This concern provides an optimized/simplified version of the "cache_key"
method. This method is about 9 times faster than the default "cache_key"
method.
The produced cache keys _are_ different from the previous ones but this
is worth the performance improvement. To showcase this I set up a
benchmark (using benchmark-ips) that compares FasterCacheKeys#cache_key
with the regular cache_key. The output of this benchmark was:
Calculating -------------------------------------
cache_key 4.825k i/100ms
cache_key_fast 21.723k i/100ms
-------------------------------------------------
cache_key 59.422k (± 7.2%) i/s - 299.150k
cache_key_fast 543.243k (± 9.2%) i/s - 2.694M
Comparison:
cache_key_fast: 543243.4 i/s
cache_key: 59422.0 i/s - 9.14x slower
To see the impact on real code I applied these changes and benchmarked
Issue#referenced_merge_requests. For an issue referencing 10 merge
requests these changes shaved off between 40 and 60 milliseconds.
