init

backend/src/services/queue.ts

@@ -0,0 +1,65 @@
+import * as store from './itemsStore.js'
+
+interface AddTask { type: 'add', id: number }
+interface SelectTask { type: 'select', id: number }
+interface DeselectTask { type: 'deselect', id: number }
+interface ReorderTask { type: 'reorder', ids: number[] }
+
+type Task = AddTask | SelectTask | DeselectTask | ReorderTask
+
+class RequestQueue {
+  private addQueue: AddTask[] = []
+  private actionQueue: ReorderTask[] = []
+  private pendingKeys = new Set<string>()
+  private pendingReorder: ReorderTask | null = null
+
+  constructor() {
+    setInterval(() => this.flushAdd(), 10_000)
+    setInterval(() => this.flushActions(), 1_000)
+  }
+
+  enqueue(task: Task): boolean {
+    if (task.type === 'reorder') {
+      this.pendingReorder = task
+      this.actionQueue = this.actionQueue.filter(t => t.type !== 'reorder')
+      this.actionQueue.push(task)
+      return true
+    }
+
+    const key = `${task.type}:${(task as AddTask | SelectTask | DeselectTask).id}`
+    if (this.pendingKeys.has(key)) return false
+    this.pendingKeys.add(key)
+
+    if (task.type === 'add') {
+      this.addQueue.push(task)
+      if (this.addQueue.length >= 100) this.flushAdd()
+    }
+    else {
+      // select/deselect применяются немедленно, чтобы GET после POST видел актуальный state
+      if (task.type === 'select') store.selectItem(task.id)
+      else if (task.type === 'deselect') store.deselectItem(task.id)
+      this.pendingKeys.delete(key)
+    }
+    return true
+  }
+
+  private flushAdd(): void {
+    const batch = this.addQueue.splice(0)
+    for (const task of batch) {
+      store.addItem(task.id)
+      this.pendingKeys.delete(`add:${task.id}`)
+    }
+  }
+
+  private flushActions(): void {
+    const batch = this.actionQueue.splice(0)
+    this.pendingReorder = null
+    for (const task of batch) {
+      if (task.type === 'reorder') {
+        store.reorderSelected(task.ids)
+      }
+    }
+  }
+}
+
+export const queue = new RequestQueue()