API filter on events and results

CHANGELOG.md

@@ -11,10 +11,14 @@
 
 #### Added
 - (#174) Add CHANGELOG.md file
+- (#179) [API] Add `eventFilter` on `ListenEvent` API to get notification when an event with a specific name occurs
+         [API] Add `taskFilter` on `ListenResult` API to get notification when a result from a specific task occurs
+         [API] Add `outputFilter` on `ListenResult` API to get notification when a result returns a specific output
 - (#183) Add a `configuration` attribute in the `mesg.yml` file to accept docker configuration for your service
 - (#187) Stop all services when the daemon stops
 
 #### Removed
 
 #### Fixed
-- (#185) Fix logs with extra characters when `mesg-core daemon logs`
+- (#179) [Doc] Outdated documentation for the CLI
+- (#185) Fix logs with extra characters when `mesg-core daemon logs`

api/core/api.proto

@@ -17,6 +17,7 @@ service Core {
 
 message ListenEventRequest {
   string serviceID = 1;
+  string eventFilter = 2;
 }
 
 message ExecuteTaskRequest {
@@ -27,6 +28,8 @@ message ExecuteTaskRequest {
 
 message ListenResultRequest {
   string serviceID = 1;
+  string taskFilter = 2;
+  string outputFilter = 3;
 }
 
 message StartServiceRequest {

api/core/listen_event.go

@@ -2,8 +2,11 @@ package core
 
 import (
 	"encoding/json"
+	"errors"
 
 	"github.com/mesg-foundation/core/database/services"
+	service "github.com/mesg-foundation/core/service"
+	"github.com/mesg-foundation/core/utils/array"
 
 	"github.com/mesg-foundation/core/event"
 	"github.com/mesg-foundation/core/pubsub"
@@ -15,14 +18,35 @@ func (s *Server) ListenEvent(request *ListenEventRequest, stream Core_ListenEven
 	if err != nil {
 		return
 	}
+	if err = validateEventKey(&service, request.EventFilter); err != nil {
+		return
+	}
 	subscription := pubsub.Subscribe(service.EventSubscriptionChannel())
 	for data := range subscription {
 		event := data.(*event.Event)
-		eventData, _ := json.Marshal(event.Data)
-		stream.Send(&EventData{
-			EventKey:  event.Key,
-			EventData: string(eventData),
-		})
+		if isSubscribedEvent(request, event) {
+			eventData, _ := json.Marshal(event.Data)
+			stream.Send(&EventData{
+				EventKey:  event.Key,
+				EventData: string(eventData),
+			})
+		}
 	}
 	return
 }
+
+func validateEventKey(service *service.Service, eventKey string) (err error) {
+	if eventKey == "" || eventKey == "*" {
+		return
+	}
+	_, ok := service.Events[eventKey]
+	if ok {
+		return
+	}
+	err = errors.New("Event '" + eventKey + "' doesn't exist in this service")
+	return
+}
+
+func isSubscribedEvent(request *ListenEventRequest, e *event.Event) bool {
+	return array.IncludedIn([]string{"", "*", e.Key}, request.EventFilter)
+}

api/core/listen_event_test.go

@@ -0,0 +1,39 @@
+package core
+
+import (
+	"testing"
+
+	"github.com/mesg-foundation/core/event"
+	"github.com/mesg-foundation/core/service"
+	"github.com/stvp/assert"
+)
+
+func TestValidateEventKey(t *testing.T) {
+	s := &service.Service{
+		Events: map[string]*service.Event{
+			"test": &service.Event{},
+		},
+	}
+	assert.Nil(t, validateEventKey(s, ""))
+	assert.Nil(t, validateEventKey(s, "*"))
+	assert.Nil(t, validateEventKey(s, "test"))
+	assert.NotNil(t, validateEventKey(s, "xxx"))
+}
+
+func TestIsSubscribedEvent(t *testing.T) {
+	e := &event.Event{Key: "test"}
+	r := &ListenEventRequest{}
+	assert.True(t, isSubscribedEvent(r, e))
+
+	r = &ListenEventRequest{EventFilter: ""}
+	assert.True(t, isSubscribedEvent(r, e))
+
+	r = &ListenEventRequest{EventFilter: "*"}
+	assert.True(t, isSubscribedEvent(r, e))
+
+	r = &ListenEventRequest{EventFilter: "test"}
+	assert.True(t, isSubscribedEvent(r, e))
+
+	r = &ListenEventRequest{EventFilter: "xxx"}
+	assert.False(t, isSubscribedEvent(r, e))
+}

api/core/listen_result.go

@@ -2,29 +2,81 @@ package core
 
 import (
 	"encoding/json"
+	"errors"
 
 	"github.com/mesg-foundation/core/database/services"
+	service "github.com/mesg-foundation/core/service"
+	"github.com/mesg-foundation/core/utils/array"
 
 	"github.com/mesg-foundation/core/execution"
 	"github.com/mesg-foundation/core/pubsub"
 )
 
-// ListenResult will listne for results from a services
+// ListenResult will listen for results from a services
 func (s *Server) ListenResult(request *ListenResultRequest, stream Core_ListenResultServer) (err error) {
 	service, err := services.Get(request.ServiceID)
 	if err != nil {
 		return
 	}
+	if err = validateTaskKey(&service, request.TaskFilter); err != nil {
+		return
+	}
+	if err = validateOutputKey(&service, request.TaskFilter, request.OutputFilter); err != nil {
+		return
+	}
 	subscription := pubsub.Subscribe(service.ResultSubscriptionChannel())
 	for data := range subscription {
 		execution := data.(*execution.Execution)
-		outputs, _ := json.Marshal(execution.OutputData)
-		stream.Send(&ResultData{
-			ExecutionID: execution.ID,
-			TaskKey:     execution.Task,
-			OutputKey:   execution.Output,
-			OutputData:  string(outputs),
-		})
+		if isSubscribedTask(request, execution) && isSubscribedOutput(request, execution) {
+			outputs, _ := json.Marshal(execution.OutputData)
+			stream.Send(&ResultData{
+				ExecutionID: execution.ID,
+				TaskKey:     execution.Task,
+				OutputKey:   execution.Output,
+				OutputData:  string(outputs),
+			})
+		}
+	}
+	return
+}
+
+func validateTaskKey(service *service.Service, taskKey string) (err error) {
+	if taskKey == "" || taskKey == "*" {
+		return
+	}
+	_, ok := service.Tasks[taskKey]
+	if ok {
+		return
+	}
+	err = errors.New("Task '" + taskKey + "' doesn't exist in this service")
+	return
+}
+
+func validateOutputKey(service *service.Service, taskKey string, outputFilter string) (err error) {
+	if outputFilter == "" || outputFilter == "*" {
+		return
+	}
+	if taskKey == "" {
+		err = errors.New("Cannot filter output without specifying a task")
+		return
+	}
+	task, ok := service.Tasks[taskKey]
+	if !ok {
+		err = errors.New("Task '" + taskKey + "' doesn't exist in this service")
+		return
 	}
+	_, ok = task.Outputs[outputFilter]
+	if ok {
+		return
+	}
+	err = errors.New("Output '" + outputFilter + "' doesn't exist in the task '" + taskKey + "' of this service")
 	return
 }
+
+func isSubscribedTask(request *ListenResultRequest, e *execution.Execution) bool {
+	return array.IncludedIn([]string{"", "*", e.Task}, request.TaskFilter)
+}
+
+func isSubscribedOutput(request *ListenResultRequest, e *execution.Execution) bool {
+	return array.IncludedIn([]string{"", "*", e.Output}, request.OutputFilter)
+}