/// <summary>
/// Find the begging of the message payload. Possible header before start delimiter will be removed from the message
/// </summary>
/// <param name="readBytes">Number of bytes read from the stream</param>
/// <param name="context">Read context</param>
/// <returns>True if start was found, otherwise false</returns>
private bool FindStart(int readBytes, DelimitedMessageContext context)
{
if (StartDelimiter.Length == 0)
{
return(true);
}
var searchStart = context.CurrentIndex > StartDelimiter.Length ? context.CurrentIndex - StartDelimiter.Length : 0;
var searchEnd = (context.CurrentIndex + readBytes) - StartDelimiter.Length;
// Skip non protocol related boiler plate at message start
for (var index = searchStart; index <= searchEnd; index++)
{
var segment = new ArraySegment <byte>(context.ReadBuffer, index, StartDelimiter.Length);
if (!StartDelimiter.SequenceEqual(segment))
{
continue;
}
context.MessageStart = index;
return(true);
}
return(false);
}
/// <summary>
/// Move message overlap to front of read buffer and reset the context
/// </summary>
/// <param name="readBytes">Number of bytes read from the stream. Used to calculate overlap</param>
/// <param name="context">Message context</param>
/// <returns>Overlap bytes - used for recursive stream processing</returns>
private static int ResetContext(int readBytes, DelimitedMessageContext context)
{
// Move shit to front of buffer if we have overlap
// Entire read buffer Full first message
var overlap = (readBytes + context.CurrentIndex) - (context.MessageEnd + 1);
if (overlap > 0)
{
Buffer.BlockCopy(context.ReadBuffer, context.MessageEnd + 1, context.ReadBuffer, 0, overlap);
}
// Reset message
context.StartFound = false;
context.MessageStart = 0;
context.CurrentIndex = 0;
return(overlap);
}
