Updated dpcore

- Added immediate flush for buffer (i.e. no chunked encoding)
- Added support for stream mode proxy sniffing logic

src/mod/dynamicproxy/dpcore/flush.go

@@ -0,0 +1,38 @@
+package dpcore
+
+import (
+	"mime"
+	"net/http"
+	"time"
+)
+
+// Auto sniff of flush interval from header
+func (p *ReverseProxy) getFlushInterval(req *http.Request, res *http.Response) time.Duration {
+	contentType := req.Header.Get("Content-Type")
+	if actualContentType, _, _ := mime.ParseMediaType(contentType); actualContentType == "text/event-stream" {
+		return -1
+	}
+
+	if req.ContentLength == -1 || p.isBidirectionalStream(req, res) {
+		return -1
+	}
+
+	//Cannot sniff anything. Use default value
+	return p.FlushInterval
+
+}
+
+// Check for bidirectional stream, copy from Caddy :D
+func (p *ReverseProxy) isBidirectionalStream(req *http.Request, res *http.Response) bool {
+	// We have to check the encoding here; only flush headers with identity encoding.
+	// Non-identity encoding might combine with "encode" directive, and in that case,
+	// if body size larger than enc.MinLength, upper level encode handle might have
+	// Content-Encoding header to write.
+	// (see https://github.com/caddyserver/caddy/issues/3606 for use case)
+	ae := req.Header.Get("Accept-Encoding")
+
+	return req.ProtoMajor == 2 &&
+		res.ProtoMajor == 2 &&
+		res.ContentLength == -1 &&
+		(ae == "identity" || ae == "")
+}