feat: cache media play-url by session and debounce open

src/views/MediaView/MediaView.vue

@@ -102,13 +102,19 @@ const activeLive = reactive({
   dockId: '',
   sessionId: '',
   playUrl: '',
+  playUrlExpiresAt: 0,
   phase: '',
   leaseExpiresAt: 0,
 })
+const PLAY_URL_FRESH_MS = 30_000
+const PLAY_EXPIRE_FALLBACK_SEC = 270
 let heartbeatTimer = null
 let openSeq = 0
 let disposed = false
 let rejoinBusy = false
+let playUrlPromise = null
+let playUrlSessionId = ''
+let opening = false
 
 const LEASE_INVALID_CODE = 57006
 
@@ -144,14 +150,59 @@ function clearHeartbeat() {
 
 function resetActiveLive() {
   clearHeartbeat()
+  playUrlPromise = null
+  playUrlSessionId = ''
   activeLive.id = ''
   activeLive.dockId = ''
   activeLive.sessionId = ''
   activeLive.playUrl = ''
+  activeLive.playUrlExpiresAt = 0
   activeLive.phase = ''
   activeLive.leaseExpiresAt = 0
 }
 
+async function ensurePlayUrl(dockId, sessionId, { force = false } = {}) {
+  if (!dockId || !sessionId) return null
+
+  if (
+    !force &&
+    activeLive.sessionId === sessionId &&
+    activeLive.playUrl &&
+    activeLive.playUrlExpiresAt * 1000 - Date.now() > PLAY_URL_FRESH_MS
+  ) {
+    return {
+      playUrl: activeLive.playUrl,
+      expiresAt: activeLive.playUrlExpiresAt,
+    }
+  }
+
+  if (playUrlPromise && playUrlSessionId === sessionId) {
+    return playUrlPromise
+  }
+
+  const seq = openSeq
+  playUrlSessionId = sessionId
+  playUrlPromise = getLivePlayURL(dockId, sessionId)
+    .then((play) => {
+      if (disposed || seq !== openSeq || activeLive.sessionId !== sessionId) return play
+      const nowSec = Math.floor(Date.now() / 1000)
+      const expiresAt = Number(play?.expiresAt) || nowSec + PLAY_EXPIRE_FALLBACK_SEC
+      if (play?.playUrl) {
+        activeLive.playUrl = play.playUrl
+        activeLive.playUrlExpiresAt = expiresAt
+      }
+      return play
+    })
+    .finally(() => {
+      if (playUrlSessionId === sessionId) {
+        playUrlPromise = null
+        playUrlSessionId = ''
+      }
+    })
+
+  return playUrlPromise
+}
+
 function scheduleHeartbeat(expiresAt) {
   clearHeartbeat()
   if (disposed || !activeLive.dockId || !activeLive.sessionId) return
@@ -165,6 +216,18 @@ function scheduleHeartbeat(expiresAt) {
       const result = await heartbeatLive(dockId, sessionId)
       if (disposed || activeLive.sessionId !== sessionId || activeLive.dockId !== dockId) return
       if (result?.session?.phase) activeLive.phase = result.session.phase
+      if (result?.session?.phase === 'streaming' && !activeLive.playUrl) {
+        try {
+          await ensurePlayUrl(dockId, sessionId)
+        } catch (playErr) {
+          if (disposed || activeLive.sessionId !== sessionId) return
+          if (isLeaseInvalidError(playErr)) {
+            await rejoinAfterLeaseInvalid(streamId, dockId)
+            return
+          }
+          console.warn('[media] ensure play-url after heartbeat failed', playErr)
+        }
+      }
       scheduleHeartbeat(result.leaseExpiresAt)
     } catch (e) {
       if (disposed || activeLive.sessionId !== sessionId || activeLive.dockId !== dockId) return
@@ -236,24 +299,23 @@ async function load() {
 }
 
 async function openLive(stream) {
-  if (disposed || !stream?.dockId) return
+  if (disposed || !stream?.dockId || opening) return
   if (activeLive.id === stream.id && activeLive.playUrl) {
     await closeActiveLive()
     return
   }
 
-  // closeActiveLive 会 bump openSeq，使旧 in-flight join 失效；之后再取本次 seq
   await closeActiveLive()
+  if (disposed) return
+  opening = true
   const seq = ++openSeq
-
   try {
     const result = await joinLiveWithRetry(stream.dockId, {}, {
-      shouldContinue: () => seq === openSeq && !disposed,
+      shouldContinue: () => seq === openSeq && !disposed && opening,
     })
     const session = result?.session
     const sessionId = session?.id
 
-    // 页面已切走/关闭：不要写入状态，立刻释放刚拿到的 viewer lease
     if (seq !== openSeq || disposed) {
       if (sessionId) await safeLeave(stream.dockId, sessionId)
       return
@@ -269,6 +331,7 @@ async function openLive(stream) {
     activeLive.sessionId = sessionId
     activeLive.phase = session.phase || ''
     activeLive.playUrl = ''
+    activeLive.playUrlExpiresAt = 0
     scheduleHeartbeat(result.leaseExpiresAt)
 
     if (session.phase !== 'streaming') {
@@ -276,11 +339,13 @@ async function openLive(stream) {
       return
     }
 
-    const play = await getLivePlayURL(stream.dockId, sessionId)
+    const play = await ensurePlayUrl(stream.dockId, sessionId)
     if (seq !== openSeq || disposed || activeLive.sessionId !== sessionId) return
     if (play?.playUrl && !play.playUrl.startsWith('fake://')) {
+      if (!activeLive.playUrl) {
         activeLive.playUrl = play.playUrl
-    } else {
+      }
+    } else if (!activeLive.playUrl) {
       ui.toast('控制面已验证，当前未配置可播放媒体流')
     }
   } catch (e) {
@@ -291,6 +356,8 @@ async function openLive(stream) {
     }
     await closeActiveLive()
     ui.toast(e.message || '打开直播失败')
+  } finally {
+    opening = false
   }
 }