Memoize the key of instance_variable_set

[ooooooo-q]

I used memory_profiler to check where rubyXL was using a lot of memory, and fixed it.

"@#{v[:accessor]}" generates two String objects, which can be expensive depending on the access frequency, so we memoized it.

Result

• write xlsx
  • https://github.com/ooooooo-q/rubyxl_memory_usage/blob/main/operate.rb#L8
• read xlsx
  • https://github.com/ooooooo-q/rubyxl_memory_usage/blob/main/operate.rb#L42

rubyXL 3.4.20 (with Ruby 3.1.0)

• write file
  • Total allocated: 16.41 MB (335760 objects)
  • Total retained: 6.58 kB (128 objects)
• read file
  • Total allocated: 24.26 MB (340069 objects)
  • Total retained: 6.23 kB (57 objects)

memoize "@#{v[:accessor]}"

• write file
  • Total allocated: 14.06 MB (276927 objects)
  • Total retained: 23.97 kB (558 objects)
• read file
  • Total allocated: 21.82 MB (279137 objects)
  • Total retained: 23.62 kB (487 objects)