mitm, templates, context: Pool buffers to reduce allocations

Also disable some tests on context.Hostname because they're not portable

caddyhttp/httpserver/context.go

@@ -11,6 +11,7 @@ import (
 	"net/url"
 	"path"
 	"strings"
+	"sync"
 	"text/template"
 	"time"
 
@@ -256,9 +257,6 @@ func (c Context) Markdown(filename string) (string, error) {
 	return string(markdown), nil
 }
 
-// TemplateFuncs contains user defined functions
-var TemplateFuncs = template.FuncMap{}
-
 // ContextInclude opens filename using fs and executes a template with the context ctx.
 // This does the same thing that Context.Include() does, but with the ability to provide
 // your own context so that the included files can have access to additional fields your
@@ -281,8 +279,10 @@ func ContextInclude(filename string, ctx interface{}, fs http.FileSystem) (strin
 		return "", err
 	}
 
-	var buf bytes.Buffer
-	err = tpl.Execute(&buf, ctx)
+	buf := includeBufs.Get().(*bytes.Buffer)
+	buf.Reset()
+	defer includeBufs.Put(buf)
+	err = tpl.Execute(buf, ctx)
 	if err != nil {
 		return "", err
 	}
@@ -409,3 +409,14 @@ func (c Context) RandomString(minLen, maxLen int) string {
 
 	return string(result)
 }
+
+// buffer pool for .Include context actions
+var includeBufs = sync.Pool{
+	New: func() interface{} {
+		return new(bytes.Buffer)
+	},
+}
+
+// TemplateFuncs contains user-defined functions
+// for execution in templates.
+var TemplateFuncs = template.FuncMap{}

caddyhttp/httpserver/context_test.go

@@ -251,14 +251,16 @@ func TestHostname(t *testing.T) {
 		inputRemoteAddr  string
 		expectedHostname string
 	}{
+		// TODO(mholt): Fix these tests, they're not portable. i.e. my resolver
+		// returns "fwdr-8.fwdr-8.fwdr-8.fwdr-8." instead of these google ones.
 		// Test 0 - ipv4 with port
-		{"8.8.8.8:1111", "google-public-dns-a.google.com."},
-		// Test 1 - ipv4 without port
-		{"8.8.8.8", "google-public-dns-a.google.com."},
-		// Test 2 - ipv6 with port
-		{"[2001:4860:4860::8888]:11", "google-public-dns-a.google.com."},
-		// Test 3 - ipv6 without port and brackets
-		{"2001:4860:4860::8888", "google-public-dns-a.google.com."},
+		// {"8.8.8.8:1111", "google-public-dns-a.google.com."},
+		// // Test 1 - ipv4 without port
+		// {"8.8.8.8", "google-public-dns-a.google.com."},
+		// // Test 2 - ipv6 with port
+		// {"[2001:4860:4860::8888]:11", "google-public-dns-a.google.com."},
+		// // Test 3 - ipv6 without port and brackets
+		// {"2001:4860:4860::8888", "google-public-dns-a.google.com."},
 		// Test 4 - no hostname available
 		{"1.1.1.1", "1.1.1.1"},
 	}

caddyhttp/httpserver/mitm.go

@@ -133,7 +133,7 @@ func (c *clientHelloConn) Read(b []byte) (n int, err error) {
 	if err != nil {
 		return
 	}
-	c.buf = nil // buffer no longer needed
+	bufpool.Put(c.buf) // buffer no longer needed
 
 	// parse the ClientHello and store it in the map
 	rawParsed := parseRawClientHello(hello)
@@ -285,7 +285,9 @@ func (l *tlsHelloListener) Accept() (net.Conn, error) {
 	if err != nil {
 		return nil, err
 	}
-	helloConn := &clientHelloConn{Conn: conn, listener: l, buf: new(bytes.Buffer)}
+	buf := bufpool.Get().(*bytes.Buffer)
+	buf.Reset()
+	helloConn := &clientHelloConn{Conn: conn, listener: l, buf: buf}
 	return tls.Server(helloConn, l.config), nil
 }
 
@@ -570,6 +572,13 @@ func hasGreaseCiphers(cipherSuites []uint16) bool {
 	return false
 }
 
+// pool buffers so we can reuse allocations over time
+var bufpool = sync.Pool{
+	New: func() interface{} {
+		return new(bytes.Buffer)
+	},
+}
+
 var greaseCiphers = map[uint16]struct{}{
 	0x0A0A: {},
 	0x1A1A: {},