I have an eventmachine app where one script is reading from a file, sending data to another script line by line, and the "server" script is acting upon that data. Unfortunately, the "server" script fails to execute receive_data as it should. I know that a connection is being made because it eecutes post_init, and I know the sender script is sending data. Here is some of my code along with how I start the server.
module BT_Server
def post_init
puts "-- someone connected to the echo server!"
end
def receive_data(data)
puts "hi"
int, time, *int_macs = data.split("-")
# more stuff that isn't needed here
end
def bt_left(dev)
dev.save
if t = Device.macs.index(dev.mac)
Device.all[t].add_int(dev.int, dev.t_0, dev.t_l)
else
Device.new(dev.mac, dev.int, dev.t_0, dev.t_l)
end
return false
end
def unbind
puts "disconnection"
end
end
EventMachine::run {
EventMachine::start_server 'localhost', 8081, BT_Server
puts t_0 = Time.new
puts 'listening...'
}
Note: I have the Module definition in a separate file, along with my classes, which I require into the server script, if that makes any difference.
i tested your code and it outputs 'hi' every time i send something via telnet.
from my point of view, the code is correct.
are you sure the sending script is working? try with a manual telnet on port 8081.
regards.
Related
I'm developing API, based on EventMachine echo server. It listens requests on specific port and returns html-page with qr-code on it, which is generated depending on params from request query. The problem is that evaluating method, which packs string into qr-code takes from 8 to 11 seconds, it is unacceptable. I have no ideas why it happens, except it could be associated with event-machine.
P.S. In irb the same code RQRCode::QRCode.new(my_string, :size => 10,:level => :l) takes less than 1 second.
I have tried two different gems: rqrcode and barby+rqrcode. Both show the same results.
Code example:
require 'eventmachine'
require 'rqrcode'
class Handler < EventMachine::Connection
def receive_data(data)
puts Time.now
qrcode = RQRCode::QRCode.new('some_string', :size => 10,:level => :l)
puts Time.now
return qrcode
end
end
EventMachine::run {
EventMachine::start_server("0.0.0.0", 8081, Handler)
puts "Listening..."
}
Output:
2015-05-12 18:03:38 +0300
2015-05-12 18:03:48 +0300
It looks like you need to call close_connection. Here's EventMachine's echo server example
require 'eventmachine'
module EchoServer
def post_init
puts "-- someone connected to the echo server!"
end
def receive_data data
send_data ">>>you sent: #{data}"
close_connection if data =~ /quit/i # <---- This is what you're missing -----
end
def unbind
puts "-- someone disconnected from the echo server!"
end
end
# Note that this will block current thread.
EventMachine.run {
EventMachine.start_server "127.0.0.1", 8081, EchoServer
}
If your timestamps are always (nearly) exactly 10 seconds apart, I'd wager the request is ending because of a timeout rather than because of a response. After you respond with the QR data, call close_connection to let the browser know you're finished properly.
Edit It also looks like you're not calling send_data (and referencing Tume instead of Time). It looks like you need to use send_data, not return. Is your code snippet what's actually running on your server?
Update Running in debug mode was significantly slowing down QR generation.
The problem was that I've run server in debug-mode from RubyMine. Starting server from console solves the problem, qr-code generation takes about 1 sec.
I have a faye server (nodejs) running on localhost, and I am trying to setup a server side ruby client which needs to publish on the server on a regular basis. This is the code I am trying to use.
(Please ignore the commented code to start with).
I make a class variable ##client and initialize it as soon as the class loads. I define a class method pub whose task is to publish something on the faye server.
In the end, I just call the pub method twice. The first publication callback is received successfully, but the second publication doesn't make either of callback or the errback. And since the control has not been given back to the app, the app just hangs there.
If I make the gobal variable $client (currently commented), the behaviour is the same. But if I make the client everytime pub is called, then the publish goes on smoothly. I initiate it in EM.run loop or outside, the behavior is same. (as expected)
I don't want to make a new connection everytime I want to publish something since that defeats the purpose. Also, if I create a new client in EM.run everytime I call the method, the client connections don't close by themselves. I can see them open in lsof command as open files, and soon I'll start getting too many open files error I think.
I don't really understand Event Machine correctly, maybe I am missing something there.
require 'faye'
require 'eventmachine'
# $client = Faye::Client.new('http://localhost:5050/faye')
class Fayeclient
puts "#{__LINE__}: Reactor running: " + EM.reactor_running?.to_s
# if !defined? ##client or ##client.nil?
##client = Faye::Client.new('http://localhost:5050/faye')
puts "Created client: " + ##client.inspect
# end
def self.pub
puts "#{__LINE__}: Reactor running: " + EM.reactor_running?.to_s
# client = Faye::Client.new('http://localhost:5050/faye') #$client
# client = ##client
EM.run {
#client = Faye::Client.new('http://localhost:5050/faye') #$client
puts "#{__LINE__}: Reactor running: " + EM.reactor_running?.to_s
puts ##client.inspect
publication = ##client.publish('/foo', 'text' =>'Hello world')
puts "Publishing: #{publication.inspect}"
# puts "Publication methods: #{publication.methods}"
publication.callback do
puts "Did it #{publication.inspect}"
EM.stop_event_loop
puts "#{__LINE__}: Reactor running: " + EM.reactor_running?.to_s
# puts "#{client.methods}"
# puts client.inspect
# client.remove_all_listeners
# puts client.inspect
end
publication.errback do |error |
puts error.inspect
EM.stop_event_loop
end
}
puts "Outside event loop"
puts "#{__LINE__}: Reactor running: " + EM.reactor_running?.to_s
end
end
Fayeclient.pub
Fayeclient.pub
EM.run call is blocking, you have to run it on a separate thread, and eventually join it when all is over. In the example I'm using Singleton but it's up to you.
This does correctly the 2 faye calls.
#!/usr/bin/env ruby
#
require 'faye'
require 'singleton'
require 'eventmachine'
class Fayeclient
include Singleton
attr_accessor :em_thread, :client
def initialize
self.em_thread = Thread.new do
EM.run
end
self.client = Faye::Client.new('http://localhost:8890/faye')
end
def pub
puts "#{__LINE__}: Reactor running: " + EM.reactor_running?.to_s
puts client.inspect
publication = client.publish('/foo', 'text' =>'Hello world')
puts "Publishing: #{publication.inspect}"
publication.callback do
puts "Did it #{publication.inspect}"
EM.stop_event_loop
puts "#{__LINE__}: Reactor running: " + EM.reactor_running?.to_s
end
publication.errback do |error |
puts error.inspect
EM.stop_event_loop
end
end
end
Fayeclient.instance.pub
Fayeclient.instance.pub
Fayeclient.instance.em_thread.join
In my personal experience, anyway, having to deal with EventMachine inside Rails application can be a mess, some webserver uses EM, other does not so, and when you want to test from console it may not work as expected.
My solution is to fallback to http calls:
RestClient.post "http://localhost:#{Rails.configuration.faye_port}/faye", message: {foo: 'bar'}.to_json
I found this solution simpler and easy to customize, if you don't need to receive message from this piece of code.
I am new to ruby and thought it would be a great idea to rebuild a simple chat program I made in C#.
I am using Ruby 2.0.0 MRI (Matz’s Ruby Implementation).
The problem is I want to have I/O for simple server commands while the server is running.
This is the server that was taken from the sample. I added the commands method that uses gets() to get input. I want this method to run as a thread in the background, but the thread is blocking the other thread.
require 'socket' # Get sockets from stdlib
server = TCPServer.open(2000) # Socket to listen on port 2000
def commands
x = 1
while x == 1
exitProgram = gets.chomp
if exitProgram == "exit" || exitProgram == "Exit"
x = 2
abort("Exiting the program.")
end
end
end
def main
Thread.start(commands)
Thread.start(server.accept)
loop { # Servers run forever
Thread.start(server.accept) do |client|
client.puts(Time.now.ctime) # Send the time to the client
client.puts "Closing the connection. Bye!"
client.close # Disconnect from the client
end
}
end
main
This is the client so far.
require 'socket' # Sockets are in standard library
hostname = 'localhost'
port = 2000
s = TCPSocket.open(hostname, port)
while line = s.gets # Read lines from the socket
puts line.chop # And print with platform line terminator
end
s.close # Close the socket when done
gets.chomp
Read the documentation for Thread.new (which is the same as Thread.start here)
Thread.start(commands) runs the commands method and passes its return value to a thread (which then does nothing). It's blocking because you aren't starting any threads when gets is called. You want
Thread.start { commands }
Here's a similar demo script that works just like you would expect
def commands
while gets.strip !~ /^exit$/i
puts "Invalid command"
end
abort "Exiting the program"
end
Thread.start { commands }
loop do
puts "Type exit:"
sleep 2
end
My first question concerning Ruby.
I'm trying to test EventMachine interaction inside the Reactor loop - I guess it could be classified as "functional" testing.
Say I have two classes - a server and a client. And I want to test both sides - I need to be sure about their interaction.
Server:
require 'singleton'
class EchoServer < EM::Connection
include EM::Protocols::LineProtocol
def post_init
puts "-- someone connected to the echo server!"
end
def receive_data data
send_data ">>>you sent: #{data}"
close_connection if data =~ /quit/i
end
def unbind
puts "-- someone disconnected from the echo server!"
end
end
Client:
class EchoClient < EM::Connection
include EM::Protocols::LineProtocol
def post_init
send_data "Hello"
end
def receive_data(data)
#message = data
p data
end
def unbind
puts "-- someone disconnected from the echo server!"
end
end
So, I've tried different approaches and came up with nothing.
The fundamental question is - could I somehow test my code with RSpec, using should_recive?
EventMachine parameter should be a class or a module, so I can't send instantiated/mocked code inside. Right?
Something like this?
describe 'simple rspec test' do
it 'should pass the test' do
EventMachine.run {
EventMachine::start_server "127.0.0.1", 8081, EchoServer
puts 'running echo server on 8081'
EchoServer.should_receive(:receive_data)
EventMachine.connect '127.0.0.1', 8081, EchoClient
EventMachine.add_timer 1 do
puts 'Second passed. Stop loop.'
EventMachine.stop_event_loop
end
}
end
end
And, if not, how would you do it with EM::SpecHelper? I have this code using it, and can't figure out what I'm doing wrong.
describe 'when server is run and client sends data' do
include EM::SpecHelper
default_timeout 2
def start_server
EM.start_server('0.0.0.0', 12345) { |ws|
yield ws if block_given?
}
end
def start_client
client = EM.connect('0.0.0.0', 12345, FakeWebSocketClient)
yield client if block_given?
return client
end
describe "examples from the spec" do
it "should accept a single-frame text message" do
em {
start_server
start_client { |client|
client.onopen {
client.send_data("\x04\x05Hello")
}
}
}
end
end
end
Tried a lot of variations of these tests and I just can't figure it out. I'm sure I'm missing something here...
Thanks for your help.
The simplest solution that I can think of is to change this:
EchoServer.should_receive(:receive_data)
To this:
EchoServer.any_instance.should_receive(:receive_data)
Since EM is expecting a class to start a server, the above any_instance trick will expect any instance of that class to receive that method.
The EMSpecHelper example (while being official/standard) is quite convoluted, I'd rather stick with the first rspec and use any_instance, just for simplicity's sake.
I'm trying to run a mock webserver within a thread within a class. I've tried passing the class' #server property to the thread block but as soon as I try to do server.accept the thread stops. Is there some way to make this work? I want to basically be able to run a webserver off of this script while still taking user input via stdin.gets. Is this possible?
class Server
def initialize()
#server = TCPServer.new(8080)
end
def run()
#thread = Thread.new(#server) { |server|
while true
newsock = server.accept
puts "some stuff after accept!"
next if !newsock
# some other stuff
end
}
end
end
def processCommand()
# some user commands here
end
test = Server.new
while true do
processCommand(STDIN.gets)
end
In the above sample, the thread dies on server.accept
In the code you posted, you're not calling Server#run. That's probably just an oversight in making the post. Server.accept is supposed to block a thread, returning only when someone has connected.
Anyone who goes into writing an HTTP server with bright eyes soon learns that it's more fun to let someone else do that work. For quick and dirty HTTP servers, I've got good results enlisting the aid of WEBrick. It's a part of the Ruby library. Here's a WEBrick server that will serve up "Boo!" When you connect your browser to localhost:8080/:
#!/usr/bin/ruby1.8
require 'webrick'
class MiniServer
def initialize
Thread.new do
Thread::abort_on_exception = true
server = WEBrick::HTTPServer.new(:BindAddress=>'127.0.0.1',
:Port=>8080,
:Logger=>WEBrick::Log.new('/dev/stdout'))
server.mount('/', Servlet, self)
server.start
end
end
private
class Servlet < WEBrick::HTTPServlet::AbstractServlet
def initialize(webrick_server, mini_server)
end
def do_GET(req, resp)
resp.body = "<html><head></head><body>Boo!</body></html>"
end
alias :do_POST :do_GET
end
end
server = MiniServer.new
gets
I don't know ruby, but it looks like server.accept is blocking until you get a tcp connection... your thread will continue as soon as a connection is accepted.
You should start the server in your main thread and then spawn a new thread for each connection that you accept, that way your server will immediately go to accept another connection and your thread will service the one that was just accepted.