feat: session load perf (#17186)

packages/app/src/pages/session.tsx

@@ -27,6 +27,7 @@ import { base64Encode, checksum } from "@opencode-ai/util/encode"
 import { useNavigate, useSearchParams } from "@solidjs/router"
 import { NewSessionView, SessionHeader } from "@/components/session"
 import { useComments } from "@/context/comments"
+import { getSessionPrefetch, SESSION_PREFETCH_TTL } from "@/context/global-sync/session-prefetch"
 import { useGlobalSync } from "@/context/global-sync"
 import { useLanguage } from "@/context/language"
 import { useLayout } from "@/context/layout"
@@ -437,7 +438,6 @@ export default function Page() {
       (next, prev) => {
         if (!prev) return
         if (next.dir === prev.dir && next.id === prev.id) return
-        if (prev.id) sync.session.evict(prev.id, prev.dir)
         if (!next.id) resetSessionModel(local)
       },
       { defer: true },
@@ -464,6 +464,10 @@ export default function Page() {
   }, sessionKey())
 
   let reviewFrame: number | undefined
+  let refreshFrame: number | undefined
+  let refreshTimer: number | undefined
+  let diffFrame: number | undefined
+  let diffTimer: number | undefined
 
   createComputed((prev) => {
     const open = desktopReviewOpen()
@@ -623,10 +627,36 @@ export default function Page() {
 
   createEffect(
     on([() => sdk.directory, () => params.id] as const, ([, id]) => {
+      if (refreshFrame !== undefined) cancelAnimationFrame(refreshFrame)
+      if (refreshTimer !== undefined) window.clearTimeout(refreshTimer)
+      refreshFrame = undefined
+      refreshTimer = undefined
       if (!id) return
+
+      const cached = untrack(() => sync.data.message[id] !== undefined)
+      const stale = !cached
+        ? false
+        : (() => {
+            const info = getSessionPrefetch(sdk.directory, id)
+            if (!info) return true
+            return Date.now() - info.at > SESSION_PREFETCH_TTL
+          })()
+      const todos = untrack(() => sync.data.todo[id] !== undefined || globalSync.data.session_todo[id] !== undefined)
+
       untrack(() => {
         void sync.session.sync(id)
-        void sync.session.todo(id)
+      })
+
+      refreshFrame = requestAnimationFrame(() => {
+        refreshFrame = undefined
+        refreshTimer = window.setTimeout(() => {
+          refreshTimer = undefined
+          if (params.id !== id) return
+          untrack(() => {
+            if (stale) void sync.session.sync(id, { force: true })
+            void sync.session.todo(id, todos ? { force: true } : undefined)
+          })
+        }, 0)
       })
     }),
   )
@@ -1064,6 +1094,39 @@ export default function Page() {
     void sync.session.diff(id)
   })
 
+  createEffect(
+    on(
+      () =>
+        [
+          sessionKey(),
+          isDesktop()
+            ? desktopFileTreeOpen() || (desktopReviewOpen() && activeTab() === "review")
+            : store.mobileTab === "changes",
+        ] as const,
+      ([key, wants]) => {
+        if (diffFrame !== undefined) cancelAnimationFrame(diffFrame)
+        if (diffTimer !== undefined) window.clearTimeout(diffTimer)
+        diffFrame = undefined
+        diffTimer = undefined
+        if (!wants) return
+
+        const id = params.id
+        if (!id) return
+        if (!untrack(() => sync.data.session_diff[id] !== undefined)) return
+
+        diffFrame = requestAnimationFrame(() => {
+          diffFrame = undefined
+          diffTimer = window.setTimeout(() => {
+            diffTimer = undefined
+            if (sessionKey() !== key) return
+            void sync.session.diff(id, { force: true })
+          }, 0)
+        })
+      },
+      { defer: true },
+    ),
+  )
+
   let treeDir: string | undefined
   createEffect(() => {
     const dir = sdk.directory
@@ -1326,6 +1389,10 @@ export default function Page() {
   onCleanup(() => {
     document.removeEventListener("keydown", handleKeyDown)
     if (reviewFrame !== undefined) cancelAnimationFrame(reviewFrame)
+    if (refreshFrame !== undefined) cancelAnimationFrame(refreshFrame)
+    if (refreshTimer !== undefined) window.clearTimeout(refreshTimer)
+    if (diffFrame !== undefined) cancelAnimationFrame(diffFrame)
+    if (diffTimer !== undefined) window.clearTimeout(diffTimer)
     if (scrollStateFrame !== undefined) cancelAnimationFrame(scrollStateFrame)
   })