feat: streamable audio

Signed-off-by: Neko Ayaka <neko@ayaka.moe>

composables/queue.ts

@@ -0,0 +1,94 @@
+import { ref } from 'vue'
+import type { Ref } from 'vue'
+
+export interface HandlerContext<T> {
+  data: T
+  itemsToBeProcessed: () => number
+}
+
+interface Events<T> {
+  add: Array<(payload: T) => void>
+  pick: Array<(payload: T) => void>
+  processing: Array<(payload: T, handler: (param: HandlerContext<T>) => Promise<any>) => void>
+  error: Array<(payload: T, error: Error, handler: (param: HandlerContext<T>) => Promise<any>) => void>
+  processed: Array<<R>(payload: T, result: R, handler: (param: HandlerContext<T>) => Promise<any>) => void>
+  done: Array<(payload: T) => void>
+}
+
+export function useQueue<T>(options: {
+  handlers: Array<(param: {
+    data: T
+    itemsToBeProcessed: () => number
+  }) => Promise<void>>
+}) {
+  const queue = ref<T[]>([]) as Ref<T[]>
+  const isProcessing = ref(false)
+  const internalEventHandler: Events<T> = {
+    add: [],
+    pick: [],
+    processing: [],
+    error: [],
+    processed: [],
+    done: [],
+  }
+
+  function on<E extends keyof Events<T>>(eventName: E, handler: Events<T>[E][number]) {
+    internalEventHandler[eventName].push(handler as any)
+  }
+
+  function emit<E extends keyof Events<T>>(eventName: E, ...params: Parameters<Events<T>[E][number]>) {
+    const handlers = internalEventHandler[eventName] as Events<T>[E]
+    handlers.forEach((handler) => {
+      (handler as any)(...params)
+    })
+  }
+
+  function add(payload: T) {
+    queue.value.push(payload)
+    emit('add', payload)
+  }
+
+  function pick() {
+    const payload = queue.value.shift()
+    if (!payload)
+      return
+
+    emit('pick', payload)
+    return payload
+  }
+
+  async function handleItem() {
+    if (isProcessing.value)
+      return
+
+    const payload = pick()
+    if (!payload)
+      return
+
+    isProcessing.value = true
+
+    for (const handler of options.handlers) {
+      emit('processing', payload, handler)
+      try {
+        const result = await handler({ data: payload, itemsToBeProcessed: () => queue.value.length })
+        emit('processed', payload, result, handler)
+      }
+      catch (err) {
+        emit('error', payload, err as Error, handler)
+        continue
+      }
+    }
+
+    isProcessing.value = false
+    emit('done', payload)
+  }
+
+  on('add', handleItem)
+  on('done', handleItem)
+
+  return {
+    add,
+    on,
+    queue,
+  }
+}