Class: Legs

Inherits:
Object
  • Object
show all
Defined in:
lib/legs.rb

Defined Under Namespace

Classes: RemoteError, RequestError, Result, StartBlockError

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(host = 'localhost', port = 30274) ⇒ Legs

Legs.new for a client, subclass to make a server, .new then makes server and client!



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# File 'lib/legs.rb', line 11

def initialize(host = 'localhost', port = 30274)
  self.class.start(port) if self.class != Legs && !self.class.started?
  ObjectSpace.define_finalizer(self) { self.close! }
  @parent = false; @responses = Hash.new; @meta = {}; @disconnected = false
  @responses_mutex = Mutex.new; @socket_mutex = Mutex.new
  
  if host.instance_of?(TCPSocket)
    @socket = host
    @parent = port unless port.instance_of?(Numeric)
  elsif host.instance_of?(String)
    @socket = TCPSocket.new(host, port)
    self.class.outgoing_mutex.synchronize { self.class.outgoing.push self }
  else
    raise "First argument needs to be a hostname, ip, or socket"
  end
  
  
  @handle_data = Proc.new do |data|
    data = json_restore(JSON.parse(data))
    
    if data['method']
      (@parent || self.class).__data!(data, self)
    elsif data['error'] and data['id'].nil?
      raise data['error']
    else
      @responses_mutex.synchronize { @responses[data['id']] = data }
    end
  end
  
  @thread = Thread.new do
    until @socket.closed?
      begin
        close! if @socket.eof?
        data = nil
        @socket_mutex.synchronize { data = @socket.gets(self.class.terminator) rescue nil }
        if data.nil?
          close!
        else
          @handle_data[data]
        end
      rescue JSON::ParserError => e
        send_data!({"error" => "JSON provided is invalid. See http://json.org/ to see how to format correctly."})
      rescue IOError => e
        close!
      end
    end
  end
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing ⇒ Object

sends a normal RPC request that has a response catch all the rogue calls and make them work niftily



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# File 'lib/legs.rb', line 108

def send!(method, *args, &blk)
  puts "Call #{inspect}: #{method}(#{args.map(&:inspect).join(', ')})" if self.class.log?
  id = get_unique_number
  send_data! 'method' => method.to_s, 'params' => args, 'id' => id
  
  worker = Proc.new do
    sleep 0.1 until @responses_mutex.synchronize { @responses.keys.include?(id) }
    
    result = Legs::Result.new(@responses_mutex.synchronize { @responses.delete(id) })
    puts ">> #{method} #=> #{result.data['result'].inspect}" if self.class.log?
    result
  end
  
  if blk.respond_to?(:call); Thread.new { blk[worker.call] }
  else; worker.call.value; end
end

Class Attribute Details

.incoming ⇒ Object (readonly) Also known as: users

Returns the value of attribute incoming.



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# File 'lib/legs.rb', line 204

def incoming
  @incoming
end

.incoming_mutex ⇒ Object (readonly)

Returns the value of attribute incoming_mutex.



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# File 'lib/legs.rb', line 204

def incoming_mutex
  @incoming_mutex
end

.log ⇒ Object Also known as: log?

Returns the value of attribute log.



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# File 'lib/legs.rb', line 203

def log
  @log
end

.messages_mutex ⇒ Object (readonly)

Returns the value of attribute messages_mutex.



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# File 'lib/legs.rb', line 204

def messages_mutex
  @messages_mutex
end

.outgoing ⇒ Object (readonly)

Returns the value of attribute outgoing.



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# File 'lib/legs.rb', line 204

def outgoing
  @outgoing
end

.outgoing_mutex ⇒ Object (readonly)

Returns the value of attribute outgoing_mutex.



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# File 'lib/legs.rb', line 204

def outgoing_mutex
  @outgoing_mutex
end

.server_object ⇒ Object (readonly)

Returns the value of attribute server_object.



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# File 'lib/legs.rb', line 204

def server_object
  @server_object
end

.terminator ⇒ Object

Returns the value of attribute terminator.



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# File 'lib/legs.rb', line 203

def terminator
  @terminator
end

Instance Attribute Details

#meta ⇒ Object (readonly)

general getters



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# File 'lib/legs.rb', line 7

def meta
  @meta
end

#parent ⇒ Object (readonly)

general getters



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# File 'lib/legs.rb', line 7

def parent
  @parent
end

#socket ⇒ Object (readonly)

general getters



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# File 'lib/legs.rb', line 7

def socket
  @socket
end

Class Method Details

.__data!(data, from) ⇒ Object

gets called to handle all incoming messages (RPC requests)



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# File 'lib/legs.rb', line 344

def __data!(data, from)
  @messages.enq [data, from]
end

.__make_symbol(name) ⇒ Object

lets the marshaler transport symbols



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# File 'lib/legs.rb', line 359

def __make_symbol(name); name.to_sym; end

.connections ⇒ Object

returns an array of all connections



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# File 'lib/legs.rb', line 333

def connections
  @incoming + @outgoing
end

.define_method(name, &blk) ⇒ Object

add’s a method to the ‘server’



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# File 'lib/legs.rb', line 356

def define_method(name, &blk); @server_class.class_eval { define_method(name, &blk) }; end

.event(name, sender, *extras) ⇒ Object

add an event call to the server’s message queue



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# File 'lib/legs.rb', line 338

def event(name, sender, *extras)
  return unless @server_object.respond_to?("on_#{name}")
  __data!({'method' => "on_#{name}", 'params' => extras.to_a, 'id' => nil}, sender)
end

.initializer ⇒ Object 



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# File 'lib/legs.rb', line 209

def initializer
  ObjectSpace.define_finalizer(self) { self.stop! }
  @incoming = []; @outgoing = []; @messages = Queue.new; @terminator = "\n"; @log = false
  @incoming_mutex = Mutex.new; @outgoing_mutex = Mutex.new; @started = false
end

.open(*args) {|client| ... } ⇒ Object

People say this syntax is too funny not to have… whatever. Works like IO and File and what have you

Yields:

  • (client) 


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# File 'lib/legs.rb', line 349

def open(*args)
  client = Legs.new(*args)
  yield(client)
  client.close!
end

.start(port = 30274, &blk) ⇒ Object

starts the server, pass nil for port to make a ‘server’ that doesn’t actually accept connections This is useful for adding methods to Legs so that systems you connect to can call methods back on you



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# File 'lib/legs.rb', line 218

def start(port=30274, &blk)
  return @server_class.module_eval(&blk) if started? and blk.respond_to? :call
  @started = true
  
  # makes a nice clean class to hold all the server methods.
  if @server_class.nil?
    @server_class = Class.new
    @server_class.module_eval do
      private
      attr_reader :server, :caller
      
      # sends a notification message to all connected clients
      def broadcast(*args)
        if args.first.is_a?(Array)
          list = args.shift
          method = args.shift
        elsif args.first.is_a?(String) or args.first.is_a?(Symbol)
          list = server.incoming
          method = args.shift
        else
          raise "You need to specify a 'method' to broadcast out to"
        end
        
        list.each { |user| user.notify!(method, *args) }
      end
      
      # Finds a user by the value of a certain property... like find_user_by :object_id, 12345
      def find_user_by_object_id value
        server.incoming.find { |user| user.object_id == value }
      end
      
      # finds user's with the specified meta keys matching the specified values, can use regexps and stuff, like a case block
      def find_users_by_meta hash = nil
        raise "You need to give find_users_by_meta a hash to check the user's meta hash against" if hash.nil?
        server.incoming.select do |user|
          hash.all? { |key, value| value === user.meta[key] }
        end
      end
      
      public # makes it public again for the user code
    end
  end
  
  @server_class.module_eval(&blk) if blk.respond_to?(:call)
  
  if @server_object.nil?
    @server_object = @server_class.allocate
    @server_object.instance_variable_set(:@server, self)
    @server_object.instance_eval { initialize }
  end

  @message_processor = Thread.new do
    while started?
      sleep 0.01 while @messages.empty?
      data, from = @messages.deq
      method = data['method']; params = data['params']
      methods = @server_object.public_methods(false)
      
      # close dead connections
      if data['method'] == '**remote__disconnecting**'
        from.close!
        next
      else
        begin
          raise "Supplied method is not a String" unless method.is_a?(String)
          raise "Supplied params object is not an Array" unless params.is_a?(Array)
          raise "Cannot run '#{method}' because it is not defined in this server" unless methods.include?(method.to_s) or methods.include? :method_missing
          
          puts "Call #{method}(#{params.map(&:inspect).join(', ')})" if log?
          
          @server_object.instance_variable_set(:@caller, from)
          
          result = nil
          
          @incoming_mutex.synchronize do
            if methods.include?(method.to_s)
              result = @server_object.__send__(method.to_s, *params)
            else
              result = @server_object.method_missing(method.to_s, *params)
            end
          end
          
          puts ">> #{method} #=> #{result.inspect}" if log?
          
          from.send_data!({'id' => data['id'], 'result' => result}) unless data['id'].nil?
          
        rescue Exception => e
          from.send_data!({'error' => e, 'id' => data['id']}) unless data['id'].nil?
          puts "Error: #{e}\nBacktrace: " + e.backtrace.join("\n   ") if log?
        end
      end
    end
  end unless @message_processor and @message_processor.alive?
  
  if ( port.nil? or port == false ) == false and @listener.nil?
    @listener = TCPServer.new(port)
    
    @acceptor_thread = Thread.new do
      while started?
        user = Legs.new(@listener.accept, self)
        @incoming_mutex.synchronize { @incoming.push user }
        puts "User #{user.object_id} connected, number of users: #{@incoming.length}" if log?
        self.event :connect, user
      end
    end
  end
end

.started? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/legs.rb', line 207

def started?; @started; end

.stop ⇒ Object

stops the server, disconnects the clients



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# File 'lib/legs.rb', line 327

def stop
  @started = false
  @incoming.each { |user| user.close! }
end

Instance Method Details

#close! ⇒ Object

closes the connection and the threads and stuff for this user



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# File 'lib/legs.rb', line 64

def close!
  return if @disconnected == true
  
  @disconnected = true
  puts "User #{inspect} disconnecting" if self.class.log?
  
  # notify the remote side
  notify!('**remote__disconnecting**') rescue nil
  
  if @parent
    @parent.event(:disconnect, self)
    @parent.incoming_mutex.synchronize { @parent.incoming.delete(self) }
  else
    self.class.outgoing_mutex.synchronize { self.class.outgoing.delete(self) }
  end
  
  Thread.new { sleep(1); @socket.close rescue nil }
end

#connected? ⇒ Boolean

I think you can guess this one

Returns:

  • (Boolean) 


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# File 'lib/legs.rb', line 61

def connected?; self.class.connections.include?(self); end

#inspect ⇒ Object 



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# File 'lib/legs.rb', line 8

def inspect; "<Legs:#{object_id} Meta: #{@meta.inspect}>"; end

#notify!(method, *args, &blk) ⇒ Object

send a notification to this user



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# File 'lib/legs.rb', line 84

def notify!(method, *args, &blk)
  puts "Notify #{inspect}: #{method}(#{args.map(&:inspect).join(', ')})" if self.class.log?
  send_data!({'method' => method.to_s, 'params' => args, 'id' => nil})
end

#send!(method, *args, &blk) ⇒ Object Also known as: method_missing

sends a normal RPC request that has a response



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# File 'lib/legs.rb', line 90

def send!(method, *args, &blk)
  puts "Call #{inspect}: #{method}(#{args.map(&:inspect).join(', ')})" if self.class.log?
  id = get_unique_number
  send_data! 'method' => method.to_s, 'params' => args, 'id' => id
  
  worker = Proc.new do
    sleep 0.1 until @responses_mutex.synchronize { @responses.keys.include?(id) }
    
    result = Legs::Result.new(@responses_mutex.synchronize { @responses.delete(id) })
    puts ">> #{method} #=> #{result.data['result'].inspect}" if self.class.log?
    result
  end
  
  if blk.respond_to?(:call); Thread.new { blk[worker.call] }
  else; worker.call.value; end
end

#send_data!(data) ⇒ Object

sends raw object over the socket



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# File 'lib/legs.rb', line 111

def send_data!(data)
  raise "Lost remote connection" unless connected?
  raw = JSON.generate(json_marshal(data)) + self.class.terminator
  @socket_mutex.synchronize { @socket.write(raw) }
end