mastodon/app/lib/request_pool.rb
2023-02-20 11:01:20 +01:00

115 lines
2.4 KiB
Ruby

# frozen_string_literal: true
require_relative './connection_pool/shared_connection_pool'
class RequestPool
def self.current
@current ||= RequestPool.new
end
class Reaper
attr_reader :pool, :frequency
def initialize(pool, frequency)
@pool = pool
@frequency = frequency
end
def run
return unless frequency&.positive?
Thread.new(frequency, pool) do |t, p|
loop do
sleep t
p.flush
end
end
end
end
MAX_IDLE_TIME = 30
WAIT_TIMEOUT = 5
MAX_POOL_SIZE = ENV.fetch('MAX_REQUEST_POOL_SIZE', 512).to_i
class Connection
attr_reader :site, :last_used_at, :created_at, :in_use, :dead, :fresh
def initialize(site)
@site = site
@http_client = http_client
@last_used_at = nil
@created_at = current_time
@dead = false
@fresh = true
end
def use
@last_used_at = current_time
@in_use = true
retries = 0
begin
yield @http_client
rescue HTTP::ConnectionError
# It's possible the connection was closed, so let's
# try re-opening it once
close
if @fresh || retries.positive?
raise
else
@http_client = http_client
retries += 1
retry
end
rescue
# If this connection raises errors of any kind, it's
# better if it gets reaped as soon as possible
close
@dead = true
raise
end
ensure
@fresh = false
@in_use = false
end
def seconds_idle
current_time - (@last_used_at || @created_at)
end
def close
@http_client.close
end
private
def http_client
Request.http_client.persistent(@site, timeout: MAX_IDLE_TIME)
end
def current_time
Process.clock_gettime(Process::CLOCK_MONOTONIC)
end
end
def initialize
@pool = ConnectionPool::SharedConnectionPool.new(size: MAX_POOL_SIZE, timeout: WAIT_TIMEOUT) { |site| Connection.new(site) }
@reaper = Reaper.new(self, 30)
@reaper.run
end
def with(site, &block)
@pool.with(site) do |connection|
ActiveSupport::Notifications.instrument('with.request_pool', miss: connection.fresh, host: connection.site) do
connection.use(&block)
end
end
end
delegate :size, :flush, to: :@pool
end