// $Id$
//
-// Copyright (C) 2007
-// Fraunhofer Institut fuer offene Kommunikationssysteme (FOKUS)
-// Kompetenzzentrum fuer Satelitenkommunikation (SatCom)
+// Copyright (C) 2007
+// Fraunhofer Institute for Open Communication Systems (FOKUS)
+// Competence Center NETwork research (NET), St. Augustin, GERMANY
// Stefan Bund <g0dil@berlios.de>
//
// This program is free software; you can redistribute it and/or modify
// Free Software Foundation, Inc.,
// 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-/** \mainpage RateStuffer: A simple example featuring the Packet Processing Infrastructure
+using namespace senf::ppi::module;
+
+/** \mainpage Example introducing the Packet Processing Infrastructure
This example application implements a simple PPI application: It will read UDP packets from an
input port and will forward them to another port at a fixed packet rate. If the input stream
does not provide enough packets, empty UDP packets will be sent instead.
-
+
\section run Running the example
Running the example is a little bit more complicated since we need to provide example UDP
<pre>
# nc -u -l -p 44345
</pre>
-
+
The next command starts the \c ratestuffer
<pre>
# cd .../Examples/RateStuffer
\section setup Module setup
- \image html ratestuffer.png
+ \diaimage ratestuffer.dia
Above image depicts the module setup implementing the rate stuffer. A
- senf::ppi::module::ActiveSocketReader reads the incoming UDP packets and sends them into a
+ senf::ppi::module::ActiveSocketSource reads the incoming UDP packets and sends them into a
senf::ppi::module::PassiveQueue (via a senf::ppi::module::ThrottleBarrier).
The \a queue feeds the packets into a senf::ppi::module::PriorityJoin. The CloneSource
\a generator is fed as second input into the \a join to provide the stuffing packets.
The RateFilter \a rateFilter reads packets from it's input at a fixed rate and writes them into
- the senf::ppi::module::PassiveSocketWriter \a udpWriter. The senf::ppi::module::PriorityJoin
+ the senf::ppi::module::PassiveSocketSink \a udpSink. The senf::ppi::module::PriorityJoin
ensures that read requests of the RateStuffer's input are always serviced, either from the \a
queue or, if the \a queue output is throttled, from the \a generator.
\until }
- The event is initialized to fire eery \a interval nanoseconds. The traffic is routed 'across'
+ The event is initialized to fire every \a interval nanoseconds. The traffic is routed 'across'
the timer which controls the traffic. This routing lets the module automatically handle
throttling events. The timer is registered to call RateFilter::timeout().
\skip class
\until rateFilter
-
- First the needed modules are declared. We have
- \li the \a barrier to discard incoming packets sent to fast
- \li the \a queue to receive incoming packets and create throttling notifications
- \li the \a generator to create the stuffing packets
- \li the \a join to combine the input stream from the \a queue with the stuffing packet stream
- \li the \a rateFilter to generate the fixed rate output stream
+
+ First the needed modules are declared. We have
+ - the \a barrier to discard incoming packets sent to fast
+ - the \a queue to receive incoming packets and create throttling notifications
+ - the \a generator to create the stuffing packets
+ - the \a join to combine the input stream from the \a queue with the stuffing packet stream
+ - the \a rateFilter to generate the fixed rate output stream
\until output
The constructor now initializes all the local objects. We pass the template \a packet to the \a
generator and set the timing \a interval of the \a rateFilter.
-
+
The \a input and \a output connector references are bound to the corresponding connectors we
want to expose: \a input to the \a barrier's \a input and \a output to the \a rateFilter's \a
output.
The \a inputSocket is listening on port 44344 while the \a outputSocket will send packets to
port 44345 on localhost. The \a outputSocket uses the senf::ConnectedUDPv4SocketProtocol which
- is compatible with the senf::ppi::module::PassiveSocketWriter module.
+ is compatible with the senf::ppi::module::PassiveSocketSink module.
- \until udpWriter
+ \until udpSink
Here we allocate the components:
- \li \a udpReader to read the packets from \a inputSocket
- \li \a stuffer for the real work and
- \li \a udpWriter to send the packets to \a outputSocket
+ - \a udpSource to read the packets from \a inputSocket
+ - \a stuffer for the real work and
+ - \a udpSink to send the packets to \a outputSocket
- \until udpWriter
+ \until udpSink
The \ref senf::ppi::connect() calls setup the necessary connections.
-
- \until run
The module setup is complete, \ref senf::ppi::run() is called to enter the event loop.
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