The EPL plug-in APIs for C and C++
Note: | The information in this section is deprecated. It applies to the old API which will be removed in a future release. It is recommended that you use the new API for writing EPL plug-ins in C++. |
The correlator_plugin.hpp header file provides the functionality of the EPL plug-in C++ API. The file is located in the include folder of your Apama installation. The file is extensively documented and is recommended as a reference to the functionality available within the definitions of the classes listed below.
The equivalent header file for the EPL plug-in C API is correlator_plugin.h. This will not explicitly be covered here, as it is broadly identical in functionality to the C++ header file. The only difference is that the functionality presented as class methods in the C++ API is presented as C functions in the C API. This file is also located in the include folder.
The C++ header defines several types. First it defines two enumerations:
AP_TypeDiscriminator - Identifies the type of the data item encapsulated by an
AP_Type “smart union” object. Its values map to EPL types.
AP_ErrorCode – Specifies the error codes that can be returned by plug-in functions that do not throw exceptions. In this release of the API, these are just the C-linkage initialization and destructor functions.
Then it defines a number of exceptions. All exception classes inherit from AP_PluginException, and they are AP_TypeException, AP_UnimplementedException, AP_BoundsException and AP_SerialisationException.
