PluginFunction.hpp

//
// Copyright (c) 2004-2017 Cloud Software Group, Inc. All rights reserved.
//

#ifndef STREAMBASE_PLUGIN_FUNCTION_H
#define STREAMBASE_PLUGIN_FUNCTION_H

#include "StreamBase.hpp"
#include "StreamBaseVersion.hpp"

#include "Plugin.hpp"
#include "DataType.hpp"
#include "PluginException.hpp"
#include "PluginRegistry.hpp"

SB_NAMESPACE_BEGIN;

class PluginFunctionRep;

/// A plugin function.
class SB_EXPORT PluginFunction : public Plugin {
  public:
    virtual ~PluginFunction() {}

    /// Check to make sure the argument types are valid for this
    /// function.
    /// @param arg_types The types of the arguments to this function.
    /// @throw TypecheckException if the argument types are not
    /// appropriate.
    virtual void typecheck(const Schema &arg_types) {}

    /// Evaluate this function over the arguments and place the return
    /// value in retval.
    /// @param retval Value where the output of this function should
    /// be placed. Its type will match the type returned from the
    /// typecheck method.
    /// @param args Values corresponding to the arguments. Their types
    /// will match the types passed to typecheck.
    /// @throw PluginEvalException if anything goes wrong.
    virtual void eval(Tuple &retval, Tuple &args) = 0;
};

#ifndef DOXYGEN_SKIP
typedef PluginRegistryInfo<PluginFunction> PluginFunctionRegistryInfo;

void SB_EXPORT plugin_function_callback(const PluginFunctionRegistryInfo &info);

template<>
struct PluginRegistryCallback<PluginFunctionRegistryInfo> {
    void operator()(const PluginFunctionRegistryInfo &info)
    {
        plugin_function_callback(info);
    }
};

typedef PluginRegistryCallback<PluginFunctionRegistryInfo> PluginFunctionRegistryCallback;

typedef PluginRegistry<PluginFunction,
                       PluginFunctionRegistryInfo,
                       PluginFunctionRegistryCallback> PluginFunctionRegistry;

#ifdef WIN32
// See PluginAggregate.hpp for a description of why this is here...

#ifndef STREAMBASE_PLUGIN_VERSION_DEFINED
#define STREAMBASE_PLUGIN_VERSION_DEFINED
// this function is used to determine what streambase version the plugin was compiled against
extern "C" __declspec( dllexport ) inline const char*streambase_plugin_version() {return ((char *)&StreamBaseVersion::INFO_LINE);}
#endif

class SB_EXPORT PluginRegistryFunction {
    public:
        static bool Add(PluginRegistry<PluginFunction, PluginRegistryInfo<PluginFunction>, PluginRegistryCallback< PluginRegistryInfo<PluginFunction> > >::Info* streambase_plugin_info) {
            return (PluginRegistry<PluginFunction>::get().add(*streambase_plugin_info), true);
        }
};

#define STREAMBASE_DEFINE_PLUGIN_FUNCTION(ClassName, FuncName) \
    const SimplePluginRegistryInfo<PluginFunction, ClassName> ClassName::_streambase_plugin_info(FuncName); \
    bool ClassName::_streambase_plugin_registered= \
    PluginRegistryFunction::Add((PluginRegistryInfo<PluginFunction>*)&(ClassName::_streambase_plugin_info));

#define STREAMBASE_DECLARE_PLUGIN_FUNCTION(ClassName) \
    public: \
        static const SimplePluginRegistryInfo<PluginFunction, ClassName> _streambase_plugin_info; \
        static bool _streambase_plugin_registered;

#else
#define STREAMBASE_DECLARE_PLUGIN_FUNCTION(ClassName) \
    STREAMBASE_DECLARE_PLUGIN_REG_CLASS(PluginFunction, ClassName)

#define STREAMBASE_DEFINE_PLUGIN_FUNCTION(ClassName, FuncName) \
    STREAMBASE_DEFINE_PLUGIN_REG_CLASS_WITH_KEY(PluginFunction, ClassName, FuncName)
#endif

#endif // !defined(DOXYGEN_SKIP)

SB_NAMESPACE_END;
#endif //PLUGIN_FUNCTION_H