New config framework for the different schedulers

lib/scheduler/configmap.go

@@ -3,45 +3,75 @@ package scheduler
 import (
 	"encoding/json"
 	"fmt"
+	"sync"
 )
 
+// ConfigMap can contain mixed scheduler config types
+type ConfigMap map[string]Config
+
+// ConfigConstructor is a simple function that returns a concrete Config instance
+// with the specified name and all default values correctly initialized
+type ConfigConstructor func(name string, rawJSON []byte) (Config, error)
+
+var (
+	configTypesMutex   sync.RWMutex
+	configConstructors = make(map[string]ConfigConstructor)
+)
+
+// RegisterConfigType adds the supplied ConfigConstructor as the constructor for its
+// type in the configConstructors map, in a thread-safe manner
+func RegisterConfigType(configType string, constructor ConfigConstructor) {
+	configTypesMutex.Lock()
+	defer configTypesMutex.Unlock()
+
+	if constructor == nil {
+		panic("scheduler configs: constructor is nil")
+	}
+	if _, configTypeExists := configConstructors[configType]; configTypeExists {
+		panic("scheduler configs: RegisterConfigType called twice for  " + configType)
+	}
+
+	configConstructors[configType] = constructor
+}
+
 // GetParsedConfig returns a struct instance corresponding to the supplied
 // config type. It will be fully initialized - with both the default values of
 // the type, as well as with whatever the user had specified in the JSON
 func GetParsedConfig(name, configType string, rawJSON []byte) (result Config, err error) {
-	switch configType {
-	case constantLoopingVUsType:
-		config := NewConstantLoopingVUsConfig(name)
-		err = json.Unmarshal(rawJSON, &config)
-		result = config
-	case variableLoopingVUsType:
-		config := NewVariableLoopingVUsConfig(name)
-		err = json.Unmarshal(rawJSON, &config)
-		result = config
-	case sharedIterationsType:
-		config := NewSharedIterationsConfig(name)
-		err = json.Unmarshal(rawJSON, &config)
-		result = config
-	case perVUIterationsType:
-		config := NewPerVUIterationsConfig(name)
-		err = json.Unmarshal(rawJSON, &config)
-		result = config
-	case constantArrivalRateType:
-		config := NewConstantArrivalRateConfig(name)
-		err = json.Unmarshal(rawJSON, &config)
-		result = config
-	case variableArrivalRateType:
-		config := NewVariableArrivalRateConfig(name)
-		err = json.Unmarshal(rawJSON, &config)
-		result = config
-	default:
+	configTypesMutex.Lock()
+	defer configTypesMutex.Unlock()
+
+	constructor, exists := configConstructors[configType]
+	if !exists {
 		return nil, fmt.Errorf("unknown execution scheduler type '%s'", configType)
 	}
-	return
-}
+	return constructor(name, rawJSON)
+	/*
+		switch configType {
+		case constantLoopingVUsType:
+			config := NewConstantLoopingVUsConfig(name)
+			err = json.Unmarshal(rawJSON, &config)
+			result = config
+		case variableLoopingVUsType:
+			config := NewVariableLoopingVUsConfig(name)
+			err = json.Unmarshal(rawJSON, &config)
+			result = config
+		case sharedIterationsType:
+			config := NewSharedIterationsConfig(name)
+			err = json.Unmarshal(rawJSON, &config)
+			result = config
+		case perVUIterationsType:
+			config := NewPerVUIterationsConfig(name)
+			err = json.Unmarshal(rawJSON, &config)
+			result = config
+		case constantArrivalRateType:
 
-// ConfigMap can contain mixed scheduler config types
-type ConfigMap map[string]Config
+		case variableArrivalRateType:
+			config := NewVariableArrivalRateConfig(name)
+			err = json.Unmarshal(rawJSON, &config)
+			result = config
+	*/
+}
 
 // UnmarshalJSON implements the json.Unmarshaler interface in a two-step manner,
 // creating the correct type of configs based on the `type` property.

lib/scheduler/constant_arrival_rate.go

@@ -1,6 +1,7 @@
 package scheduler
 
 import (
+	"encoding/json"
 	"fmt"
 	"time"
 
@@ -10,6 +11,14 @@ import (
 
 const constantArrivalRateType = "constant-arrival-rate"
 
+func init() {
+	RegisterConfigType(constantArrivalRateType, func(name string, rawJSON []byte) (Config, error) {
+		config := NewConstantArrivalRateConfig(name)
+		err := json.Unmarshal(rawJSON, &config)
+		return config, err
+	})
+}
+
 // ConstantArrivalRateConfig stores config for the constant arrival-rate scheduler
 type ConstantArrivalRateConfig struct {
 	BaseConfig

lib/scheduler/constant_looping_vus.go

@@ -1,6 +1,7 @@
 package scheduler
 
 import (
+	"encoding/json"
 	"fmt"
 	"time"
 
@@ -10,6 +11,14 @@ import (
 
 const constantLoopingVUsType = "constant-looping-vus"
 
+func init() {
+	RegisterConfigType(constantLoopingVUsType, func(name string, rawJSON []byte) (Config, error) {
+		config := NewConstantLoopingVUsConfig(name)
+		err := json.Unmarshal(rawJSON, &config)
+		return config, err
+	})
+}
+
 // The minimum duration we'll allow users to schedule. This doesn't affect the stages
 // configuration, where 0-duration virtual stages are allowed for instantaneous VU jumps
 const minDuration = 1 * time.Second

lib/scheduler/per_vu_iterations.go

@@ -1,6 +1,7 @@
 package scheduler
 
 import (
+	"encoding/json"
 	"fmt"
 	"time"
 
@@ -10,6 +11,14 @@ import (
 
 const perVUIterationsType = "per-vu-iterations"
 
+func init() {
+	RegisterConfigType(perVUIterationsType, func(name string, rawJSON []byte) (Config, error) {
+		config := NewPerVUIterationsConfig(name)
+		err := json.Unmarshal(rawJSON, &config)
+		return config, err
+	})
+}
+
 // PerVUIteationsConfig stores the number of VUs iterations, as well as maxDuration settings
 type PerVUIteationsConfig struct {
 	BaseConfig

lib/scheduler/shared_iterations.go

@@ -1,6 +1,7 @@
 package scheduler
 
 import (
+	"encoding/json"
 	"fmt"
 	"time"
 
@@ -10,6 +11,14 @@ import (
 
 const sharedIterationsType = "shared-iterations"
 
+func init() {
+	RegisterConfigType(sharedIterationsType, func(name string, rawJSON []byte) (Config, error) {
+		config := NewSharedIterationsConfig(name)
+		err := json.Unmarshal(rawJSON, &config)
+		return config, err
+	})
+}
+
 // SharedIteationsConfig stores the number of VUs iterations, as well as maxDuration settings
 type SharedIteationsConfig struct {
 	BaseConfig

lib/scheduler/variable_arrival_rate.go

@@ -11,6 +11,14 @@ import (
 
 const variableArrivalRateType = "variable-arrival-rate"
 
+func init() {
+	RegisterConfigType(variableArrivalRateType, func(name string, rawJSON []byte) (Config, error) {
+		config := NewVariableArrivalRateConfig(name)
+		err := json.Unmarshal(rawJSON, &config)
+		return config, err
+	})
+}
+
 // VariableArrivalRateConfig stores config for the variable arrival-rate scheduler
 type VariableArrivalRateConfig struct {
 	BaseConfig

lib/scheduler/variable_looping_vus.go

@@ -1,6 +1,7 @@
 package scheduler
 
 import (
+	"encoding/json"
 	"fmt"
 
 	"github.com/loadimpact/k6/lib/types"
@@ -9,6 +10,14 @@ import (
 
 const variableLoopingVUsType = "variable-looping-vus"
 
+func init() {
+	RegisterConfigType(variableLoopingVUsType, func(name string, rawJSON []byte) (Config, error) {
+		config := NewVariableLoopingVUsConfig(name)
+		err := json.Unmarshal(rawJSON, &config)
+		return config, err
+	})
+}
+
 // Stage contains
 type Stage struct {
 	Duration types.NullDuration `json:"duration"`