Remove RespStream type and replace with chan-based API for download-s…

…tyle rpcs

example/cmd/client/main.go

@@ -15,7 +15,6 @@ package main
 
 import (
 	"context"
-	"io"
 	"log"
 	"net/http"
 	"time"
@@ -75,19 +74,16 @@ func main() {
 		khps := float64(ii-1) / took.Seconds() / 1000
 		log.Printf("Received %.1f kHats per second (%d hats in %f seconds)\n", khps, ii-1, took.Seconds())
 	}
-	for ; true; ii++ { // Receive all the hats
-		hat, err = hatStream.Next(context.Background())
-		if err != nil {
-			if err == io.EOF {
-				break
-			}
+	for hatOrErr := range hatStream {
+		if hatOrErr.Err != nil {
 			printResults()
-			log.Fatal(err)
+			log.Fatal(hatOrErr.Err)
 		}
 		if ii%printEvery == 0 {
 			khps := float64(ii) / time.Now().Sub(reqSentAt).Seconds() / 1000
-			log.Printf("\t[%4.1f khps] %6d %+v\n", khps, ii, hat)
+			log.Printf("\t[%4.1f khps] %6d %+v\n", khps, ii, hatOrErr.Msg)
 		}
+		ii++
 	}
 	printResults()
 }

example/cmd/server/main.go

@@ -47,7 +47,7 @@ func (h *randomHaberdasher) MakeHat(ctx context.Context, size *example.Size) (*e
 	return newRandomHat(size.Inches)
 }
 
-func (h *randomHaberdasher) MakeHats(ctx context.Context, req *example.MakeHatsReq) (example.HatStream, error) {
+func (h *randomHaberdasher) MakeHats(ctx context.Context, req *example.MakeHatsReq) (<-chan example.HatOrError, error) {
 	if req.Quantity < 0 {
 		return nil, errNegativeQuantity
 	}
@@ -63,12 +63,12 @@ func (h *randomHaberdasher) MakeHats(ctx context.Context, req *example.MakeHatsR
 			select {
 			case <-ctx.Done():
 				return
-			case ch <- example.HatOrError{Hat: hat, Err: err}:
+			case ch <- example.HatOrError{Msg: hat, Err: err}:
 			}
 		}
 		close(ch)
 	}()
-	return example.NewHatStream(ch), nil
+	return ch, nil
 }
 
 func main() {

example/cmd/server/main_test.go

@@ -16,7 +16,6 @@ package main
 import (
 	"context"
 	"fmt"
-	"io"
 	"log"
 	"net/http"
 	"os"
@@ -116,8 +115,8 @@ func TestMakeHatsTooSmall(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
-			_, err = hatStream.Next(context.Background())
-			err = compareErrors(err, errTooSmall)
+			hatOrErr := <-hatStream
+			err = compareErrors(hatOrErr.Err, errTooSmall)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -148,14 +147,11 @@ func TestMakeHatsLargeQuantities(t *testing.T) {
 					t.Fatalf(`MakeHats request failed: %#v (hatStream=%#v)`, err, hatStream)
 				}
 				ii := int32(0)
-				for ; true; ii++ {
-					_, err = hatStream.Next(context.Background())
-					if err == io.EOF {
-						break
-					}
-					if err != nil {
-						t.Fatal(err)
+				for hatOrErr := range hatStream {
+					if hatOrErr.Err != nil {
+						t.Fatal(hatOrErr.Err)
 					}
+					ii++
 				}
 				if ii != re.req.Quantity {
 					t.Fatalf(`Expected to receive %d hats, got %d`, re.req.Quantity, ii)
@@ -189,14 +185,11 @@ func benchmarkMakeHats(b *testing.B, cc example.Haberdasher) {
 		b.Fatal(err)
 	}
 	ii := 0
-	for ; true; ii++ {
-		_, err = hatStream.Next(context.Background())
-		if err != nil {
-			if err == io.EOF {
-				break
-			}
-			b.Fatal(err)
+	for hatOrErr := range hatStream {
+		if hatOrErr.Err != nil {
+			b.Fatal(hatOrErr.Err)
 		}
+		ii++
 	}
 	if ii != b.N {
 		b.Fatalf(`Expected to receive %d hats, got %d`, b.N, ii)