Javascript 从Session服务存储需要很长时间

我有一个函数，它应该从sessionStorage返回字典（如果存在），如果没有，它将从API加载字典到sessionStorage，然后返回字典

self.getDictionary = function(dictionary){
        var deferred = $q.defer();
        var saved_dictionary = JSON.parse($window.sessionStorage.getItem('dictionary_' + dictionary));

        if (saved_dictionary && saved_dictionary !== "null"){
            deferred.resolve(saved_dictionary);
        } else {
            var apiData = {module: "Dictionaries", method: "getDictionary", data: {name: dictionary}};
            apiService.execute(apiData).then(function (response) {
                $window.sessionStorage.setItem('dictionary_' + dictionary, JSON.stringify(response));
                deferred.resolve(response);
            });
        }
        return deferred.promise;
    };

我试图缓存字典，因为它可能非常大（大约0.5mb JSON）

示例字典：

{"DictionaryName":"Gaming","DictionaryCategory":[{"CategoryName":"Games","MandatoryAtLeast":1,"CategoryWords":[{"title":"zelda","score":1,"exact":true,"mandatory":false,"reject":false},{"title":"mass effect","score":1,"exact":false,"mandatory":true,"reject":false},{"title":"pokemon","score":1,"exact":false,"mandatory":true,"reject":false},{"title":"fallout","score":1,"exact":false,"mandatory":false,"reject":false},{"title":"cs:go","score":1,"exact":true,"mandatory":false,"reject":false},{"title":"sims","score":1,"exact":false,"mandatory":false,"reject":false},{"title":"until dawn","score":1,"exact":false,"mandatory":false,"reject":false},{"title":"deus ex","score":1,"exact":false,"mandatory":false,"reject":false},{"title":"skyrim","score":1,"exact":false,"mandatory":true,"reject":false}]},{"CategoryName":"Companies","MandatoryAtLeast":1,"CategoryWords":[{"title":"bioware","score":1,"exact":false,"mandatory":true,"reject":false},{"title":"bethesda","score":1,"exact":false,"mandatory":false,"reject":false},{"title":"steam","score":1,"exact":false,"mandatory":true,"reject":false},{"title":"valve","score":1,"exact":false,"mandatory":false,"reject":false},{"title":"alienware","score":1,"exact":false,"mandatory":false,"reject":false}]},{"CategoryName":"other","MandatoryAtLeast":1,"CategoryWords":[{"title":"gamer","score":1,"exact":false,"mandatory":true,"reject":false},{"title":"mods","score":1,"exact":false,"mandatory":false,"reject":false},{"title":"horror","score":1,"exact":false,"mandatory":false,"reject":false},{"title":"survival","score":1,"exact":true,"mandatory":false,"reject":false},{"title":"multiplayer","score":1,"exact":false,"mandatory":false,"reject":false},{"title":"action","score":1,"exact":true,"mandatory":true,"reject":false},{"title":"fps","score":1,"exact":false,"mandatory":true,"reject":false},{"title":"shooter","score":1,"exact":false,"mandatory":false,"reject":false},{"title":"mmo","score":1,"exact":false,"mandatory":true,"reject":false}]}]}

问题是，从缓存中提供字典没有帮助。从sessionStorage提供字典所需的时间几乎与从远程API加载字典所需的时间相同

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为什么从会话存储返回要花这么长时间？

调试后，问题似乎不是会话存储

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问题是AngularJS需要一段时间来渲染1000+个元素的ng重复。这是下一件我必须研究的事情

为什么在调用

JSON.parse（）

之前不检查

sessionStorage

中是否定义了key？我想我可以，但我认为这不会有太大的区别。据我所知，对空值调用JSON.parse（）是可以忽略的。多长时间是多长时间？所花费的时间会带来什么问题？当您存储数据时，我假设它必须通过浏览器以某种方式序列化。我不希望花费那么长的时间，但是，我的第一个测试是尝试存储少量的数据，并从那里进一步得出结论/进行调试。而且，一旦检索到数据，似乎也不会将其存储在内存中。一旦它被解析，当它作为对象存储在服务中时访问它会快得多