hyperloop-rails / powerstation

A Tool for Detecting Performance Bugs in Rails Applications

PowerStation

Powerstation is a tool that finds performance bugs in Rails applications, for example, API misuse, repeated query, etc.

Using the tool

There are two ways to use Powerstation:

• As a RubyMine plugin that you can download from the jetbrains website. The source code is included in this repo under powerstation/IDE_plugin.

• As command line tool. The instructions and source code are included in this repo under powerstation/command_line_tool.

Both of these uses a static code checker that we have built to detect performance issues. The source code of the checker is in static-checker.

These are packaged in two separate branches (IDE_plugin, static-checker) in case you prefer checkout each part individually, for example:

$ git clone -b static-checker --single-branch https://github.com/hyperloop-rails/static-checker.git

Currently detected bugs

1. Loop invariant queries

2. Dead store queries

3. Unused data-retrieval queries

4. Common sub-expression queries

5. API misuses

6. Inefficient data rendering

Details of these are explained in our documentation.

See our main website for more details. Feel free to submit issues and pull requests!

powerstation's Issues

Exclude `log` directory from analysis

It looks like the script greps everything inside the current directory.

Some directories should likely be excluded by default, like the /log directory, which frequently contains large files that don't have application code.

Still relevant to check `any?` & `where.first` ?

I believe more current versions of ActiveRecord address this. Notice that AR is using LIMIT 1 and isn't loading the result set into memory.

irb(main):007:0> User.where(email: 'email').exists?
  User Exists (1.0ms)  SELECT  1 AS one FROM `users` WHERE `users`.`email` = 'email' LIMIT 1
=> false
irb(main):008:0> User.where(email: 'email').any?
  User Exists (0.4ms)  SELECT  1 AS one FROM `users` WHERE `users`.`email` = 'email' LIMIT 1
=> false
irb(main):009:0> User.find_by(email: 'email')
  User Load (0.4ms)  SELECT  `users`.* FROM `users` WHERE `users`.`email` = 'email' LIMIT 1
=> nil
irb(main):010:0> User.where(email: 'email').first
  User Load (0.5ms)  SELECT  `users`.* FROM `users` WHERE `users`.`email` = 'email' ORDER BY `users`.`id` ASC LIMIT 1
=> nil

Credit to @mccallumjack.

No results directory created

No errors reported by Analyze, but when calling Show, exception occurs :

When I check in the PW-src directory, there is No results directory created.

However something ran as the code from the project has been copied to PW-src

Error on show :