public ConvertStatus ConvertData(ReadOnlySpan <char> inputData, int inputIndex, int inputCount, Span <byte> outputData, int outputIndex, int outputCount, bool flush, out int inputUsed, out int outputUsed)
{
int inputEnd = inputIndex + inputCount;
int outputEnd = outputIndex + outputCount;
inputUsed = outputUsed = 0;
while (true)
{
switch (_currentState)
{
case State.Reset:
Reset();
goto case State.BeginReadingPrefix;
case State.BeginReadingPrefix:
if ((_flags & SettingsFlags.FlagHasPrefixes) == 0)
{
goto case State.BeginReading;
}
_currentState = State.ReadingPrefix;
goto case State.ReadingPrefix;
case State.ReadingPrefix:
{
int matchLength = AffixMatcher.TryMatchAffix(inputData, inputIndex, inputEnd, flush, _decodingPrefixes);
if (matchLength < 0) // need more data..
{
return(ConvertStatus.InputRequired);
}
if ((matchLength == 0) && ((_flags & SettingsFlags.FlagRequirePrefix) != 0))
{
throw new FormatException(Resources.DecoderPrefixRequired);
}
inputIndex += matchLength;
inputUsed += matchLength;
goto case State.BeginReading;
}
case State.BeginReading:
_decodedBits = _decodedCount = 0;
_currentState = State.Reading;
goto case State.Reading;
case State.Reading:
while ((_decodedCount < 8) && (inputIndex < inputEnd))
{
char inputChar = inputData[inputIndex++];
if (inputChar >= 128)
{
if ((_flags & SettingsFlags.FlagIgnoreInvalidCharacters) == 0)
{
throw new FormatException(Resources.DecoderInvalidCharacter);
}
// ignoring invalid characters..
inputUsed++;
continue;
}
do
{
// check the character against the postfix characters, this happens before we
// try to decode (in case the postfix overlaps the alphabet -or- does not)
if ((_decodingAffixTable[inputChar] & 0x02) != 0)
{
int matchLength = AffixMatcher.TryMatchAffix(inputData, inputIndex - 1, inputEnd, flush, _decodingPostfixes);
// incomplete match, need more data...
if (matchLength < 0)
{
return(ConvertStatus.InputRequired);
}
if (matchLength == 0)
{
break;
}
// any match must use all of the remaining input..
if (matchLength != inputEnd - inputIndex + 1)
{
break;
}
// have a match and it's at what appears to be the end of the input, but
// we can't actually accept it unless we're flushing..
if (!flush)
{
return(ConvertStatus.InputRequired);
}
// this is a good match, adjust the indices and move to flushing..
inputIndex += matchLength - 1;
inputUsed += matchLength;
_postfixRead = true;
goto case State.Flushing;
}
} while (false);
// inputChar is always 127 or less here (due to check above)
byte decodedValue = _decodingTable[inputChar];
if ((decodedValue & SettingsCharacterTypes.CharTypeMask) == SettingsCharacterTypes.CharAlphabet)
{
_decodedBits = (_decodedBits << 4) | (uint)(decodedValue & 0x0F);
_decodedCount++;
}
else if (decodedValue != SettingsCharacterTypes.CharSpecialIgnored)
{
// all non-ignored characters are treated as invalid..
if ((_flags & SettingsFlags.FlagIgnoreInvalidCharacters) == 0)
{
throw new FormatException(Resources.DecoderInvalidCharacter);
}
}
inputUsed++;
}
if (_decodedCount == 8)
{
goto case State.BeginWriting;
}
if (flush)
{
goto case State.Flushing;
}
return(ConvertStatus.InputRequired);
case State.BeginWriting:
_currentState = State.Writing;
goto case State.Writing;
case State.Writing:
while ((_decodedCount < 12) && (outputIndex < outputEnd))
{
outputData[outputIndex++] = (byte)((_decodedBits & 0xFF000000) >> 24);
outputUsed++;
_decodedBits <<= 8;
_decodedCount++;
}
if (_decodedCount == 12)
{
goto case State.BeginReading;
}
return(ConvertStatus.OutputRequired);
case State.Flushing:
if ((_decodedCount & 0x01) != 0)
{
// an odd number of input characters is invalid..
if ((_flags & SettingsFlags.FlagIgnoreInvalidFinalQuantum) == 0)
{
throw new FormatException(Resources.DecoderTruncatedQuantum);
}
_decodedBits >>= 4;
_decodedCount--;
}
if (_decodedCount == 0)
{
goto case State.Finished;
}
_decodedBits <<= (int)(8 * (4u - (_decodedCount >> 1)));
_decodedCount = 12u - (_decodedCount >> 1);
goto case State.BeginWriting;
case State.Finished:
if (((_flags & SettingsFlags.FlagRequirePostfix) != 0) && (!_postfixRead))
{
throw new FormatException(Resources.DecoderPostfixRequired);
}
_currentState = State.Reset;
return(ConvertStatus.Complete);
case State.ReturnToPreviousState:
System.Diagnostics.Debug.Assert(_previousState != State.ReturnToPreviousState);
_currentState = _previousState;
_previousState = State.ReturnToPreviousState;
continue;
}
throw new InvalidOperationException("Unreachable code, reached.");
}
}
public ConvertStatus ConvertData(ReadOnlySpan <char> inputData, int inputIndex, int inputCount, Span <byte> outputData, int outputIndex, int outputCount, bool flush, out int inputUsed, out int outputUsed)
{
int inputEnd = inputIndex + inputCount;
int outputEnd = outputIndex + outputCount;
inputUsed = outputUsed = 0;
while (true)
{
switch (_currentState)
{
case State.Reset:
Reset();
goto case State.BeginReadingPrefix;
case State.BeginReadingPrefix:
if ((_flags & SettingsFlags.FlagHasPrefixes) == 0)
{
goto case State.BeginReading;
}
_currentState = State.ReadingPrefix;
goto case State.ReadingPrefix;
case State.ReadingPrefix:
{
int matchLength = AffixMatcher.TryMatchAffix(inputData, inputIndex, inputEnd, flush, _decodingPrefixes);
if (matchLength < 0) // need more data..
{
return(ConvertStatus.InputRequired);
}
if ((matchLength == 0) && ((_flags & SettingsFlags.FlagRequirePrefix) != 0))
{
throw new FormatException(Resources.DecoderPrefixRequired);
}
inputIndex += matchLength;
inputUsed += matchLength;
goto case State.BeginReading;
}
case State.BeginReading:
_decodedBits = _decodedCount = 0;
_currentState = State.Reading;
goto case State.Reading;
case State.ContinueReading:
_currentState = State.Reading;
goto case State.Reading;
case State.Reading:
while ((_decodedCount < 8) && (inputIndex < inputEnd))
{
char inputChar = inputData[inputIndex++];
if (inputChar >= 128)
{
if ((_flags & SettingsFlags.FlagIgnoreInvalidCharacters) == 0)
{
throw new FormatException(Resources.DecoderInvalidCharacter);
}
// ignoring invalid characters..
inputUsed++;
continue;
}
do
{
// check the character against the postfix characters, this happens before we
// try to decode (in case the postfix overlaps the alphabet -or- does not)
if ((_decodingAffixTable[inputChar] & 0x02) != 0)
{
int matchLength = AffixMatcher.TryMatchAffix(inputData, inputIndex - 1, inputEnd, flush, _decodingPostfixes);
// incomplete match, need more data...
if (matchLength < 0)
{
return(ConvertStatus.InputRequired);
}
if (matchLength == 0)
{
break;
}
// any match must use all of the remaining input..
if (matchLength != inputEnd - inputIndex + 1)
{
break;
}
// have a match and it's at what appears to be the end of the input, but
// we can't actually accept it unless we're flushing..
if (!flush)
{
return(ConvertStatus.InputRequired);
}
// this is a good match, adjust the indices and move to flushing..
inputIndex += matchLength - 1;
inputUsed += matchLength;
_postfixRead = true;
goto case State.Flushing;
}
} while (false);
// inputChar is always 127 or less here (due to check above)
byte decodedValue = _decodingTable[inputChar];
if ((decodedValue & SettingsCharacterTypes.CharTypeMask) == SettingsCharacterTypes.CharAlphabet)
{
_decodedBits = (_decodedBits << 5) | (uint)(decodedValue & 0x1F);
_decodedCount++;
}
else if (decodedValue != SettingsCharacterTypes.CharSpecialIgnored)
{
// padding characters are handled in the reading padding state..
if (decodedValue == SettingsCharacterTypes.CharSpecialPadding)
{
goto case State.BeginReadingPadding;
}
// all other characters are considered invalid..
if ((_flags & SettingsFlags.FlagIgnoreInvalidCharacters) == 0)
{
throw new FormatException(Resources.DecoderInvalidCharacter);
}
}
inputUsed++;
}
if (_decodedCount == 8)
{
goto case State.BeginWriting;
}
if (flush)
{
goto case State.Flushing;
}
return(ConvertStatus.InputRequired);
case State.BeginWriting:
_currentState = State.Writing;
goto case State.Writing;
case State.Writing:
while ((_decodedCount < 13) && (outputIndex < outputEnd))
{
outputData[outputIndex++] = (byte)((_decodedBits & 0xFF00000000ul) >> 32);
outputUsed++;
_decodedBits <<= 8;
_decodedCount++;
}
if (_decodedCount == 13)
{
goto case State.BeginReading;
}
return(ConvertStatus.OutputRequired);
case State.BeginReadingPadding:
// determine the amount of padding that we should expect if this is the
// final quantum of the input..
_paddingRead = 1;
_paddingRequired = Base32Codec.PadInfo[PadInfoDecoding, _decodedCount];
if ((_paddingRequired == 0) && ((_flags & SettingsFlags.FlagIgnoreInvalidPadding) == 0))
{
throw new FormatException(Resources.DecoderInvalidPadding);
}
// reading state doesn't "use" the first padding character, so we have to..
inputUsed++;
_currentState = State.ReadingPadding;
goto case State.ReadingPadding;
case State.ReadingPadding:
while (inputIndex < inputEnd)
{
char inputChar = inputData[inputIndex++];
if (inputChar >= 128)
{
// character is invalid, if we're ignoring invalid characters then we can just keep
// going otherwise, now is the time to fail..
if ((_flags & SettingsFlags.FlagIgnoreInvalidCharacters) == 0)
{
throw new FormatException(Resources.DecoderInvalidCharacter);
}
inputUsed++;
continue;
}
do
{
// check the input character against the affix table, if it is the start of
// a possible postfix, try to match it..
if ((_decodingAffixTable[inputChar] & 0x02) != 0)
{
// match the input data against the postfixes..
int matchLength = AffixMatcher.TryMatchAffix(inputData, inputIndex - 1, inputEnd, flush, _decodingPostfixes);
if (matchLength < 0)
{
return(ConvertStatus.InputRequired); // need more data to determine
}
if (matchLength == 0)
{
break; // definative non-match
}
// any match must use all of the remaining input..
if (matchLength != inputEnd - inputIndex + 1)
{
break;
}
// have a match and it's at what appears to be the end of the input, but
// we can't actually accept it unless we're flushing..
if (!flush)
{
return(ConvertStatus.InputRequired);
}
// this is a good match, adjust the indices and move to flushing..
inputIndex += matchLength - 1;
inputUsed += matchLength;
_postfixRead = true;
goto case State.Flushing;
}
} while (false);
// inputChar is always 127 or less here (due to check above)
byte decodedValue = _decodingTable[inputChar];
if (decodedValue == SettingsCharacterTypes.CharSpecialPadding)
{
_paddingRead++;
if (_paddingRead > _paddingRequired)
{
if ((_flags & SettingsFlags.FlagIgnoreInvalidPadding) == 0)
{
throw new FormatException(Resources.DecoderInvalidPadding);
}
// reset _paddingRead so that we don't overflow it..
_paddingRead = (byte)(_paddingRequired + 1);
}
inputUsed++;
continue;
}
else if ((decodedValue & SettingsCharacterTypes.CharTypeMask) == SettingsCharacterTypes.CharAlphabet)
{
// all of the padding that we've read is invalid...
if ((_flags & SettingsFlags.FlagIgnoreInvalidPadding) == 0)
{
throw new FormatException(Resources.DecoderInvalidPadding);
}
// go back to the reading state..
_paddingRead = 0;
inputIndex--;
goto case State.ContinueReading;
}
else if ((decodedValue == SettingsCharacterTypes.CharSpecialIgnored) || ((_flags & SettingsFlags.FlagIgnoreInvalidCharacters) != 0))
{
// always ignored character, or invalid character that we are ignoring...
inputUsed++;
continue;
}
// anything else is an invalid character..
throw new FormatException(Resources.DecoderInvalidCharacter);
}
// we only reach this point if we've run out of input..
if (flush)
{
goto case State.Flushing;
}
return(ConvertStatus.InputRequired);
case State.Flushing:
{
bool invalidQuantum = (PadInfo[PadInfoUnusedBits, _decodedCount] >= 5);
if (invalidQuantum)
{
// an incorrect number of characters in the last quantum..
if ((_flags & SettingsFlags.FlagIgnoreInvalidFinalQuantum) == 0)
{
throw new FormatException(Resources.DecoderTruncatedQuantum);
}
// if we require padding, then this is an error state, because there is no correct
// padding for an invalid last quantum..
if ((_flags & SettingsFlags.FlagRequirePadding) != 0)
{
throw new FormatException(Resources.DecoderInvalidPadding);
}
// remove characters from the quantum to make it "valid" and adjust the decoded bits
// appropriately..
var toRemove = PadInfo[PadInfoRemove, _decodedCount];
_decodedCount -= toRemove;
_decodedBits >>= (toRemove * 5);
}
if ((_flags & SettingsFlags.FlagRequirePadding) != 0)
{
// valid padding is required, there are few problems here. First is that
// we may have an invalid quantum, which means any padding is invalid
var requiredPadding = PadInfo[PadInfoDecoding, _decodedCount];
if (_paddingRead < requiredPadding)
{
throw new FormatException(Resources.DecoderPaddingRequired);
}
else if ((_paddingRead > requiredPadding) && ((_flags & SettingsFlags.FlagIgnoreInvalidPadding) == 0))
{
throw new FormatException(Resources.DecoderInvalidPadding);
}
}
}
if (_decodedCount == 0)
{
goto case State.Finished;
}
if ((_flags & SettingsFlags.FlagRequireTrailingZeroBits) != 0)
{
// ensure that the unused trailing bits are all zero, this can detect truncation
// in some cases ..
uint unusedBits = (1u << PadInfo[PadInfoUnusedBits, _decodedCount]) - 1u;
if ((_decodedBits & unusedBits) != 0)
{
throw new FormatException(Resources.DecoderUnusedBitNonZero);
}
}
// adjust decodedBits and decodedCount so that we can flush the final quantum..
_decodedBits <<= (int)(40u - (5u * _decodedCount));
_decodedCount = 13u - ((5u * _decodedCount) >> 3);
goto case State.BeginWriting;
case State.Finished:
if (((_flags & SettingsFlags.FlagRequirePostfix) != 0) && (!_postfixRead))
{
throw new FormatException(Resources.DecoderPostfixRequired);
}
_currentState = State.Reset;
return(ConvertStatus.Complete);
case State.ReturnToPreviousState:
System.Diagnostics.Debug.Assert(_previousState != State.ReturnToPreviousState);
_currentState = _previousState;
_previousState = State.ReturnToPreviousState;
continue;
}
throw new InvalidOperationException("Unreachable code, reached.");
}
}
public ConvertStatus ConvertData(ReadOnlySpan <char> inputData, int inputIndex, int inputCount, Span <byte> outputData, int outputIndex, int outputCount, bool flush, out int inputUsed, out int outputUsed)
{
int inputEnd = inputIndex + inputCount;
int outputEnd = outputIndex + outputCount;
inputUsed = outputUsed = 0;
while (true)
{
switch (_currentState)
{
case State.Reset:
Reset();
goto case State.BeginReadingPrefix;
case State.BeginReadingPrefix:
if ((_flags & SettingsFlags.FlagHasPrefixes) == 0)
{
goto case State.BeginReading;
}
_currentState = State.ReadingPrefix;
goto case State.ReadingPrefix;
case State.ReadingPrefix:
{
int matchLength = AffixMatcher.TryMatchAffix(inputData, inputIndex, inputEnd, flush, _decodingPrefixes);
if (matchLength < 0) // need more data..
{
return(ConvertStatus.InputRequired);
}
if ((matchLength == 0) && ((_flags & SettingsFlags.FlagRequirePrefix) != 0))
{
throw new FormatException(Resources.DecoderPrefixRequired);
}
inputIndex += matchLength;
inputUsed += matchLength;
goto case State.BeginReading;
}
case State.BeginReading:
_decodedBits = _decodedCount = 0;
_currentState = State.Reading;
goto case State.Reading;
case State.Reading:
while ((_decodedCount < 5) && (inputIndex < inputEnd))
{
char inputChar = inputData[inputIndex++];
if (inputChar >= 128)
{
if ((_flags & SettingsFlags.FlagIgnoreInvalidCharacters) == 0)
{
throw new FormatException(Resources.DecoderInvalidCharacter);
}
// ignoring invalid characters..
inputUsed++;
continue;
}
do
{
// check the character against the postfix characters, this happens before we
// try to decode (in case the postfix overlaps the alphabet -or- does not)
if ((_decodingAffixTable[inputChar] & 0x02) != 0)
{
int matchLength = AffixMatcher.TryMatchAffix(inputData, inputIndex - 1, inputEnd, flush, _decodingPostfixes);
// incomplete match, need more data...
if (matchLength < 0)
{
return(ConvertStatus.InputRequired);
}
if (matchLength == 0)
{
break;
}
// any match must use all of the remaining input..
if (matchLength != inputEnd - inputIndex + 1)
{
break;
}
// have a match and it's at what appears to be the end of the input, but
// we can't actually accept it unless we're flushing..
if (!flush)
{
return(ConvertStatus.InputRequired);
}
// this is a good match, adjust the indices and move to flushing..
inputIndex += matchLength - 1;
inputUsed += matchLength;
_postfixRead = true;
goto case State.Flushing;
}
} while (false);
// inputChar is always 127 or less here (due to check above)
byte decodedValue = _decodingTable[inputChar];
if ((decodedValue & SettingsCharacterTypes.CharTypeMask) == SettingsCharacterTypes.CharAlphabet)
{
_decodedBits = (_decodedBits * 85) + decodedValue;
_decodedCount++;
}
else if ((decodedValue >= SettingsCharacterTypes.CharSpecialZ) && (_decodedCount == 0))
{
if (decodedValue == SettingsCharacterTypes.CharSpecialY)
{
_decodedBits = 0x20202020ul;
}
// special characters are abbreviations for
_decodedCount = 5;
}
else if (decodedValue != SettingsCharacterTypes.CharSpecialIgnored)
{
// all non-ignored characters are treated as invalid..
if ((_flags & SettingsFlags.FlagIgnoreInvalidCharacters) == 0)
{
throw new FormatException(Resources.DecoderInvalidCharacter);
}
}
inputUsed++;
}
if (_decodedCount == 5)
{
goto case State.BeginWriting;
}
if (flush)
{
goto case State.Flushing;
}
return(ConvertStatus.InputRequired);
case State.BeginWriting:
if (_decodedBits > uint.MaxValue)
{
// 5 digits of base85 can exceed the maximum uint value, if it does, the encoding
// is bad (but we can ignore if configured to do so)
if ((_flags & SettingsFlags.FlagIgnoreOverflow) == 0)
{
throw new FormatException(Resources.DecoderOverflow);
}
// ignoring overflow, discard any overflow bits .. anything we do here is going to
// produce the "wrong" value (since we have no way of knowing what the correct value
// is supposed to be)
_decodedBits &= 0xFFFFFFFF;
}
_currentState = State.Writing;
goto case State.Writing;
case State.Writing:
while ((_decodedCount < 9) && (outputIndex < outputEnd))
{
outputData[outputIndex++] = (byte)((_decodedBits & 0xFF000000ul) >> 24);
outputUsed++;
_decodedBits <<= 8;
_decodedCount++;
}
if (_decodedCount == 9)
{
goto case State.BeginReading;
}
return(ConvertStatus.OutputRequired);
case State.Flushing:
if (_decodedCount == 0)
{
goto case State.Finished;
}
if (((_flags & SettingsFlags.FlagRequireCompleteFinalQuantum) != 0) || (_decodedCount == 1))
{
// configured to require a full quantum even at the end, if we're not
// ignoring invalid quantums then we're in an error state.. or the quantum
// is actually invalid (decodedCount == 1)
if ((_flags & SettingsFlags.FlagIgnoreInvalidFinalQuantum) == 0)
{
throw new FormatException(Resources.DecoderTruncatedQuantum);
}
// nothing more to write..
goto case State.Finished;
}
{
int paddingCount = 5 - (int)_decodedCount;
for (int padCount = 0; padCount < paddingCount; padCount++)
{
_decodedBits = (_decodedBits * 85) + 84;
}
// adjust decodedCount to write the correct number of bytes..
_decodedCount = 5u + (uint)paddingCount;
}
goto case State.BeginWriting;
case State.Finished:
if (((_flags & SettingsFlags.FlagRequirePostfix) != 0) && (!_postfixRead))
{
throw new FormatException(Resources.DecoderPostfixRequired);
}
_currentState = State.Reset;
return(ConvertStatus.Complete);
case State.ReturnToPreviousState:
System.Diagnostics.Debug.Assert(_previousState != State.ReturnToPreviousState);
_currentState = _previousState;
_previousState = State.ReturnToPreviousState;
continue;
}
throw new InvalidOperationException("Unreachable code, reached.");
}
}
