Apama  10.15.3.4
com::softwareag::connectivity::AbstractSimpleCodec Class Referenceabstract

Base class that simplifies implementation of codec plug-ins that deal only with individual messages not batches, and ignore messages with null payloads. More...

#include <sag_connectivity_plugins.hpp>

Inheritance diagram for com::softwareag::connectivity::AbstractSimpleCodec:
com::softwareag::connectivity::AbstractCodec com::softwareag::connectivity::Plugin com::softwareag::connectivity::HostSide com::softwareag::connectivity::TransportSide

Public Member Functions

 AbstractSimpleCodec (const PluginConstructorParameters::CodecConstructorParameters &params)
 Constructor. More...
 
virtual void sendBatchTowardsHost (Message *start, Message *end)
 Implements batch sending, calling transformMessageTowardsHost(Message &) for each message individually. More...
 
virtual void sendBatchTowardsTransport (Message *start, Message *end)
 Implements batch sending, calling transformMessageTowardsTransport(Message &) for each message individually. More...
 
virtual bool transformMessageTowardsHost (Message &msg)=0
 Abstract method that must be implemented to handle transformation of an individual message. More...
 
virtual bool transformMessageTowardsTransport (Message &msg)=0
 Abstract method that must be implemented to handle transformation of an individual message in a transport-wards direction. More...
 
virtual bool transformNullPayloadTowardsHost (Message &msg)
 Transform a message with a null payload in a host-wards direction. More...
 
virtual bool transformNullPayloadTowardsTransport (Message &msg)
 Transform a message with a null payload in a transport-wards direction. More...
 
virtual bool handleException (Message &m, bool towardsTransport)
 Handle an exception thrown while delivering a message. More...
 
- Public Member Functions inherited from com::softwareag::connectivity::AbstractCodec
 AbstractCodec (const PluginConstructorParameters::CodecConstructorParameters &params)
 Constructor. More...
 
- Public Member Functions inherited from com::softwareag::connectivity::Plugin
virtual ~Plugin ()
 This destructor must be virtual. More...
 
virtual void start ()
 Called when an entire chain has been created and the plugin is allowed to start up (after all plugins are connected together). More...
 
virtual void hostReady ()
 Called some time after start(), when the host is ready to start receiving input (sends will be queued until this point). More...
 
virtual void shutdown ()
 Stop processing messages and terminate and join any background threads. More...
 
const std::string & getName () const
 The name used for this plug-in in the configuration file. More...
 
- Public Member Functions inherited from com::softwareag::connectivity::HostSide
virtual ~HostSide ()
 Ensure virtual destruction. More...
 
void sendBatchTowardsHost (Message &&message)
 Overload for sending a batch containing a single message. More...
 
template<typename IT >
auto sendBatchTowardsHost (const IT &begin, const IT &end) -> typename std::enable_if< !std::is_const< ampl::remove_ref_t< decltype(*begin)>>::value &&ampl::is_same< Message, ampl::remove_const_t< ampl::remove_ref_t< decltype(*begin)>>>::value, void >::type
 Overload for sending messages using an iterator range. More...
 
- Public Member Functions inherited from com::softwareag::connectivity::TransportSide
virtual ~TransportSide ()
 Ensure virtual destruction. More...
 
void sendBatchTowardsTransport (Message &&message)
 Overload for sending a batch containing a single message. More...
 
template<typename IT >
auto sendBatchTowardsTransport (const IT &begin, const IT &end) -> typename std::enable_if< !std::is_const< ampl::remove_ref_t< decltype(*begin)>>::value &&ampl::is_same< Message, ampl::remove_const_t< ampl::remove_ref_t< decltype(*begin)>>>::value, void >::type
 Overload for sending messages using an iterator range. More...
 

Additional Inherited Members

- Public Types inherited from com::softwareag::connectivity::HostSide
typedef std::unique_ptr< HostSideptr_t
 Pointers to HostSides should always be this ptr_t type, which is a std::unique_ptr. More...
 
- Public Types inherited from com::softwareag::connectivity::TransportSide
typedef std::unique_ptr< TransportSideptr_t
 Pointers to TransportSides should always be this ptr_t type, which is a std::unique_ptr. More...
 
- Public Attributes inherited from com::softwareag::connectivity::Plugin
Logger logger
 Logging for writing to the host log file. More...
 
- Protected Member Functions inherited from com::softwareag::connectivity::Plugin
StatusReportergetStatusReporter ()
 Allows reporting status information from this plug-in, such as online or failed status and number of messages sent/received in each direction. More...
 
- Protected Attributes inherited from com::softwareag::connectivity::AbstractCodec
HostSide::ptr_t hostSide
 The next plug-in in the chain towards host. More...
 
TransportSide::ptr_t transportSide
 The next plug-in in the chain towards transport. More...
 
- Protected Attributes inherited from com::softwareag::connectivity::Plugin
const std::string pluginName
 The name used for this plug-in in the configuration file. More...
 
const std::string chainId
 The identifier used for the chain this plug-in is part of. More...
 
map_t config
 The configuration of this plug-in. More...
 
const PluginHost::ptr_t host
 Interface to support miscellaneous requests from this plug-in to the host system. More...
 

Detailed Description

Base class that simplifies implementation of codec plug-ins that deal only with individual messages not batches, and ignore messages with null payloads.

To export a codec class for use in the host you should use the SAG_DECLARE_CONNECTIVITY_CODEC_CLASS(Class) macro, and provide a public constructor with the same signature as AbstractSimpleCodec(const PluginConstructorParameters::CodecConstructorParameters &).

Handles batches of messages and ignoring null payload messages (by default). Implementors will typically subclass this class, providing an implementation of the transformMessageTowardsHost(Message&) and transformMessageTowardsTransport(Message&) methods.

If you don't need to handle messages a batch at a time, then you should derive from this class. If you do then you should directly derive from AbstractCodec.

Constructor & Destructor Documentation

◆ AbstractSimpleCodec()

com::softwareag::connectivity::AbstractSimpleCodec::AbstractSimpleCodec ( const PluginConstructorParameters::CodecConstructorParameters params)
inline

Constructor.

A subclass should provide its own constructor with the same signature as this one.

A plug-in should throw an exception from the constructor if there is a problem with the configuration or any other error that will prevent the plug-in from working correctly.

Parameters
paramsProvides access to the configuration for this plug-in, and other capabilities.
Since
9.12.0.1

Member Function Documentation

◆ handleException()

virtual bool com::softwareag::connectivity::AbstractSimpleCodec::handleException ( Message m,
bool  towardsTransport 
)
inlinevirtual

Handle an exception thrown while delivering a message.

Default is to log a warning and discard a message.

This is called from within a catch block, so if you need to know the exception thrown then you can rethrow it yourself:

try {
throw;
} catch (const type &ex) { ...
}
Parameters
mThe Message that caused the error is passed in by reference.
towardsTransportset to true if it was transformMessageTowardsTransport that threw or false if it was transformMessageTowardsHost that threw
Returns
If you wish to fix the message and then continue passing it on then return true, if it should be discarded then should return false

◆ sendBatchTowardsHost()

virtual void com::softwareag::connectivity::AbstractSimpleCodec::sendBatchTowardsHost ( Message start,
Message end 
)
inlinevirtual

Implements batch sending, calling transformMessageTowardsHost(Message &) for each message individually.

Exceptions from transformMessageTowardsHost are caught and handleException(Message &, bool) is called (the default implementation is to log a warning and discard the event) If handleException or transformMessageTowardsHost returns false then that event is removed, but processing continues for the next message.

Implements com::softwareag::connectivity::HostSide.

◆ sendBatchTowardsTransport()

virtual void com::softwareag::connectivity::AbstractSimpleCodec::sendBatchTowardsTransport ( Message start,
Message end 
)
inlinevirtual

Implements batch sending, calling transformMessageTowardsTransport(Message &) for each message individually.

Exceptions from transformMessageTowardsTransport are caught and handleException(Message &, bool) is called (the default implementation is to log a warning and discard the event). If handleException or transformMessageTowardsTransport returns false then that event is removed, but processing continues for the next message.

Implements com::softwareag::connectivity::TransportSide.

◆ transformMessageTowardsHost()

virtual bool com::softwareag::connectivity::AbstractSimpleCodec::transformMessageTowardsHost ( Message msg)
pure virtual

Abstract method that must be implemented to handle transformation of an individual message.

in a host-wards direction

Returns
true to keep the message and false (or throw) to delete it

◆ transformMessageTowardsTransport()

virtual bool com::softwareag::connectivity::AbstractSimpleCodec::transformMessageTowardsTransport ( Message msg)
pure virtual

Abstract method that must be implemented to handle transformation of an individual message in a transport-wards direction.

Returns
true to keep the message and false (or throw) to delete it

◆ transformNullPayloadTowardsHost()

virtual bool com::softwareag::connectivity::AbstractSimpleCodec::transformNullPayloadTowardsHost ( Message msg)
inlinevirtual

Transform a message with a null payload in a host-wards direction.

default is to do nothing

Returns
true to keep the message and false (or throw) to delete it

◆ transformNullPayloadTowardsTransport()

virtual bool com::softwareag::connectivity::AbstractSimpleCodec::transformNullPayloadTowardsTransport ( Message msg)
inlinevirtual

Transform a message with a null payload in a transport-wards direction.

default is to do nothing

Returns
true to keep the message and false (or throw) to delete it

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