* Add LastModified: option to the HttpOptions and handle it properly in HttpOpRequest::prepareRequest()
* grid_name could be empty if an invalid grid was passed in.
The new helper functions check_curl_easy_setopt() and
check_curl_multi_setopt() encapsulate the pervasive idiom:
code = curl_{easy,multi}_setopt(handle, option, arg);
check_curl_{easy,multi}_code(code, option);
But since each of these helper functions contains its own local CURL{,M}code
variable 'code', having a caller-scope variable reused for every such call is
no longer necessary -- in fact is no longer used at all. That produces a fatal
warning with MSVC. Get rid of those now-unused variables.
Under pipelining, requests were given a 5x timeout factor due to the
way that the timeout clock works in libcurl. Under CDN load,
connections were not being torn down quickly and it was only
this timer that led to disconnect and retry. So, we want to
break a connection that isn't making progress but that isn't
immediately possible. We'll compromise with a 60S timeout that
(we hope) will be neither too long for stalled connections nor
too short for large asset transfer requests.
Incorporate the new libcurl 7.38.0 build with curl bug 1420
workaround. Add developer-centric testing code to evaluate
the workaround or a future fix for 1420.
as transfers can appear delayed with deep pipelining and more
requests in the pool. Added bad HTTP status error (typically
getting a 0 back as HTTP status from libcurl) to the list of
retryable errors. There's a response stream problem with libcurl
and pipelining that induces this problem. Retrying helps but
may not be entirely safe. Watch bug 1420 on the libcurl sourceforge
bug tracker. Extend options of test/example program to include
un-ranged requests. Document the excessive data transfer induced
when ranged requests are disabled. This is an abnormal mode for
very rare users so we'll just eat that for now.
some problems disabling pipelining on a multi handle with outstanding
requests so build a more conservative system that allows requests
to drain before setting curl multi options. Would rather not have
this but it is significantly safer. "HttpPipelining" debug setting
is now fully dynamic. Connection limits can also be made dynamic
in the near future. Upped the default connection count back to 8 for
now but will revisit this in the tuning phase. It might be time to
combine mesh and textures into a single asset class. For normal
server operations that would be a clear path, but for server under
load, the current scheme may be better. Minor cleanup in logging
to elminate some redundant strings. Might add some more tracing to the
stall logic 'just in case'.
fmartian