytes + count;
int charCount = count; // Assume 1 char / byte
// Shouldn't have anything in fallback buffer for GetCharCount
// (don't have to check m_throwOnOverflow for count)
Debug.Assert(decoder == null ||
!decoder.InternalHasFallbackBuffer || decoder.FallbackBuffer.Remaining == 0,
"[DBCSCodePageEncoding.GetCharCount]Expected empty fallback buffer at start");
DecoderFallbackBufferHelper fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
// If we have a left over byte, use it
if (decoder != null && decoder.bLeftOver > 0)
{
// We have a left over byte?
if (count == 0)
{
// No input though
if (!decoder.MustFlush)
{
// Don't have to flush
return 0;
}
Debug.Assert(fallbackBuffer == null,
"[DBCSCodePageEncoding.GetCharCount]Expected empty fallback buffer");
fallbackBuffer = decoder.FallbackBuffer;
fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
fallbackHelper.InternalInitialize(bytes, null);
byte[] byteBuffer = new byte[] { unchecked((byte)decoder.bLeftOver) };
return fallbackHelper.InternalFallback(byteBuffer, bytes);
}
// Get our full info
int iBytes = decoder.bLeftOver << 8;
iBytes |= (*bytes);
bytes++;
// This is either 1 known char or fallback
// Already counted 1 char
// Look up our bytes
char cDecoder = mapBytesToUnicode[iBytes];
if (cDecoder == 0 && iBytes != 0)
{
// Deallocate preallocated one
charCount--;
// We'll need a fallback
Debug.Assert(fallbackBuffer == null,
"[DBCSCodePageEncoding.GetCharCount]Expected empty fallback buffer for unknown pair");
fallbackBuffer = decoder.FallbackBuffer;
fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
fallbackHelper.InternalInitialize(byteEnd - count, null);
// Do fallback, we know there are 2 bytes
byte[] byteBuffer = new byte[] { unchecked((byte)(iBytes >> 8)), unchecked((byte)iBytes) };
charCount += fallbackHelper.InternalFallback(byteBuffer, bytes);
}
// else we already reserved space for this one.
}
// Loop, watch out for fallbacks
while (bytes < byteEnd)
{
// Faster if don't use *bytes++;
int iBytes = *bytes;
bytes++;
char c = mapBytesToUnicode[iBytes];
// See if it was a double byte character
if (c == LEAD_BYTE_CHAR)
{
// It's a lead byte
charCount--; // deallocate preallocated lead byte
if (bytes < byteEnd)
{
// Have another to use, so use it
iBytes <<= 8;
iBytes |= *bytes;
bytes++;
c = mapBytesToUnicode[iBytes];
}
else
{
// No input left
if (decoder == null || decoder.MustFlush)
{
// have to flush anyway, set to unknown so we use fallback
charCount++; // reallocate deallocated lead byte
c = UNKNOWN_CHAR_FLAG;
}
else
{
// We'll stick it in decoder
break;
}
}
}
// See if it was unknown.
// Unknown and known chars already allocated, but fallbacks aren't
if (c == UNKNOWN_CHAR_FLAG && iBytes != 0)
{
if (fallbackBuffer == null)
{
if (decoder == null)
fallbackBuffer = DecoderFallback.CreateFallbackBuffer();
else
fallbackBuffer = decoder.FallbackBuffer;
fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
fallbackHelper.InternalInitialize(byteEnd - count, null);
}
// Do fallback
charCount--; // Get rid of preallocated extra char
byte[] byteBuffer = null;
if (iBytes < 0x100)
byteBuffer = new byte[] { unchecked((byte)iBytes) };
else
byteBuffer = new byte[] { unchecked((byte)(iBytes >> 8)), unchecked((byte)iBytes) };
charCount += fallbackHelper.InternalFallback(byteBuffer, bytes);
}
}
// Shouldn't have anything in fallback buffer for GetChars
Debug.Assert(decoder == null || !decoder.m_throwOnOverflow ||
!decoder.InternalHasFallbackBuffer || decoder.FallbackBuffer.Remaining == 0,
"[DBCSCodePageEncoding.GetCharCount]Expected empty fallback buffer at end");
// Return our count
return charCount;
}
public override unsafe int GetChars(byte *bytes, int byteCount,
char *chars, int charCount, DecoderNLS decoder)
{
// Just need to ASSERT, this is called by something else internal that checked parameters already
Debug.Assert(bytes != null, "[SBCSCodePageEncoding.GetChars]bytes is null");
Debug.Assert(byteCount >= 0, "[SBCSCodePageEncoding.GetChars]byteCount is negative");
Debug.Assert(chars != null, "[SBCSCodePageEncoding.GetChars]chars is null");
Debug.Assert(charCount >= 0, "[SBCSCodePageEncoding.GetChars]charCount is negative");
CheckMemorySection();
// See if we have best fit
bool bUseBestFit = false;
// Do it fast way if using ? replacement or best fit fallbacks
byte *byteEnd = bytes + byteCount;
byte *byteStart = bytes;
char *charStart = chars;
// Only need decoder fallback buffer if not using default replacement fallback or best fit fallback.
DecoderReplacementFallback fallback = null;
if (decoder == null)
{
fallback = DecoderFallback as DecoderReplacementFallback;
bUseBestFit = DecoderFallback is InternalDecoderBestFitFallback;
}
else
{
fallback = decoder.Fallback as DecoderReplacementFallback;
bUseBestFit = decoder.Fallback is InternalDecoderBestFitFallback;
Debug.Assert(!decoder.m_throwOnOverflow || !decoder.InternalHasFallbackBuffer ||
decoder.FallbackBuffer.Remaining == 0,
"[SBCSCodePageEncoding.GetChars]Expected empty fallback buffer at start");
}
if (bUseBestFit || (fallback != null && fallback.MaxCharCount == 1))
{
// Try it the fast way
char replacementChar;
if (fallback == null)
{
replacementChar = '?'; // Best fit always has ? for fallback for SBCS
}
else
{
replacementChar = fallback.DefaultString[0];
}
// Need byteCount chars, otherwise too small buffer
if (charCount < byteCount)
{
// Need at least 1 output byte, throw if must throw
ThrowCharsOverflow(decoder, charCount < 1);
// Not throwing, use what we can
byteEnd = bytes + charCount;
}
// Quick loop, just do '?' replacement because we don't have fallbacks for decodings.
while (bytes < byteEnd)
{
char c;
if (bUseBestFit)
{
if (arrayBytesBestFit == null)
{
ReadBestFitTable();
}
c = arrayBytesBestFit[*bytes];
}
else
{
c = _mapBytesToUnicode[*bytes];
}
bytes++;
if (c == UNKNOWN_CHAR)
{
// This is an invalid byte in the ASCII encoding.
*chars = replacementChar;
}
else
{
*chars = c;
}
chars++;
}
// bytes & chars used are the same
if (decoder != null)
{
decoder.m_bytesUsed = (int)(bytes - byteStart);
}
return((int)(chars - charStart));
}
// Slower way's going to need a fallback buffer
DecoderFallbackBuffer fallbackBuffer = null;
byte[] byteBuffer = new byte[1];
char * charEnd = chars + charCount;
DecoderFallbackBufferHelper fallbackHelper = new DecoderFallbackBufferHelper(null);
// Not quite so fast loop
while (bytes < byteEnd)
{
// Faster if don't use *bytes++;
char c = _mapBytesToUnicode[*bytes];
bytes++;
// See if it was unknown
if (c == UNKNOWN_CHAR)
{
// Make sure we have a fallback buffer
if (fallbackBuffer == null)
{
if (decoder == null)
{
fallbackBuffer = DecoderFallback.CreateFallbackBuffer();
}
else
{
fallbackBuffer = decoder.FallbackBuffer;
}
fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
fallbackHelper.InternalInitialize(byteEnd - byteCount, charEnd);
}
// Use fallback buffer
Debug.Assert(bytes > byteStart,
"[SBCSCodePageEncoding.GetChars]Expected bytes to have advanced already (unknown byte)");
byteBuffer[0] = *(bytes - 1);
// Fallback adds fallback to chars, but doesn't increment chars unless the whole thing fits.
if (!fallbackHelper.InternalFallback(byteBuffer, bytes, ref chars))
{
// May or may not throw, but we didn't get this byte
bytes--; // unused byte
fallbackHelper.InternalReset(); // Didn't fall this back
ThrowCharsOverflow(decoder, bytes == byteStart); // throw?
break; // don't throw, but stop loop
}
}
else
{
// Make sure we have buffer space
if (chars >= charEnd)
{
Debug.Assert(bytes > byteStart,
"[SBCSCodePageEncoding.GetChars]Expected bytes to have advanced already (known byte)");
bytes--; // unused byte
ThrowCharsOverflow(decoder, bytes == byteStart); // throw?
break; // don't throw, but stop loop
}
*(chars) = c;
chars++;
}
}
// Might have had decoder fallback stuff.
if (decoder != null)
{
decoder.m_bytesUsed = (int)(bytes - byteStart);
}
// Expect Empty fallback buffer for GetChars
Debug.Assert(fallbackBuffer == null || fallbackBuffer.Remaining == 0,
"[SBCSEncoding.GetChars]Expected Empty fallback buffer at end");
return((int)(chars - charStart));
}
// This is internal and called by something else,
public override unsafe int GetCharCount(byte *bytes, int count, DecoderNLS decoder)
{
// Just assert, we're called internally so these should be safe, checked already
Debug.Assert(bytes != null, "[SBCSCodePageEncoding.GetCharCount]bytes is null");
Debug.Assert(count >= 0, "[SBCSCodePageEncoding.GetCharCount]byteCount is negative");
CheckMemorySection();
// See if we have best fit
bool bUseBestFit = false;
// Only need decoder fallback buffer if not using default replacement fallback or best fit fallback.
DecoderReplacementFallback fallback = null;
if (decoder == null)
{
fallback = DecoderFallback as DecoderReplacementFallback;
bUseBestFit = DecoderFallback is InternalDecoderBestFitFallback;
}
else
{
fallback = decoder.Fallback as DecoderReplacementFallback;
bUseBestFit = decoder.Fallback is InternalDecoderBestFitFallback;
Debug.Assert(!decoder.m_throwOnOverflow || !decoder.InternalHasFallbackBuffer ||
decoder.FallbackBuffer.Remaining == 0,
"[SBCSCodePageEncoding.GetChars]Expected empty fallback buffer at start");
}
if (bUseBestFit || (fallback != null && fallback.MaxCharCount == 1))
{
// Just return length, SBCS stay the same length because they don't map to surrogate
// pairs and we don't have a decoder fallback.
return(count);
}
// Might need one of these later
DecoderFallbackBuffer fallbackBuffer = null;
DecoderFallbackBufferHelper fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
// Have to do it the hard way.
// Assume charCount will be == count
int charCount = count;
byte[] byteBuffer = new byte[1];
// Do it our fast way
byte *byteEnd = bytes + count;
// Quick loop
while (bytes < byteEnd)
{
// Faster if don't use *bytes++;
char c;
c = _mapBytesToUnicode[*bytes];
bytes++;
// If unknown we have to do fallback count
if (c == UNKNOWN_CHAR)
{
// Must have a fallback buffer
if (fallbackBuffer == null)
{
// Need to adjust count so we get real start
if (decoder == null)
{
fallbackBuffer = DecoderFallback.CreateFallbackBuffer();
}
else
{
fallbackBuffer = decoder.FallbackBuffer;
}
fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
fallbackHelper.InternalInitialize(byteEnd - count, null);
}
// Use fallback buffer
byteBuffer[0] = *(bytes - 1);
charCount--; // We'd already reserved one for *(bytes-1)
charCount += fallbackHelper.InternalFallback(byteBuffer, bytes);
}
}
// Fallback buffer must be empty
Debug.Assert(fallbackBuffer == null || fallbackBuffer.Remaining == 0,
"[SBCSEncoding.GetCharCount]Expected Empty fallback buffer at end");
// Converted sequence is same length as input
return(charCount);
}
public unsafe override int GetChars(byte* bytes, int byteCount,
char* chars, int charCount, DecoderNLS decoder)
{
// Just need to ASSERT, this is called by something else internal that checked parameters already
Debug.Assert(bytes != null, "[SBCSCodePageEncoding.GetChars]bytes is null");
Debug.Assert(byteCount >= 0, "[SBCSCodePageEncoding.GetChars]byteCount is negative");
Debug.Assert(chars != null, "[SBCSCodePageEncoding.GetChars]chars is null");
Debug.Assert(charCount >= 0, "[SBCSCodePageEncoding.GetChars]charCount is negative");
CheckMemorySection();
// See if we have best fit
bool bUseBestFit = false;
// Do it fast way if using ? replacement or best fit fallbacks
byte* byteEnd = bytes + byteCount;
byte* byteStart = bytes;
char* charStart = chars;
// Only need decoder fallback buffer if not using default replacement fallback or best fit fallback.
DecoderReplacementFallback fallback = null;
if (decoder == null)
{
fallback = DecoderFallback as DecoderReplacementFallback;
bUseBestFit = DecoderFallback is InternalDecoderBestFitFallback;
}
else
{
fallback = decoder.Fallback as DecoderReplacementFallback;
bUseBestFit = decoder.Fallback is InternalDecoderBestFitFallback;
Debug.Assert(!decoder.m_throwOnOverflow || !decoder.InternalHasFallbackBuffer ||
decoder.FallbackBuffer.Remaining == 0,
"[SBCSCodePageEncoding.GetChars]Expected empty fallback buffer at start");
}
if (bUseBestFit || (fallback != null && fallback.MaxCharCount == 1))
{
// Try it the fast way
char replacementChar;
if (fallback == null)
replacementChar = '?'; // Best fit always has ? for fallback for SBCS
else
replacementChar = fallback.DefaultString[0];
// Need byteCount chars, otherwise too small buffer
if (charCount < byteCount)
{
// Need at least 1 output byte, throw if must throw
ThrowCharsOverflow(decoder, charCount < 1);
// Not throwing, use what we can
byteEnd = bytes + charCount;
}
// Quick loop, just do '?' replacement because we don't have fallbacks for decodings.
while (bytes < byteEnd)
{
char c;
if (bUseBestFit)
{
if (arrayBytesBestFit == null)
{
ReadBestFitTable();
}
c = arrayBytesBestFit[*bytes];
}
else
c = _mapBytesToUnicode[*bytes];
bytes++;
if (c == UNKNOWN_CHAR)
// This is an invalid byte in the ASCII encoding.
*chars = replacementChar;
else
*chars = c;
chars++;
}
// bytes & chars used are the same
if (decoder != null)
decoder.m_bytesUsed = (int)(bytes - byteStart);
return (int)(chars - charStart);
}
// Slower way's going to need a fallback buffer
DecoderFallbackBuffer fallbackBuffer = null;
byte[] byteBuffer = new byte[1];
char* charEnd = chars + charCount;
DecoderFallbackBufferHelper fallbackHelper = new DecoderFallbackBufferHelper(
decoder != null ? decoder.FallbackBuffer : DecoderFallback.CreateFallbackBuffer());
// Not quite so fast loop
while (bytes < byteEnd)
{
// Faster if don't use *bytes++;
char c = _mapBytesToUnicode[*bytes];
bytes++;
// See if it was unknown
if (c == UNKNOWN_CHAR)
{
// Make sure we have a fallback buffer
if (fallbackBuffer == null)
{
if (decoder == null)
fallbackBuffer = DecoderFallback.CreateFallbackBuffer();
else
fallbackBuffer = decoder.FallbackBuffer;
fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
fallbackHelper.InternalInitialize(byteEnd - byteCount, charEnd);
}
// Use fallback buffer
Debug.Assert(bytes > byteStart,
"[SBCSCodePageEncoding.GetChars]Expected bytes to have advanced already (unknown byte)");
byteBuffer[0] = *(bytes - 1);
// Fallback adds fallback to chars, but doesn't increment chars unless the whole thing fits.
if (!fallbackHelper.InternalFallback(byteBuffer, bytes, ref chars))
{
// May or may not throw, but we didn't get this byte
bytes--; // unused byte
fallbackHelper.InternalReset(); // Didn't fall this back
ThrowCharsOverflow(decoder, bytes == byteStart); // throw?
break; // don't throw, but stop loop
}
}
else
{
// Make sure we have buffer space
if (chars >= charEnd)
{
Debug.Assert(bytes > byteStart,
"[SBCSCodePageEncoding.GetChars]Expected bytes to have advanced already (known byte)");
bytes--; // unused byte
ThrowCharsOverflow(decoder, bytes == byteStart); // throw?
break; // don't throw, but stop loop
}
*(chars) = c;
chars++;
}
}
// Might have had decoder fallback stuff.
if (decoder != null)
decoder.m_bytesUsed = (int)(bytes - byteStart);
// Expect Empty fallback buffer for GetChars
Debug.Assert(fallbackBuffer == null || fallbackBuffer.Remaining == 0,
"[SBCSEncoding.GetChars]Expected Empty fallback buffer at end");
return (int)(chars - charStart);
}
public unsafe override int GetCharCount(byte* bytes, int count, DecoderNLS decoder)
{
// Just assert, we're called internally so these should be safe, checked already
Debug.Assert(bytes != null, "[SBCSCodePageEncoding.GetCharCount]bytes is null");
Debug.Assert(count >= 0, "[SBCSCodePageEncoding.GetCharCount]byteCount is negative");
CheckMemorySection();
// See if we have best fit
bool bUseBestFit = false;
// Only need decoder fallback buffer if not using default replacement fallback or best fit fallback.
DecoderReplacementFallback fallback = null;
if (decoder == null)
{
fallback = DecoderFallback as DecoderReplacementFallback;
bUseBestFit = DecoderFallback is InternalDecoderBestFitFallback;
}
else
{
fallback = decoder.Fallback as DecoderReplacementFallback;
bUseBestFit = decoder.Fallback is InternalDecoderBestFitFallback;
Debug.Assert(!decoder.m_throwOnOverflow || !decoder.InternalHasFallbackBuffer ||
decoder.FallbackBuffer.Remaining == 0,
"[SBCSCodePageEncoding.GetChars]Expected empty fallback buffer at start");
}
if (bUseBestFit || (fallback != null && fallback.MaxCharCount == 1))
{
// Just return length, SBCS stay the same length because they don't map to surrogate
// pairs and we don't have a decoder fallback.
return count;
}
// Might need one of these later
DecoderFallbackBuffer fallbackBuffer = null;
DecoderFallbackBufferHelper fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
// Have to do it the hard way.
// Assume charCount will be == count
int charCount = count;
byte[] byteBuffer = new byte[1];
// Do it our fast way
byte* byteEnd = bytes + count;
// Quick loop
while (bytes < byteEnd)
{
// Faster if don't use *bytes++;
char c;
c = _mapBytesToUnicode[*bytes];
bytes++;
// If unknown we have to do fallback count
if (c == UNKNOWN_CHAR)
{
// Must have a fallback buffer
if (fallbackBuffer == null)
{
// Need to adjust count so we get real start
if (decoder == null)
fallbackBuffer = DecoderFallback.CreateFallbackBuffer();
else
fallbackBuffer = decoder.FallbackBuffer;
fallbackHelper = new DecoderFallbackBufferHelper(fallbackBuffer);
fallbackHelper.InternalInitialize(byteEnd - count, null);
}
// Use fallback buffer
byteBuffer[0] = *(bytes - 1);
charCount--; // We'd already reserved one for *(bytes-1)
charCount += fallbackHelper.InternalFallback(byteBuffer, bytes);
}
}
// Fallback buffer must be empty
Debug.Assert(fallbackBuffer == null || fallbackBuffer.Remaining == 0,
"[SBCSEncoding.GetCharCount]Expected Empty fallback buffer at end");
// Converted sequence is same length as input
return charCount;
}