TUN-3403: Unit test for origin/proxy to test serving HTTP and Websocket

vendor/github.com/gobwas/pool/pbufio/pbufio_go19.go

@@ -0,0 +1,27 @@
+// +build !go1.10
+
+package pbufio
+
+import "bufio"
+
+func writerSize(bw *bufio.Writer) int {
+	return bw.Available() + bw.Buffered()
+}
+
+// readerSize returns buffer size of the given buffered reader.
+// NOTE: current workaround implementation resets underlying io.Reader.
+func readerSize(br *bufio.Reader) int {
+	br.Reset(sizeReader)
+	br.ReadByte()
+	n := br.Buffered() + 1
+	br.Reset(nil)
+	return n
+}
+
+var sizeReader optimisticReader
+
+type optimisticReader struct{}
+
+func (optimisticReader) Read(p []byte) (int, error) {
+	return len(p), nil
+}