Class: Ionian::Socket

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

Overview

A convenient wrapper for TCP, UDP, and Unix client sockets.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(existing_socket = nil, **kwargs) {|socket| ... } ⇒ Socket

Creates a new socket or wraps an existing socket.

Parameters:

  • existing_socket (Socket) (defaults to: nil) —

    An instantiated socket to be wrapped in and returned as an Ionian::Socket (for example, TCPSocket). A new socket will be created if this parameter is nil.

  • kwargs (Hash) —

    :host is mandatory.

Options Hash (**kwargs):

  • :host (String) —

    IP or hostname to connect to. Can contain the port in the format “host:port”.

  • :port (Fixnum) — default: 23 —

    Connection’s port number. Unused by the :unix protocol.

  • :protocol (:tcp, :udp, :unix) — default: :tcp —

    Type of socket to create. :udp will be automatically selected for addresses in the multicast range, or if the broadcast flag is set.

  • :connect_timeout (Fixnum) — default: nil —

    Number of seconds to wait when connecting before timing out. Raises Errno::EHOSTUNREACH.

  • :persistent (Boolean) — default: true —

    The socket remains open after data is sent if this is true. The socket closes after data is sent and a packet is received if this is false.

  • :bind_port (Boolean) — default: :port —

    Local UDP port to bind to for receiving data, if different than the remote port being connected to.

  • :broadcast (Boolean) — default: false —

    Enable the SO_BROADCAST flag. Sets protocol to :udp implicitly.

  • :reuse_addr (Boolean) — default: false —

    Enable the SO_REUSEADDR flag. Allows local address reuse.

  • :no_delay (Boolean) — default: false —

    Enable the TCP_NODELAY flag. Disables Nagle algorithm.

  • :cork (Boolean) — default: false —

    Enable the TCP_CORK flag. Buffers multiple writes into one segment.

  • :linger (Boolean) — default: false —

    Enable the SO_LINGER flag. When #close is called, waits for the send buffer to empty before closing the socket.

  • :expression (Regexp, String) —

    Overrides the Extension::IO#read_match regular expression for received data.

Yield Parameters:

  • socket (Ionian::Socket) —

    This socket is yielded to the block. Socket flushes and closes when exiting the block.



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# File 'lib/ionian/socket.rb', line 76

def initialize existing_socket = nil, **kwargs, &block
  @socket = existing_socket
  
  @ionian_listeners = []
  
  @expression = kwargs.fetch :expression, nil
  
  if existing_socket
    # Convert existing socket.
    @socket.extend Ionian::Extension::IO
    @socket.extend Ionian::Extension::Socket
    
    if existing_socket.is_a? UNIXSocket
      @host = existing_socket.path
      @port = nil
    else
      @host = existing_socket.remote_address.ip_address if existing_socket
      @port = existing_socket.remote_address.ip_port if existing_socket
    end
  
    if @socket.is_a? TCPSocket
      @protocol = :tcp
    elsif @socket.is_a? UDPSocket
      @protocol = :udp
    elsif @socket.is_a? UNIXSocket
      @protocol = :unix
    end
    
    @persistent = true # Existing sockets are always persistent.
    
    @socket.expression = @expression if @expression
    
    initialize_socket_methods
    
  else
    # Initialize new socket.
    
    # Parse host out of "host:port" if specified.
    host_port_array = kwargs.fetch(:host).to_s.split ':'
    
    @host           = host_port_array[0]
    @port           = kwargs.fetch :port, (host_port_array[1] || 23).to_i
    @bind_port      = kwargs.fetch :bind_port, @port
    @connect_timeout = kwargs.fetch :connect_timeout, nil
    
    @broadcast      = kwargs.fetch :broadcast, false
    
    # Automatically select UDP for the multicast range. Otherwise default to TCP.
    default_protocol = :tcp
    default_protocol = :udp  if Ionian::Extension::Socket.multicast? @host
    default_protocol = :unix if @host.start_with? '/'
    default_protocol = :udp  if @broadcast
    
    @protocol       = kwargs.fetch :protocol,   default_protocol
    @persistent     = kwargs.fetch :persistent, true
    @persistent     = true if @protocol == :udp
    
    @reuse_addr     = kwargs.fetch :reuse_addr, false
    @cork           = kwargs.fetch :cork,       false
    @no_delay       = kwargs.fetch :no_delay,   @persistent ? false : true
    
    # Default to false for persistent sockets, true for
    # nonpersistent sockets. When nonpersistent, the socket
    # should remain open to send data in the buffer after
    # close is called (typically right after write).
    # @linger         = kwargs.fetch :linger,     @persistent ? false : true
    # TODO: For some reason linger = true is causing tests to fail.
    @linger         = kwargs.fetch :linger,     false
  
    
    create_socket if @persistent
  end
  
  if block
    block.call self
    unless self.closed?
      self.flush
      self.close
    end
  end
end

Instance Attribute Details

#bind_port ⇒ Object (readonly)

Local port number.



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# File 'lib/ionian/socket.rb', line 15

def bind_port
  @bind_port
end

#host ⇒ Object (readonly)

IP address or URL of server.



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# File 'lib/ionian/socket.rb', line 9

def host
  @host
end

#port ⇒ Object (readonly)

Remote port number.



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# File 'lib/ionian/socket.rb', line 12

def port
  @port
end

#protocol ⇒ Object (readonly) Also known as: protocol?

Returns a symbol of the type of protocol this socket uses: :tcp, :udp, :unix



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# File 'lib/ionian/socket.rb', line 19

def protocol
  @protocol
end

Instance Method Details

#closed? ⇒ Boolean

Returns true if the socket is closed.

Returns:

  • (Boolean) 


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# File 'lib/ionian/socket.rb', line 226

def closed?
  return true unless @socket
  @socket.closed?
end

#cmd(data, **kwargs) {|match| ... } ⇒ Array<MatchData>

Send a command (data) to the socket.

Parameters:

Yield Parameters:

  • match (MatchData) —

    Received match.

Returns:

  • (Array<MatchData>) —

    An array of received matches.

See Also:



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# File 'lib/ionian/socket.rb', line 183

def cmd data, **kwargs, &block
  create_socket unless @persistent
  
  write data
  @socket.flush
  
  matches = @socket.read_match(kwargs) { |match| yield match if block_given? }
  @socket.close unless @persistent
  
  matches
end

#expression ⇒ Object

Returns the regular expression used to match incoming data.



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# File 'lib/ionian/socket.rb', line 159

def expression
  @expression || @socket.expression
end

#expression=(exp) ⇒ Object

Set the regular expression used to match incoming data.



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# File 'lib/ionian/socket.rb', line 164

def expression= exp
  @expression = exp
  @socket.expression = exp if @socket
end

#flush ⇒ Object

Flushes buffered data to the operating system. This method has no effect on non-persistent sockets.



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# File 'lib/ionian/socket.rb', line 233

def flush
  @socket.flush if @persistent
end

#has_data?(**kwargs) ⇒ Boolean

Returns true if there is data in the receive buffer. Args:

Timeout: Number of seconds to wait for data until
  giving up. Set to nil for blocking.

Returns:

  • (Boolean) 


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# File 'lib/ionian/socket.rb', line 220

def has_data? **kwargs
  return false unless @socket
  @socket.has_data? kwargs
end

#persistent? ⇒ Boolean

Returns true if the socket remains open after writing data.

Returns:

  • (Boolean) 


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# File 'lib/ionian/socket.rb', line 170

def persistent?
  @persistent == false || @persistent == nil ? false : true
end

#puts(*string) ⇒ Object

Writes the given string(s) to the socket and appends a newline character to any string not already ending with one.



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# File 'lib/ionian/socket.rb', line 239

def puts *string
  self.write string.map{ |s| s.chomp }.join("\n") + "\n"
end

#register_observer(&block) ⇒ Object Also known as: on_match

Register a block to be called when #run_match receives matched data. Method callbacks can be registered with &object.method(:method). Returns a reference to the given block. block = ionian_socket.register_observer { … }



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# File 'lib/ionian/socket.rb', line 199

def register_observer &block
  @ionian_listeners << block unless @ionian_listeners.include? block
  @socket.register_observer &block if @socket
  block
end

#unregister_observer(&block) ⇒ Object

Unregister a block from being called when matched data is received.



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# File 'lib/ionian/socket.rb', line 208

def unregister_observer &block
  @ionian_listeners.delete_if { |o| o == block }
  @socket.unregister_observer &block if @socket
  block
end

#write(string) ⇒ Object Also known as: <<

Writes the given string to the socket. Returns the number of bytes written.



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# File 'lib/ionian/socket.rb', line 245

def write string
  create_socket unless @persistent
  
  num_bytes = 0
  
  if @protocol == :udp
    num_bytes = @socket.send string, 0
  else
    num_bytes = @socket.write string
  end
  
  unless @persistent
    @socket.flush
    
    # Read in data to prevent RST packets.
    # TODO: Shutdown read stream instead?
    @socket.read_all nonblocking: true
    
    # TODO: Sleep added so that data can be read on the receiving
    # end. Can this be changed to shutdown write?
    # Why isn't so_linger taking care of this?
    # sleep 0.01
    @socket.close
  end
  
  num_bytes
end