initial middleware refactor

server/server.go

@@ -0,0 +1,54 @@
+// Copyright 2016 The Chihaya Authors. All rights reserved.
+// Use of this source code is governed by the BSD 2-Clause license,
+// which can be found in the LICENSE file.
+
+// Package server implements an abstraction over servers meant to be run       .
+// alongside a tracker.
+//
+// Servers may be implementations of different transport protocols or have their
+// own custom behavior.
+package server
+
+import (
+	"fmt"
+
+	"github.com/chihaya/chihaya/config"
+	"github.com/chihaya/chihaya/tracker"
+)
+
+var constructors = make(map[string]Constructor)
+
+// Constructor is a function that creates a new Server.
+type Constructor func(*config.ServerConfig, *tracker.Tracker) (Server, error)
+
+// Register makes a Constructor available by the provided name.
+//
+// If this function is called twice with the same name or if the Constructor is
+// nil, it panics.
+func Register(name string, con Constructor) {
+	if con == nil {
+		panic("server: could not register nil Constructor")
+	}
+	if _, dup := constructors[name]; dup {
+		panic("server: could not register duplicate Constructor: " + name)
+	}
+	constructors[name] = con
+}
+
+// New creates a Server specified by a configuration.
+func New(cfg *config.ServerConfig, tkr *tracker.Tracker) (Server, error) {
+	con, ok := constructors[cfg.Name]
+	if !ok {
+		return nil, fmt.Errorf(
+			"server: unknown Constructor %q (forgotten import?)",
+			cfg.Name,
+		)
+	}
+	return con(cfg, tkr)
+}
+
+// Server represents one instance of a server accessing the tracker.
+type Server interface {
+	Start()
+	Stop()
+}