ros::Connection Class Reference

Encapsulates a connection to a remote host, independent of the transport type. More...

#include <connection.h>

Public Types
typedef boost::function< void(const ConnectionPtr &, DropReason reason)>	DropFunc
enum	DropReason { TransportDisconnect, HeaderError, Destructing }
typedef boost::signal< void(const ConnectionPtr &, DropReason reason)>	DropSignal
Public Member Functions
boost::signals::connection	addDropListener (const DropFunc &slot)
	Add a callback to be called when this connection has dropped.
	Connection ()
void	drop (DropReason reason)
	Drop this connection. Anything added as a drop listener through addDropListener will get called back when this connection has been dropped.
std::string	getCallerId ()
Header &	getHeader ()
	Get the Header associated with this connection.
std::string	getRemoteString ()
const TransportPtr &	getTransport ()
	Get the Transport associated with this connection.
void	initialize (const TransportPtr &transport, bool is_server, const HeaderReceivedFunc &header_func)
	Initialize this connection.
bool	isDropped ()
	Returns whether or not this connection has been dropped.
bool	isSendingHeaderError ()
	Returns true if we're currently sending a header error (and will be automatically dropped when it's finished).
void	read (uint32_t size, const ReadFinishedFunc &finished_callback)
	Read a number of bytes, calling a callback when finished.
void	removeDropListener (const boost::signals::connection &c)
void	sendHeaderError (const std::string &error_message)
	Send a header error message, of the form "error=<message>". Drops the connection once the data has written successfully (or fails to write).
void	setHeader (const Header &header)
	Set the Header associated with this connection (used with UDPROS, which receives the connection during XMLRPC negotiation).
void	setHeaderReceivedCallback (const HeaderReceivedFunc &func)
	Set the header receipt callback.
void	write (const boost::shared_array< uint8_t > &buffer, uint32_t size, const WriteFinishedFunc &finished_callback, bool immedate=true)
	Write a buffer of bytes, calling a callback when finished.
void	writeHeader (const M_string &key_vals, const WriteFinishedFunc &finished_callback)
	Send a list of string key/value pairs as a header message.
	~Connection ()
Private Member Functions
void	onDisconnect (const TransportPtr &transport)
	Called by the Transport when it has been disconnected, either through a call to close() or through an error in the connection (such as a remote disconnect).
void	onErrorHeaderWritten (const ConnectionPtr &conn)
void	onHeaderLengthRead (const ConnectionPtr &conn, const boost::shared_array< uint8_t > &buffer, uint32_t size, bool success)
void	onHeaderRead (const ConnectionPtr &conn, const boost::shared_array< uint8_t > &buffer, uint32_t size, bool success)
void	onHeaderWritten (const ConnectionPtr &conn)
void	onReadable (const TransportPtr &transport)
	Called by the Transport when there is data available to be read.
void	onWriteable (const TransportPtr &transport)
	Called by the Transport when it is possible to write data.
void	readTransport ()
	Read data off our transport. Also manages calling the read callback. If there is any data to be read, read() will read it until the fixed read buffer is filled.
void	writeTransport ()
	Write data to our transport. Also manages calling the write callback.
Private Attributes
boost::recursive_mutex	drop_mutex_
	Synchronizes drop() calls.
DropSignal	drop_signal_
	Signal raised when this connection is dropped.
bool	dropped_
	Have we dropped?
volatile uint32_t	has_read_callback_
volatile uint32_t	has_write_callback_
Header	header_
	Incoming header.
HeaderReceivedFunc	header_func_
	Function that handles the incoming header.
WriteFinishedFunc	header_written_callback_
	Function to call when the outgoing header has finished writing.
bool	is_server_
	Are we a server? Servers wait for clients to send a header and then send a header in response.
boost::shared_array< uint8_t >	read_buffer_
	Read buffer that ends up being passed to the read callback.
ReadFinishedFunc	read_callback_
	Function to call when the read is finished.
uint32_t	read_filled_
	Amount of data currently in the read buffer, in bytes.
boost::recursive_mutex	read_mutex_
	Mutex used for protecting reading. Recursive because a read can immediately cause another read through the callback.
uint32_t	read_size_
	Size of the read buffer, in bytes.
bool	reading_
	Flag telling us if we're in the middle of a read (mostly to avoid recursive deadlocking).
bool	sending_header_error_
	If we're sending a header error we disable most other calls.
TransportPtr	transport_
	Transport associated with us.
boost::shared_array< uint8_t >	write_buffer_
	Buffer to write from.
WriteFinishedFunc	write_callback_
	Function to call when the current write is finished.
boost::mutex	write_callback_mutex_
boost::recursive_mutex	write_mutex_
	Mutex used for protecting writing. Recursive because a write can immediately cause another write through the callback.
uint32_t	write_sent_
	Amount of data we've written from the write buffer.
uint32_t	write_size_
	Size of the write buffer.
bool	writing_
	Flag telling us if we're in the middle of a write (mostly used to avoid recursive deadlocking).

Detailed Description

Encapsulates a connection to a remote host, independent of the transport type.

Connection provides automatic header negotiation, as well as easy ways of reading and writing arbitrary amounts of data without having to set up your own state machines.

Definition at line 68 of file connection.h.

Member Typedef Documentation

typedef boost::function<void(const ConnectionPtr&, DropReason reason)> ros::Connection::DropFunc

Definition at line 146 of file connection.h.

typedef boost::signal<void(const ConnectionPtr&, DropReason reason)> ros::Connection::DropSignal

Definition at line 145 of file connection.h.

Member Enumeration Documentation

enum ros::Connection::DropReason

Enumerator:

TransportDisconnect
HeaderError
Destructing

Definition at line 71 of file connection.h.

Constructor & Destructor Documentation

ros::Connection::Connection ( )

Definition at line 47 of file connection.cpp.

ros::Connection::~Connection ( )

Definition at line 62 of file connection.cpp.

Member Function Documentation

boost::signals::connection ros::Connection::addDropListener ( const DropFunc & slot )

Add a callback to be called when this connection has dropped.

Definition at line 87 of file connection.cpp.

void ros::Connection::drop ( DropReason reason )

Drop this connection. Anything added as a drop listener through addDropListener will get called back when this connection has been dropped.

Definition at line 322 of file connection.cpp.

std::string ros::Connection::getCallerId ( )

Definition at line 456 of file connection.cpp.

Header& ros::Connection::getHeader ( ) [inline]

Get the Header associated with this connection.

Definition at line 165 of file connection.h.

std::string ros::Connection::getRemoteString ( )

Definition at line 467 of file connection.cpp.

const TransportPtr& ros::Connection::getTransport ( ) [inline]

Get the Transport associated with this connection.

Definition at line 161 of file connection.h.

void ros::Connection::initialize	(	const TransportPtr &	transport,
		bool	is_server,
		const HeaderReceivedFunc &	header_func
	)

Initialize this connection.

Definition at line 69 of file connection.cpp.

bool ros::Connection::isDropped ( )

Returns whether or not this connection has been dropped.

Definition at line 342 of file connection.cpp.

bool ros::Connection::isSendingHeaderError ( ) [inline]

Returns true if we're currently sending a header error (and will be automatically dropped when it's finished).

Definition at line 99 of file connection.h.

void ros::Connection::onDisconnect ( const TransportPtr & transport ) [private]

Called by the Transport when it has been disconnected, either through a call to close() or through an error in the connection (such as a remote disconnect).

Definition at line 315 of file connection.cpp.

void ros::Connection::onErrorHeaderWritten ( const ConnectionPtr & conn ) [private]

Definition at line 443 of file connection.cpp.

void ros::Connection::onHeaderLengthRead	(	const ConnectionPtr &	conn,
		const boost::shared_array< uint8_t > &	buffer,
		uint32_t	size,
		bool	success
	)			`[private]`

Definition at line 380 of file connection.cpp.

void ros::Connection::onHeaderRead	(	const ConnectionPtr &	conn,
		const boost::shared_array< uint8_t > &	buffer,
		uint32_t	size,
		bool	success
	)			`[private]`

Definition at line 402 of file connection.cpp.

void ros::Connection::onHeaderWritten ( const ConnectionPtr & conn ) [private]

Definition at line 434 of file connection.cpp.

void ros::Connection::onReadable ( const TransportPtr & transport ) [private]

Called by the Transport when there is data available to be read.

Definition at line 99 of file connection.cpp.

void ros::Connection::onWriteable ( const TransportPtr & transport ) [private]

Called by the Transport when it is possible to write data.

Definition at line 255 of file connection.cpp.

void ros::Connection::read	(	uint32_t	size,
		const ReadFinishedFunc &	finished_callback
	)

Read a number of bytes, calling a callback when finished.

read() will not queue up multiple reads. Once read() has been called, it is not valid to call it again until the finished callback has been called. It is valid to call read() from within the finished callback.

The finished callback is of the form void(const ConnectionPtr&, const boost::shared_array<uint8_t>&, uint32_t)

Note:: The finished callback may be called from within this call to read() if the data has already arrived

Parameters:

	size	The size, in bytes, of data to read
	finished_callback	The function to call when this read is finished

Definition at line 262 of file connection.cpp.

void ros::Connection::readTransport ( ) [private]

Read data off our transport. Also manages calling the read callback. If there is any data to be read, read() will read it until the fixed read buffer is filled.

Definition at line 106 of file connection.cpp.

void ros::Connection::removeDropListener ( const boost::signals::connection & c )

Definition at line 93 of file connection.cpp.

void ros::Connection::sendHeaderError ( const std::string & error_message )

Send a header error message, of the form "error=<message>". Drops the connection once the data has written successfully (or fails to write).

Parameters:

error_message

The error message

Definition at line 371 of file connection.cpp.

void ros::Connection::setHeader ( const Header & header ) [inline]

Set the Header associated with this connection (used with UDPROS, which receives the connection during XMLRPC negotiation).

Definition at line 171 of file connection.h.

void ros::Connection::setHeaderReceivedCallback ( const HeaderReceivedFunc & func )

Set the header receipt callback.

Definition at line 448 of file connection.cpp.

void ros::Connection::write	(	const boost::shared_array< uint8_t > &	buffer,
		uint32_t	size,
		const WriteFinishedFunc &	finished_callback,
		bool	immedate = `true`
	)

Write a buffer of bytes, calling a callback when finished.

write() will not queue up multiple writes. Once write() has been called, it is not valid to call it again until the finished callback has been called. It is valid to call write() from within the finished callback.

* The finished callback is of the form void(const ConnectionPtr&)

Note:: The finished callback may be called from within this call to write() if the data can be written immediately

Parameters:

	buffer	The buffer of data to write
	size	The size of the buffer, in bytes
	finished_callback	The function to call when the write has finished
	immediate	Whether to immediately try to write as much data as possible to the socket or to pass the data off to the server thread

Definition at line 287 of file connection.cpp.

void ros::Connection::writeHeader	(	const M_string &	key_vals,
		const WriteFinishedFunc &	finished_callback
	)

Send a list of string key/value pairs as a header message.

Parameters:

	key_vals	The values to send. Neither keys nor values can have any newlines in them
	finished_callback	The function to call when the header has finished writing

Definition at line 348 of file connection.cpp.

void ros::Connection::writeTransport ( ) [private]

Write data to our transport. Also manages calling the write callback.

Definition at line 191 of file connection.cpp.

Member Data Documentation

boost::recursive_mutex ros::Connection::drop_mutex_ [private]

Synchronizes drop() calls.

Definition at line 260 of file connection.h.

DropSignal ros::Connection::drop_signal_ [private]

Signal raised when this connection is dropped.

Definition at line 257 of file connection.h.

bool ros::Connection::dropped_ [private]

Have we dropped?

Definition at line 210 of file connection.h.

volatile uint32_t ros::Connection::has_read_callback_ [private]

flag telling us if there is a read callback 32-bit loads and stores are atomic on x86 and PPC... TODO: use a cross-platform atomic operations library to ensure this is done atomically

Definition at line 233 of file connection.h.

volatile uint32_t ros::Connection::has_write_callback_ [private]

flag telling us if there is a write callback 32-bit loads and stores are atomic on x86 and PPC... TODO: use a cross-platform atomic operations library to ensure this is done atomically

Definition at line 251 of file connection.h.

Header ros::Connection::header_ [private]

Incoming header.

Definition at line 212 of file connection.h.

HeaderReceivedFunc ros::Connection::header_func_ [private]

Function that handles the incoming header.

Definition at line 216 of file connection.h.

WriteFinishedFunc ros::Connection::header_written_callback_ [private]

Function to call when the outgoing header has finished writing.

Definition at line 254 of file connection.h.

bool ros::Connection::is_server_ [private]

Are we a server? Servers wait for clients to send a header and then send a header in response.