Microsoft.AspNet.Server.Kestrel.Infrastructure.MemoryPoolIterator2.Take C# (CSharp) Method

        public int Take()
        {
            if (_block == null)
            {
                return -1;
            }
            else if (_index < _block.End)
            {
                return _block.Array[_index++];
            }

            var block = _block;
            var index = _index;
            while (true)
            {
                if (index < block.End)
                {
                    _block = block;
                    _index = index + 1;
                    return block.Array[index];
                }
                else if (block.Next == null)
                {
                    return -1;
                }
                else
                {
                    block = block.Next;
                    index = block.Start;
                }
            }
        }

        /// <summary>
        /// Checks 9 bytes from <paramref name="begin"/>  correspond to a known HTTP version.
        /// </summary>
        /// <remarks>
        /// A "known HTTP version" Is is either HTTP/1.0 or HTTP/1.1.
        /// Since those fit in 8 bytes, they can be optimally looked up by reading those bytes as a long. Once
        /// in that format, it can be checked against the known versions.
        /// The Known versions will be checked with the required '\r'.
        /// To optimize performance the HTTP/1.1 will be checked first.
        /// </remarks>
        /// <param name="begin">The iterator from which to start the known string lookup.</param>
        /// <param name="scan">If we found a valid method, then scan will be updated to new position</param>
        /// <param name="knownMethod">A reference to a pre-allocated known string, if the input matches any.</param>
        /// <returns><c>true</c> if the input matches a known string, <c>false</c> otherwise.</returns>
        public static bool GetKnownVersion(this MemoryPoolIterator2 begin, ref MemoryPoolIterator2 scan, out string knownVersion)
        {
            knownVersion = null;
            var value = begin.PeekLong();

            if (value == _http11VersionLong)
            {
                knownVersion = Http11Version;
                scan.Skip(8);
                if (scan.Take() == '\r')
                {
                    return(true);
                }
            }
            else if (value == _http10VersionLong)
            {
                knownVersion = Http10Version;
                scan.Skip(8);
                if (scan.Take() == '\r')
                {
                    return(true);
                }
            }

            knownVersion = null;
            return(false);
        }