From 092299891f07326f65b27e050c7aa8a9595b3445 Mon Sep 17 00:00:00 2001
From: zeripath <art27@cantab.net>
Date: Fri, 19 Feb 2021 10:05:35 +0000
Subject: [PATCH] Move the stopwatches to the eventsource stream (#14588)

Move the stopwatches to the eventsource stream

Use the /user/events eventsource to update the stopwatches
instead of polling /api/v1/user/stopwatches if the eventsource
is enabled.

Signed-off-by: Andrew Thornton <art27@cantab.net>
---
 routers/events/events.go                      | 32 +++++++++++
 .../js/features/eventsource.sharedworker.js   |  1 +
 web_src/js/features/stopwatch.js              | 57 ++++++++++++++++++-
 3 files changed, 89 insertions(+), 1 deletion(-)

diff --git a/routers/events/events.go b/routers/events/events.go
index a1131f29e..2b78d8603 100644
--- a/routers/events/events.go
+++ b/routers/events/events.go
@@ -5,13 +5,17 @@
 package events
 
 import (
+	"encoding/json"
 	"net/http"
 	"time"
 
+	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/convert"
 	"code.gitea.io/gitea/modules/eventsource"
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/routers/user"
 )
 
@@ -55,6 +59,8 @@ func Events(ctx *context.Context) {
 
 	timer := time.NewTicker(30 * time.Second)
 
+	stopwatchTimer := time.NewTicker(setting.UI.Notification.MinTimeout)
+
 loop:
 	for {
 		select {
@@ -75,6 +81,32 @@ loop:
 		case <-shutdownCtx.Done():
 			go unregister()
 			break loop
+		case <-stopwatchTimer.C:
+			sws, err := models.GetUserStopwatches(ctx.User.ID, models.ListOptions{})
+			if err != nil {
+				log.Error("Unable to GetUserStopwatches: %v", err)
+				continue
+			}
+			apiSWs, err := convert.ToStopWatches(sws)
+			if err != nil {
+				log.Error("Unable to APIFormat stopwatches: %v", err)
+				continue
+			}
+			dataBs, err := json.Marshal(apiSWs)
+			if err != nil {
+				log.Error("Unable to marshal stopwatches: %v", err)
+				continue
+			}
+			_, err = (&eventsource.Event{
+				Name: "stopwatches",
+				Data: string(dataBs),
+			}).WriteTo(ctx.Resp)
+			if err != nil {
+				log.Error("Unable to write to EventStream for user %s: %v", ctx.User.Name, err)
+				go unregister()
+				break loop
+			}
+			ctx.Resp.Flush()
 		case event, ok := <-messageChan:
 			if !ok {
 				break loop
diff --git a/web_src/js/features/eventsource.sharedworker.js b/web_src/js/features/eventsource.sharedworker.js
index bb4f628f6..a94551e82 100644
--- a/web_src/js/features/eventsource.sharedworker.js
+++ b/web_src/js/features/eventsource.sharedworker.js
@@ -12,6 +12,7 @@ class Source {
     this.listen('open');
     this.listen('logout');
     this.listen('notification-count');
+    this.listen('stopwatches');
     this.listen('error');
   }
 
diff --git a/web_src/js/features/stopwatch.js b/web_src/js/features/stopwatch.js
index d500fb5f0..433f042a1 100644
--- a/web_src/js/features/stopwatch.js
+++ b/web_src/js/features/stopwatch.js
@@ -17,7 +17,58 @@ export async function initStopwatch() {
     $(this).parent().trigger('submit');
   });
 
-  if (!stopwatchEl || NotificationSettings.MinTimeout <= 0) {
+  if (!stopwatchEl) {
+    return;
+  }
+
+  if (NotificationSettings.EventSourceUpdateTime > 0 && !!window.EventSource && window.SharedWorker) {
+    // Try to connect to the event source via the shared worker first
+    const worker = new SharedWorker(`${__webpack_public_path__}js/eventsource.sharedworker.js`, 'notification-worker');
+    worker.addEventListener('error', (event) => {
+      console.error(event);
+    });
+    worker.port.onmessageerror = () => {
+      console.error('Unable to deserialize message');
+    };
+    worker.port.postMessage({
+      type: 'start',
+      url: `${window.location.origin}${AppSubUrl}/user/events`,
+    });
+    worker.port.addEventListener('message', (event) => {
+      if (!event.data || !event.data.type) {
+        console.error(event);
+        return;
+      }
+      if (event.data.type === 'stopwatches') {
+        updateStopwatchData(JSON.parse(event.data.data));
+      } else if (event.data.type === 'error') {
+        console.error(event.data);
+      } else if (event.data.type === 'logout') {
+        if (event.data !== 'here') {
+          return;
+        }
+        worker.port.postMessage({
+          type: 'close',
+        });
+        worker.port.close();
+        window.location.href = AppSubUrl;
+      }
+    });
+    worker.port.addEventListener('error', (e) => {
+      console.error(e);
+    });
+    worker.port.start();
+    window.addEventListener('beforeunload', () => {
+      worker.port.postMessage({
+        type: 'close',
+      });
+      worker.port.close();
+    });
+
+    return;
+  }
+
+  if (NotificationSettings.MinTimeout <= 0) {
     return;
   }
 
@@ -59,6 +110,10 @@ async function updateStopwatch() {
     updateTimeInterval = null;
   }
 
+  return updateStopwatchData(data);
+}
+
+async function updateStopwatchData(data) {
   const watch = data[0];
   const btnEl = $('.active-stopwatch-trigger');
   if (!watch) {