fix(core): reducing service listener count

packages/core/src/context.ts

@@ -276,15 +276,16 @@ export class Context {
       disposables: [],
     })
 
-    const dispose = this.on('service', async (name) => {
-      if (!using.includes(name)) return
-      await Promise.allSettled(ctx.state.disposables.slice(1).map(dispose => dispose()))
-      callback()
-    })
-
     this.state.children.push(plugin)
     this.emit('plugin-added', plugin)
-    ctx.state.disposables.push(dispose)
+
+    if (using.length) {
+      ctx.on('service', async (name) => {
+        if (!using.includes(name)) return
+        await Promise.allSettled(ctx.state.disposables.slice(1).map(dispose => dispose()))
+        callback()
+      })
+    }
 
     const callback = () => {
       if (using.some(name => !this[name])) return
@@ -606,23 +607,11 @@ export namespace Context {
         this.emit('service', key)
         const action = value ? oldValue ? 'changed' : 'enabled' : 'disabled'
         this.logger('service').debug(key, action)
-        if (value) {
-          const dispose = () => {
-            if (this.app[privateKey] !== value) return
-            this[key] = null
-          }
-          this.state.disposables.push(dispose)
-          this.on('service', (name) => {
-            if (name !== key) return
-            remove(this.state.disposables, dispose)
-          })
-        }
       },
     })
   }
 
   service('bots')
-  service('database')
   service('model')
 
   export const deprecatedEvents: Dict<EventName & string> = {

packages/core/src/database.ts

@@ -47,6 +47,7 @@ export abstract class Service {
   protected stop(): Awaitable<void> {}
 
   constructor(protected ctx: Context, key: keyof Context.Services, immediate?: boolean) {
+    Context.service(key)
     if (immediate) ctx[key] = this as never
 
     ctx.on('ready', async () => {
@@ -55,6 +56,7 @@ export abstract class Service {
     })
 
     ctx.on('dispose', async () => {
+      if (ctx[key] === this as never) ctx[key] = null
       await this.stop()
     })
   }