# $Id$
#
# Author:: Francis Cianfrocca (gmail: blackhedd)
# Homepage:: http://rubyeventmachine.com
# Date:: 8 Apr 2006
#
# See EventMachine and EventMachine::Connection for documentation and
# usage examples.
#
#----------------------------------------------------------------------------
#
# Copyright (C) 2006-07 by Francis Cianfrocca. All Rights Reserved.
# Gmail: blackhedd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of either: 1) the GNU General Public License
# as published by the Free Software Foundation; either version 2 of the
# License, or (at your option) any later version; or 2) Ruby's License.
#
# See the file COPYING for complete licensing information.
#
#---------------------------------------------------------------------------
#
#
#-- Select in a library based on a global variable.
# PROVISIONALLY commented out this whole mechanism which selects
# a pure-Ruby EM implementation if the extension is not available.
# I expect this will cause a lot of people's code to break, as it
# exposes misconfigurations and path problems that were masked up
# till now. The reason I'm disabling it is because the pure-Ruby
# code will have problems of its own, and it's not nearly as fast
# anyway. Suggested by a problem report from Moshe Litvin. 05Jun07.
#
# 05Dec07: Re-enabled the pure-ruby mechanism, but without the automatic
# fallback feature that tripped up Moshe Litvin. We shouldn't fail over to
# the pure Ruby version because it's possible that the user intended to
# run the extension but failed to do so because of a compilation or
# similar error. So we require either a global variable or an environment
# string be set in order to select the pure-Ruby version.
#
unless defined?($eventmachine_library)
$eventmachine_library = ENV['EVENTMACHINE_LIBRARY'] || :cascade
end
$eventmachine_library = $eventmachine_library.to_sym
case $eventmachine_library
when :pure_ruby
require 'pr_eventmachine'
when :extension
require 'rubyeventmachine'
when :java
require 'jeventmachine'
else # :cascade
# This is the case that most user code will take.
# Prefer the extension if available.
begin
if RUBY_PLATFORM =~ /java/
require 'java'
require 'jeventmachine'
$eventmachine_library = :java
else
require 'rubyeventmachine'
$eventmachine_library = :extension
end
rescue LoadError
warn "# EventMachine fell back to pure ruby mode" if $DEBUG
require 'pr_eventmachine'
$eventmachine_library = :pure_ruby
end
end
require "eventmachine_version"
require 'em/deferrable'
require 'em/future'
require 'em/eventable'
require 'em/messages'
require 'em/streamer'
require 'em/spawnable'
require 'shellwords'
#-- Additional requires are at the BOTTOM of this file, because they
#-- depend on stuff defined in here. Refactor that someday.
# == Introduction
# EventMachine provides a fast, lightweight framework for implementing
# Ruby programs that can use the network to communicate with other
# processes. Using EventMachine, Ruby programmers can easily connect
# to remote servers and act as servers themselves. EventMachine does not
# supplant the Ruby IP libraries. It does provide an alternate technique
# for those applications requiring better performance, scalability,
# and discipline over the behavior of network sockets, than is easily
# obtainable using the built-in libraries, especially in applications
# which are structurally well-suited for the event-driven programming model.
#
# EventMachine provides a perpetual event-loop which your programs can
# start and stop. Within the event loop, TCP network connections are
# initiated and accepted, based on EventMachine methods called by your
# program. You also define callback methods which are called by EventMachine
# when events of interest occur within the event-loop.
#
# User programs will be called back when the following events occur:
# * When the event loop accepts network connections from remote peers
# * When data is received from network connections
# * When connections are closed, either by the local or the remote side
# * When user-defined timers expire
#
# == Usage example
#
# Here's a fully-functional echo server implemented in EventMachine:
#
# require 'rubygems'
# require 'eventmachine'
#
# module EchoServer
# def receive_data data
# send_data ">>>you sent: #{data}"
# close_connection if data =~ /quit/i
# end
# end
#
# EventMachine::run {
# EventMachine::start_server "192.168.0.100", 8081, EchoServer
# }
#
# What's going on here? Well, we have defined the module EchoServer to
# implement the semantics of the echo protocol (more about that shortly).
# The last three lines invoke the event-machine itself, which runs forever
# unless one of your callbacks terminates it. The block that you supply
# to EventMachine::run contains code that runs immediately after the event
# machine is initialized and before it starts looping. This is the place
# to open up a TCP server by specifying the address and port it will listen
# on, together with the module that will process the data.
#
# Our EchoServer is extremely simple as the echo protocol doesn't require
# much work. Basically you want to send back to the remote peer whatever
# data it sends you. We'll dress it up with a little extra text to make it
# interesting. Also, we'll close the connection in case the received data
# contains the word "quit."
#
# So what about this module EchoServer? Well, whenever a network connection
# (either a client or a server) starts up, EventMachine instantiates an anonymous
# class, that your module has been mixed into. Exactly one of these class
# instances is created for each connection. Whenever an event occurs on a
# given connection, its corresponding object automatically calls specific
# instance methods which your module may redefine. The code in your module
# always runs in the context of a class instance, so you can create instance
# variables as you wish and they will be carried over to other callbacks
# made on that same connection.
#
# Looking back up at EchoServer, you can see that we've defined the method
# receive_data which (big surprise) is called whenever data has been received
# from the remote end of the connection. Very simple. We get the data
# (a String object) and can do whatever we wish with it. In this case,
# we use the method send_data to return the received data to the caller,
# with some extra text added in. And if the user sends the word "quit,"
# we'll close the connection with (naturally) close_connection.
# (Notice that closing the connection doesn't terminate the processing loop,
# or change the fact that your echo server is still accepting connections!)
#
#
# == Questions and Futures
# Would it be useful for EventMachine to incorporate the Observer pattern
# and make use of the corresponding Ruby observer package?
# Interesting thought.
#
#
module EventMachine
class FileNotFoundException < Exception; end
class << self
attr_reader :threadpool
end
# EventMachine::run initializes and runs an event loop.
# This method only returns if user-callback code calls stop_event_loop.
# Use the supplied block to define your clients and servers.
# The block is called by EventMachine::run immediately after initializing
# its internal event loop but before running the loop.
# Therefore this block is the right place to call start_server if you
# want to accept connections from remote clients.
#
# For programs that are structured as servers, it's usually appropriate
# to start an event loop by calling EventMachine::run, and let it
# run forever. It's also possible to use EventMachine::run to make a single
# client-connection to a remote server, process the data flow from that
# single connection, and then call stop_event_loop to force EventMachine::run
# to return. Your program will then continue from the point immediately
# following the call to EventMachine::run.
#
# You can of course do both client and servers simultaneously in the same program.
# One of the strengths of the event-driven programming model is that the
# handling of network events on many different connections will be interleaved,
# and scheduled according to the actual events themselves. This maximizes
# efficiency.
#
# === Server usage example
#
# See the text at the top of this file for an example of an echo server.
#
# === Client usage example
#
# See the description of stop_event_loop for an extremely simple client example.
#
#--
# Obsoleted the use_threads mechanism.
# 25Nov06: Added the begin/ensure block. We need to be sure that release_machine
# gets called even if an exception gets thrown within any of the user code
# that the event loop runs. The best way to see this is to run a unit
# test with two functions, each of which calls EventMachine#run and each of
# which throws something inside of #run. Without the ensure, the second test
# will start without release_machine being called and will immediately throw
# a C++ runtime error.
#
def EventMachine::run blk=nil, tail=nil, &block
@tails ||= []
tail and @tails.unshift(tail)
if reactor_running?
(b = blk || block) and b.call # next_tick(b)
else
@conns = {}
@acceptors = {}
@timers = {}
@wrapped_exception = nil
begin
@reactor_running = true
initialize_event_machine
(b = blk || block) and add_timer(0, b)
if @next_tick_queue && !@next_tick_queue.empty?
add_timer(0) { signal_loopbreak }
end
run_machine
ensure
begin
release_machine
ensure
if @threadpool
@threadpool.each { |t| t.exit }
@threadpool.each { |t| t.kill! if t.alive? }
@threadqueue = nil
@resultqueue = nil
end
@threadpool = nil
end
@reactor_running = false
end
until @tails.empty?
@tails.pop.call
end
raise @wrapped_exception if @wrapped_exception
end
end
# Sugars a common use case. Will pass the given block to #run, but will terminate
# the reactor loop and exit the function as soon as the code in the block completes.
# (Normally, #run keeps running indefinitely, even after the block supplied to it
# finishes running, until user code calls #stop.)
#
def EventMachine::run_block &block
pr = proc {
block.call
EventMachine::stop
}
run(&pr)
end
# fork_reactor forks a new process and calls EM#run inside of it, passing your block.
#--
# This implementation is subject to change, especially if we clean up the relationship
# of EM#run to @reactor_running.
# Original patch by Aman Gupta.
#
def EventMachine::fork_reactor &block
Kernel.fork do
if self.reactor_running?
self.stop_event_loop
self.release_machine
self.instance_variable_set( '@reactor_running', false )
end
self.run block
end
end
# +deprecated+
#--
# EventMachine#run_without_threads is semantically identical
# to EventMachine#run, but it runs somewhat faster.
# However, it must not be used in applications that spin
# Ruby threads.
def EventMachine::run_without_threads &block
#EventMachine::run false, &block
EventMachine::run(&block)
end
# EventMachine#add_timer adds a one-shot timer to the event loop.
# Call it with one or two parameters. The first parameters is a delay-time
# expressed in seconds (not milliseconds). The second parameter, if
# present, must be a proc object. If a proc object is not given, then you
# can also simply pass a block to the method call.
#
# EventMachine#add_timer may be called from the block passed to EventMachine#run
# or from any callback method. It schedules execution of the proc or block
# passed to add_timer, after the passage of an interval of time equal to
# at least the number of seconds specified in the first parameter to
# the call.
#
# EventMachine#add_timer is a non-blocking call. Callbacks can and will
# be called during the interval of time that the timer is in effect.
# There is no built-in limit to the number of timers that can be outstanding at
# any given time.
#
# === Usage example
#
# This example shows how easy timers are to use. Observe that two timers are
# initiated simultaneously. Also, notice that the event loop will continue
# to run even after the second timer event is processed, since there was
# no call to EventMachine#stop_event_loop. There will be no activity, of
# course, since no network clients or servers are defined. Stop the program
# with Ctrl-C.
#
# require 'rubygems'
# require 'eventmachine'
#
# EventMachine::run {
# puts "Starting the run now: #{Time.now}"
# EventMachine::add_timer 5, proc { puts "Executing timer event: #{Time.now}" }
# EventMachine::add_timer( 10 ) { puts "Executing timer event: #{Time.now}" }
# }
#
#
#--
# Changed 04Oct06: We now pass the interval as an integer number of milliseconds.
#
def EventMachine::add_timer *args, &block
interval = args.shift
code = args.shift || block
if code
# check too many timers!
s = add_oneshot_timer((interval * 1000).to_i)
@timers[s] = code
s
end
end
# EventMachine#add_periodic_timer adds a periodic timer to the event loop.
# It takes the same parameters as the one-shot timer method, EventMachine#add_timer.
# This method schedules execution of the given block repeatedly, at intervals
# of time at least as great as the number of seconds given in the first
# parameter to the call.
#
# === Usage example
#
# The following sample program will write a dollar-sign to stderr every five seconds.
# (Of course if the program defined network clients and/or servers, they would
# be doing their work while the periodic timer is counting off.)
#
# EventMachine::run {
# EventMachine::add_periodic_timer( 5 ) { $stderr.write "$" }
# }
#
def EventMachine::add_periodic_timer *args, &block
interval = args.shift
code = args.shift || block
if code
block_1 = proc {
code.call
EventMachine::add_periodic_timer interval, code
}
add_timer interval, block_1
end
end
#--
#
def EventMachine::cancel_timer signature
@timers[signature] = proc{} if @timers.has_key?(signature)
end
# stop_event_loop may called from within a callback method
# while EventMachine's processing loop is running.
# It causes the processing loop to stop executing, which
# will cause all open connections and accepting servers
# to be run down and closed. Callbacks for connection-termination
# will be called as part of the processing of stop_event_loop.
# (There currently is no option to panic-stop the loop without
# closing connections.) When all of this processing is complete,
# the call to EventMachine::run which started the processing loop
# will return and program flow will resume from the statement
# following EventMachine::run call.
#
# === Usage example
#
# require 'rubygems'
# require 'eventmachine'
#
# module Redmond
#
# def post_init
# puts "We're sending a dumb HTTP request to the remote peer."
# send_data "GET / HTTP/1.1\r\nHost: www.microsoft.com\r\n\r\n"
# end
#
# def receive_data data
# puts "We received #{data.length} bytes from the remote peer."
# puts "We're going to stop the event loop now."
# EventMachine::stop_event_loop
# end
#
# def unbind
# puts "A connection has terminated."
# end
#
# end
#
# puts "We're starting the event loop now."
# EventMachine::run {
# EventMachine::connect "www.microsoft.com", 80, Redmond
# }
# puts "The event loop has stopped."
#
# This program will produce approximately the following output:
#
# We're starting the event loop now.
# We're sending a dumb HTTP request to the remote peer.
# We received 1440 bytes from the remote peer.
# We're going to stop the event loop now.
# A connection has terminated.
# The event loop has stopped.
#
#
def EventMachine::stop_event_loop
EventMachine::stop
end
# EventMachine::start_server initiates a TCP server (socket
# acceptor) on the specified IP address and port.
# The IP address must be valid on the machine where the program
# runs, and the process must be privileged enough to listen
# on the specified port (on Unix-like systems, superuser privileges
# are usually required to listen on any port lower than 1024).
# Only one listener may be running on any given address/port
# combination. start_server will fail if the given address and port
# are already listening on the machine, either because of a prior call
# to start_server or some unrelated process running on the machine.
# If start_server succeeds, the new network listener becomes active
# immediately and starts accepting connections from remote peers,
# and these connections generate callback events that are processed
# by the code specified in the handler parameter to start_server.
#
# The optional handler which is passed to start_server is the key
# to EventMachine's ability to handle particular network protocols.
# The handler parameter passed to start_server must be a Ruby Module
# that you must define. When the network server that is started by
# start_server accepts a new connection, it instantiates a new
# object of an anonymous class that is inherited from EventMachine::Connection,
# into which the methods from your handler have been mixed.
# Your handler module may redefine any of the methods in EventMachine::Connection
# in order to implement the specific behavior of the network protocol.
#
# Callbacks invoked in response to network events always take place
# within the execution context of the object derived from EventMachine::Connection
# extended by your handler module. There is one object per connection, and
# all of the callbacks invoked for a particular connection take the form
# of instance methods called against the corresponding EventMachine::Connection
# object. Therefore, you are free to define whatever instance variables you
# wish, in order to contain the per-connection state required by the network protocol you are
# implementing.
#
# start_server is often called inside the block passed to EventMachine::run,
# but it can be called from any EventMachine callback. start_server will fail
# unless the EventMachine event loop is currently running (which is why
# it's often called in the block suppled to EventMachine::run).
#
# You may call start_server any number of times to start up network
# listeners on different address/port combinations. The servers will
# all run simultaneously. More interestingly, each individual call to start_server
# can specify a different handler module and thus implement a different
# network protocol from all the others.
#
# === Usage example
# Here is an example of a server that counts lines of input from the remote
# peer and sends back the total number of lines received, after each line.
# Try the example with more than one client connection opened via telnet,
# and you will see that the line count increments independently on each
# of the client connections. Also very important to note, is that the
# handler for the receive_data function, which our handler redefines, may
# not assume that the data it receives observes any kind of message boundaries.
# Also, to use this example, be sure to change the server and port parameters
# to the start_server call to values appropriate for your environment.
#
# require 'rubygems'
# require 'eventmachine'
#
# module LineCounter
#
# MaxLinesPerConnection = 10
#
# def post_init
# puts "Received a new connection"
# @data_received = ""
# @line_count = 0
# end
#
# def receive_data data
# @data_received << data
# while @data_received.slice!( /^[^\n]*[\n]/m )
# @line_count += 1
# send_data "received #{@line_count} lines so far\r\n"
# @line_count == MaxLinesPerConnection and close_connection_after_writing
# end
# end
#
# end # module LineCounter
#
# EventMachine::run {
# host,port = "192.168.0.100", 8090
# EventMachine::start_server host, port, LineCounter
# puts "Now accepting connections on address #{host}, port #{port}..."
# EventMachine::add_periodic_timer( 10 ) { $stderr.write "*" }
# }
#
#
def EventMachine::start_server server, port=nil, handler=nil, *args, &block
begin
port = Integer(port)
rescue ArgumentError, TypeError
# there was no port, so server must be a unix domain socket
# the port argument is actually the handler, and the handler is one of the args
args.unshift handler if handler
handler = port
port = nil
end if port
klass = if (handler and handler.is_a?(Class))
raise ArgumentError, 'must provide module or subclass of EventMachine::Connection' unless Connection > handler
handler
else
Class.new( Connection ) {handler and include handler}
end
arity = klass.instance_method(:initialize).arity
expected = arity >= 0 ? arity : -(arity + 1)
if (arity >= 0 and args.size != expected) or (arity < 0 and args.size < expected)
raise ArgumentError, "wrong number of arguments for #{klass}#initialize (#{args.size} for #{expected})"
end
s = if port
start_tcp_server server, port
else
start_unix_server server
end
@acceptors[s] = [klass,args,block]
s
end
# Stop a TCP server socket that was started with EventMachine#start_server.
#--
# Requested by Kirk Haines. TODO, this isn't OOP enough. We ought somehow
# to have #start_server return an object that has a close or a stop method on it.
#
def EventMachine::stop_server signature
EventMachine::stop_tcp_server signature
end
def EventMachine::start_unix_domain_server filename, *args, &block
start_server filename, *args, &block
end
# EventMachine#connect initiates a TCP connection to a remote
# server and sets up event-handling for the connection.
# You can call EventMachine#connect in the block supplied
# to EventMachine#run or in any callback method.
#
# EventMachine#connect takes the IP address (or hostname) and
# port of the remote server you want to connect to.
# It also takes an optional handler Module which you must define, that
# contains the callbacks that will be invoked by the event loop
# on behalf of the connection.
#
# See the description of EventMachine#start_server for a discussion
# of the handler Module. All of the details given in that description
# apply for connections created with EventMachine#connect.
#
# === Usage Example
#
# Here's a program which connects to a web server, sends a naive
# request, parses the HTTP header of the response, and then
# (antisocially) ends the event loop, which automatically drops the connection
# (and incidentally calls the connection's unbind method).
#
# require 'rubygems'
# require 'eventmachine'
#
# module DumbHttpClient
#
# def post_init
# send_data "GET / HTTP/1.1\r\nHost: _\r\n\r\n"
# @data = ""
# end
#
# def receive_data data
# @data << data
# if @data =~ /[\n][\r]*[\n]/m
# puts "RECEIVED HTTP HEADER:"
# $`.each {|line| puts ">>> #{line}" }
#
# puts "Now we'll terminate the loop, which will also close the connection"
# EventMachine::stop_event_loop
# end
# end
#
# def unbind
# puts "A connection has terminated"
# end
#
# end # DumbHttpClient
#
#
# EventMachine::run {
# EventMachine::connect "www.bayshorenetworks.com", 80, DumbHttpClient
# }
# puts "The event loop has ended"
#
#
# There are times when it's more convenient to define a protocol handler
# as a Class rather than a Module. Here's how to do this:
#
# class MyProtocolHandler < EventMachine::Connection
# def initialize *args
# super
# # whatever else you want to do here
# end
#
# #.......your other class code
# end # class MyProtocolHandler
#
# If you do this, then an instance of your class will be instantiated to handle
# every network connection created by your code or accepted by servers that you
# create. If you redefine #post_init in your protocol-handler class, your
# #post_init method will be called _inside_ the call to #super that you will
# make in your #initialize method (if you provide one).
#
#--
# EventMachine::connect initiates a TCP connection to a remote
# server and sets up event-handling for the connection.
# It internally creates an object that should not be handled
# by the caller. HOWEVER, it's often convenient to get the
# object to set up interfacing to other objects in the system.
# We return the newly-created anonymous-class object to the caller.
# It's expected that a considerable amount of code will depend
# on this behavior, so don't change it.
#
# Ok, added support for a user-defined block, 13Apr06.
# This leads us to an interesting choice because of the
# presence of the post_init call, which happens in the
# initialize method of the new object. We call the user's
# block and pass the new object to it. This is a great
# way to do protocol-specific initiation. It happens
# AFTER post_init has been called on the object, which I
# certainly hope is the right choice.
# Don't change this lightly, because accepted connections
# are different from connected ones and we don't want
# to have them behave differently with respect to post_init
# if at all possible.
#
def EventMachine::connect server, port=nil, handler=nil, *args, &block
connect2 server, port, handler, {}, *args, &block
end
def EventMachine::connect2 server, port=nil, handler=nil, options={}, *args
begin
port = Integer(port)
rescue ArgumentError, TypeError
# there was no port, so server must be a unix domain socket
# the port argument is actually the handler, and the handler is one of the args
args.unshift handler if handler
handler = port
port = nil
end if port
klass = if (handler and handler.is_a?(Class))
raise ArgumentError, 'must provide module or subclass of EventMachine::Connection' unless Connection > handler
handler
else
Class.new( Connection ) {handler and include handler}
end
arity = klass.instance_method(:initialize).arity
expected = arity >= 0 ? arity : -(arity + 1)
if (arity >= 0 and args.size != expected) or (arity < 0 and args.size < expected)
raise ArgumentError, "wrong number of arguments for #{klass}#initialize (#{args.size} for #{expected})"
end
s = if port
connect_server server, port, options[:bind_host]
else
connect_unix_server server
end
c = klass.new s, *args
@conns[s] = c
block_given? and yield c
c
end
# EventMachine::attach registers a given file descriptor or IO object with the eventloop
#
# If the handler provided has the functions notify_readable or notify_writable defined,
# EventMachine will not read or write from the socket, and instead fire the corresponding
# callback on the handler.
#
# To detach the file descriptor, use EventMachine::Connection#detach
#
# === Usage Example
#
# module SimpleHttpClient
# def initialize sock
# @sock = sock
# end
#
# def notify_readable
# header = @sock.readline
#
# if header == "\r\n"
# # detach returns the file descriptor number (fd == @sock.fileno)
# fd = detach
# end
# rescue EOFError
# detach
# end
#
# def unbind
# EM.next_tick do
# # socket is detached from the eventloop, but still open
# data = @sock.read
# end
# end
# end
#
# EM.run{
# $sock = TCPSocket.new('site.com', 80)
# $sock.write("GET / HTTP/1.0\r\n\r\n")
# EM.attach $sock, SimpleHttpClient, $sock
# }
#
#--
# Thanks to Riham Aldakkak (eSpace Technologies) for the initial patch
def EventMachine::attach io, handler=nil, *args
klass = if (handler and handler.is_a?(Class))
raise ArgumentError, 'must provide module or subclass of EventMachine::Connection' unless Connection > handler
handler
else
Class.new( Connection ) {handler and include handler}
end
arity = klass.instance_method(:initialize).arity
expected = arity >= 0 ? arity : -(arity + 1)
if (arity >= 0 and args.size != expected) or (arity < 0 and args.size < expected)
raise ArgumentError, "wrong number of arguments for #{klass}#initialize (#{args.size} for #{expected})"
end
readmode = klass.public_instance_methods.any?{|m| m.to_sym == :notify_readable }
writemode = klass.public_instance_methods.any?{|m| m.to_sym == :notify_writable }
s = attach_fd io.respond_to?(:fileno) ? io.fileno : io, readmode, writemode
c = klass.new s, *args
@conns[s] = c
block_given? and yield c
c
end
#--
# EXPERIMENTAL. DO NOT RELY ON THIS METHOD TO BE HERE IN THIS FORM, OR AT ALL.
# (03Nov06)
# Observe, the test for already-connected FAILS if we call a reconnect inside post_init,
# because we haven't set up the connection in @conns by that point.
# RESIST THE TEMPTATION to "fix" this problem by redefining the behavior of post_init.
#
# Changed 22Nov06: if called on an already-connected handler, just return the
# handler and do nothing more. Originally this condition raised an exception.
# We may want to change it yet again and call the block, if any.
#
def EventMachine::reconnect server, port, handler
raise "invalid handler" unless handler.respond_to?(:connection_completed)
#raise "still connected" if @conns.has_key?(handler.signature)
return handler if @conns.has_key?(handler.signature)
s = connect_server server, port
handler.signature = s
@conns[s] = handler
block_given? and yield handler
handler
end
# Make a connection to a Unix-domain socket. This is not implemented on Windows platforms.
# The parameter socketname is a String which identifies the Unix-domain socket you want
# to connect to. socketname is the name of a file on your local system, and in most cases
# is a fully-qualified path name. Make sure that your process has enough local permissions
# to open the Unix-domain socket.
# See also the documentation for #connect_server. This method behaves like #connect_server
# in all respects except for the fact that it connects to a local Unix-domain
# socket rather than a TCP socket.
# NOTE: this functionality will soon be subsumed into the #connect method. This method
# will still be supported as an alias.
#--
# For making connections to Unix-domain sockets.
# Eventually this has to get properly documented and unified with the TCP-connect methods.
# Note how nearly identical this is to EventMachine#connect
def EventMachine::connect_unix_domain socketname, *args, &blk
connect socketname, *args, &blk
end
# EventMachine#open_datagram_socket is for support of UDP-based
# protocols. Its usage is similar to that of EventMachine#start_server.
# It takes three parameters: an IP address (which must be valid
# on the machine which executes the method), a port number,
# and an optional Module name which will handle the data.
# This method will create a new UDP (datagram) socket and
# bind it to the address and port that you specify.
# The normal callbacks (see EventMachine#start_server) will
# be called as events of interest occur on the newly-created
# socket, but there are some differences in how they behave.
#
# Connection#receive_data will be called when a datagram packet
# is received on the socket, but unlike TCP sockets, the message
# boundaries of the received data will be respected. In other words,
# if the remote peer sent you a datagram of a particular size,
# you may rely on Connection#receive_data to give you the
# exact data in the packet, with the original data length.
# Also observe that Connection#receive_data may be called with a
# zero-length data payload, since empty datagrams are permitted
# in UDP.
#
# Connection#send_data is available with UDP packets as with TCP,
# but there is an important difference. Because UDP communications
# are connectionless, there is no implicit recipient for the packets you
# send. Ordinarily you must specify the recipient for each packet you send.
# However, EventMachine
# provides for the typical pattern of receiving a UDP datagram
# from a remote peer, performing some operation, and then sending
# one or more packets in response to the same remote peer.
# To support this model easily, just use Connection#send_data
# in the code that you supply for Connection:receive_data.
# EventMachine will
# provide an implicit return address for any messages sent to
# Connection#send_data within the context of a Connection#receive_data callback,
# and your response will automatically go to the correct remote peer.
# (TODO: Example-code needed!)
#
# Observe that the port number that you supply to EventMachine#open_datagram_socket
# may be zero. In this case, EventMachine will create a UDP socket
# that is bound to an ephemeral (not well-known) port.
# This is not appropriate for servers that must publish a well-known
# port to which remote peers may send datagrams. But it can be useful
# for clients that send datagrams to other servers.
# If you do this, you will receive any responses from the remote
# servers through the normal Connection#receive_data callback.
# Observe that you will probably have issues with firewalls blocking
# the ephemeral port numbers, so this technique is most appropriate for LANs.
# (TODO: Need an example!)
#
# If you wish to send datagrams to arbitrary remote peers (not
# necessarily ones that have sent data to which you are responding),
# then see Connection#send_datagram.
#
# DO NOT call send_data from a datagram socket
# outside of a #receive_data method. Use #send_datagram. If you do use #send_data
# outside of a #receive_data method, you'll get a confusing error
# because there is no "peer," as #send_data requires. (Inside of #receive_data,
# #send_data "fakes" the peer as described above.)
#
#--
# Replaced the implementation on 01Oct06. Thanks to Tobias Gustafsson for pointing
# out that this originally did not take a class but only a module.
#
def self::open_datagram_socket address, port, handler=nil, *args
klass = if (handler and handler.is_a?(Class))
raise ArgumentError, 'must provide module or subclass of EventMachine::Connection' unless Connection > handler
handler
else
Class.new( Connection ) {handler and include handler}
end
arity = klass.instance_method(:initialize).arity
expected = arity >= 0 ? arity : -(arity + 1)
if (arity >= 0 and args.size != expected) or (arity < 0 and args.size < expected)
raise ArgumentError, "wrong number of arguments for #{klass}#initialize (#{args.size} for #{expected})"
end
s = open_udp_socket address, port
c = klass.new s, *args
@conns[s] = c
block_given? and yield c
c
end
# For advanced users. This function sets the default timer granularity, which by default is
# slightly smaller than 100 milliseconds. Call this function to set a higher or lower granularity.
# The function affects the behavior of #add_timer and #add_periodic_timer. Most applications
# will not need to call this function.
#
# The argument is a number of milliseconds. Avoid setting the quantum to very low values because
# that may reduce performance under some extreme conditions. We recommend that you not set a quantum
# lower than 10.
#
# You may only call this function while an EventMachine loop is running (that is, after a call to
# EventMachine#run and before a subsequent call to EventMachine#stop).
#
def self::set_quantum mills
set_timer_quantum mills.to_i
end
# Sets the maximum number of timers and periodic timers that may be outstanding at any
# given time. You only need to call #set_max_timers if you need more than the default
# number of timers, which on most platforms is 1000.
# Call this method before calling EventMachine#run.
#
def self::set_max_timers ct
set_max_timer_count ct
end
# Gets the current maximum number of allowed timers
#
def self::get_max_timers
get_max_timer_count
end
# Returns the total number of connections (file descriptors) currently held by the reactor.
# Note that a tick must pass after the 'initiation' of a connection for this number to increment.
#
# For example, $count will be 0 in this case:
#
# EM.run {
# EM.connect("rubyeventmachine.com", 80)
# $count = EM.connection_count
# }
#
# In this example, $count will be 1 since the connection has been established in the next loop of the reactor.
#
# EM.run {
# EM.connect("rubyeventmachine.com", 80)
# EM.next_tick {
# $count = EM.connection_count
# }
# }
#
def self::connection_count
self::get_connection_count
end
#--
# The is the responder for the loopback-signalled event.
# It can be fired either by code running on a separate thread (EM#defer) or on
# the main thread (EM#next_tick).
# It will often happen that a next_tick handler will reschedule itself. We
# consume a copy of the tick queue so that tick events scheduled by tick events
# have to wait for the next pass through the reactor core.
#
def self::run_deferred_callbacks # :nodoc:
until (@resultqueue ||= []).empty?
result,cback = @resultqueue.pop
cback.call result if cback
end
@next_tick_queue ||= []
if (l = @next_tick_queue.length) > 0
l.times {|i| @next_tick_queue[i].call}
@next_tick_queue.slice!( 0...l )
end
=begin
(@next_tick_queue ||= []).length.times {
cback=@next_tick_queue.pop and cback.call
}
=end
=begin
if (@next_tick_queue ||= []) and @next_tick_queue.length > 0
ary = @next_tick_queue.dup
@next_tick_queue.clear
until ary.empty?
cback=ary.pop and cback.call
end
end
=end
end
# #defer is for integrating blocking operations into EventMachine's control flow.
# Call #defer with one or two blocks, as shown below (the second block is optional):
#
# operation = proc {
# # perform a long-running operation here, such as a database query.
# "result" # as usual, the last expression evaluated in the block will be the return value.
# }
# callback = proc {|result|
# # do something with result here, such as send it back to a network client.
# }
#
# EventMachine.defer( operation, callback )
#
# The action of #defer is to take the block specified in the first parameter (the "operation")
# and schedule it for asynchronous execution on an internal thread pool maintained by EventMachine.
# When the operation completes, it will pass the result computed by the block (if any)
# back to the EventMachine reactor. Then, EventMachine calls the block specified in the
# second parameter to #defer (the "callback"), as part of its normal, synchronous
# event handling loop. The result computed by the operation block is passed as a parameter
# to the callback. You may omit the callback parameter if you don't need to execute any code
# after the operation completes.
#
# Caveats:
# Note carefully that the code in your deferred operation will be executed on a separate
# thread from the main EventMachine processing and all other Ruby threads that may exist in
# your program. Also, multiple deferred operations may be running at once! Therefore, you
# are responsible for ensuring that your operation code is threadsafe. [Need more explanation
# and examples.]
# Don't write a deferred operation that will block forever. If so, the current implementation will
# not detect the problem, and the thread will never be returned to the pool. EventMachine limits
# the number of threads in its pool, so if you do this enough times, your subsequent deferred
# operations won't get a chance to run. [We might put in a timer to detect this problem.]
#
#--
# OBSERVE that #next_tick hacks into this mechanism, so don't make any changes here
# without syncing there.
#
# Running with $VERBOSE set to true gives a warning unless all ivars are defined when
# they appear in rvalues. But we DON'T ever want to initialize @threadqueue unless we
# need it, because the Ruby threads are so heavyweight. We end up with this bizarre
# way of initializing @threadqueue because EventMachine is a Module, not a Class, and
# has no constructor.
#
def self::defer op = nil, callback = nil, &blk
unless @threadpool
require 'thread'
@threadpool = []
@threadqueue = Queue.new
@resultqueue = Queue.new
spawn_threadpool
end
@threadqueue << [op||blk,callback]
end
def self.spawn_threadpool
until @threadpool.size == 20
thread = Thread.new do
while true
op, cback = *@threadqueue.pop
result = op.call
@resultqueue << [result, cback]
EventMachine.signal_loopbreak
end
end
@threadpool << thread
end
end
# Schedules a proc for execution immediately after the next "turn" through the reactor
# core. An advanced technique, this can be useful for improving memory management and/or
# application responsiveness, especially when scheduling large amounts of data for
# writing to a network connection. TODO, we need a FAQ entry on this subject.
#
# #next_tick takes either a single argument (which must be a Proc) or a block.
# And I'm taking suggestions for a better name for this method.
#--
# This works by adding to the @resultqueue that's used for #defer.
# The general idea is that next_tick is used when we want to give the reactor a chance
# to let other operations run, either to balance the load out more evenly, or to let
# outbound network buffers drain, or both. So we probably do NOT want to block, and
# we probably do NOT want to be spinning any threads. A program that uses next_tick
# but not #defer shouldn't suffer the penalty of having Ruby threads running. They're
# extremely expensive even if they're just sleeping.
#
def self::next_tick pr=nil, &block
raise "no argument or block given" unless ((pr && pr.respond_to?(:call)) or block)
(@next_tick_queue ||= []) << ( pr || block )
signal_loopbreak if reactor_running?
=begin
(@next_tick_procs ||= []) << (pr || block)
if @next_tick_procs.length == 1
add_timer(0) {
@next_tick_procs.each {|t| t.call}
@next_tick_procs.clear
}
end
=end
end
# A wrapper over the setuid system call. Particularly useful when opening a network
# server on a privileged port because you can use this call to drop privileges
# after opening the port. Also very useful after a call to #set_descriptor_table_size,
# which generally requires that you start your process with root privileges.
#
# This method has no effective implementation on Windows or in the pure-Ruby
# implementation of EventMachine.
# Call #set_effective_user by passing it a string containing the effective name
# of the user whose privilege-level your process should attain.
# This method is intended for use in enforcing security requirements, consequently
# it will throw a fatal error and end your program if it fails.
#
def self::set_effective_user username
EventMachine::setuid_string username
end
# Sets the maximum number of file or socket descriptors that your process may open.
# You can pass this method an integer specifying the new size of the descriptor table.
# Returns the new descriptor-table size, which may be less than the number you
# requested. If you call this method with no arguments, it will simply return
# the current size of the descriptor table without attempting to change it.
#
# The new limit on open descriptors ONLY applies to sockets and other descriptors
# that belong to EventMachine. It has NO EFFECT on the number of descriptors
# you can create in ordinary Ruby code.
#
# Not available on all platforms. Increasing the number of descriptors beyond its
# default limit usually requires superuser privileges. (See #set_effective_user
# for a way to drop superuser privileges while your program is running.)
#
def self::set_descriptor_table_size n_descriptors=nil
EventMachine::set_rlimit_nofile n_descriptors
end
# Run an external process. This does not currently work on Windows.
#
# module RubyCounter
# def post_init
# # count up to 5
# send_data "5\n"
# end
# def receive_data data
# puts "ruby sent me: #{data}"
# end
# def unbind
# puts "ruby died with exit status: #{get_status.exitstatus}"
# end
# end
#
# EM.run{
# EM.popen("ruby -e' $stdout.sync = true; gets.to_i.times{ |i| puts i+1; sleep 1 } '", RubyCounter)
# }
#
# Also see EM::DeferrableChildProcess and EM::system
#--
# At this moment, it's only available on Unix.
# Perhaps misnamed since the underlying function uses socketpair and is full-duplex.
#
def self::popen cmd, handler=nil, *args
klass = if (handler and handler.is_a?(Class))
raise ArgumentError, 'must provide module or subclass of EventMachine::Connection' unless Connection > handler
handler
else
Class.new( Connection ) {handler and include handler}
end
w = Shellwords::shellwords( cmd )
w.unshift( w.first ) if w.first
s = invoke_popen( w )
c = klass.new s, *args
@conns[s] = c
yield(c) if block_given?
c
end
# Tells you whether the EventMachine reactor loop is currently running. Returns true or
# false. Useful when writing libraries that want to run event-driven code, but may
# be running in programs that are already event-driven. In such cases, if EventMachine#reactor_running?
# returns false, your code can invoke EventMachine#run and run your application code inside
# the block passed to that method. If EventMachine#reactor_running? returns true, just
# execute your event-aware code.
#
# This method is necessary because calling EventMachine#run inside of another call to
# EventMachine#run generates a fatal error.
#
def self::reactor_running?
(@reactor_running || false)
end
# (Experimental)
#
#
def EventMachine::open_keyboard handler=nil, *args
klass = if (handler and handler.is_a?(Class))
raise ArgumentError, 'must provide module or subclass of EventMachine::Connection' unless Connection > handler
handler
else
Class.new( Connection ) {handler and include handler}
end
arity = klass.instance_method(:initialize).arity
expected = arity >= 0 ? arity : -(arity + 1)
if (arity >= 0 and args.size != expected) or (arity < 0 and args.size < expected)
raise ArgumentError, "wrong number of arguments for #{klass}#initialize (#{args.size} for #{expected})"
end
s = read_keyboard
c = klass.new s, *args
@conns[s] = c
block_given? and yield c
c
end
# Catch-all for errors raised during event loop callbacks.
#
# EM.error_handler{ |e|
# puts "Error raised during event loop: #{e.message}"
# }
#
def EventMachine::error_handler cb = nil, &blk
if cb or blk
@error_handler = cb || blk
elsif instance_variable_defined? :@error_handler
remove_instance_variable :@error_handler
end
end
private
def EventMachine::event_callback conn_binding, opcode, data
#
# Changed 27Dec07: Eliminated the hookable error handling.
# No one was using it, and it degraded performance significantly.
# It's in original_event_callback, which is dead code.
#
# Changed 25Jul08: Added a partial solution to the problem of exceptions
# raised in user-written event-handlers. If such exceptions are not caught,
# we must cause the reactor to stop, and then re-raise the exception.
# Otherwise, the reactor doesn't stop and it's left on the call stack.
# This is partial because we only added it to #unbind, where it's critical
# (to keep unbind handlers from being re-entered when a stopping reactor
# runs down open connections). It should go on the other calls to user
# code, but the performance impact may be too large.
#
if opcode == ConnectionUnbound
if c = @conns.delete( conn_binding )
begin
c.unbind
rescue
@wrapped_exception = $!
stop
end
elsif c = @acceptors.delete( conn_binding )
# no-op
else
raise ConnectionNotBound, "recieved ConnectionUnbound for an unknown signature: #{conn_binding}"
end
elsif opcode == ConnectionAccepted
accep,args,blk = @acceptors[conn_binding]
raise NoHandlerForAcceptedConnection unless accep
c = accep.new data, *args
@conns[data] = c
blk and blk.call(c)
c # (needed?)
elsif opcode == ConnectionCompleted
c = @conns[conn_binding] or raise ConnectionNotBound, "received ConnectionCompleted for unknown signature: #{conn_binding}"
c.connection_completed
##
# The remaining code is a fallback for the pure ruby reactor. Usually these events are handled in the C event_callback() in rubymain.cpp
elsif opcode == TimerFired
t = @timers.delete( data ) or raise UnknownTimerFired, "timer data: #{data}"
t.call
elsif opcode == ConnectionData
c = @conns[conn_binding] or raise ConnectionNotBound, "received data #{data} for unknown signature: #{conn_binding}"
c.receive_data data
elsif opcode == LoopbreakSignalled
run_deferred_callbacks
elsif opcode == ConnectionNotifyReadable
c = @conns[conn_binding] or raise ConnectionNotBound
c.notify_readable
elsif opcode == ConnectionNotifyWritable
c = @conns[conn_binding] or raise ConnectionNotBound
c.notify_writable
end
end
#--
# The original event_callback below handled runtime errors in ruby and degraded performance significantly.
# An optional C-based error handler is now available via EM::error_handler
#
# private
# def EventMachine::original_event_callback conn_binding, opcode, data
# #
# # Added 03Oct07: Any code path that invokes user-written code must
# # wrap itself in a begin/rescue for RuntimeErrors, that calls the
# # user-overridable class method #handle_runtime_error.
# #
# if opcode == ConnectionData
# c = @conns[conn_binding] or raise ConnectionNotBound
# begin
# c.receive_data data
# rescue
# EventMachine.handle_runtime_error
# end
# elsif opcode == ConnectionUnbound
# if c = @conns.delete( conn_binding )
# begin
# c.unbind
# rescue
# EventMachine.handle_runtime_error
# end
# elsif c = @acceptors.delete( conn_binding )
# # no-op
# else
# raise ConnectionNotBound
# end
# elsif opcode == ConnectionAccepted
# accep,args,blk = @acceptors[conn_binding]
# raise NoHandlerForAcceptedConnection unless accep
# c = accep.new data, *args
# @conns[data] = c
# begin
# blk and blk.call(c)
# rescue
# EventMachine.handle_runtime_error
# end
# c # (needed?)
# elsif opcode == TimerFired
# t = @timers.delete( data ) or raise UnknownTimerFired
# begin
# t.call
# rescue
# EventMachine.handle_runtime_error
# end
# elsif opcode == ConnectionCompleted
# c = @conns[conn_binding] or raise ConnectionNotBound
# begin
# c.connection_completed
# rescue
# EventMachine.handle_runtime_error
# end
# elsif opcode == LoopbreakSignalled
# begin
# run_deferred_callbacks
# rescue
# EventMachine.handle_runtime_error
# end
# end
# end
#
#
# # Default handler for RuntimeErrors that are raised in user code.
# # The default behavior is to re-raise the error, which ends your program.
# # To override the default behavior, re-implement this method in your code.
# # For example:
# #
# # module EventMachine
# # def self.handle_runtime_error
# # $>.puts $!
# # end
# # end
# #
# #--
# # We need to ensure that any code path which invokes user code rescues RuntimeError
# # and calls this method. The obvious place to do that is in #event_callback,
# # but, scurrilously, it turns out that we need to be finer grained that that.
# # Periodic timers, in particular, wrap their invocations of user code inside
# # procs that do other stuff we can't not do, like schedule the next invocation.
# # This is a potential non-robustness, since we need to remember to hook in the
# # error handler whenever and wherever we change how user code is invoked.
# #
# def EventMachine::handle_runtime_error
# @runtime_error_hook ? @runtime_error_hook.call : raise
# end
#
# # Sets a handler for RuntimeErrors that are raised in user code.
# # Pass a block with no parameters. You can also call this method without a block,
# # which restores the default behavior (see #handle_runtime_error).
# #
# def EventMachine::set_runtime_error_hook &blk
# @runtime_error_hook = blk
# end
# Documentation stub
#--
# This is a provisional implementation of a stream-oriented file access object.
# We also experiment with wrapping up some better exception reporting.
class << self
def _open_file_for_writing filename, handler=nil
klass = if (handler and handler.is_a?(Class))
raise ArgumentError, 'must provide module or subclass of EventMachine::Connection' unless Connection > handler
handler
else
Class.new( Connection ) {handler and include handler}
end
s = _write_file filename
c = klass.new s
@conns[s] = c
block_given? and yield c
c
end
end
# EventMachine::Connection is a class that is instantiated
# by EventMachine's processing loop whenever a new connection
# is created. (New connections can be either initiated locally
# to a remote server or accepted locally from a remote client.)
# When a Connection object is instantiated, it mixes in
# the functionality contained in the user-defined module
# specified in calls to EventMachine#connect or EventMachine#start_server.
# User-defined handler modules may redefine any or all of the standard
# methods defined here, as well as add arbitrary additional code
# that will also be mixed in.
#
# EventMachine manages one object inherited from EventMachine::Connection
# (and containing the mixed-in user code) for every network connection
# that is active at any given time.
# The event loop will automatically call methods on EventMachine::Connection
# objects whenever specific events occur on the corresponding connections,
# as described below.
#
# This class is never instantiated by user code, and does not publish an
# initialize method. The instance methods of EventMachine::Connection
# which may be called by the event loop are: post_init, receive_data,
# and unbind. All of the other instance methods defined here are called
# only by user code.
#
class Connection
# EXPERIMENTAL. Added the reconnect methods, which may go away.
attr_accessor :signature
# Override .new so subclasses don't have to call super and can ignore
# connection-specific arguments
#
def self.new(sig, *args) #:nodoc:
allocate.instance_eval do
# Call a superclass's #initialize if it has one
initialize(*args)
# Store signature and run #post_init
@signature = sig
associate_callback_target sig
post_init
self
end
end
# Stubbed initialize so legacy superclasses can safely call super
#
def initialize(*args) #:nodoc:
end
def associate_callback_target(sig) #:nodoc:
# no-op for the time being, to match similar no-op in rubymain.cpp
end
# EventMachine::Connection#post_init is called by the event loop
# immediately after the network connection has been established,
# and before resumption of the network loop.
# This method is generally not called by user code, but is called automatically
# by the event loop. The base-class implementation is a no-op.
# This is a very good place to initialize instance variables that will
# be used throughout the lifetime of the network connection.
#
def post_init
end
# EventMachine::Connection#receive_data is called by the event loop
# whenever data has been received by the network connection.
# It is never called by user code.
# receive_data is called with a single parameter, a String containing
# the network protocol data, which may of course be binary. You will
# generally redefine this method to perform your own processing of the incoming data.
#
# Here's a key point which is essential to understanding the event-driven
# programming model: EventMachine knows absolutely nothing about the protocol
# which your code implements. You must not make any assumptions about
# the size of the incoming data packets, or about their alignment on any
# particular intra-message or PDU boundaries (such as line breaks).
# receive_data can and will send you arbitrary chunks of data, with the
# only guarantee being that the data is presented to your code in the order
# it was collected from the network. Don't even assume that the chunks of
# data will correspond to network packets, as EventMachine can and will coalesce
# several incoming packets into one, to improve performance. The implication for your
# code is that you generally will need to implement some kind of a state machine
# in your redefined implementation of receive_data. For a better understanding
# of this, read through the examples of specific protocol handlers given
# elsewhere in this package. (STUB, WE MUST ADD THESE!)
#
# The base-class implementation of receive_data (which will be invoked if
# you don't redefine it) simply prints the size of each incoming data packet
# to stdout.
#
def receive_data data
puts "............>>>#{data.length}"
end
# #ssl_handshake_completed is called by EventMachine when the SSL/TLS handshake has
# been completed, as a result of calling #start_tls to initiate SSL/TLS on the connection.
#
# This callback exists because #post_init and #connection_completed are not reliable
# for indicating when an SSL/TLS connection is ready to have it's certificate queried for.
#
# See #get_peer_cert for application and example.
def ssl_handshake_completed
end
# EventMachine::Connection#unbind is called by the framework whenever a connection
# (either a server or client connection) is closed. The close can occur because
# your code intentionally closes it (see close_connection and close_connection_after_writing),
# because the remote peer closed the connection, or because of a network error.
# You may not assume that the network connection is still open and able to send or
# receive data when the callback to unbind is made. This is intended only to give
# you a chance to clean up associations your code may have made to the connection
# object while it was open.
#
def unbind
end
# EventMachine::Connection#close_connection is called only by user code, and never
# by the event loop. You may call this method against a connection object in any
# callback handler, whether or not the callback was made against the connection
# you want to close. close_connection schedules the connection to be closed
# at the next available opportunity within the event loop. You may not assume that
# the connection is closed when close_connection returns. In particular, the framework
# will callback the unbind method for the particular connection at a point shortly
# after you call close_connection. You may assume that the unbind callback will
# take place sometime after your call to close_connection completes. In other words,
# the unbind callback will not re-enter your code "inside" of your call to close_connection.
# However, it's not guaranteed that a future version of EventMachine will not change
# this behavior.
#
# close_connection will silently discard any outbound data which you have
# sent to the connection using EventMachine::Connection#send_data but which has not
# yet been sent across the network. If you want to avoid this behavior, use
# EventMachine::Connection#close_connection_after_writing.
#
def close_connection after_writing = false
EventMachine::close_connection @signature, after_writing
end
# EventMachine::Connection#detach will remove the given connection from the event loop.
# The connection's socket remains open and its file descriptor number is returned
def detach
EventMachine::detach_fd @signature
end
# EventMachine::Connection#close_connection_after_writing is a variant of close_connection.
# All of the descriptive comments given for close_connection also apply to
# close_connection_after_writing, with one exception: If the connection has
# outbound data sent using send_dat but which has not yet been sent across the network,
# close_connection_after_writing will schedule the connection to be closed after
# all of the outbound data has been safely written to the remote peer.
#
# Depending on the amount of outgoing data and the speed of the network,
# considerable time may elapse between your call to close_connection_after_writing
# and the actual closing of the socket (at which time the unbind callback will be called
# by the event loop). During this time, you may not call send_data to transmit
# additional data (that is, the connection is closed for further writes). In very
# rare cases, you may experience a receive_data callback after your call to close_connection_after_writing,
# depending on whether incoming data was in the process of being received on the connection
# at the moment when you called close_connection_after_writing. Your protocol handler must
# be prepared to properly deal with such data (probably by ignoring it).
#
def close_connection_after_writing
close_connection true
end
# EventMachine::Connection#send_data is only called by user code, never by
# the event loop. You call this method to send data to the remote end of the
# network connection. send_data is called with a single String argument, which
# may of course contain binary data. You can call send_data any number of times.
# send_data is an instance method of an object derived from EventMachine::Connection
# and containing your mixed-in handler code), so if you call it without qualification
# within a callback function, the data will be sent to the same network connection
# that generated the callback. Calling self.send_data is exactly equivalent.
#
# You can also call send_data to write to a connection other than the one
# whose callback you are calling send_data from. This is done by recording
# the value of the connection in any callback function (the value self), in any
# variable visible to other callback invocations on the same or different
# connection objects. (Need an example to make that clear.)
#
def send_data data
size = data.bytesize if data.respond_to?(:bytesize)
size ||= data.size
EventMachine::send_data @signature, data, size
end
# Returns true if the connection is in an error state, false otherwise.
# In general, you can detect the occurrence of communication errors or unexpected
# disconnection by the remote peer by handing the #unbind method. In some cases, however,
# it's useful to check the status of the connection using #error? before attempting to send data.
# This function is synchronous: it will return immediately without blocking.
#
#
def error?
EventMachine::report_connection_error_status(@signature) != 0
end
# #connection_completed is called by the event loop when a remote TCP connection
# attempt completes successfully. You can expect to get this notification after calls
# to EventMachine#connect. Remember that EventMachine makes remote connections
# asynchronously, just as with any other kind of network event. #connection_completed
# is intended primarily to assist with network diagnostics. For normal protocol
# handling, use #post_init to perform initial work on a new connection (such as
# send an initial set of data).
# #post_init will always be called. #connection_completed will only be called in case
# of a successful completion. A connection-attempt which fails will receive a call
# to #unbind after the failure.
def connection_completed
end
# Call #start_tls at any point to initiate TLS encryption on connected streams.
# The method is smart enough to know whether it should perform a server-side
# or a client-side handshake. An appropriate place to call #start_tls is in
# your redefined #post_init method, or in the #connection_completed handler for
# an outbound connection.
#
# #start_tls takes an optional parameter hash that allows you to specify certificate
# and other options to be used with this Connection object. Here are the currently-supported
# options:
# :cert_chain_file : takes a String, which is interpreted as the name of a readable file in the
# local filesystem. The file is expected to contain a chain of X509 certificates in
# PEM format, with the most-resolved certificate at the top of the file, successive
# intermediate certs in the middle, and the root (or CA) cert at the bottom.
#
# :private_key_file : tales a String, which is interpreted as the name of a readable file in the
# local filesystem. The file must contain a private key in PEM format.
#
#--
# TODO: support passing an encryption parameter, which can be string or Proc, to get a passphrase
# for encrypted private keys.
# TODO: support passing key material via raw strings or Procs that return strings instead of
# just filenames.
# What will get nasty is whether we have to define a location for storing this stuff as files.
# In general, the OpenSSL interfaces for dealing with certs and keys in files are much better
# behaved than the ones for raw chunks of memory.
#
def start_tls args={}
priv_key, cert_chain = args.values_at(:private_key_file, :cert_chain_file)
[priv_key, cert_chain].each do |file|
next if file.nil? or file.empty?
raise FileNotFoundException,
"Could not find #{file} for start_tls" unless File.exists? file
end
EventMachine::set_tls_parms(@signature, priv_key || '', cert_chain || '')
EventMachine::start_tls @signature
end
# If SSL/TLS is active on the connection, #get_peer_cert returns the remote X509 certificate
# as a String, in the popular PEM format. This can then be used for arbitrary validation
# of a peer's certificate in your code.
#
# This should be called in/after the #ssl_handshake_completed callback, which indicates
# that SSL/TLS is active. Using this callback is important, because the certificate may not
# be available until the time it is executed. Using #post_init or #connection_completed is
# not adequate, because the SSL handshake may still be taking place.
#
# #get_peer_cert will return nil if:
#
# * EventMachine is not built with OpenSSL support
# * SSL/TLS is not active on the connection
# * SSL/TLS handshake is not yet complete
# * Remote peer for any other reason has not presented a certificate
#
# === Example:
#
# module Handler
#
# def post_init
# puts "Starting TLS"
# start_tls
# end
#
# def ssl_handshake_completed
# puts get_peer_cert
# close_connection
# end
#
# def unbind
# EventMachine::stop_event_loop
# end
#
# end
#
# EM.run {
# EventMachine::connect "mail.google.com", 443, Handler
# }
#
# Output:
# -----BEGIN CERTIFICATE-----
# MIIDIjCCAougAwIBAgIQbldpChBPqv+BdPg4iwgN8TANBgkqhkiG9w0BAQUFADBM
# MQswCQYDVQQGEwJaQTElMCMGA1UEChMcVGhhd3RlIENvbnN1bHRpbmcgKFB0eSkg
# THRkLjEWMBQGA1UEAxMNVGhhd3RlIFNHQyBDQTAeFw0wODA1MDIxNjMyNTRaFw0w
# OTA1MDIxNjMyNTRaMGkxCzAJBgNVBAYTAlVTMRMwEQYDVQQIEwpDYWxpZm9ybmlh
# MRYwFAYDVQQHEw1Nb3VudGFpbiBWaWV3MRMwEQYDVQQKEwpHb29nbGUgSW5jMRgw
# FgYDVQQDEw9tYWlsLmdvb2dsZS5jb20wgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJ
# AoGBALlkxdh2QXegdElukCSOV2+8PKiONIS+8Tu9K7MQsYpqtLNC860zwOPQ2NLI
# 3Zp4jwuXVTrtzGuiqf5Jioh35Ig3CqDXtLyZoypjZUQcq4mlLzHlhIQ4EhSjDmA7
# Ffw9y3ckSOQgdBQWNLbquHh9AbEUjmhkrYxIqKXeCnRKhv6nAgMBAAGjgecwgeQw
# KAYDVR0lBCEwHwYIKwYBBQUHAwEGCCsGAQUFBwMCBglghkgBhvhCBAEwNgYDVR0f
# BC8wLTAroCmgJ4YlaHR0cDovL2NybC50aGF3dGUuY29tL1RoYXd0ZVNHQ0NBLmNy
# bDByBggrBgEFBQcBAQRmMGQwIgYIKwYBBQUHMAGGFmh0dHA6Ly9vY3NwLnRoYXd0
# ZS5jb20wPgYIKwYBBQUHMAKGMmh0dHA6Ly93d3cudGhhd3RlLmNvbS9yZXBvc2l0
# b3J5L1RoYXd0ZV9TR0NfQ0EuY3J0MAwGA1UdEwEB/wQCMAAwDQYJKoZIhvcNAQEF
# BQADgYEAsRwpLg1dgCR1gYDK185MFGukXMeQFUvhGqF8eT/CjpdvezyKVuz84gSu
# 6ccMXgcPQZGQN/F4Xug+Q01eccJjRSVfdvR5qwpqCj+6BFl5oiKDBsveSkrmL5dz
# s2bn7TdTSYKcLeBkjXxDLHGBqLJ6TNCJ3c4/cbbG5JhGvoema94=
# -----END CERTIFICATE-----
#
# You can do whatever you want with the certificate String, such as load it
# as a certificate object using the OpenSSL library, and check it's fields.
def get_peer_cert
EventMachine::get_peer_cert @signature
end
# send_datagram is for sending UDP messages.
# This method may be called from any Connection object that refers
# to an open datagram socket (see EventMachine#open_datagram_socket).
# The method sends a UDP (datagram) packet containing the data you specify,
# to a remote peer specified by the IP address and port that you give
# as parameters to the method.
# Observe that you may send a zero-length packet (empty string).
# However, you may not send an arbitrarily-large data packet because
# your operating system will enforce a platform-specific limit on
# the size of the outbound packet. (Your kernel
# will respond in a platform-specific way if you send an overlarge
# packet: some will send a truncated packet, some will complain, and
# some will silently drop your request).
# On LANs, it's usually OK to send datagrams up to about 4000 bytes in length,
# but to be really safe, send messages smaller than the Ethernet-packet
# size (typically about 1400 bytes). Some very restrictive WANs
# will either drop or truncate packets larger than about 500 bytes.
#--
# Added the Integer wrapper around the port parameter per suggestion by
# Matthieu Riou, after he passed a String and spent hours tearing his hair out.
#
def send_datagram data, recipient_address, recipient_port
data = data.to_s
EventMachine::send_datagram @signature, data, data.length, recipient_address, Integer(recipient_port)
end
# #get_peername is used with stream-connections to obtain the identity
# of the remotely-connected peer. If a peername is available, this method
# returns a sockaddr structure. The method returns nil if no peername is available.
# You can use Socket#unpack_sockaddr_in and its variants to obtain the
# values contained in the peername structure returned from #get_peername.
def get_peername
EventMachine::get_peername @signature
end
# #get_sockname is used with stream-connections to obtain the identity
# of the local side of the connection. If a local name is available, this method
# returns a sockaddr structure. The method returns nil if no local name is available.
# You can use Socket#unpack_sockaddr_in and its variants to obtain the
# values contained in the local-name structure returned from #get_sockname.
def get_sockname
EventMachine::get_sockname @signature
end
# Returns the PID (kernel process identifier) of a subprocess
# associated with this Connection object. For use with EventMachine#popen
# and similar methods. Returns nil when there is no meaningful subprocess.
#--
#
def get_pid
EventMachine::get_subprocess_pid @signature
end
# Returns a subprocess exit status. Only useful for #popen. Call it in your
# #unbind handler.
#
def get_status
EventMachine::get_subprocess_status @signature
end
# comm_inactivity_timeout returns the current value (in seconds) of the inactivity-timeout
# property of network-connection and datagram-socket objects. A nonzero value
# indicates that the connection or socket will automatically be closed if no read or write
# activity takes place for at least that number of seconds.
# A zero value (the default) specifies that no automatic timeout will take place.
def comm_inactivity_timeout
EventMachine::get_comm_inactivity_timeout @signature
end
# Alias for #set_comm_inactivity_timeout.
def comm_inactivity_timeout= value
self.send :set_comm_inactivity_timeout, value
end
# comm_inactivity_timeout= allows you to set the inactivity-timeout property for
# a network connection or datagram socket. Specify a non-negative numeric value in seconds.
# If the value is greater than zero, the connection or socket will automatically be closed
# if no read or write activity takes place for at least that number of seconds.
# Specify a value of zero to indicate that no automatic timeout should take place.
# Zero is the default value.
def set_comm_inactivity_timeout value
EventMachine::set_comm_inactivity_timeout @signature, value
end
#--
# EXPERIMENTAL. DO NOT RELY ON THIS METHOD TO REMAIN SUPPORTED.
# (03Nov06)
def reconnect server, port
EventMachine::reconnect server, port, self
end
# Like EventMachine::Connection#send_data, this sends data to the remote end of
# the network connection. EventMachine::Connection@send_file_data takes a
# filename as an argument, though, and sends the contents of the file, in one
# chunk. Contributed by Kirk Haines.
#
def send_file_data filename
EventMachine::send_file_data @signature, filename
end
# Open a file on the filesystem and send it to the remote peer. This returns an
# object of type EventMachine::Deferrable. The object's callbacks will be executed
# on the reactor main thread when the file has been completely scheduled for
# transmission to the remote peer. Its errbacks will be called in case of an error
# (such as file-not-found). #stream_file_data employs various strategems to achieve
# the fastest possible performance, balanced against minimum consumption of memory.
#
# You can control the behavior of #stream_file_data with the optional arguments parameter.
# Currently-supported arguments are:
# :http_chunks, a boolean flag which defaults false. If true, this flag streams the
# file data in a format compatible with the HTTP chunked-transfer encoding.
#
# Warning: this feature has an implicit dependency on an outboard extension,
# evma_fastfilereader. You must install this extension in order to use #stream_file_data
# with files larger than a certain size (currently 8192 bytes).
#
def stream_file_data filename, args={}
EventMachine::FileStreamer.new( self, filename, args )
end
# TODO, document this
#
#
class EventMachine::PeriodicTimer
attr_accessor :interval
def initialize *args, &block
@interval = args.shift
@code = args.shift || block
schedule
end
def schedule
EventMachine::add_timer @interval, proc {self.fire}
end
def fire
unless @cancelled
@code.call
schedule
end
end
def cancel
@cancelled = true
end
end
# TODO, document this
#
#
class EventMachine::Timer
def initialize *args, &block
@signature = EventMachine::add_timer(*args, &block)
end
def cancel
EventMachine.send :cancel_timer, @signature
end
end
end
# Is inside of protocols/ but not in the namespace?
require 'protocols/buftok'
module Protocols
# In this module, we define standard protocol implementations.
# They get included from separate source files.
# TODO / XXX: We're munging the LOAD_PATH!
# A good citizen would use eventmachine/protocols/tcptest.
# TODO : various autotools are completely useless with the lack of naming
# convention, we need to correct that!
autoload :TcpConnectTester, 'protocols/tcptest'
autoload :HttpClient, 'protocols/httpclient'
autoload :LineAndTextProtocol, 'protocols/line_and_text'
autoload :HeaderAndContentProtocol, 'protocols/header_and_content'
autoload :LineText2, 'protocols/linetext2'
autoload :HttpClient2, 'protocols/httpcli2'
autoload :Stomp, 'protocols/stomp'
autoload :SmtpClient, 'protocols/smtpclient'
autoload :SmtpServer, 'protocols/smtpserver'
autoload :SASLauth, 'protocols/saslauth'
autoload :Memcache, 'protocols/memcache'
#require 'protocols/postgres' UNCOMMENT THIS LINE WHEN THE POSTGRES CODE IS READY FOR PRIME TIME.
end
end # module EventMachine
# Save everyone some typing.
EM = EventMachine
EM::P = EventMachine::Protocols
require 'em/processes'