// For multi-segment parsing of a read only sequence
private void ParseValuesSlow(
ref ReadOnlySequence <byte> buffer,
ref KeyValueAccumulator accumulator,
bool isFinalBlock)
{
var sequenceReader = new SequenceReader <byte>(buffer);
var consumed = sequenceReader.Position;
var equalsDelimiter = GetEqualsForEncoding();
var andDelimiter = GetAndForEncoding();
while (!sequenceReader.End)
{
// TODO seems there is a bug with TryReadTo (advancePastDelimiter: true). It isn't advancing past the delimiter on second read.
if (!sequenceReader.TryReadTo(out ReadOnlySequence <byte> key, equalsDelimiter, advancePastDelimiter: false) ||
!sequenceReader.IsNext(equalsDelimiter, true))
{
if (sequenceReader.Consumed > KeyLengthLimit)
{
ThrowKeyTooLargeException();
}
break;
}
if (key.Length > KeyLengthLimit)
{
ThrowKeyTooLargeException();
}
if (!sequenceReader.TryReadTo(out ReadOnlySequence <byte> value, andDelimiter, false) ||
!sequenceReader.IsNext(andDelimiter, true))
{
if (!isFinalBlock)
{
if (sequenceReader.Consumed - key.Length > ValueLengthLimit)
{
ThrowValueTooLargeException();
}
break;
}
value = buffer.Slice(sequenceReader.Position);
sequenceReader.Advance(value.Length);
}
if (value.Length > ValueLengthLimit)
{
ThrowValueTooLargeException();
}
// Need to call ToArray if the key/value spans multiple segments
var decodedKey = GetDecodedStringFromReadOnlySequence(key);
var decodedValue = GetDecodedStringFromReadOnlySequence(value);
AppendAndVerify(ref accumulator, decodedKey, decodedValue);
consumed = sequenceReader.Position;
}
buffer = buffer.Slice(consumed);
}
// Fast parsing for single span in ReadOnlySequence
private void ParseFormValuesFast(ReadOnlySpan <byte> span,
ref KeyValueAccumulator accumulator,
bool isFinalBlock,
out int consumed)
{
ReadOnlySpan <byte> key = default;
ReadOnlySpan <byte> value = default;
consumed = 0;
var equalsDelimiter = GetEqualsForEncoding();
var andDelimiter = GetAndForEncoding();
while (span.Length > 0)
{
var equals = span.IndexOf(equalsDelimiter);
if (equals == -1)
{
if (span.Length > KeyLengthLimit)
{
ThrowKeyTooLargeException();
}
break;
}
if (equals > KeyLengthLimit)
{
ThrowKeyTooLargeException();
}
key = span.Slice(0, equals);
span = span.Slice(key.Length + equalsDelimiter.Length);
value = span;
var ampersand = span.IndexOf(andDelimiter);
if (ampersand == -1)
{
if (span.Length > ValueLengthLimit)
{
ThrowValueTooLargeException();
return;
}
if (!isFinalBlock)
{
// We can't know that what is currently read is the end of the form value, that's only the case if this is the final block
// If we're not in the final block, then consume nothing
break;
}
// If we are on the final block, the remaining content in value is what we want to add to the KVAccumulator.
// Clear out the remaining span such that the loop will exit.
span = Span <byte> .Empty;
}
else
{
if (ampersand > ValueLengthLimit)
{
ThrowValueTooLargeException();
}
value = span.Slice(0, ampersand);
span = span.Slice(ampersand + andDelimiter.Length);
}
var decodedKey = GetDecodedString(key);
var decodedValue = GetDecodedString(value);
AppendAndVerify(ref accumulator, decodedKey, decodedValue);
// Cover case where we don't have an ampersand at the end.
consumed += key.Length + value.Length + (ampersand == -1 ? equalsDelimiter.Length : equalsDelimiter.Length + andDelimiter.Length);
}
}
