feat: seperate delta from note storage, improve performance

packages/core/database/cached-collection.js

@@ -0,0 +1,51 @@
+import Indexer from "./indexer";
+
+export default class CachedCollection {
+  constructor(context, type) {
+    this.map = new Map();
+    this.indexer = new Indexer(context, type);
+  }
+
+  async init() {
+    await this.indexer.init();
+    for (let id of this.indexer.indices) {
+      this.map.set(id, await this.indexer.read(id));
+    }
+  }
+
+  async addItem(item) {
+    if (!item.id) throw new Error("The item must contain the id field.");
+
+    let exists = this.map.has(item.id);
+    await this.updateItem(item);
+    if (!exists) {
+      await this.indexer.index(item.id);
+    }
+  }
+
+  async updateItem(item) {
+    if (!item.id) throw new Error("The item must contain the id field.");
+
+    this.map.set(item.id, item);
+    await this.indexer.write(item.id, item);
+  }
+
+  async removeItem(id) {
+    if (this.map.delete(id)) {
+      this.indexer.remove(id);
+      await this.indexer.deindex(id);
+    }
+  }
+
+  getItem(id) {
+    return this.map.get(id);
+  }
+
+  getAllItems() {
+    let items = [];
+    for (let value of this.map.values()) {
+      items[items.length] = value;
+    }
+    return items;
+  }
+}