reduce string allocations

[danmayer]

Fix inspired by new benchmark... We are using strings poorly a few places...Wondering if we can get JSON to use them better as well.

Prior to fix:

Allocated String Report
-----------------------------------
     40101  "^/Users/danmayer/projects/coverband/"
     40101  /Users/danmayer/projects/coverband/lib/coverband/utils/file_path_helper.rb:17

     30090  "data"
     20060  /Users/danmayer/.rvm/gems/ruby-2.3.5/gems/json-2.2.0/lib/json/common.rb:156
     10030  /Users/danmayer/projects/coverband/lib/coverband/adapters/redis_store.rb:99

     30090  "file_hash"
     20060  /Users/danmayer/.rvm/gems/ruby-2.3.5/gems/json-2.2.0/lib/json/common.rb:156
     10030  /Users/danmayer/projects/coverband/lib/coverband/adapters/redis_store.rb:99

     30090  "first_updated_at"
     20060  /Users/danmayer/.rvm/gems/ruby-2.3.5/gems/json-2.2.0/lib/json/common.rb:156
     10030  /Users/danmayer/projects/coverband/lib/coverband/adapters/redis_store.rb:99

     30090  "last_updated_at"
     20060  /Users/danmayer/.rvm/gems/ruby-2.3.5/gems/json-2.2.0/lib/json/common.rb:156
     10030  /Users/danmayer/projects/coverband/lib/coverband/adapters/redis_store.rb:99

     20060  "/Users/danmayer/projects/coverband"
     10030  /Users/danmayer/projects/coverband/lib/coverband/configuration.rb:146
     10030  /Users/danmayer/projects/coverband/lib/coverband/configuration.rb:152

     20060  "/Users/danmayer/projects/coverband/"
     10030  /Users/danmayer/projects/coverband/lib/coverband/configuration.rb:152
     10030  /Users/danmayer/projects/coverband/lib/coverband/utils/file_path_helper.rb:17

     20000  "4748375a25eb275a00c8d63c3d36cf90"
     10000  /Users/danmayer/.rvm/gems/ruby-2.3.5/gems/json-2.2.0/lib/json/common.rb:156
     10000  /Users/danmayer/projects/coverband/lib/coverband/adapters/redis_store.rb:99

     10030  "^"
     10030  /Users/danmayer/projects/coverband/lib/coverband/utils/file_path_helper.rb:17

After the fix:

Allocated String Report
-----------------------------------
     30090  "data"
     20060  /Users/danmayer/.rvm/gems/ruby-2.3.5/gems/json-2.2.0/lib/json/common.rb:156
     10030  /Users/danmayer/projects/coverband/lib/coverband/adapters/redis_store.rb:99

     30090  "file_hash"
     20060  /Users/danmayer/.rvm/gems/ruby-2.3.5/gems/json-2.2.0/lib/json/common.rb:156
     10030  /Users/danmayer/projects/coverband/lib/coverband/adapters/redis_store.rb:99

     30090  "first_updated_at"
     20060  /Users/danmayer/.rvm/gems/ruby-2.3.5/gems/json-2.2.0/lib/json/common.rb:156
     10030  /Users/danmayer/projects/coverband/lib/coverband/adapters/redis_store.rb:99

     30090  "last_updated_at"
     20060  /Users/danmayer/.rvm/gems/ruby-2.3.5/gems/json-2.2.0/lib/json/common.rb:156
     10030  /Users/danmayer/projects/coverband/lib/coverband/adapters/redis_store.rb:99

     30000  "4748375a25eb275a00c8d63c3d36cf90"
     20000  /Users/danmayer/projects/coverband/lib/coverband/adapters/redis_store.rb:99
     10000  /Users/danmayer/.rvm/gems/ruby-2.3.5/gems/json-2.2.0/lib/json/common.rb:156

       100  ""

[kbaum]

This is great! I would have thought frozen string literal would allow for reuse of strings but i guess not.

Do you see a drop in total memory allocations too?

[danmayer]

yeah, it helps with total a bit as well... a nice but small win.