Simple wrapper for ZeroConf key/value pairs. More...

#include <servus.h>

Inheritance diagram for lunchbox::Servus:

Collaboration diagram for lunchbox::Servus:

Classes
class	Result
	The ZeroConf operation result code. More...

Public Types
enum	Interface { IF_ALL = 0, IF_LOCAL = (unsigned)(-1) }

typedef std::map< std::string, std::map< std::string, std::string > >	Data

Public Member Functions
LUNCHBOX_API	Servus (const std::string &name)
	Create a new service handle. More...

virtual LUNCHBOX_API	~Servus ()
	Destruct this service. More...

LUNCHBOX_API void	set (const std::string &key, const std::string &value)
	Set a key/value pair to be announced. More...

LUNCHBOX_API Strings	getKeys () const

LUNCHBOX_API const std::string &	get (const std::string &key) const

LUNCHBOX_API Result	announce (const unsigned short port, const std::string &instance)
	Start announcing the registered key/value pairs. More...

LUNCHBOX_API void	withdraw ()
	Stop announcing the registered key/value pairs. More...

LUNCHBOX_API bool	isAnnounced () const

LUNCHBOX_API Strings	discover (const Interface addr, const unsigned browseTime)
	Discover all announced key/value pairs. More...

LUNCHBOX_API Strings	getInstances () const

LUNCHBOX_API Strings	getKeys (const std::string &instance) const

LUNCHBOX_API bool	containsKey (const std::string &instance, const std::string &key) const

LUNCHBOX_API const std::string &	get (const std::string &instance, const std::string &key) const

LUNCHBOX_API void	getData (Data &data)

Detailed Description

Simple wrapper for ZeroConf key/value pairs.

The servus class allows simple announcement and discovery of key/value pairs using ZeroConf networking. The same instance can be used to announce and/or to browse a ZeroConf service. If the Lunchbox library is compiled without zeroconf support (LUNCHBOX_USE_DNSSD is not set), this class does not do anything useful.

Example:

/* Copyright (c) 2012-2014, Stefan.Eilemann@epfl.ch
 *
 * This file is part of Lunchbox <https://github.com/Eyescale/Lunchbox>
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 3.0 as published
 * by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include "test.h"
#include <lunchbox/servus.h>
#include <lunchbox/rng.h>
#ifdef LUNCHBOX_USE_DNSSD
#  include <dns_sd.h>
#endif
int main( int, char** )
{
    lunchbox::RNG rng;
    const uint16_t port = rng.get< uint16_t >();
    lunchbox::Servus service( "_servustest._tcp" );
    std::ostringstream os;
    os << port;
    const lunchbox::Servus::Result& result = service.announce( port, os.str( ));
#ifdef LUNCHBOX_USE_DNSSD
    TEST( lunchbox::Result::SUCCESS == kDNSServiceErr_NoError );
    if( result == kDNSServiceErr_Unknown ) // happens on CI VMs
    {
        std::cerr << "Bailing, got " << result
                  << ": looks like a broken zeroconf setup" << std::endl;
        return EXIT_SUCCESS;
    }
    TESTINFO( result, result );
    service.withdraw();
    service.set( "foo", "bar" );
    TEST( service.announce( port, os.str( )));
    const lunchbox::Strings& hosts =
        service.discover( lunchbox::Servus::IF_LOCAL, 500 );
    if( hosts.empty() && getenv( "TRAVIS" ))
    {
        std::cerr << "Bailing, got no hosts on a Travis CI setup" << std::endl;
        return EXIT_SUCCESS;
    }
    TESTINFO( hosts.size() == 1, hosts.size( ));
    TESTINFO( hosts.front() == os.str(), hosts.front( ));
    TEST( service.get( hosts.front(), "foo" ) == "bar" );
    lunchbox::sleep( 500 );
    service.set( "foobar", "42" );
    lunchbox::sleep( 500 );
    service.discover( lunchbox::Servus::IF_LOCAL, 500 );
    TEST( service.get( hosts.front(), "foobar" ) == "42" );
    TEST( service.getKeys().size() == 2 );
#else
    TESTINFO( result == lunchbox::Servus::Result::NOT_SUPPORTED, result );
#endif
    return EXIT_SUCCESS;
}

Definition at line 44 of file servus.h.

Member Enumeration Documentation

enum lunchbox::Servus::Interface

Enumerator
IF_ALL	use all interfaces
IF_LOCAL	only local interfaces

Definition at line 47 of file servus.h.

Constructor & Destructor Documentation

LUNCHBOX_API lunchbox::Servus::Servus ( const std::string & name )

explicit

Create a new service handle.

Parameters

name	the service descriptor, e.g., "_gpu-sd._tcp"

Version: 0.9

virtual LUNCHBOX_API lunchbox::Servus::~Servus ( )

virtual

Destruct this service.

Member Function Documentation

LUNCHBOX_API Result lunchbox::Servus::announce	(	const unsigned short	port,
		const std::string &	instance
	)

Start announcing the registered key/value pairs.

Parameters

port	the service IP port in host byte order.
instance	a host-unique instance name, hostname is used if empty.

Returns: the success status of the operation.

Version: 0.9

LUNCHBOX_API bool lunchbox::Servus::containsKey	(	const std::string &	instance,
		const std::string &	key
	)		const

Returns: true if the given key was discovered.

Version: 0.9

LUNCHBOX_API Strings lunchbox::Servus::discover	(	const Interface	addr,
		const unsigned	browseTime
	)

Discover all announced key/value pairs.

Parameters

addr	the scope of the discovery
browseTime	the browse time, in milliseconds, to wait for new records.

Returns: all instance names found during discovery.

Version: 0.9

LUNCHBOX_API const std::string& lunchbox::Servus::get ( const std::string & key ) const

Returns: the value to the given (to be) announced key.

Version: 1.5.1

LUNCHBOX_API const std::string& lunchbox::Servus::get	(	const std::string &	instance,
		const std::string &	key
	)		const

Returns: the value of the given key and instance.

Version: 0.9

LUNCHBOX_API Strings lunchbox::Servus::getInstances ( ) const

Returns: all instances found during the last discovery.

Version: 0.9

LUNCHBOX_API Strings lunchbox::Servus::getKeys ( ) const

Returns: all (to be) announced keys.

Version: 1.5.1

LUNCHBOX_API Strings lunchbox::Servus::getKeys ( const std::string & instance ) const

Returns: all keys discovered on the given instance.

Version: 0.9

LUNCHBOX_API bool lunchbox::Servus::isAnnounced ( ) const

Returns: true if the local data is announced.

Version: 0.9

LUNCHBOX_API void lunchbox::Servus::set	(	const std::string &	key,
		const std::string &	value
	)

Set a key/value pair to be announced.

Keys should be at most eight characters, and values are truncated to 255 characters. The total length of all keys and values cannot exceed 65535 characters. Setting a value on an announced service causes an update which needs some time to propagate after this function returns, that is, calling discover() immediately afterwards will very likely not contain the new key/value pair.

Version: 0.9

LUNCHBOX_API void lunchbox::Servus::withdraw ( )

Stop announcing the registered key/value pairs.

Version: 0.9

The documentation for this class was generated from the following file:

servus.h

Classes

Public Types

Public Member Functions

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation