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<p>Hello Fritz,</p>
<o:p></o:p>
<blockquote type="cite"
cite="mid:c288abce102a4f85adce2b1388bc898b@it2media.de">
<div class="WordSection1">
<p class="MsoNormal">I cannot see any “Expires:“ header</p>
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</blockquote>
<p>That's precisely the reason why XEP makes multiple requests. <br>
</p>
<p><br>
</p>
<p>I've set up simple file sharing via "python -m http.server" and
inspected XEP's behavior with your fo but referring an image
shared via python. <br>
</p>
<p>XEP successfully cashes the image in memory while accessing it
for the first time, but as there is no <i>"Expires"</i> header
expiration date defaults to 0 which means the resource expires
immediately.</p>
<p>When XEP needs the image for the second time it can't simply use
the data from cache as it's expired, so it sends a request, but
set's "<i>If-Modified-Since" </i>header. But pythons simple
http.servers doesn't care about If-Modified-Since and simply sends
the image again. XEP checks modification date and as it's the same
as cashed data's XEP actually uses cashed data!<br>
</p>
<p>Actually starting from <span class="versionmodified changed">Python
3.7 http.server supports </span><span class="versionmodified
changed">If-Modified-Since. So I've updated python and now
http.server returns "304 Not Modified" instead of sending "200
OK" and image once again.</span></p>
<p><br>
</p>
<p>python 3.6.5<br>
</p>
<pre class="moz-signature" cols="72"><img src="cid:part1.CEE689F6.5F2233CD@renderx.com" alt="" width="544" height="207"></pre>
<p>python 3.8.5<br>
<span class="versionmodified changed"></span></p>
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<p><span class="versionmodified changed"><br>
</span></p>
<p><span class="versionmodified changed">Therefore the solution for
your issue is to make your server set "Expires" header. <br>
</span></p>
<pre class="moz-signature" cols="72">--
Regards,
Alexey Medvedev
RenderX
---
<a class="moz-txt-link-abbreviated" href="http://www.renderx.com">www.renderx.com</a></pre>
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