eventstream: adds middleware to close input-writer in case of error (#…

…3867)

* eventream template change: add unmarshal error handler to close inputWriter io.writer in case of an error for the first connection request

* make generate changes

* hand-written unit test to test for error case io.write resource is freed

* remove dead code

* bug fix: set original error for validate response handler error

* use awserr error type for any error occuring when closing input writer for eventstream

* use ioutil.NopCloser instead of io.NopCloser to satisfy older go versions

* use anonymous creds for test

* eventstream: update template for code gen

* update test and generate service clients

aws/corehandlers/handlers.go

@@ -178,7 +178,7 @@ func handleSendError(r *request.Request, err error) {
 var ValidateResponseHandler = request.NamedHandler{Name: "core.ValidateResponseHandler", Fn: func(r *request.Request) {
 	if r.HTTPResponse.StatusCode == 0 || r.HTTPResponse.StatusCode >= 300 {
 		// this may be replaced by an UnmarshalError handler
-		r.Error = awserr.New("UnknownError", "unknown error", nil)
+		r.Error = awserr.New("UnknownError", "unknown error", r.Error)
 	}
 }}
 

private/model/api/eventstream_tmpl.go

@@ -214,6 +214,14 @@ func (es *{{ $esapi.Name }}) waitStreamPartClose() {
 			es.inputWriter = inputWriter
 	}
 
+	// Closes the input-pipe writer
+	func (es *{{ $esapi.Name }}) closeInputPipe() error {
+		if es.inputWriter != nil {
+			return es.inputWriter.Close()
+		}
+		return nil
+	}	
+
 	// Send writes the event to the stream blocking until the event is written.
 	// Returns an error if the event was not written.
 	//
@@ -400,8 +408,8 @@ func (es *{{ $esapi.Name }}) safeClose() {
 		case <-t.C:
 		case <-writeCloseDone:
 		}
-		if es.inputWriter != nil {
-			es.inputWriter.Close()
+		if err := es.closeInputPipe(); err != nil {
+			es.err.SetError(err)
 		}
 	{{- end }}
 

private/model/api/operation.go

@@ -248,6 +248,15 @@ func (c *{{ .API.StructName }}) {{ .ExportedName }}Request(` +
 			{{- if $inputStream }}
 
 				req.Handlers.Sign.PushFront(es.setupInputPipe)
+				req.Handlers.UnmarshalError.PushBackNamed(request.NamedHandler{
+					Name: "InputPipeCloser",
+					Fn: func (r *request.Request) {
+							err := es.closeInputPipe()
+							if err != nil {
+								r.Error = awserr.New(eventstreamapi.InputWriterCloseErrorCode, err.Error(), r.Error)
+							}
+						},
+				})
 				req.Handlers.Build.PushBack(request.WithSetRequestHeaders(map[string]string{
 					"Content-Type": "application/vnd.amazon.eventstream",
 					"X-Amz-Content-Sha256": "STREAMING-AWS4-HMAC-SHA256-EVENTS",

private/protocol/eventstream/eventstreamapi/error.go

@@ -5,6 +5,10 @@ import (
 	"sync"
 )
 
+// InputWriterCloseErrorCode is used to denote an error occurred
+// while closing the event stream input writer.
+const InputWriterCloseErrorCode = "EventStreamInputWriterCloseError"
+
 type messageError struct {
 	code string
 	msg  string

private/protocol/eventstream/eventstreamapi/writer.go

@@ -61,49 +61,3 @@ func (w *EventWriter) marshal(event Marshaler) (eventstream.Message, error) {
 	msg.Headers.Set(EventTypeHeader, eventstream.StringValue(eventType))
 	return msg, nil
 }
-
-//type EventEncoder struct {
-//	encoder           Encoder
-//	ppayloadMarshaler protocol.PayloadMarshaler
-//	eventTypeFor      func(Marshaler) (string, error)
-//}
-//
-//func (e EventEncoder) Encode(event Marshaler) error {
-//	msg, err := e.marshal(event)
-//	if err != nil {
-//		return err
-//	}
-//
-//	return w.encoder.Encode(msg)
-//}
-//
-//func (e EventEncoder) marshal(event Marshaler) (eventstream.Message, error) {
-//	eventType, err := w.eventTypeFor(event)
-//	if err != nil {
-//		return eventstream.Message{}, err
-//	}
-//
-//	msg, err := event.MarshalEvent(w.payloadMarshaler)
-//	if err != nil {
-//		return eventstream.Message{}, err
-//	}
-//
-//	msg.Headers.Set(EventTypeHeader, eventstream.StringValue(eventType))
-//	return msg, nil
-//}
-//
-//func (w *EventWriter) marshal(event Marshaler) (eventstream.Message, error) {
-//	eventType, err := w.eventTypeFor(event)
-//	if err != nil {
-//		return eventstream.Message{}, err
-//	}
-//
-//	msg, err := event.MarshalEvent(w.payloadMarshaler)
-//	if err != nil {
-//		return eventstream.Message{}, err
-//	}
-//
-//	msg.Headers.Set(EventTypeHeader, eventstream.StringValue(eventType))
-//	return msg, nil
-//}
-//

service/transcribestreamingservice/unit_test.go

@@ -0,0 +1,69 @@
+// +build go1.10
+
+package transcribestreamingservice
+
+import (
+	"bytes"
+	"io/ioutil"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/credentials"
+	"github.com/aws/aws-sdk-go/aws/session"
+)
+
+type roundTripFunc func(req *http.Request) *http.Response
+
+func (f roundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) {
+	return f(req), nil
+}
+
+func newTestClient(fn roundTripFunc) *http.Client {
+	return &http.Client{
+		Transport: fn,
+	}
+}
+
+func TestStartStreamTranscription_Error(t *testing.T) {
+	cfg := &aws.Config{
+		Region:      aws.String("us-west-2"),
+		Credentials: credentials.AnonymousCredentials,
+		HTTPClient: newTestClient(func(req *http.Request) *http.Response {
+			return &http.Response{
+				StatusCode: http.StatusBadRequest,
+				Body:       ioutil.NopCloser(bytes.NewReader([]byte("{ \"code\" : \"BadRequestException\" }"))),
+				Header:     http.Header{},
+			}
+		}),
+	}
+	sess, err := session.NewSession(cfg)
+
+	svc := New(sess)
+	resp, err := svc.StartStreamTranscription(&StartStreamTranscriptionInput{
+		LanguageCode:         aws.String(LanguageCodeEnUs),
+		MediaEncoding:        aws.String(MediaEncodingPcm),
+		MediaSampleRateHertz: aws.Int64(int64(16000)),
+	})
+	if err == nil {
+		t.Fatalf("expect error, got none")
+	} else {
+		if e, a := "BadRequestException", err.Error(); !strings.Contains(a, e) {
+			t.Fatalf("expected error to be %v, got %v", e, a)
+		}
+	}
+
+	n, err := resp.GetStream().inputWriter.Write([]byte("text"))
+	if err == nil {
+		t.Fatalf("expected error stating write on closed pipe, got none")
+	}
+
+	if e, a := "write on closed pipe", err.Error(); !strings.Contains(a, e) {
+		t.Fatalf("expected error to contain %v, got error as %v", e, a)
+	}
+
+	if e, a := 0, n; e != a {
+		t.Fatalf("expected %d bytes to be written on inputWriter, but %v bytes were written", e, a)
+	}
+}