Apache Savan/C

  What is it?
  -----------
Savan/C is a C implementation of WS-Eventing specification. Savan/C is built on top of Axis2/C. Therefore by using Savan/C 
you can add WS-Eventing capability to Web services hosted using Axis2/C. Savan/C was designed as a general 
publisher/subscriber tool. The architecture was designed to abstract the general publisher/subscriber features so that 
people could support more than one publisher/subscriber mechanisms within the same infrastructure. 
  
  The Latest Version
  ------------------
  0.90.

  Documentation
  -------------
  The documentation not available yet.

  Acknowledgments
  ----------------
  Apache Savan/C relies heavily on the use of autoconf and libtool to
  provide a build environment.

  Installation
  ------------
  Please see the INSTALL file.

  Licensing
  ---------
  Please see the LICENSE file.

  How To Run.
  ----------
  Install savan module into <axis2 deploy folder>/modules folder. Add the Savan Phase
  information into axis2.xml as following. Search for 'SavanPhase' in the
  following xml block to identify the Savan specific entries.

    <!-- ================================================= -->
    <!-- Phases  -->
    <!-- ================================================= -->
    <phaseOrder type="inflow">
        <!-- System pre defined phases       -->
        <phase name="Transport"/>
        <phase name="PreDispatch"/>
        <phase name="Dispatch"/>
        <phase name="PostDispatch"/>
        <!-- End system pre defined phases       -->
        <!-- After PostDispatch phase, module or service author can add any phase as required  -->
        <!-- User defined phases could be added here -->
        <!--phase name="userphase1"/-->
        <!--phase name="RMPhase"/-->
        <phase name="SavanPhase"/>
    </phaseOrder>
    <phaseOrder type="outflow">
        <!-- User defined phases could be added here -->
        <!--phase name="RMPhase"/-->
        <phase name="SavanPhase"/>
        <!--phase name="userphase1"/-->
        <!--system predefined phase-->
        <phase name="MessageOut"/>
        <!--phase name="Security"/-->
    </phaseOrder>
    <phaseOrder type="INfaultflow">
        <!-- User defined phases could be added here -->
        <!--phase name="userphase1"/-->
        <!--phase name="RMPhase"/-->
        <phase name="SavanPhase"/>
    </phaseOrder>
    <phaseOrder type="Outfaultflow">
        <!-- User defined phases could be added here -->
        <!--phase name="RMPhase"/-->
        <phase name="SavanPhase"/>
        <!--phase name="userphase1"/-->
        <phase name="MessageOut"/>
    </phaseOrder>

You may find a sample axis2.xml in src/data of the source distribution or in
samples/server in binary distribution.
In the services xml file for the service which require Savan enabled
add the entry
 <module ref="savan"/>
If you need all services in the engine Savan enabled add the above entry into
axis2.xml.

In the module.xml file for the savan module give a valid path for database storage. The database name should be savan_db.
<parameter name="savan_db" locked="false">/axis2c/deploy/savan_db</parameter>

You can use the sample in the samples folder for testing.
This sample consists of two services called listener and weather and a subscriber client.
Install these samples by running the build.sh script in the smaples folder and you will find
weather and listener services added to the $AXIS2C_HOME/services folder.
Here is the weather's serivces.xml file

<service name="weather">
    <parameter name="ServiceClass" locked="xsd:false">weather</parameter>
   <description>
       This is a sample eventing data source which loads as the axis2 engine startup and
       start publishing to its subscribers.
   </description>
   <module ref="savan"/>
   <operation name="start">
           <parameter name="wsamapping" >http://ws.apache.org/axis2/c/savan/samples/pubilsher/start</parameter>
   </operation>
</service>

Now to test the sample edit the client sample in samples/client/subscriber/subscriber.c.

You may need to edit the following line to point to the listener to which the weather publish when subscriber subscribes.
    axutil_hash_set(savan_options, SAVAN_OP_KEY_NOTIFY_EPR, AXIS2_HASH_KEY_STRING,
        "http://localhost:9090/axis2/services/listener");

Now compile, install and execute the subscriber sample $AXIS2C_HOME/bin/samples/savan/subscriber.
This will prompt the user with the following screen

Select the action:
1 subscribe
2 renew
3 get status
4 unsubscribe
5 Generate weather event
6 quit

Choosing option 1 send a subscription request to the weather data source and receive a subscription id if subscription is
successful. Choosing option 5, the command line program send a weather event to the weather service data source which then emits it to the registered subscriber's data sink(listener service here) provided by subscriber.
Using option 2 the subscriber request for renew subscription request. Using option 3 the subscriber send a a status request message.
Finally it unsubscribe indicating that it has no further interest in receiving data source events by using option 4.

Please keep in mind the following when using Savan/C with Axis2/C.

1. If Axis2 C engine is running as an Apache module make sure that Apache execute user has the full access to the
    database path you included in the module.xml