perf(app): better memory management

3 files changed, 130 insertions, 13 deletions

diff --git a/packages/app/src/context/file.tsx b/packages/app/src/context/file.tsx
index 16deacfe8..7509334ed 100644
--- a/packages/app/src/context/file.tsx
+++ b/packages/app/src/context/file.tsx
@@ -151,6 +151,28 @@ const WORKSPACE_KEY = "__workspace__"
 const MAX_FILE_VIEW_SESSIONS = 20
 const MAX_VIEW_FILES = 500
 
+const MAX_FILE_CONTENT_ENTRIES = 40
+const MAX_FILE_CONTENT_BYTES = 20 * 1024 * 1024
+
+const contentLru = new Map<string, number>()
+
+function approxBytes(content: FileContent) {
+  const patchBytes =
+    content.patch?.hunks.reduce((total, hunk) => {
+      return total + hunk.lines.reduce((sum, line) => sum + line.length, 0)
+    }, 0) ?? 0
+
+  return (content.content.length + (content.diff?.length ?? 0) + patchBytes) * 2
+}
+
+function touchContent(path: string, bytes?: number) {
+  const prev = contentLru.get(path)
+  if (prev === undefined && bytes === undefined) return
+  const value = bytes ?? prev ?? 0
+  contentLru.delete(path)
+  contentLru.set(path, value)
+}
+
 type ViewSession = ReturnType<typeof createViewSession>
 
 type ViewCacheEntry = {
@@ -315,10 +337,40 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
       dir: { "": { expanded: true } },
     })
 
+    const evictContent = (keep?: Set<string>) => {
+      const protectedSet = keep ?? new Set<string>()
+      const total = () => {
+        return Array.from(contentLru.values()).reduce((sum, bytes) => sum + bytes, 0)
+      }
+
+      while (contentLru.size > MAX_FILE_CONTENT_ENTRIES || total() > MAX_FILE_CONTENT_BYTES) {
+        const path = contentLru.keys().next().value
+        if (!path) return
+
+        if (protectedSet.has(path)) {
+          touchContent(path)
+          if (contentLru.size <= protectedSet.size) return
+          continue
+        }
+
+        contentLru.delete(path)
+        if (!store.file[path]) continue
+        setStore(
+          "file",
+          path,
+          produce((draft) => {
+            draft.content = undefined
+            draft.loaded = false
+          }),
+        )
+      }
+    }
+
     createEffect(() => {
       scope()
       inflight.clear()
       treeInflight.clear()
+      contentLru.clear()
       setStore("file", {})
       setTree("node", {})
       setTree("dir", { "": { expanded: true } })
@@ -399,15 +451,20 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
         .read({ path })
         .then((x) => {
           if (scope() !== directory) return
+          const content = x.data
           setStore(
             "file",
             path,
             produce((draft) => {
               draft.loaded = true
               draft.loading = false
-              draft.content = x.data
+              draft.content = content
             }),
           )
+
+          if (!content) return
+          touchContent(path, approxBytes(content))
+          evictContent(new Set([path]))
         })
         .catch((e) => {
           if (scope() !== directory) return
@@ -597,7 +654,18 @@ export const { use: useFile, provider: FileProvider } = createSimpleContext({
       listDir(parent, { force: true })
     })
 
-    const get = (input: string) => store.file[normalize(input)]
+    const get = (input: string) => {
+      const path = normalize(input)
+      const file = store.file[path]
+      const content = file?.content
+      if (!content) return file
+      if (contentLru.has(path)) {
+        touchContent(path)
+        return file
+      }
+      touchContent(path, approxBytes(content))
+      return file
+    }
 
     const scrollTop = (input: string) => view().scrollTop(normalize(input))
     const scrollLeft = (input: string) => view().scrollLeft(normalize(input))
diff --git a/packages/app/src/context/global-sync.tsx b/packages/app/src/context/global-sync.tsx
index 4efbf62aa..fb67193ab 100644
--- a/packages/app/src/context/global-sync.tsx
+++ b/packages/app/src/context/global-sync.tsx
@@ -546,6 +546,37 @@ function createGlobalSync() {
     return promise
   }
 
+  function purgeMessageParts(setStore: SetStoreFunction<State>, messageID: string | undefined) {
+    if (!messageID) return
+    setStore(
+      produce((draft) => {
+        delete draft.part[messageID]
+      }),
+    )
+  }
+
+  function purgeSessionData(store: Store<State>, setStore: SetStoreFunction<State>, sessionID: string | undefined) {
+    if (!sessionID) return
+
+    const messages = store.message[sessionID]
+    const messageIDs = (messages ?? []).map((m) => m.id).filter((id): id is string => !!id)
+
+    setStore(
+      produce((draft) => {
+        delete draft.message[sessionID]
+        delete draft.session_diff[sessionID]
+        delete draft.todo[sessionID]
+        delete draft.permission[sessionID]
+        delete draft.question[sessionID]
+        delete draft.session_status[sessionID]
+
+        for (const messageID of messageIDs) {
+          delete draft.part[messageID]
+        }
+      }),
+    )
+  }
+
   const unsub = globalSDK.event.listen((e) => {
     const directory = e.name
     const event = e.details
@@ -651,9 +682,7 @@ function createGlobalSync() {
               }),
             )
           }
-
           cleanupSessionCaches(info.id)
-
           if (info.parentID) break
           setStore("sessionTotal", (value) => Math.max(0, value - 1))
           break
@@ -679,9 +708,7 @@ function createGlobalSync() {
             }),
           )
         }
-
         cleanupSessionCaches(sessionID)
-
         if (event.properties.info.parentID) break
         setStore("sessionTotal", (value) => Math.max(0, value - 1))
         break
@@ -757,15 +784,19 @@ function createGlobalSync() {
         break
       }
       case "message.part.removed": {
-        const parts = store.part[event.properties.messageID]
+        const messageID = event.properties.messageID
+        const parts = store.part[messageID]
         if (!parts) break
         const result = Binary.search(parts, event.properties.partID, (p) => p.id)
         if (result.found) {
           setStore(
-            "part",
-            event.properties.messageID,
             produce((draft) => {
-              draft.splice(result.index, 1)
+              const list = draft.part[messageID]
+              if (!list) return
+              const next = Binary.search(list, event.properties.partID, (p) => p.id)
+              if (!next.found) return
+              list.splice(next.index, 1)
+              if (list.length === 0) delete draft.part[messageID]
             }),
           )
         }
diff --git a/packages/app/src/context/permission.tsx b/packages/app/src/context/permission.tsx
index d85f2ef24..a701dbd1f 100644
--- a/packages/app/src/context/permission.tsx
+++ b/packages/app/src/context/permission.tsx
@@ -67,7 +67,21 @@ export const { use: usePermission, provider: PermissionProvider } = createSimple
       }),
     )
 
-    const responded = new Set<string>()
+    const MAX_RESPONDED = 1000
+    const RESPONDED_TTL_MS = 60 * 60 * 1000
+    const responded = new Map<string, number>()
+
+    function pruneResponded(now: number) {
+      for (const [id, ts] of responded) {
+        if (now - ts < RESPONDED_TTL_MS) break
+        responded.delete(id)
+      }
+
+      for (const id of responded.keys()) {
+        if (responded.size <= MAX_RESPONDED) break
+        responded.delete(id)
+      }
+    }
 
     const respond: PermissionRespondFn = (input) => {
       globalSDK.client.permission.respond(input).catch(() => {
@@ -76,8 +90,12 @@ export const { use: usePermission, provider: PermissionProvider } = createSimple
     }
 
     function respondOnce(permission: PermissionRequest, directory?: string) {
-      if (responded.has(permission.id)) return
-      responded.add(permission.id)
+      const now = Date.now()
+      const hit = responded.has(permission.id)
+      responded.delete(permission.id)
+      responded.set(permission.id, now)
+      pruneResponded(now)
+      if (hit) return
       respond({
         sessionID: permission.sessionID,
         permissionID: permission.id,