require 'socket'
require 'drb/drb'
# We need to define our own NativeException class for the cases when a native
# exception is raised by the JRuby DRb server.
class NativeException < StandardError; end
module Akephalos
# The +RemoteClient+ class provides an interface to an +Akephalos::Client+
# isntance on a remote DRb server.
#
# == Usage
# client = Akephalos::RemoteClient.new
# client.visit "http://www.oinopa.com"
# client.page.source # => "<!DOCTYPE html PUBLIC..."
class RemoteClient
# @return [DRbObject] a new instance of Akephalos::Client from the DRb
# server
def self.new(options = {})
manager.new_client(options)
end
# Starts a remove JRuby DRb server unless already running and returns an
# instance of Akephalos::ClientManager.
#
# @return [DRbObject] an instance of Akephalos::ClientManager
def self.manager
return @manager if defined?(@manager)
server_port = start!
DRb.start_service("druby://127.0.0.1:#{find_available_port}")
manager = DRbObject.new_with_uri("druby://127.0.0.1:#{server_port}")
# We want to share our local configuration with the remote server
# process, so we share an undumped version of our configuration. This
# lets us continue to make changes locally and have them reflected in the
# remote process.
manager.configuration = Akephalos.configuration.extend(DRbUndumped)
@manager = manager
end
# Start a remote server process and return when it is available for use.
def self.start!
port = find_available_port
remote_client = IO.popen("ruby #{Akephalos::BIN_DIR + 'akephalos'} #{port}")
# Set up a monitor thread to detect if the forked server exits
# prematurely.
server_monitor = Thread.new { Thread.current[:exited] = Process.wait(remote_client.pid) }
# Wait for the server to be accessible on the socket we specified.
until responsive?(port)
exit!(1) if server_monitor[:exited]
sleep 0.5
end
server_monitor.kill
# Ensure that the remote server shuts down gracefully when we are
# finished.
at_exit {
if RbConfig::CONFIG['host_os'] =~ /mswin|mingw/
system("taskkill /PID #{remote_client.pid} /F /T")
else
Process.kill(:INT, remote_client.pid)
end
}
port
end
private
# @api private
# @param [Integer] port the port to check for responsiveness
# @return [true, false] whether the port is responsive
def self.responsive?(port)
socket = TCPSocket.open('127.0.0.1', port)
true
rescue Errno::ECONNREFUSED
false
ensure
socket.close if socket
end
# @api private
# @return [Integer] the next available port
def self.find_available_port
server = TCPServer.new('127.0.0.1', 0)
server.addr[1]
ensure
server.close if server
end
end
end