Class: IO::Endpoint::Wrapper

Inherits:
Object
  • Object
show all
Includes:
Socket::Constants
Defined in:
lib/io/endpoint/wrapper.rb

Overview

Represents a wrapper for socket operations that provides scheduling and configuration.

Constant Summary collapse

ServerSocket = 
::Socket
DEFAULT = 
new

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.default ⇒ Object

Get the default wrapper instance.



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# File 'lib/io/endpoint/wrapper.rb', line 240

def self.default
	DEFAULT
end

Instance Method Details

#accept(server, timeout: nil, linger: nil, **options, &block) ⇒ Object

Bind to a local address and accept connections in a loop.



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# File 'lib/io/endpoint/wrapper.rb', line 203

def accept(server, timeout: nil, linger: nil, **options, &block)
	# Ensure we use a `loop do ... end` so that state is not leaked between iterations:
	
	loop do
		socket, address = socket_accept(server)
		
		if linger
			socket.setsockopt(SOL_SOCKET, SO_LINGER, 1)
		end
		
		if timeout
			set_timeout(socket, timeout)
		end
		
		schedule do
			# Some sockets, notably SSL sockets, need application level negotiation before they are ready:
			if socket.respond_to?(:start)
				begin
					socket.start
				rescue
					socket.close
					raise
				end
			end
			
			# It seems like OpenSSL doesn't return the address of the peer when using `accept`, so we need to get it from the socket:
			address ||= socket.remote_address
			
			yield socket, address
		end
	end
end

#async(&block) ⇒ Object

Legacy method for compatibility with older code.



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# File 'lib/io/endpoint/wrapper.rb', line 36

def async(&block)
	schedule(&block)
end

#bind(local_address, protocol: 0, reuse_address: true, reuse_port: nil, linger: nil, bound_timeout: nil, backlog: Socket::SOMAXCONN, **options, &block) ⇒ Object

Bind to a local address.

Examples:

socket = Async::IO::Socket.bind(Async::IO::Address.tcp("0.0.0.0", 9090))


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# File 'lib/io/endpoint/wrapper.rb', line 144

def bind(local_address, protocol: 0, reuse_address: true, reuse_port: nil, linger: nil, bound_timeout: nil, backlog: Socket::SOMAXCONN, **options, &block)
	socket = nil
	
	begin
		socket = ServerSocket.new(local_address.afamily, local_address.socktype, protocol)
		
		if reuse_address
			socket.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
		end
		
		if reuse_port
			socket.setsockopt(SOL_SOCKET, SO_REUSEPORT, 1)
		end
		
		if linger
			socket.setsockopt(SOL_SOCKET, SO_LINGER, 1)
		end
		
		# Set the timeout:
		if bound_timeout
			set_timeout(socket, bound_timeout)
		end
		
		socket.bind(local_address.to_sockaddr)
		
		if backlog
			begin
				# Generally speaking, bind/listen is a common pattern, but it's not applicable to all socket types. We ignore the error if it's not supported as the alternative is exposing this upstream, which seems less desirable than handling it here. In other words, `bind` in this context means "prepare it to accept connections", whatever that means for the given socket type.
				socket.listen(backlog)
			rescue Errno::EOPNOTSUPP
				# Ignore.
			end
		end
	rescue
		socket&.close
		raise
	end
	
	return socket unless block_given?
	
	schedule do
		begin
			yield socket
		ensure
			socket.close
		end
	end
end

#connect(remote_address, local_address: nil, linger: nil, timeout: nil, buffered: false, **options) ⇒ Object

Establish a connection to a given remote_address.

Examples:

socket = Async::IO::Socket.connect(Async::IO::Address.tcp("8.8.8.8", 53))


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# File 'lib/io/endpoint/wrapper.rb', line 82

def connect(remote_address, local_address: nil, linger: nil, timeout: nil, buffered: false, **options)
	socket = nil
	
	begin
		socket = ::Socket.new(remote_address.afamily, remote_address.socktype, remote_address.protocol)
		
		if linger
			socket.setsockopt(SOL_SOCKET, SO_LINGER, 1)
		end
		
		if buffered == false
			set_buffered(socket, buffered)
		end
		
		if timeout
			set_timeout(socket, timeout)
		end
		
		if local_address
			if defined?(IP_BIND_ADDRESS_NO_PORT)
				# Inform the kernel (Linux 4.2+) to not reserve an ephemeral port when using bind(2) with a port number of 0. The port will later be automatically chosen at connect(2) time, in a way that allows sharing a source port as long as the 4-tuple is unique.
				socket.setsockopt(SOL_IP, IP_BIND_ADDRESS_NO_PORT, 1)
			end
			
			socket.bind(local_address.to_sockaddr)
		end
	rescue
		socket&.close
		raise
	end
	
	begin
		socket_connect(socket, remote_address)
	rescue Exception
		socket.close
		raise
	end
	
	return socket unless block_given?
	
	begin
		yield socket
	ensure
		socket.close
	end
end

#schedule(&block) ⇒ Object

Schedule a block to run asynchronously. Uses Thread for scheduling.



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# File 'lib/io/endpoint/wrapper.rb', line 18

def schedule(&block)
	if Fiber.scheduler
		Fiber.schedule(&block)
	else
		Thread.new(&block)
	end
end

#set_buffered(socket, buffered) ⇒ Object

Set whether a socket should be buffered.



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# File 'lib/io/endpoint/wrapper.rb', line 52

def set_buffered(socket, buffered)
	case buffered
	when true
		socket.setsockopt(IPPROTO_TCP, TCP_NODELAY, 0)
	when false
		socket.setsockopt(IPPROTO_TCP, TCP_NODELAY, 1)
	end
rescue Errno::EINVAL
	# On Darwin, sometimes occurs when the connection is not yet fully formed. Empirically, TCP_NODELAY is enabled despite this result.
rescue Errno::EOPNOTSUPP
	# Some platforms may simply not support the operation.
rescue Errno::ENOPROTOOPT
	# It may not be supported by the protocol (e.g. UDP). ¯\_(ツ)_/¯
end

#set_timeout(io, timeout) ⇒ Object

Set the timeout for an IO object.



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# File 'lib/io/endpoint/wrapper.rb', line 43

def set_timeout(io, timeout)
	if io.respond_to?(:timeout=)
		io.timeout = timeout
	end
end

#socket_accept(server) ⇒ Object

Accept a connection from a bound socket. This is an extension point for subclasses to provide additional functionality.



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# File 'lib/io/endpoint/wrapper.rb', line 198

def socket_accept(server)
	server.accept
end

#socket_connect(socket, remote_address) ⇒ Object

Connect a socket to a remote address. This is an extension point for subclasses to provide additional functionality.



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# File 'lib/io/endpoint/wrapper.rb', line 72

def socket_connect(socket, remote_address)
	socket.connect(remote_address.to_sockaddr)
end