perf(disk): remove runtime caches left by earlier versions after startup

src/main/stale-runtime-cache-cleanup.ts

@@ -0,0 +1,76 @@
+import { readdir, rm } from 'node:fs/promises'
+import { join } from 'node:path'
+
+/**
+ * Removes runtime caches left by earlier GoodBuddy versions (PERF, disk).
+ *
+ * - `opencode-runtime/<app version>/`: OpenCode's shared config and skills
+ *   are prepared per app version and only the current version's directory is
+ *   ever used, so every other version-named directory is stale (~50 MB each).
+ * - `continue-host/host-v<layout>-…/`: patched Continue host bundles; only
+ *   the current layout is read. Older layouts are stale. Directories of the
+ *   current layout (other Continue versions or digests) are left alone, as
+ *   are run directories, logs, sessions and config files.
+ *
+ * Only names that match these exact patterns are touched, never anything
+ * else in the user data directory. Failures (a file in use, permissions) are
+ * ignored; the next start tries again.
+ */
+export type StaleRuntimeCacheCleanupOptions = {
+  userDataPath: string
+  appVersion: string
+  continueHostLayoutVersion: number
+}
+
+const appVersionPattern = /^\d+\.\d+\.\d+(?:-[0-9A-Za-z.-]+)?$/u
+const continueHostPattern = /^host-v(\d+)-/u
+
+async function directoryNames(path: string): Promise<string[]> {
+  try {
+    return (await readdir(path, { withFileTypes: true }))
+      .filter((entry) => entry.isDirectory() && !entry.isSymbolicLink())
+      .map((entry) => entry.name)
+  } catch {
+    return []
+  }
+}
+
+export function staleRuntimeCacheDirectories(
+  names: { opencode: readonly string[]; continueHost: readonly string[] },
+  options: Pick<StaleRuntimeCacheCleanupOptions, 'appVersion' | 'continueHostLayoutVersion'>
+): { opencode: string[]; continueHost: string[] } {
+  return {
+    opencode: names.opencode.filter((name) =>
+      appVersionPattern.test(name) && name !== options.appVersion),
+    continueHost: names.continueHost.filter((name) => {
+      const match = continueHostPattern.exec(name)
+      return match !== null && Number(match[1]) < options.continueHostLayoutVersion
+    })
+  }
+}
+
+export async function removeStaleRuntimeCaches(
+  options: StaleRuntimeCacheCleanupOptions
+): Promise<{ removed: string[] }> {
+  const opencodeRoot = join(options.userDataPath, 'opencode-runtime')
+  const continueRoot = join(options.userDataPath, 'continue-host')
+  const stale = staleRuntimeCacheDirectories({
+    opencode: await directoryNames(opencodeRoot),
+    continueHost: await directoryNames(continueRoot)
+  }, options)
+  const targets = [
+    ...stale.opencode.map((name) => join(opencodeRoot, name)),
+    ...stale.continueHost.map((name) => join(continueRoot, name))
+  ]
+  const removed: string[] = []
+  // One at a time: this runs in the background and should not compete for disk.
+  for (const target of targets) {
+    try {
+      await rm(target, { recursive: true, force: true, maxRetries: 2, retryDelay: 200 })
+      removed.push(target)
+    } catch {
+      // Left for the next start.
+    }
+  }
+  return { removed }
+}