unsafe public override int GetByteCount(char[] chars, int index, int count)
{
if (chars == null)
throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentNullException(nameof(chars)));
if (index < 0)
throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentOutOfRangeException(nameof(index), SR.Format(SR.ValueMustBeNonNegative)));
if (index > chars.Length)
throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentOutOfRangeException(nameof(index), SR.Format(SR.OffsetExceedsBufferSize, chars.Length)));
if (count < 0)
throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentOutOfRangeException(nameof(count), SR.Format(SR.ValueMustBeNonNegative)));
if (count > chars.Length - index)
throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentOutOfRangeException(nameof(count), SR.Format(SR.SizeExceedsRemainingBufferSpace, chars.Length - index)));
if (count == 0)
return 0;
if ((count % 4) != 0)
throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new FormatException(SR.Format(SR.XmlInvalidBase64Length, count.ToString(NumberFormatInfo.CurrentInfo))));
fixed (byte* _char2val = s_char2val)
{
fixed (char* _chars = &chars[index])
{
int totalCount = 0;
char* pch = _chars;
char* pchMax = _chars + count;
while (pch < pchMax)
{
DiagnosticUtility.DebugAssert(pch + 4 <= pchMax, "");
char pch0 = pch[0];
char pch1 = pch[1];
char pch2 = pch[2];
char pch3 = pch[3];
if ((pch0 | pch1 | pch2 | pch3) >= 128)
throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new FormatException(SR.Format(SR.XmlInvalidBase64Sequence, new string(pch, 0, 4), index + (int)(pch - _chars))));
// xx765432 xx107654 xx321076 xx543210
// 76543210 76543210 76543210
int v1 = _char2val[pch0];
int v2 = _char2val[pch1];
int v3 = _char2val[pch2];
int v4 = _char2val[pch3];
if (!IsValidLeadBytes(v1, v2, v3, v4) || !IsValidTailBytes(v3, v4))
throw System.Runtime.Serialization.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new FormatException(SR.Format(SR.XmlInvalidBase64Sequence, new string(pch, 0, 4), index + (int)(pch - _chars))));
int byteCount = (v4 != 64 ? 3 : (v3 != 64 ? 2 : 1));
totalCount += byteCount;
pch += 4;
}
return totalCount;
}
}
}
