Module#constants(false) should not use a hashtable internally
Module#constants always uses a hashtable to ensure that only unique constant names are returned - even when called with the
inherit argument set to false.
Rails calls constants(false) heavily during boot and the use of a hashtable causes this method to show up as a hotspot (6% of boot time is spent in Module#constants).
Our app currently takes about 6.3 seconds to boot on trunk:
6.33 real 5.20 user 1.10 sys 6.27 real 5.17 user 1.07 sys 6.27 real 5.17 user 1.07 sys 6.35 real 5.25 user 1.07 sys 6.29 real 5.18 user 1.08 sys
After applying the patch at https://github.com/charliesome/ruby/compare/optimized-constants-false, boot time drops to about 6 seconds:
6.01 real 4.90 user 1.08 sys 6.02 real 4.90 user 1.09 sys 5.95 real 4.86 user 1.07 sys 5.97 real 4.86 user 1.07 sys 6.00 real 4.88 user 1.09 sys
#1 Updated by Charlie Somerville about 3 years ago
- Status changed from Open to Closed
- % Done changed from 0 to 100
This issue was solved with changeset r43956.
Charlie, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.
- variable.c (rb_mod_constants): when calling Module#constants with inherit=false, there is no need to use a hashtable to deduplicate constant names. [Feature #9196]