Send overall (rather than per-stage) completion ratio to Studio

clients/callback_client.go

@@ -46,9 +46,13 @@ func (c CallbackClient) DoWithRetries(r *http.Request) error {
 	return nil
 }
 
-func (c CallbackClient) SendTranscodeStatus(url string, status TranscodeStatus, completionRatio float32) error {
+// Sends a Transcode Status message to the Client (initially just Studio)
+// The status strings will be useful for debugging where in the workflow we got to, but everything
+// in Studio will be driven off the overall "Completion Ratio".
+// This method will accept the completion ratio of the current stage and will translate that into the overall ratio
+func (c CallbackClient) SendTranscodeStatus(url string, status TranscodeStatus, currentStageCompletionRatio float64) error {
 	tsm := TranscodeStatusMessage{
-		CompletionRatio: completionRatio,
+		CompletionRatio: overallCompletionRatio(status, currentStageCompletionRatio),
 		Status:          status.String(),
 		Timestamp:       config.Clock.GetTimestampUTC(),
 	}
@@ -86,21 +90,54 @@ func (c CallbackClient) SendTranscodeStatusError(callbackURL, errorMsg string) e
 	return c.DoWithRetries(r)
 }
 
+// Calculate the overall completion ratio based on the completion ratio of the current stage.
+// The weighting will need to be tweaked as we understand better the relative time spent in the
+// segmenting vs. transcoding stages.
+func overallCompletionRatio(status TranscodeStatus, currentStageCompletionRatio float64) float64 {
+	// Sanity check the inputs are within the 0-1 bounds
+	if currentStageCompletionRatio < 0 {
+		currentStageCompletionRatio = 0
+	}
+	if currentStageCompletionRatio > 1 {
+		currentStageCompletionRatio = 1
+	}
+
+	// Define the "base" numbers - e.g the overall ratio we start each stage at
+	var TranscodeStatusPreparingBase float64 = 0.0
+	var TranscodeStatusPreparingTranscodingBase float64 = 0.4
+	var TranscodeStatusCompletedBase float64 = 1
+
+	switch status {
+	case TranscodeStatusPreparing:
+		return TranscodeStatusPreparingBase + (currentStageCompletionRatio * (TranscodeStatusPreparingTranscodingBase - TranscodeStatusPreparingBase))
+	case TranscodeStatusPreparingCompleted:
+		return TranscodeStatusPreparingTranscodingBase
+	case TranscodeStatusTranscoding:
+		return TranscodeStatusPreparingTranscodingBase + (currentStageCompletionRatio * (TranscodeStatusCompletedBase - TranscodeStatusPreparingTranscodingBase))
+	case TranscodeStatusCompleted:
+		return TranscodeStatusCompletedBase
+	default:
+		// Either unhandled or an error
+		return -1
+	}
+}
+
 // An enum of potential statuses a Transcode job can have
 
 type TranscodeStatus int
 
 const (
 	TranscodeStatusPreparing TranscodeStatus = iota
+	TranscodeStatusPreparingCompleted
 	TranscodeStatusTranscoding
 	TranscodeStatusCompleted
 	TranscodeStatusError
 )
 
 type TranscodeStatusMessage struct {
-	CompletionRatio float32 `json:"completion_ratio,omitempty"`
+	CompletionRatio float64 `json:"completion_ratio"` // No omitempty or we lose this for 0% completion case
 	Error           string  `json:"error,omitempty"`
-	Retriable       bool    `json:"retriable,omitempty"`
+	Retriable       *bool   `json:"retriable,omitempty"` // Has to be a pointer or we can't differentiate omission from 'false'
 	Status          string  `json:"status,omitempty"`
 	Timestamp       int64   `json:"timestamp"`
 }
@@ -109,10 +146,12 @@ func (ts TranscodeStatus) String() string {
 	switch ts {
 	case TranscodeStatusPreparing:
 		return "preparing"
+	case TranscodeStatusPreparingCompleted:
+		return "preparing-completed"
 	case TranscodeStatusTranscoding:
 		return "transcoding"
 	case TranscodeStatusCompleted:
-		return "completed"
+		return "transcoding-completed"
 	case TranscodeStatusError:
 		return "error"
 	}

clients/callback_client_test.go

@@ -1,6 +1,7 @@
 package clients
 
 import (
+	"fmt"
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
@@ -22,7 +23,7 @@ func TestItRetriesOnFailedCallbacks(t *testing.T) {
 		// Check that we got the callback we're expecting
 		body, err := ioutil.ReadAll(r.Body)
 		require.NoError(t, err)
-		require.JSONEq(t, `{"completion_ratio":1, "status":"completed", "timestamp": 123456789}`, string(body))
+		require.JSONEq(t, `{"completion_ratio":1, "status":"transcoding-completed", "timestamp": 123456789}`, string(body))
 
 		// Return HTTP error codes the first two times
 		tries += 1
@@ -54,7 +55,7 @@ func TestItEventuallyStopsRetrying(t *testing.T) {
 		// Check that we got the callback we're expecting
 		body, err := ioutil.ReadAll(r.Body)
 		require.NoError(t, err)
-		require.JSONEq(t, `{"completion_ratio":1, "status":"completed", "timestamp": 123456789}`, string(body))
+		require.JSONEq(t, `{"completion_ratio":1, "status":"transcoding-completed", "timestamp": 123456789}`, string(body))
 
 		tries += 1
 
@@ -81,7 +82,7 @@ func TestTranscodeStatusErrorNotifcation(t *testing.T) {
 		// Check that we got the callback we're expecting
 		body, err := ioutil.ReadAll(r.Body)
 		require.NoError(t, err)
-		require.JSONEq(t, `{"error": "something went wrong", "status":"error", "timestamp": 123456789}`, string(body))
+		require.JSONEq(t, `{"completion_ratio": 0, "error": "something went wrong", "status":"error", "timestamp": 123456789}`, string(body))
 
 		w.WriteHeader(http.StatusOK)
 	}))
@@ -91,3 +92,21 @@ func TestTranscodeStatusErrorNotifcation(t *testing.T) {
 	client := NewCallbackClient()
 	require.NoError(t, client.SendTranscodeStatusError(svr.URL, "something went wrong"))
 }
+
+func TestItCalculatesTheOverallCompletionRatioCorrectly(t *testing.T) {
+	testCases := []struct {
+		status                         TranscodeStatus
+		completionRatio                float64
+		expectedOverallCompletionRatio float64
+	}{
+		{TranscodeStatusPreparing, 0.5, 0.2},           // Half complete in the Preparing stage (i.e half way between 0 and 0.4)
+		{TranscodeStatusPreparingCompleted, 1234, 0.4}, // Preparing Completed should always == 0.4 for now, regardless of what's reported as the stage ratio
+		{TranscodeStatusTranscoding, 0.5, 0.7},         // Half complete in the Transcoding stage (i.e half way between 0.4 and 1)
+		{TranscodeStatusCompleted, 5678, 1},            // Completed should always == 1, regardless of what's reported as the stage ratio
+	}
+	for _, tc := range testCases {
+		t.Run(fmt.Sprintf("%f in %s", tc.completionRatio, tc.status), func(t *testing.T) {
+			require.Equal(t, tc.expectedOverallCompletionRatio, overallCompletionRatio(tc.status, tc.completionRatio))
+		})
+	}
+}