Add doppel and tls packages

mtglib/internal/doppel/init.go

@@ -0,0 +1,38 @@
+package doppel
+
+import (
+	"context"
+	"net/http"
+	"time"
+
+	"github.com/9seconds/mtg/v2/essentials"
+	"github.com/9seconds/mtg/v2/mtglib/internal/tls"
+)
+
+const (
+	// Please see Stats description
+	// https://blog.cloudflare.com/optimizing-tls-over-tcp-to-reduce-latency/
+	// https://github.com/cloudflare/sslconfig/blob/master/patches/nginx__dynamic_tls_records.patch
+	TLSRecordSizeStart = 1369
+	TLSRecordSizeAccel = 4229
+	TLSRecordSizeMax   = 16384 - tls.SizeHeader
+
+	TLSCounterAccelAfter = 40
+	TLSCounterMaxAfter   = TLSCounterAccelAfter + 20
+
+	TLSRecordSizeResetAfter = time.Second
+)
+
+// copypasted from mtglib
+type Network interface {
+	// Dial establishes context-free TCP connections.
+	Dial(network, address string) (essentials.Conn, error)
+
+	// DialContext dials using a context. This is a preferrable way of
+	// establishing TCP connections.
+	DialContext(ctx context.Context, network, address string) (essentials.Conn, error)
+
+	// MakeHTTPClient build an HTTP client with given dial function. If nothing is
+	// provided, then DialContext of this interface is going to be used.
+	MakeHTTPClient(func(ctx context.Context, network, address string) (essentials.Conn, error)) *http.Client
+}