idler: improve the imap idler

Rewrite the imap idler to make it more fault tolerant and prevent hangs
(and possibly short writes).

Fixes: https://todo.sr.ht/~rjarry/aerc/208
Signed-off-by: Koni Marti <koni.marti@gmail.com>
Tested-by: Karel Balej <balejk@matfyz.cz>
Acked-by: Robin Jarry <robin@jarry.cc>

1 files changed, 5 insertions, 19 deletions

diff --git a/worker/middleware/gmailworker.go b/worker/middleware/gmailworker.go
index 807f7bff..f9924732 100644
--- a/worker/middleware/gmailworker.go
+++ b/worker/middleware/gmailworker.go
@@ -8,20 +8,14 @@ import (
 	"github.com/emersion/go-imap/client"
 )
 
-type idler interface {
-	Start()
-	Stop() error
-}
-
 type gmailWorker struct {
 	types.WorkerInteractor
 	mu     sync.Mutex
 	client *client.Client
-	idler  idler
 }
 
 // NewGmailWorker returns an IMAP middleware for the X-GM-EXT-1 extension
-func NewGmailWorker(base types.WorkerInteractor, c *client.Client, i idler,
+func NewGmailWorker(base types.WorkerInteractor, c *client.Client,
 ) types.WorkerInteractor {
 	base.Infof("loading worker middleware: X-GM-EXT-1")
 
@@ -29,37 +23,30 @@ func NewGmailWorker(base types.WorkerInteractor, c *client.Client, i idler,
 	for iter := base; iter != nil; iter = iter.Unwrap() {
 		if g, ok := iter.(*gmailWorker); ok {
 			base.Infof("already loaded; resetting")
-			err := g.reset(c, i)
+			err := g.reset(c)
 			if err != nil {
 				base.Errorf("reset failed: %v", err)
 			}
 			return base
 		}
 	}
-	return &gmailWorker{WorkerInteractor: base, client: c, idler: i}
+	return &gmailWorker{WorkerInteractor: base, client: c}
 }
 
 func (g *gmailWorker) Unwrap() types.WorkerInteractor {
 	return g.WorkerInteractor
 }
 
-func (g *gmailWorker) reset(c *client.Client, i idler) error {
+func (g *gmailWorker) reset(c *client.Client) error {
 	g.mu.Lock()
 	defer g.mu.Unlock()
 	g.client = c
-	g.idler = i
 	return nil
 }
 
 func (g *gmailWorker) ProcessAction(msg types.WorkerMessage) types.WorkerMessage {
-	switch msg := msg.(type) {
-	case *types.FetchMessageHeaders:
+	if msg, ok := msg.(*types.FetchMessageHeaders); ok && len(msg.Uids) > 0 {
 		g.mu.Lock()
-		err := g.idler.Stop()
-		if err != nil {
-			g.Errorf("idler reported an error: %v", err)
-			break
-		}
 
 		handler := xgmext.NewHandler(g.client)
 		uids, err := handler.FetchEntireThreads(msg.Uids)
@@ -71,7 +58,6 @@ func (g *gmailWorker) ProcessAction(msg types.WorkerMessage) types.WorkerMessage
 			msg.Uids = uids
 		}
 
-		g.idler.Start()
 		g.mu.Unlock()
 	}
 	return g.WorkerInteractor.ProcessAction(msg)