initial middleware refactor

pkg/event/event.go

@@ -0,0 +1,70 @@
+// 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 event implements type-level constraints for dealing with the events
+// communicated via BitTorrent announce.
+package event
+
+import (
+	"errors"
+	"strings"
+)
+
+// ErrUnknownEvent is returned when New fails to return an event.
+var ErrUnknownEvent = errors.New("unknown event")
+
+// Event represents an event done by a BitTorrent client.
+type event uint8
+
+const (
+	// None is the event when a BitTorrent client announces due to time lapsed
+	// since the previous announce.
+	None event = iota
+
+	// Started is the event sent by a BitTorrent client when it joins a swarm.
+	Started
+
+	// Stopped is the event sent by a BitTorrent client when it leaves a swarm.
+	Stopped
+
+	// Completed is the event sent by a BitTorrent client when it finishes
+	// downloading all of the required chunks.
+	Completed
+)
+
+var (
+	eventToString = make(map[event]string)
+	stringToEvent = make(map[string]event)
+)
+
+func init() {
+	eventToString[None] = "none"
+	eventToString[Started] = "started"
+	eventToString[Stopped] = "stopped"
+	eventToString[Completed] = "completed"
+
+	stringToEvent[""] = None
+	stringToEvent["none"] = None
+	stringToEvent["started"] = Started
+	stringToEvent["stopped"] = Stopped
+	stringToEvent["completed"] = Completed
+}
+
+// New returns the proper Event given a string.
+func New(eventStr string) (event, error) {
+	if e, ok := stringToEvent[strings.ToLower(eventStr)]; ok {
+		return e, nil
+	}
+
+	return None, ErrUnknownEvent
+}
+
+// String implements Stringer for an event.
+func (e event) String() string {
+	if name, ok := eventToString[e]; ok {
+		return name
+	}
+
+	panic("event: event has no associated name")
+}

pkg/event/event_test.go

@@ -0,0 +1,33 @@
+// 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 event
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNew(t *testing.T) {
+	var table = []struct {
+		data        string
+		expected    event
+		expectedErr error
+	}{
+		{"", None, nil},
+		{"NONE", None, nil},
+		{"none", None, nil},
+		{"started", Started, nil},
+		{"stopped", Stopped, nil},
+		{"completed", Completed, nil},
+		{"notAnEvent", None, ErrUnknownEvent},
+	}
+
+	for _, tt := range table {
+		got, err := New(tt.data)
+		assert.Equal(t, err, tt.expectedErr, "errors should equal the expected value")
+		assert.Equal(t, got, tt.expected, "events should equal the expected value")
+	}
+}