Time.utc uses timegmw() and it uses leap second information.
If the given time is larger than known_leap_seconds_limit, it calls
find_time_t, which uses localtime(3) and calls stat(2) in it.
This patch avoid it by setting known_leap_seconds_limit to 0 if the timezone doesn't have leapsecond information (if no leap second is found "now", I assume the timezone doesn't have leapsecond information).
Before:
% time ./miniruby --disable-gem -e'time = Time.now; year = time.year; month = time.month; day = time.day; hour = time.hour; min = time.min; sec = time.sec + time.subsec; i = 0; while i < 100000; ::Time.utc(year, month, day, hour, min, sec); i += 1; end'
./miniruby --disable-gem 0.35s user 0.19s system 99% cpu 0.542 total
After:
% time ./miniruby --disable-gem -e'time = Time.now; year = time.year; month = time.month; day = time.day; hour = time.hour; min = time.min; sec = time.sec + time.subsec; i = 0; while i < 100000; ::Time.utc(year, month, day, hour, min, sec); i += 1; end'
./miniruby --disable-gem 0.23s user 0.00s system 99% cpu 0.233 total
Added by naruse (Yui NARUSE) almost 7 years ago
Optimize Time.utc
Time.utc uses timegmw() and it uses leap second information.
If the given time is larger than known_leap_seconds_limit, it calls
find_time_t, which uses localtime(3) and calls stat(2) in it.
This patch avoid it by setting known_leap_seconds_limit to 0 if the timezone doesn't have leapsecond information (if no leap second is found "now", I assume the timezone doesn't have leapsecond information).
Before:
% time ./miniruby --disable-gem -e'time = Time.now; year = time.year; month = time.month; day = time.day; hour = time.hour; min = time.min; sec = time.sec + time.subsec; i = 0; while i < 100000; ::Time.utc(year, month, day, hour, min, sec); i += 1; end'
./miniruby --disable-gem 0.35s user 0.19s system 99% cpu 0.542 total
After:
% time ./miniruby --disable-gem -e'time = Time.now; year = time.year; month = time.month; day = time.day; hour = time.hour; min = time.min; sec = time.sec + time.subsec; i = 0; while i < 100000; ::Time.utc(year, month, day, hour, min, sec); i += 1; end'
./miniruby --disable-gem 0.23s user 0.00s system 99% cpu 0.233 total
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63848 b2dd03c8-39d4-4d8f-98ff-823fe69b080e