lib/zold/node/farmers.rb
# frozen_string_literal: true
# Copyright (c) 2018-2023 Zerocracy
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the 'Software'), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
require 'open3'
require 'backtrace'
require 'zold/score'
require 'shellwords'
require_relative '../log'
require_relative '../age'
# Farmers.
# Author:: Yegor Bugayenko (yegor256@gmail.com)
# Copyright:: Copyright (c) 2018 Yegor Bugayenko
# License:: MIT
module Zold
# Farmer
module Farmers
# Kill a process
def self.kill(log, pid, start)
Process.kill('KILL', pid)
log.debug("Process ##{pid} killed after #{Age.new(start)} of activity")
rescue StandardError => e
log.debug("No need to kill process ##{pid} since it's dead already: #{e.message}")
end
# Plain and simple
class Plain
def initialize(log: Log::NULL)
@log = log
end
def up(score)
score.next
end
end
# In a child process using fork
class Fork
def initialize(log: Log::NULL)
@log = log
end
def up(score)
start = Time.now
stdout, stdin = IO.pipe
pid = Process.fork do
stdin.puts(score.next)
end
at_exit { Farmers.kill(@log, pid, start) }
Process.wait
stdin.close
text = stdout.read.strip
stdout.close
raise "No score was calculated in the process ##{pid} in #{Age.new(start)}" if text.empty?
after = Score.parse(text)
@log.debug("Next score #{after.value}/#{after.strength} found in proc ##{pid} \
for #{after.host}:#{after.port} in #{Age.new(start)}: #{after.suffixes}")
after
end
end
# In a child process
class Spawn
def initialize(log: Log::NULL)
@log = log
end
def up(score)
start = Time.now
bin = File.expand_path(File.join(File.dirname(__FILE__), '../../../bin/zold'))
raise "Zold binary not found at #{bin}" unless File.exist?(bin)
cmd = [
'ruby',
Shellwords.escape(bin),
'--skip-upgrades',
"--info-tid=#{Shellwords.escape(Thread.current.thread_variable_get(:tid))}",
"--info-thread=#{Shellwords.escape(Thread.current.name)}",
"--info-start=#{Shellwords.escape(Time.now.utc.iso8601)}",
'--low-priority',
'next',
Shellwords.escape(score)
].join(' ')
Open3.popen2e(cmd) do |stdin, stdout, thr|
Thread.current.thread_variable_set(:pid, thr.pid.to_s)
at_exit { Farmers.kill(@log, thr.pid, start) }
@log.debug("Scoring started in proc ##{thr.pid} \
for #{score.value}/#{score.strength} at #{score.host}:#{score.port}")
begin
stdin.close
buffer = +''
loop do
begin
buffer << stdout.read_nonblock(16 * 1024)
rescue IO::WaitReadable
# nothing to do here
rescue StandardError => e
@log.error(buffer)
raise e
end
break if buffer.end_with?("\n") && thr.value.to_i.zero?
if stdout.closed?
raise "Failed to calculate the score (##{thr.value}): #{buffer}" unless thr.value.to_i.zero?
break
end
sleep(1)
Thread.current.thread_variable_set(:buffer, buffer.length.to_s)
end
after = Score.parse(buffer.strip)
@log.debug("Next score #{after.value}/#{after.strength} found in proc ##{thr.pid} \
for #{after.host}:#{after.port} in #{Age.new(start)}: #{after.suffixes}")
after
ensure
Farmers.kill(@log, thr.pid, start)
end
end
end
end
end
end