我的 Django 分析中间件错了吗？

Question

我正在分析我的“即将部署”站点，我已经找到并更正了中间件。原始版本的时间要小得多。

from django.db import connection
from time import time
from operator import add
import re

# http://stackoverflow.com/a/17777539/409102
class StatsMiddleware(object):

    def __init__(self):
        self.regexp = re.compile(
            r'(?P<cmt><!--\s*STATS:(?P<fmt>.*?)ENDSTATS\s*-->)'
        )

    def process_request(self, request):
        request.stats_middleware = ( len(connection.queries), time() )

    def process_view(self, request, view_func, view_args, view_kwargs):
        '''
        In your base template, put this:
        <div id="stats">
        <!-- STATS: Total: %(total_time).2fs Python: %(python_time).2fs DB: %(db_time).2fs Queries: %(db_queries)d ENDSTATS -->

        <!-- Q_STATS -->
        </div>
        '''

        # Uncomment the following if you want to get stats on DEBUG=True only
        #if not settings.DEBUG:
        #    return None

        # get number of db queries before we do anything
        # time the view
        n, start = request.stats_middleware

        response = view_func(request, *view_args, **view_kwargs)

        # replace the comment if found        
        if response:
            try:
                # detects TemplateResponse which are not yet rendered
                if response.is_rendered:
                    rendered_content = response.content
                else:
                    rendered_content = response.rendered_content
            except AttributeError:  # django < 1.5
                rendered_content = response.content

            if rendered_content:
                s = rendered_content
                match = self.regexp.search(s)

                # compute the db time for the queries just run
                db_queries = len(connection.queries) - n
                db_time = 0.0
                for q in connection.queries[n:]:
                    db_time += float(q['time'])

                if( "prof_sql" in request.GET ):
                    qq = "<table><thead><tr><td>time</td><td>SQL</td></tr></thead><tbody>"
                    for q in connection.queries[n:]:
                        qq += "<tr><td>{0}</td><td>{1}</td></tr>".format(q['time'],q['sql'])
                    qq += "</tbody></table>"
                    s = s.replace("<!-- Q_STATS -->", "<br/> Queries<br/>" + qq )
                    response.content = s


                # compute time now
                total_time = time() - start
                python_time = total_time - db_time

                stats = {
                    'total_time': total_time * 1000,
                    'python_time': python_time * 1000,
                    'db_time': db_time * 1000.0,
                    'db_queries': db_queries,
                }

                if match:
                    s = (s[:match.start('cmt')] +
                        match.group('fmt') % stats +
                        s[match.end('cmt'):])
                    response.content = s
        return response

这是来自 chrome 和中间件的结果的屏幕：

这 50 毫秒的差异是最好的情况，“幸运”发生在我要截屏时。

编辑：如果不清楚我在问什么。我不知道我的中间件是不是错了，因为它打印<10ms和chrome打印>60ms，而且我已经做对了。

EDIT2：还是问题太简单了？如果我的中间件没问题，为什么它会打印出不好的结果，以及我该如何“修复它”，以便它将正确的值打印到 HTML。

Answer 1

等待初始响应所花费的时间，也称为 Time To First Byte。除了等待服务器传递响应所花费的时间之外，此时间还捕获到服务器的往返延迟。

https://developer.chrome.com/devtools/docs/network

您的中间件只是服务器端。