有没有办法告诉流星集合是静态的(永远不会改变)? [英] Is there a way to tell meteor a collection is static (will never change)?

问题描述

在我的流星项目上，用户可以发布事件，并且他们必须(通过自动完成功能)选择它将在哪个城市进行.我有法国城市的完整列表，并且永远不会更新.

On my meteor project users can post events and they have to choose (via an autocomplete) in which city it will take place. I have a full list of french cities and it will never be updated.

我想基于自动完成功能的输入来使用集合和发布-订阅，因为我不希望客户端下载完整的数据库(5MB).有没有一种方法可以使流星告诉该流派静态"?还是没有区别?

I want to use a collection and publish-subscribes based on the input of the autocomplete because I don't want the client to download the full database (5MB). Is there a way, for performance, to tell meteor that this collection is "static"? Or does it make no difference?

有人可以建议一种不同的方法吗?

Could anyone suggest a different approach?

推荐答案

当您想告诉服务器集合是静态的"时，我知道有两种潜在的优化方法:

When you "want to tell the server that a collection is static", I am aware of two potential optimizations:

1. 不要使用实时查询来观察数据库，因为数据永远不会改变
2. 不要将此查询的结果存储在合并框中，因为它不需要跟踪和与其他数据(节省内存和CPU)相比

1. Don't observe the database using a live query because the data will never change
2. Don't store the results of this query in the merge box because it doesn't need to be tracked and compared with other data (saving memory and CPU)

(1)是您可以通过构造自己的发布游标而轻松完成的操作.但是，如果有任何客户端正在观察相同的查询，我相信Meteor(至少在将来)将对此进行优化，因此对于任何数量的客户端，它仍然只是一个实时查询.至于(2)，我不知道有任何简单的方法可以执行此操作，因为它可能会破坏在多个出版物和订阅.

(1) is something you can do rather easily by constructing your own publish cursor. However, if any client is observing the same query, I believe Meteor will (at least in the future) optimize for that so it's still just one live query for any number of clients. As for (2), I am not aware of any straightforward way to do this because it could potentially mess up the data merging over multiple publications and subscriptions.

为避免使用实时查询，可以将数据手动添加到publish函数中，而不是返回游标，这将导致调用.observe()函数将数据连接到预订.这是一个简单的示例:

To avoid using a live query, you can manually add data to the publish function instead of returning a cursor, which causes the .observe() function to be called to hook up data to the subscription. Here's a simple example:

Meteor.publish(function() {
    var sub = this;
    var args = {}; // what you're find()ing

    Foo.find(args).forEach(function(document) {
        sub.added("client_collection_name", document._id, document);
    });

    sub.ready();
});

这将导致数据被添加到客户端的client_collection_name中，该名称可能与Foo引用的集合具有相同的名称，或有所不同.请注意，您可以对出版物进行许多其他操作(另请参见上面的链接.)

This will cause the data to be added to client_collection_name on the client side, which could have the same name as the collection referenced by Foo, or something different. Be aware that you can do many other things with publications (also, see the link above.)

更新:要解决(2)中的问题(根据集合的大小可能存在很大问题)，有必要完全绕开Meteor.请参阅 https://stackoverflow.com/a/21835534/586086 .另一种方法是将集合fetch() ed作为方法调用返回，尽管这没有压缩的好处.

UPDATE: To resolve issues from (2), which can be potentially very problematic depending on the size of the collection, it's necessary to bypass Meteor altogether. See https://stackoverflow.com/a/21835534/586086 for one way to do it. Another way is to just return the collection fetch()ed as a method call, although this doesn't have the benefits of compression.

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