如何使Flask /使Ajax HTTP连接保持活动状态？ [英] How to make Flask/ keep Ajax HTTP connection alive?

问题描述

我有一个jQuery Ajax调用，像这样：

I have a jQuery Ajax call, like so:

    $("#tags").keyup(function(event) {
      $.ajax({url: "/terms",
        type: "POST",
        contentType: "application/json",
        data: JSON.stringify({"prefix": $("#tags").val() }),
        dataType: "json",
        success: function(response) { display_terms(response.terms); },
      });

我有这样的Flask方法：

I have a Flask method like so:

@app.route("/terms", methods=["POST"])
def terms_by_prefix():
    req = flask.request.json
    tlist = terms.find_by_prefix(req["prefix"])
    return flask.jsonify({'terms': tlist})

tcpdump显示HTTP对话框：

tcpdump shows the HTTP dialog:

POST /terms HTTP/1.1
Host: 127.0.0.1:5000
User-Agent: Mozilla/5.0 (X11; Linux i686; rv:12.0) Gecko/20100101 Firefox/12.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
Content-Type: application/json; charset=UTF-8
X-Requested-With: XMLHttpRequest
Referer: http://127.0.0.1:5000/
Content-Length: 27
Pragma: no-cache
Cache-Control: no-cache

{"prefix":"foo"}

但是，Flask无需保持活动状态即可答复。

However, Flask replies without keep-alive.

HTTP/1.0 200 OK
Content-Type: application/json
Content-Length: 445
Server: Werkzeug/0.8.3 Python/2.7.2+
Date: Wed, 09 May 2012 17:55:04 GMT

{"terms": [...]}

是真的吗

推荐答案

Werkzeug的集成Web服务器基于Python标准库的BaseHTTPServer构建。如果将HTTPHTTP协议版本设置为1.1，则BaseHTTPServer似乎支持Keep-Alives。

Werkzeug's integrated web server builds on BaseHTTPServer from Python's standard library. BaseHTTPServer seems to support Keep-Alives if you set its HTTP protocol version to 1.1.

Werkzeug不会这样做，但是如果您准备入侵Flask用于实例化Werkzeug的BaseWSGIServer的机器，则可以自己完成。请参见 Flask.run（），该调用调用 werkzeug.serving.run_simple（）。您要做的事情归结为 BaseWSGIServer.protocol_version = HTTP / 1.1 。

Werkzeug doesn't do it but if you're ready to hack into the machinery that Flask uses to instantiate Werkzeug's BaseWSGIServer, you can do it yourself. See Flask.run() which calls werkzeug.serving.run_simple(). What you have to do boils down to BaseWSGIServer.protocol_version = "HTTP/1.1".

我尚未测试解决方案。我想您确实知道Flask的网络服务器应仅用于开发。

I haven't tested the solution. I suppose you do know that Flask's web server ought to be used for development only.

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