feat: session load perf (#17186)

3 files changed, 52 insertions, 16 deletions

diff --git a/packages/app/src/pages/layout/sidebar-items.tsx b/packages/app/src/pages/layout/sidebar-items.tsx
index 8dc03755e..b6c8fedb1 100644
--- a/packages/app/src/pages/layout/sidebar-items.tsx
+++ b/packages/app/src/pages/layout/sidebar-items.tsx
@@ -10,6 +10,7 @@ import { base64Encode } from "@opencode-ai/util/encode"
 import { getFilename } from "@opencode-ai/util/path"
 import { A, useNavigate, useParams } from "@solidjs/router"
 import { type Accessor, createMemo, For, type JSX, Match, onCleanup, Show, Switch } from "solid-js"
+import { getSessionPrefetch, SESSION_PREFETCH_TTL } from "@/context/global-sync/session-prefetch"
 import { useGlobalSync } from "@/context/global-sync"
 import { useLanguage } from "@/context/language"
 import { getAvatarColors, type LocalProject, useLayout } from "@/context/layout"
@@ -67,6 +68,8 @@ export const ProjectIcon = (props: { project: LocalProject; class?: string; noti
 
 export type SessionItemProps = {
   session: Session
+  list: Session[]
+  navList?: Accessor<Session[]>
   slug: string
   mobile?: boolean
   dense?: boolean
@@ -95,18 +98,18 @@ const SessionRow = (props: {
   setHoverSession: (id: string | undefined) => void
   clearHoverProjectSoon: () => void
   sidebarOpened: Accessor<boolean>
-  prefetchSession: (session: Session, priority?: "high" | "low") => void
-  scheduleHoverPrefetch: () => void
+  warmHover: () => void
+  warmPress: () => void
+  warmFocus: () => void
   cancelHoverPrefetch: () => void
 }): JSX.Element => (
   <A
     href={`/${props.slug}/session/${props.session.id}`}
     class={`flex items-center justify-between gap-3 min-w-0 text-left w-full focus:outline-none transition-[padding] ${props.mobile ? "pr-7" : ""} group-hover/session:pr-7 group-focus-within/session:pr-7 group-active/session:pr-7 ${props.dense ? "py-0.5" : "py-1"}`}
-    onPointerEnter={props.scheduleHoverPrefetch}
+    onPointerDown={props.warmPress}
+    onPointerEnter={props.warmHover}
     onPointerLeave={props.cancelHoverPrefetch}
-    onMouseEnter={props.scheduleHoverPrefetch}
-    onMouseLeave={props.cancelHoverPrefetch}
-    onFocus={() => props.prefetchSession(props.session, "high")}
+    onFocus={props.warmFocus}
     onClick={() => {
       props.setHoverSession(undefined)
       if (props.sidebarOpened()) return
@@ -225,11 +228,37 @@ export const SessionItem = (props: SessionItemProps): JSX.Element => {
   const hoverMessages = createMemo(() =>
     sessionStore.message[props.session.id]?.filter((message): message is UserMessage => message.role === "user"),
   )
-  const hoverReady = createMemo(() => sessionStore.message[props.session.id] !== undefined)
+  const hoverReady = createMemo(() => {
+    if (sessionStore.message[props.session.id] === undefined) return false
+    if (props.session.id === params.id) return true
+    const info = getSessionPrefetch(props.session.directory, props.session.id)
+    if (!info) return false
+    return Date.now() - info.at < SESSION_PREFETCH_TTL
+  })
   const hoverAllowed = createMemo(() => !props.mobile && props.sidebarExpanded())
   const hoverEnabled = createMemo(() => (props.popover ?? true) && hoverAllowed())
   const isActive = createMemo(() => props.session.id === params.id)
 
+  const warm = (span: number, priority: "high" | "low") => {
+    const nav = props.navList?.()
+    const list = nav?.some((item) => item.id === props.session.id && item.directory === props.session.directory)
+      ? nav
+      : props.list
+
+    props.prefetchSession(props.session, priority)
+
+    const idx = list.findIndex((item) => item.id === props.session.id && item.directory === props.session.directory)
+    if (idx === -1) return
+
+    for (let step = 1; step <= span; step++) {
+      const next = list[idx + step]
+      if (next) props.prefetchSession(next, step === 1 ? "high" : priority)
+
+      const prev = list[idx - step]
+      if (prev) props.prefetchSession(prev, step === 1 ? "high" : priority)
+    }
+  }
+
   const hoverPrefetch = {
     current: undefined as ReturnType<typeof setTimeout> | undefined,
   }
@@ -239,11 +268,12 @@ export const SessionItem = (props: SessionItemProps): JSX.Element => {
     hoverPrefetch.current = undefined
   }
   const scheduleHoverPrefetch = () => {
+    warm(1, "high")
     if (hoverPrefetch.current !== undefined) return
     hoverPrefetch.current = setTimeout(() => {
       hoverPrefetch.current = undefined
-      props.prefetchSession(props.session)
-    }, 200)
+      warm(2, "low")
+    }, 80)
   }
 
   onCleanup(cancelHoverPrefetch)
@@ -267,8 +297,9 @@ export const SessionItem = (props: SessionItemProps): JSX.Element => {
       setHoverSession={props.setHoverSession}
       clearHoverProjectSoon={props.clearHoverProjectSoon}
       sidebarOpened={layout.sidebar.opened}
-      prefetchSession={props.prefetchSession}
-      scheduleHoverPrefetch={scheduleHoverPrefetch}
+      warmHover={scheduleHoverPrefetch}
+      warmPress={() => warm(2, "high")}
+      warmFocus={() => warm(2, "high")}
       cancelHoverPrefetch={cancelHoverPrefetch}
     />
   )
diff --git a/packages/app/src/pages/layout/sidebar-project.tsx b/packages/app/src/pages/layout/sidebar-project.tsx
index 551090fd5..a26bc1831 100644
--- a/packages/app/src/pages/layout/sidebar-project.tsx
+++ b/packages/app/src/pages/layout/sidebar-project.tsx
@@ -30,7 +30,7 @@ export type ProjectSidebarContext = {
   workspacesEnabled: (project: LocalProject) => boolean
   workspaceIds: (project: LocalProject) => string[]
   workspaceLabel: (directory: string, branch?: string, projectId?: string) => string
-  sessionProps: Omit<SessionItemProps, "session" | "slug" | "children" | "mobile" | "dense" | "popover">
+  sessionProps: Omit<SessionItemProps, "session" | "list" | "slug" | "children" | "mobile" | "dense" | "popover">
   setHoverSession: (id: string | undefined) => void
 }
 
@@ -204,11 +204,12 @@ const ProjectPreviewPanel = (props: {
       <Show
         when={props.workspaceEnabled()}
         fallback={
-          <For each={props.projectSessions()}>
+          <For each={props.projectSessions().slice(0, 2)}>
             {(session) => (
               <SessionItem
                 {...props.ctx.sessionProps}
                 session={session}
+                list={props.projectSessions()}
                 slug={base64Encode(props.project.worktree)}
                 dense
                 mobile={props.mobile}
@@ -231,11 +232,12 @@ const ProjectPreviewPanel = (props: {
                   </div>
                   <span class="truncate text-14-medium text-text-base">{props.label(directory)}</span>
                 </div>
-                <For each={sessions()}>
+                <For each={sessions().slice(0, 2)}>
                   {(session) => (
                     <SessionItem
                       {...props.ctx.sessionProps}
                       session={session}
+                      list={sessions()}
                       slug={base64Encode(directory)}
                       dense
                       mobile={props.mobile}
@@ -317,11 +319,11 @@ export const SortableProject = (props: {
   }
 
   const projectStore = createMemo(() => globalSync.child(props.project.worktree, { bootstrap: false })[0])
-  const projectSessions = createMemo(() => sortedRootSessions(projectStore(), props.sortNow()).slice(0, 2))
+  const projectSessions = createMemo(() => sortedRootSessions(projectStore(), props.sortNow()))
   const projectChildren = createMemo(() => childMapByParent(projectStore().session))
   const workspaceSessions = (directory: string) => {
     const [data] = globalSync.child(directory, { bootstrap: false })
-    return sortedRootSessions(data, props.sortNow()).slice(0, 2)
+    return sortedRootSessions(data, props.sortNow())
   }
   const workspaceChildren = (directory: string) => {
     const [data] = globalSync.child(directory, { bootstrap: false })
diff --git a/packages/app/src/pages/layout/sidebar-workspace.tsx b/packages/app/src/pages/layout/sidebar-workspace.tsx
index 5eb5e71cd..48c63e547 100644
--- a/packages/app/src/pages/layout/sidebar-workspace.tsx
+++ b/packages/app/src/pages/layout/sidebar-workspace.tsx
@@ -32,6 +32,7 @@ type InlineEditorComponent = (props: {
 
 export type WorkspaceSidebarContext = {
   currentDir: Accessor<string>
+  navList: Accessor<Session[]>
   sidebarExpanded: Accessor<boolean>
   sidebarHovering: Accessor<boolean>
   nav: Accessor<HTMLElement | undefined>
@@ -265,6 +266,8 @@ const WorkspaceSessionList = (props: {
       {(session) => (
         <SessionItem
           session={session}
+          list={props.sessions()}
+          navList={props.ctx.navList}
           slug={props.slug()}
           mobile={props.mobile}
           popover={props.popover}