Created
July 31, 2019 00:56
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Save NickLaMuro/20dc0795410abf448402c54f707a59dc to your computer and use it in GitHub Desktop.
Example of the .git_transaction feature in https://github.com/ManageIQ/manageiq/pull/19074
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| $ bin/rails r tmp/test_git_transaction.rb | |
| ** Using session_store: ActionDispatch::Session::MemCacheStore | |
| ** ManageIQ master, codename: J-release | |
| starting... | |
| creating record... done! (id: 21) | |
| > Process 53627 has started... | |
| > Process 53628 has started... | |
| > Process 53629 has started... | |
| > Process.53628: starting .git_transaction... | |
| > Process.53629: starting .git_transaction... | |
| > Process.53628: lock aquired! | |
| > Process.53628: > .update_repo... | |
| > Process.53628: lockfile skip | |
| > Process.53628: lockfile skip | |
| > Process.53628: preforming clone... | |
| > Process.53627: starting .git_transaction... | |
| > Process.53628: > .transaction... | |
| > Process.53628: > .refresh_branches... | |
| > Process.53628: lockfile skip | |
| > Process.53628: > .refresh_tags... | |
| > Process.53628: lockfile skip | |
| > Process.53628: > .save!... | |
| > Process.53628: released lock! | |
| > Process.53628: .git_transaction complete! | |
| > Process.53629: lock aquired! | |
| > Process.53629: > .update_repo... | |
| > Process.53629: lockfile skip | |
| > Process.53629: lockfile skip | |
| > Process.53629: > .transaction... | |
| > Process.53629: > .refresh_branches... | |
| > Process.53629: lockfile skip | |
| > Process.53629: > .refresh_tags... | |
| > Process.53629: lockfile skip | |
| > Process.53629: > .save!... | |
| > Process.53629: released lock! | |
| > Process.53629: .git_transaction complete! | |
| > Process.53627: lock aquired! | |
| > Process.53627: > .update_repo... | |
| > Process.53627: lockfile skip | |
| > Process.53627: lockfile skip | |
| > Process.53627: > .transaction... | |
| > Process.53627: > .refresh_branches... | |
| > Process.53627: lockfile skip | |
| > Process.53627: > .refresh_tags... | |
| > Process.53627: lockfile skip | |
| > Process.53627: > .save!... | |
| > Process.53627: released lock! | |
| > Process.53627: .git_transaction complete! | |
| completed! |
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| # test_git_transaction.rb | |
| # | |
| # Usage: bin/rails r test_git_transaction.rb | |
| # | |
| # A simple rails runner script for testing GitRepository#git_transaction | |
| # | |
| # Creates a GitRepository record in the main process, then spins up child | |
| # processes (using fork) to run a quick sleep, and then a `git_transaction` | |
| # where the child process will attempt to do a `GitRepository#refresh`. | |
| # | |
| # The outer `git_transaction` is unnecessary (I think), but it helps illustrate | |
| # the nested usage of the method. The first process to get the filelock will | |
| # be the only one that will perform the `git clone`. | |
| module GitRepositoryPatch | |
| # Re-written to add logging | |
| def refresh | |
| PIDColor.log " > .update_repo..." | |
| update_repo | |
| PIDColor.log " > .transaction..." | |
| transaction do | |
| PIDColor.log " > .refresh_branches..." | |
| refresh_branches | |
| PIDColor.log " > .refresh_tags..." | |
| refresh_tags | |
| self.last_refresh_on = Time.now.utc | |
| PIDColor.log " > .save!..." | |
| save! | |
| end | |
| end | |
| private | |
| # Slight overwrite to inject a puts for this script | |
| def clone_repo | |
| puts " > #{PIDColor.id 'Process.'}: preforming clone..." | |
| super | |
| end | |
| # Log when we do and don't actually acquire a lock in a process | |
| def acquire_git_lock | |
| result = super | |
| msg = result ? "lock aquired!" : "lockfile skip" | |
| PIDColor.log msg | |
| PIDColor.log " `defined? @git_lock`: #{(defined? @git_lock).inspect}" if $DEBUG | |
| PIDColor.log " `@git_lock.nil?`: #{@git_lock.nil?.inspect}" if $DEBUG | |
| result | |
| end | |
| # Log when when the lock is finally released | |
| def release_git_lock | |
| puts "calling .release_git_lock..." if $DEBUG | |
| puts " before: @git_lock => #{@git_lock.inspect}" if $DEBUG | |
| super | |
| puts " after: @git_lock => #{@git_lock.inspect}" if $DEBUG | |
| PIDColor.log "released lock!" if @git_lock.nil? | |
| end | |
| end | |
| GitRepository # force autoload | |
| class GitRepository | |
| prepend GitRepositoryPatch | |
| end | |
| class PIDColor | |
| def self.id prefix = "" | |
| if STDOUT.tty? && $pid_color | |
| id ||= "\e[#{$pid_color}m#{prefix}#{Process.pid}\e[0m" | |
| else | |
| Process.pid.to_s | |
| end | |
| end | |
| def self.log msg | |
| puts " > #{id 'Process.'}: #{msg}" | |
| end | |
| end | |
| # Ugh... thanks Obama... | |
| # | |
| # just kidding, I solely blame Apple... | |
| # | |
| # https://github.com/darkskyapp/forecast-ruby/issues/13 | |
| # | |
| # You will probably eactually have to export this in the terminal you are | |
| # running this from: | |
| # | |
| # export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES | |
| # | |
| # cuz reasons... | |
| # | |
| ENV["OBJC_DISABLE_INITIALIZE_FORK_SAFETY"] = "YES" | |
| threads = [] | |
| git_url = "https://github.com/NickLaMuro/ansible-tower-samples.git" | |
| $pid_color = 30 | |
| puts "starting..." | |
| print "creating record..." | |
| new_repo = GitRepository.create!(:url => git_url) | |
| puts " done! (id: #{new_repo.id})" | |
| 3.times do | |
| $pid_color += 1 | |
| fork do | |
| puts " > Process #{PIDColor.id} has started..." | |
| sleep 1 | |
| git_repo = GitRepository.find(new_repo.id) | |
| PIDColor.log "starting .git_transaction..." | |
| git_repo.git_transaction do | |
| git_repo.refresh | |
| end | |
| PIDColor.log ".git_transaction complete!" | |
| end | |
| end | |
| Process.waitall | |
| # Cleanup | |
| begin | |
| GitRepository.find(new_repo.id).destroy! | |
| rescue ActiveRecord::StatementInvalid | |
| # Most likely the other threads will kill the parent's database connection, | |
| # so this makes sure we reconnect if the above fails, and tries again. | |
| ActiveRecord::Base.connection.reconnect! | |
| retry | |
| end | |
| puts "completed!" |
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