feat: writing filetime reads to disk to persist across process being killed

packages/opencode/src/file/time.ts

@@ -1,5 +1,6 @@
 import { Instance } from "../project/instance"
 import { Log } from "../util/log"
+import { Storage } from "../storage/storage"
 
 export namespace FileTime {
   const log = Log.create({ service: "file.time" })
@@ -19,14 +20,35 @@ export namespace FileTime {
     const { read } = state()
     read[sessionID] = read[sessionID] || {}
     read[sessionID][file] = new Date()
+
+    Storage.write(["filetime", sessionID, Buffer.from(file).toString("base64url")], {
+      time: read[sessionID][file]!.toISOString(),
+      path: file,
+    }).catch(() => {})
   }
 
-  export function get(sessionID: string, file: string) {
-    return state().read[sessionID]?.[file]
+  export async function get(sessionID: string, file: string) {
+    const memTime = state().read[sessionID]?.[file]
+    if (memTime) return memTime
+
+    const stored = await Storage.read<{ time: string; path: string }>([
+      "filetime",
+      sessionID,
+      Buffer.from(file).toString("base64url"),
+    ]).catch(() => undefined)
+
+    if (stored?.time) {
+      const date = new Date(stored.time)
+      const { read } = state()
+      read[sessionID] = read[sessionID] || {}
+      read[sessionID][file] = date
+      return date
+    }
+    return undefined
   }
 
   export async function assert(sessionID: string, filepath: string) {
-    const time = get(sessionID, filepath)
+    const time = await get(sessionID, filepath)
     if (!time) throw new Error(`You must read the file ${filepath} before overwriting it. Use the Read tool first`)
     const stats = await Bun.file(filepath).stat()
     if (stats.mtime.getTime() > time.getTime()) {