Reduce regex usage #141
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Reduce regex usage #141
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Codecov Report
@@ Coverage Diff @@
## master #141 +/- ##
=========================================
+ Coverage 96.1% 96.1% +<.01%
=========================================
Files 34 34
Lines 2951 2956 +5
=========================================
+ Hits 2836 2841 +5
Misses 115 115
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Description of the Change
Removed frequent call to regex compile - thus saving CPU time. This was discovered through callgrind that pointed at regex compilation happening during URL normalization. The resulting code improves average time to serve requests by ~15% (during the load tests performed as part of the travis builds) and ~50% improvement in TP99 on INTERNAL_SELECT.
Quantitative Performance Benefits
It is possible to observe the performance improvement in output of the following travis builds:
Baseline (INTERNAL_SELECT): https://travis-ci.org/etr/libhttpserver/jobs/482289425
50% 5
66% 5
75% 6
80% 7
90% 8
95% 10
98% 13
99% 13
100% 25 (longest request)
New version (INTERNAL SELECT): https://travis-ci.org/etr/libhttpserver/jobs/482774149
50% 5
66% 5
75% 5
80% 5
90% 5
95% 6
98% 6
99% 7
100% 21 (longest request)
Baseline (THREAD_PER_CONNECTION): https://travis-ci.org/etr/libhttpserver/jobs/482289426
50% 11
66% 12
75% 12
80% 13
90% 14
95% 15
98% 18
99% 20
100% 365 (longest request)
New version (THREAD_PER_CONNECTION): https://travis-ci.org/etr/libhttpserver/jobs/482774150
50% 8
66% 9
75% 10
80% 10
90% 12
95% 14
98% 18
99% 21
100% 202 (longest request)
Possible Drawbacks
None real.
Verification Process
Tested using travis.
Applicable Issues
None
Release Notes
Reduced the CPU time spent in normalizing URLs (thus saving ~15% on average per request).