System.Web.HttpRequest.BufferlessInputStream.Read C# (CSharp) Method

			public override int Read (byte [] buffer, int offset, int count)
			{
				if (buffer == null)
					throw new ArgumentNullException ("buffer");

				if (offset < 0 || count < 0)
					throw new ArgumentOutOfRangeException ("offset or count less than zero.");

				if (buffer.Length - offset < count )
					throw new ArgumentException ("offset+count",
								     "The size of the buffer is less than offset + count.");

				if (count == 0 || request.worker_request == null)
					return 0;

				if (!checked_maxRequestLength) {
					int content_length_kb = content_length / 1024;
					HttpRuntimeSection config = HttpRuntime.Section;
					if (content_length_kb > config.MaxRequestLength)
						throw HttpException.NewWithCode (400, "Upload size exceeds httpRuntime limit.", WebEventCodes.RuntimeErrorPostTooLarge);
					else
						checked_maxRequestLength = true;
				}

				// Serve the bytes we might have preloaded already.
				if (!preloaded_served) {
					if (preloadedBuffer == null)
						preloadedBuffer = request.worker_request.GetPreloadedEntityBody ();

					if (preloadedBuffer != null) {
						long bytes_left = preloadedBuffer.Length-position;
						int n = (int) Math.Min (count, bytes_left);
						Array.Copy (preloadedBuffer, position, buffer, offset, n);
						position += n;

						if (n == bytes_left)
							preloaded_served = true;

						return n;
					}
					else
						preloaded_served = true;
				}

				// serve bytes from worker request if available
				if (position < content_length) {
					long bytes_left = content_length-position;
					int n = count;

					if (bytes_left < count)
						n = (int) bytes_left;

					int bytes_read = request.worker_request.ReadEntityBody (buffer, offset, n);
					position += bytes_read;
					return bytes_read;
				}

				return 0;
			}