From d2ef57bcfa362f4be18fa187bbf4949386618103 Mon Sep 17 00:00:00 2001
From: Anthony Fu <anthonyfu117@hotmail.com>
Date: Sat, 14 Jan 2023 10:55:09 +0100
Subject: [PATCH] perf: cache userSettings, improve #1013

---
 composables/users.ts                | 42 ++++++++++++++++++++---------
 error.vue                           |  3 +++
 plugins/setup-head-script.server.ts |  8 +++---
 3 files changed, 36 insertions(+), 17 deletions(-)

diff --git a/composables/users.ts b/composables/users.ts
index c68d90d2..2966979e 100644
--- a/composables/users.ts
+++ b/composables/users.ts
@@ -1,6 +1,6 @@
 import { createClient, fetchV1Instance } from 'masto'
 import type { mastodon } from 'masto'
-import type { Ref } from 'vue'
+import type { EffectScope, Ref } from 'vue'
 import type { MaybeComputedRef, RemovableRef } from '@vueuse/core'
 import type { ElkMasto, UserLogin } from '~/types'
 import {
@@ -266,18 +266,34 @@ export function checkLogin() {
   return true
 }
 
+interface UseUserLocalStorageCache {
+  scope: EffectScope
+  value: Ref<Record<string, any>>
+}
+
 /**
  * Create reactive storage for the current user
  */
 export function useUserLocalStorage<T extends object>(key: string, initial: () => T) {
-  const all = useLocalStorage<Record<string, T>>(key, {}, { deep: true })
-  return computed(() => {
-    const id = currentUser.value?.account.id
-      ? currentUser.value.account.acct
-      : '[anonymous]'
-    all.value[id] = Object.assign(initial(), all.value[id] || {})
-    return all.value[id]
-  })
+  // @ts-expect-error bind value to the function
+  const map: Map<string, UseUserLocalStorageCache> = useUserLocalStorage._ = useUserLocalStorage._ || new Map()
+
+  if (!map.has(key)) {
+    const scope = effectScope(true)
+    const value = scope.run(() => {
+      const all = useLocalStorage<Record<string, T>>(key, {}, { deep: true })
+      return computed(() => {
+        const id = currentUser.value?.account.id
+          ? currentUser.value.account.acct
+          : '[anonymous]'
+        all.value[id] = Object.assign(initial(), all.value[id] || {})
+        return all.value[id]
+      })
+    })
+    map.set(key, { scope, value: value! })
+  }
+
+  return map.get(key)!.value
 }
 
 /**
@@ -290,10 +306,12 @@ export function clearUserLocalStorage(account?: mastodon.v1.Account) {
     return
 
   const id = `${account.acct}@${currentInstance.value?.uri || currentServer.value}`
+
   // @ts-expect-error bind value to the function
-  ;(useUserLocalStorage._ as Map<string, Ref<Record<string, any>>> | undefined)?.forEach((storage) => {
-    if (storage.value[id])
-      delete storage.value[id]
+  const cacheMap = useUserLocalStorage._ as Map<string, UseUserLocalStorageCache> | undefined
+  cacheMap?.forEach(({ value }) => {
+    if (value.value[id])
+      delete value.value[id]
   })
 }
 
diff --git a/error.vue b/error.vue
index 1e5aa429..84dc9ff1 100644
--- a/error.vue
+++ b/error.vue
@@ -11,6 +11,9 @@ const errorCodes: Record<number, string> = {
   404: 'Page not found',
 }
 
+if (process.dev)
+  console.error(error)
+
 const defaultMessage = 'Something went wrong'
 
 const message = error.message ?? errorCodes[error.statusCode!] ?? defaultMessage
diff --git a/plugins/setup-head-script.server.ts b/plugins/setup-head-script.server.ts
index 36cccad1..27962c07 100644
--- a/plugins/setup-head-script.server.ts
+++ b/plugins/setup-head-script.server.ts
@@ -11,15 +11,13 @@ export default defineNuxtPlugin(() => {
         innerHTML: `
 ;(function() {
   const handle = localStorage.getItem('${STORAGE_KEY_CURRENT_USER_HANDLE}')
-  if (!handle)
-    return
+  if (!handle) { return }
   const allSettings = JSON.parse(localStorage.getItem('${STORAGE_KEY_SETTINGS}') || '{}')
   const settings = allSettings[handle]
-  if (!settings)
-    return
+  if (!settings) { return }
 
   const html = document.querySelector('html')
-  ${process.dev ? 'console.log(\'settings\', settings)' : ''}
+  ${process.dev ? 'console.log({ settings })' : ''}
 
   const { fontSize, language } = settings || {}