Close sesh with defer

This commit adds a way to close the session of dmsg via a defer statement with a go routine in it inside the fun RoundTrip().

The goroutine checks if the response body is closed every 10 seconds and if it is closed then we clsoe the session if not then we keep checking till it's closed or if context is closed.

dmsgget/dmsgget.go

@@ -110,7 +110,7 @@ func (dg *DmsgGet) Run(ctx context.Context, log *logging.Logger, skStr string, a
 	}
 	defer closeDmsg()
 
-	httpC := http.Client{Transport: dmsghttp.MakeHTTPTransport(dmsgC)}
+	httpC := http.Client{Transport: dmsghttp.MakeHTTPTransport(ctx, dmsgC)}
 
 	for i := 0; i < dg.dlF.Tries; i++ {
 		log.Infof("Download attempt %d/%d ...", i, dg.dlF.Tries)

dmsgget/dmsgget_test.go

@@ -172,5 +172,8 @@ func newHTTPClient(t *testing.T, dc disc.APIClient) *http.Client {
 	t.Cleanup(func() { assert.NoError(t, dmsgC.Close()) })
 	<-dmsgC.Ready()
 
-	return &http.Client{Transport: dmsghttp.MakeHTTPTransport(dmsgC)}
+	log := logging.MustGetLogger(fmt.Sprintf("http_client"))
+	ctx, cancel := cmdutil.SignalContext(context.Background(), log)
+	defer cancel()
+	return &http.Client{Transport: dmsghttp.MakeHTTPTransport(ctx, dmsgC)}
 }

dmsghttp/examples_test.go

@@ -12,8 +12,10 @@ import (
 
 	"github.com/skycoin/dmsg"
 	"github.com/skycoin/dmsg/cipher"
+	"github.com/skycoin/dmsg/cmdutil"
 	"github.com/skycoin/dmsg/disc"
 	"github.com/skycoin/dmsg/dmsghttp"
+	"github.com/skycoin/skycoin/src/util/logging"
 )
 
 func ExampleMakeHTTPTransport() {
@@ -87,8 +89,11 @@ func ExampleMakeHTTPTransport() {
 	go dmsgC2.Serve(context.Background())
 	<-dmsgC2.Ready()
 
+	log := logging.MustGetLogger(fmt.Sprintf("http_client"))
+	ctx, cancel := cmdutil.SignalContext(context.Background(), log)
+	defer cancel()
 	// Run HTTP client.
-	httpC := http.Client{Transport: dmsghttp.MakeHTTPTransport(dmsgC2)}
+	httpC := http.Client{Transport: dmsghttp.MakeHTTPTransport(ctx, dmsgC2)}
 	resp, err := httpC.Get(fmt.Sprintf("http://%s:%d/", c1PK.String(), dmsgHTTPPort))
 	if err != nil {
 		panic(err)

dmsghttp/http_transport.go

@@ -2,8 +2,10 @@ package dmsghttp
 
 import (
 	"bufio"
+	"context"
 	"fmt"
 	"net/http"
+	"time"
 
 	"github.com/skycoin/dmsg"
 )
@@ -13,12 +15,16 @@ const defaultHTTPPort = uint16(80)
 // HTTPTransport implements http.RoundTripper
 // Do not confuse this with a Skywire Transport implementation.
 type HTTPTransport struct {
+	ctx   context.Context
 	dmsgC *dmsg.Client
 }
 
 // MakeHTTPTransport makes an HTTPTransport.
-func MakeHTTPTransport(dmsgC *dmsg.Client) HTTPTransport {
-	return HTTPTransport{dmsgC: dmsgC}
+func MakeHTTPTransport(ctx context.Context, dmsgC *dmsg.Client) HTTPTransport {
+	return HTTPTransport{
+		ctx:   ctx,
+		dmsgC: dmsgC,
+	}
 }
 
 // RoundTrip implements golang's http package support for alternative HTTP transport protocols.
@@ -39,10 +45,42 @@ func (t HTTPTransport) RoundTrip(req *http.Request) (*http.Response, error) {
 	if err != nil {
 		return nil, err
 	}
-
 	if err := req.Write(stream); err != nil {
 		return nil, err
 	}
 	bufR := bufio.NewReader(stream)
-	return http.ReadResponse(bufR, req)
+	resp, err := http.ReadResponse(bufR, req)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		go test(t.ctx, resp, stream)
+	}()
+
+	return resp, nil
+}
+
+func test(ctx context.Context, resp *http.Response, stream *dmsg.Stream) {
+	ticker := time.NewTicker(time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			_, err := resp.Body.Read(nil)
+			log := stream.Logger()
+			log.Errorf("err %v", err)
+			if err == nil {
+				// can still read from body so it's not closed
+
+			} else if err != nil && err.Error() == "http: invalid Read on closed Body" {
+				stream.Close()
+				return
+			}
+		}
+	}
+
 }

dmsghttp/http_transport_test.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/skycoin/dmsg"
 	"github.com/skycoin/dmsg/cipher"
+	"github.com/skycoin/dmsg/cmdutil"
 	"github.com/skycoin/dmsg/disc"
 )
 
@@ -63,10 +64,13 @@ func TestHTTPTransport_RoundTrip(t *testing.T) {
 		startHTTPServer(t, server0Results, lis)
 		addr := lis.Addr().String()
 
+		log := logging.MustGetLogger(fmt.Sprintf("http_client"))
+		ctx, cancel := cmdutil.SignalContext(context.Background(), log)
+		defer cancel()
 		// Arrange: create http clients (in which each http client has an underlying dmsg client).
-		httpC1 := http.Client{Transport: MakeHTTPTransport(newDmsgClient(t, dc, minSessions, "client1"))}
-		httpC2 := http.Client{Transport: MakeHTTPTransport(newDmsgClient(t, dc, minSessions, "client2"))}
-		httpC3 := http.Client{Transport: MakeHTTPTransport(newDmsgClient(t, dc, minSessions, "client3"))}
+		httpC1 := http.Client{Transport: MakeHTTPTransport(ctx, newDmsgClient(t, dc, minSessions, "client1"))}
+		httpC2 := http.Client{Transport: MakeHTTPTransport(ctx, newDmsgClient(t, dc, minSessions, "client2"))}
+		httpC3 := http.Client{Transport: MakeHTTPTransport(ctx, newDmsgClient(t, dc, minSessions, "client3"))}
 		httpC1.Timeout = timeout
 		httpC2.Timeout = timeout
 		httpC3.Timeout = timeout