Add Finalize method to backends, to be used in reload

backend.go

@@ -11,6 +11,7 @@ import (
 type Backend interface {
 	Initialize(BackendConfig) error
 	Process(client *Client, user, host string) string
+	Finalize() error
 }
 
 const CommandMaxLength = 1024

backends/dummy.go

@@ -20,7 +20,7 @@ type dummyConfig struct {
 	LogReceivedMails bool `json:"log_received_mails"`
 }
 
-func (b *DummyBackend) Initialize(backendConfig guerrilla.BackendConfig) error {
+func (b *DummyBackend) loadConfig(backendConfig guerrilla.BackendConfig) error {
 	var converted bool
 	b.config.LogReceivedMails, converted = backendConfig["log_received_mails"].(bool)
 	if !converted {
@@ -29,6 +29,14 @@ func (b *DummyBackend) Initialize(backendConfig guerrilla.BackendConfig) error {
 	return nil
 }
 
+func (b *DummyBackend) Initialize(backendConfig guerrilla.BackendConfig) error {
+	return b.loadConfig(backendConfig)
+}
+
+func (b *DummyBackend) Finalize() error {
+	return nil
+}
+
 func (b *DummyBackend) Process(client *guerrilla.Client, user, host string) string {
 	if b.config.LogReceivedMails {
 		log.Infof("Mail from: %s@%s", user, host)

backends/guerrilla_db_redis.go

@@ -2,6 +2,7 @@ package backends
 
 import (
 	"fmt"
+	"sync"
 	"time"
 
 	log "github.com/Sirupsen/logrus"
@@ -19,7 +20,9 @@ func init() {
 }
 
 type GuerrillaDBAndRedisBackend struct {
-	config guerrillaDBAndRedisConfig
+	config       guerrillaDBAndRedisConfig
+	saveMailChan chan *savePayload
+	wg           *sync.WaitGroup
 }
 
 type guerrillaDBAndRedisConfig struct {
@@ -38,7 +41,7 @@ func convertError(name string) error {
 	return fmt.Errorf("failed to load backend config field (%s)", name)
 }
 
-func (g *GuerrillaDBAndRedisBackend) Initialize(backendConfig guerrilla.BackendConfig) error {
+func (g *GuerrillaDBAndRedisBackend) loadConfig(backendConfig guerrilla.BackendConfig) error {
 	var converted bool
 
 	if g.config.NumberOfWorkers, converted = backendConfig["save_workers_size"].(int); !converted {
@@ -69,13 +72,23 @@ func (g *GuerrillaDBAndRedisBackend) Initialize(backendConfig guerrilla.BackendC
 		return convertError("primary_mail_host")
 	}
 
+	return nil
+}
+
+func (g *GuerrillaDBAndRedisBackend) Initialize(backendConfig guerrilla.BackendConfig) error {
+	err := g.loadConfig(backendConfig)
+	if err != nil {
+		return err
+	}
+
 	if err := g.testDbConnections(); err != nil {
 		return err
 	}
 
-	SaveMailChan = make(chan *savePayload, g.config.NumberOfWorkers)
+	g.saveMailChan = make(chan *savePayload, g.config.NumberOfWorkers)
 
 	// start some savemail workers
+	g.wg.Add(g.config.NumberOfWorkers)
 	for i := 0; i < g.config.NumberOfWorkers; i++ {
 		go g.saveMail()
 	}
@@ -83,10 +96,16 @@ func (g *GuerrillaDBAndRedisBackend) Initialize(backendConfig guerrilla.BackendC
 	return nil
 }
 
+func (g *GuerrillaDBAndRedisBackend) Finalize() error {
+	close(g.saveMailChan)
+	g.wg.Wait()
+	return nil
+}
+
 func (g *GuerrillaDBAndRedisBackend) Process(client *guerrilla.Client, user, host string) string {
 	// to do: timeout when adding to SaveMailChan
 	// place on the channel so that one of the save mail workers can pick it up
-	SaveMailChan <- &savePayload{client: client, user: user, host: host}
+	g.saveMailChan <- &savePayload{client: client, user: user, host: host}
 	// wait for the save to complete
 	// or timeout
 	select {
@@ -107,8 +126,6 @@ type savePayload struct {
 	host   string
 }
 
-var SaveMailChan chan *savePayload
-
 type redisClient struct {
 	count int
 	conn  redis.Conn
@@ -145,7 +162,13 @@ func (g *GuerrillaDBAndRedisBackend) saveMail() {
 
 	//  receives values from the channel repeatedly until it is closed.
 	for {
-		payload := <-SaveMailChan
+		payload := <-g.saveMailChan
+		if payload == nil {
+			log.Debug("No more payload")
+			g.wg.Done()
+			return
+		}
+
 		recipient = payload.user + "@" + payload.host
 		to = payload.user + "@" + g.config.PrimaryHost
 		length = len(payload.client.Data)