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frontend/node_modules/rc-virtual-list/es/utils/CacheMap.js

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+import _classCallCheck from "@babel/runtime/helpers/esm/classCallCheck";
+import _createClass from "@babel/runtime/helpers/esm/createClass";
+import _defineProperty from "@babel/runtime/helpers/esm/defineProperty";
+// Firefox has low performance of map.
+var CacheMap = /*#__PURE__*/function () {
+  function CacheMap() {
+    _classCallCheck(this, CacheMap);
+    _defineProperty(this, "maps", void 0);
+    // Used for cache key
+    // `useMemo` no need to update if `id` not change
+    _defineProperty(this, "id", 0);
+    _defineProperty(this, "diffRecords", new Map());
+    this.maps = Object.create(null);
+  }
+  _createClass(CacheMap, [{
+    key: "set",
+    value: function set(key, value) {
+      // Record prev value
+      this.diffRecords.set(key, this.maps[key]);
+      this.maps[key] = value;
+      this.id += 1;
+    }
+  }, {
+    key: "get",
+    value: function get(key) {
+      return this.maps[key];
+    }
+
+    /**
+     * CacheMap will record the key changed.
+     * To help to know what's update in the next render.
+     */
+  }, {
+    key: "resetRecord",
+    value: function resetRecord() {
+      this.diffRecords.clear();
+    }
+  }, {
+    key: "getRecord",
+    value: function getRecord() {
+      return this.diffRecords;
+    }
+  }]);
+  return CacheMap;
+}();
+export default CacheMap;