Updated dpcore

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

src/mod/dynamicproxy/dpcore/maxLatencyWriter.go

@@ -0,0 +1,73 @@
+package dpcore
+
+/*
+
+Max Latency Writer
+
+This script implements a io writer with periodic flushing base on a ticker
+Mostly based on httputil.ReverseProxy
+
+*/
+
+import (
+	"io"
+	"sync"
+	"time"
+)
+
+type maxLatencyWriter struct {
+	dst          io.Writer
+	flush        func() error
+	latency      time.Duration // non-zero; negative means to flush immediately
+	mu           sync.Mutex    // protects t, flushPending, and dst.Flush
+	t            *time.Timer
+	flushPending bool
+}
+
+func (m *maxLatencyWriter) Write(p []byte) (n int, err error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	n, err = m.dst.Write(p)
+	if m.latency < 0 {
+		//Flush immediately
+		m.flush()
+		return
+	}
+
+	if m.flushPending {
+		//Flush in next tick cycle
+		return
+	}
+
+	if m.t == nil {
+		m.t = time.AfterFunc(m.latency, m.delayedFlush)
+	} else {
+		m.t.Reset(m.latency)
+	}
+
+	m.flushPending = true
+	return
+
+}
+
+func (m *maxLatencyWriter) delayedFlush() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if !m.flushPending {
+		// if stop was called but AfterFunc already started this goroutine
+		return
+	}
+
+	m.flush()
+	m.flushPending = false
+}
+
+func (m *maxLatencyWriter) stop() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	m.flushPending = false
+	if m.t != nil {
+		m.t.Stop()
+	}
+}