Slightly simplify the queue settings code to help reduce the risk of problems

modules/queue/helper.go

@@ -9,25 +9,56 @@ import (
 	"reflect"
 )
 
+// Mappable represents an interface that can MapTo another interface
+type Mappable interface {
+	MapTo(v interface{}) error
+}
+
 // toConfig will attempt to convert a given configuration cfg into the provided exemplar type.
 //
 // It will tolerate the cfg being passed as a []byte or string of a json representation of the
 // exemplar or the correct type of the exemplar itself
 func toConfig(exemplar, cfg interface{}) (interface{}, error) {
+
+	// First of all check if we've got the same type as the exemplar - if so it's all fine.
 	if reflect.TypeOf(cfg).AssignableTo(reflect.TypeOf(exemplar)) {
 		return cfg, nil
 	}
 
+	// Now if not - does it provide a MapTo function we can try?
+	if mappable, ok := cfg.(Mappable); ok {
+		newVal := reflect.New(reflect.TypeOf(exemplar))
+		if err := mappable.MapTo(newVal.Interface()); err == nil {
+			return newVal.Elem().Interface(), nil
+		}
+		// MapTo has failed us ... let's try the json route ...
+	}
+
+	// OK we've been passed a byte array right?
 	configBytes, ok := cfg.([]byte)
 	if !ok {
-		configStr, ok := cfg.(string)
-		if !ok {
-			return nil, ErrInvalidConfiguration{cfg: cfg}
-		}
+		// oh ... it's a string then?
+		var configStr string
+
+		configStr, ok = cfg.(string)
 		configBytes = []byte(configStr)
 	}
+	if !ok {
+		// hmm ... can we marshal it to json?
+		var err error
+
+		configBytes, err = json.Marshal(cfg)
+		ok = (err == nil)
+	}
+	if !ok {
+		// no ... we've tried hard enough at this point - throw an error!
+		return nil, ErrInvalidConfiguration{cfg: cfg}
+	}
+
+	// OK unmarshal the byte array into a new copy of the exemplar
 	newVal := reflect.New(reflect.TypeOf(exemplar))
 	if err := json.Unmarshal(configBytes, newVal.Interface()); err != nil {
+		// If we can't unmarshal it then return an error!
 		return nil, ErrInvalidConfiguration{cfg: cfg, err: err}
 	}
 	return newVal.Elem().Interface(), nil

modules/queue/setting.go

@@ -27,27 +27,10 @@ func validType(t string) (Type, error) {
 
 func getQueueSettings(name string) (setting.QueueSettings, []byte) {
 	q := setting.GetQueueSettings(name)
-	opts := make(map[string]interface{})
-	opts["Name"] = name
-	opts["QueueLength"] = q.Length
-	opts["BatchLength"] = q.BatchLength
-	opts["DataDir"] = q.DataDir
-	opts["Addresses"] = q.Addresses
-	opts["Network"] = q.Network
-	opts["Password"] = q.Password
-	opts["DBIndex"] = q.DBIndex
-	opts["QueueName"] = q.QueueName
-	opts["SetName"] = q.SetName
-	opts["Workers"] = q.Workers
-	opts["MaxWorkers"] = q.MaxWorkers
-	opts["BlockTimeout"] = q.BlockTimeout
-	opts["BoostTimeout"] = q.BoostTimeout
-	opts["BoostWorkers"] = q.BoostWorkers
-	opts["ConnectionString"] = q.ConnectionString
 
-	cfg, err := json.Marshal(opts)
+	cfg, err := json.Marshal(q)
 	if err != nil {
-		log.Error("Unable to marshall generic options: %v Error: %v", opts, err)
+		log.Error("Unable to marshall generic options: %v Error: %v", q, err)
 		log.Error("Unable to create queue for %s", name, err)
 		return q, []byte{}
 	}
@@ -75,7 +58,7 @@ func CreateQueue(name string, handle HandlerFunc, exemplar interface{}) Queue {
 			Timeout:     q.Timeout,
 			MaxAttempts: q.MaxAttempts,
 			Config:      cfg,
-			QueueLength: q.Length,
+			QueueLength: q.QueueLength,
 			Name:        name,
 		}, exemplar)
 	}
@@ -114,7 +97,7 @@ func CreateUniqueQueue(name string, handle HandlerFunc, exemplar interface{}) Un
 			Timeout:     q.Timeout,
 			MaxAttempts: q.MaxAttempts,
 			Config:      cfg,
-			QueueLength: q.Length,
+			QueueLength: q.QueueLength,
 		}, exemplar)
 	}
 	if err != nil {

modules/setting/queue.go

@@ -16,8 +16,9 @@ import (
 
 // QueueSettings represent the settings for a queue from the ini
 type QueueSettings struct {
+	Name             string
 	DataDir          string
-	Length           int
+	QueueLength      int `ini:"LENGTH"`
 	BatchLength      int
 	ConnectionString string
 	Type             string
@@ -44,6 +45,8 @@ var Queue = QueueSettings{}
 func GetQueueSettings(name string) QueueSettings {
 	q := QueueSettings{}
 	sec := Cfg.Section("queue." + name)
+	q.Name = name
+
 	// DataDir is not directly inheritable
 	q.DataDir = filepath.Join(Queue.DataDir, name)
 	// QueueName is not directly inheritable either
@@ -65,8 +68,9 @@ func GetQueueSettings(name string) QueueSettings {
 		q.DataDir = filepath.Join(AppDataPath, q.DataDir)
 	}
 	_, _ = sec.NewKey("DATADIR", q.DataDir)
+
 	// The rest are...
-	q.Length = sec.Key("LENGTH").MustInt(Queue.Length)
+	q.QueueLength = sec.Key("LENGTH").MustInt(Queue.QueueLength)
 	q.BatchLength = sec.Key("BATCH_LENGTH").MustInt(Queue.BatchLength)
 	q.ConnectionString = sec.Key("CONN_STR").MustString(Queue.ConnectionString)
 	q.Type = sec.Key("TYPE").MustString(Queue.Type)
@@ -91,7 +95,7 @@ func NewQueueService() {
 	if !filepath.IsAbs(Queue.DataDir) {
 		Queue.DataDir = filepath.Join(AppDataPath, Queue.DataDir)
 	}
-	Queue.Length = sec.Key("LENGTH").MustInt(20)
+	Queue.QueueLength = sec.Key("LENGTH").MustInt(20)
 	Queue.BatchLength = sec.Key("BATCH_LENGTH").MustInt(20)
 	Queue.ConnectionString = sec.Key("CONN_STR").MustString("")
 	Queue.Type = sec.Key("TYPE").MustString("persistable-channel")