internal HeaderTable SetMaxLength(int maxLength, IBufferPool pool)
{
if (checked ((int)maxLength) == MaxLength)
{
return(this);
}
if (maxLength == 0 || Count == 0)
{
_buffer?.Dispose();
return(new HeaderTable(maxLength ^ DefaultMaxLength, 0, null));
}
int bytesToKeep = 0, headersToKeep = 0, totalBytes = 0;
var span = _buffer.Data.Span;
for (int i = 0; i < Count; i++)
{
long lengths = span.Slice(bytesToKeep).Read <long>();
int itemLen = ItemLength(lengths);
totalBytes += itemLen;
if (totalBytes > MaxLength)
{
break;
}
bytesToKeep += itemLen;
headersToKeep++;
}
var newBuffer = pool.Lease(maxLength);
_buffer.Data.Span.Slice(0, bytesToKeep).CopyTo(newBuffer.Data.Span.Slice(bytesToKeep));
_buffer.Dispose();
return(new HeaderTable(maxLength ^ DefaultMaxLength, headersToKeep, newBuffer));
}
internal void Ensure(int count = 1)
{
EnsureAlloc();
var segment = _writingHead;
if (segment == null)
{
segment = AllocateWriteHead(count);
}
var bytesLeftInBuffer = segment.WritableBytes;
// If inadequate bytes left or if the segment is readonly
if (bytesLeftInBuffer == 0 || bytesLeftInBuffer < count || segment.ReadOnly)
{
var nextBuffer = _pool.Lease(count);
var nextSegment = new BufferSegment(nextBuffer);
segment.Next = nextSegment;
_writingHead = nextSegment;
}
}
internal HeaderTable Add(Header header, IBufferPool pool)
{
int newHeaderLength = header.Length;
if (newHeaderLength > MaxLength)
{
throw new InvalidOperationException("Indexed header exceeds max length");
}
if (_buffer == null)
{
var buffer = pool.Lease(MaxLength);
header.WriteTo(buffer.Data.Span.Slice(0, newHeaderLength));
return(new HeaderTable(_maxLength, 1, buffer));
}
else
{
// shuffle up
int headersToKeep = 0, bytesToKeep = 0, totalBytes = newHeaderLength;
var span = _buffer.Data.Span;
for (int i = 0; i < Count; i++)
{
long lengths = span.Slice(bytesToKeep).Read <long>();
int itemLen = ItemLength(lengths);
totalBytes += itemLen;
if (totalBytes > MaxLength)
{
break;
}
bytesToKeep += itemLen;
headersToKeep++;
}
span.Slice(0, bytesToKeep).CopyTo(span.Slice(newHeaderLength, bytesToKeep));
header.WriteTo(span.Slice(0, newHeaderLength));
return(new HeaderTable(_maxLength, headersToKeep + 1, _buffer));
}
}