discourse/migrations/lib/converters/base/worker.rb
Gerhard Schlager 5ac69076c1
REFACTOR: Simplify converter steps in migration tooling (#29779)
* Remove unused `report_progress_in_percent` option from step
* Remove `use_custom_progress_increment` option from the step because we can figure it out by looking at the progress
* Introduce `StepTracker` to for logging warnings and errors and tracking step progress
* Make it easier to log warnings and errors in all methods of `Step` without the need to pass around a `stats` object
2024-11-19 23:54:37 +01:00

95 lines
2.4 KiB
Ruby

# frozen_string_literal: true
require "oj"
module Migrations::Converters::Base
class Worker
OJ_SETTINGS = { mode: :object, class_cache: true, symbol_keys: true }
def initialize(index, input_queue, output_queue, job)
@index = index
@input_queue = input_queue
@output_queue = output_queue
@job = job
@threads = []
@mutex = Mutex.new
@data_processed = ConditionVariable.new
end
def start
parent_input_stream, parent_output_stream = IO.pipe
fork_input_stream, fork_output_stream = IO.pipe
worker_pid =
start_fork(parent_input_stream, parent_output_stream, fork_input_stream, fork_output_stream)
fork_output_stream.close
parent_input_stream.close
start_input_thread(parent_output_stream, worker_pid)
start_output_thread(fork_input_stream)
self
end
def wait
@threads.each(&:join)
end
private
def start_fork(parent_input_stream, parent_output_stream, fork_input_stream, fork_output_stream)
::Migrations::ForkManager.fork do
begin
Process.setproctitle("worker_process#{@index}")
parent_output_stream.close
fork_input_stream.close
Oj.load(parent_input_stream, OJ_SETTINGS) do |data|
result = @job.run(data)
Oj.to_stream(fork_output_stream, result, OJ_SETTINGS)
end
rescue SignalException
exit(1)
ensure
@job.cleanup
end
end
end
def start_input_thread(output_stream, worker_pid)
@threads << Thread.new do
Thread.current.name = "worker_#{@index}_input"
begin
while (data = @input_queue.pop)
Oj.to_stream(output_stream, data, OJ_SETTINGS)
@mutex.synchronize { @data_processed.wait(@mutex) }
end
ensure
output_stream.close
Process.waitpid(worker_pid)
end
end
end
def start_output_thread(input_stream)
@threads << Thread.new do
Thread.current.name = "worker_#{@index}_output"
begin
Oj.load(input_stream, OJ_SETTINGS) do |data|
@output_queue.push(data)
@mutex.synchronize { @data_processed.signal }
end
ensure
input_stream.close
@mutex.synchronize { @data_processed.signal }
end
end
end
end
end