teca_programmable_reduce.h

#ifndef teca_programmable_reduce_h
#define teca_programmable_reduce_h
 
#include "teca_programmable_reduce_fwd.h"
#include "teca_programmable_algorithm_fwd.h"
#include "teca_index_reduce.h"
#include "teca_dataset_fwd.h"
#include "teca_metadata.h"
 
#include <string>
#include <vector>
 
// callbacks implement a user defined reduction over time steps
class teca_programmable_reduce : public teca_index_reduce
{
public:
    TECA_ALGORITHM_STATIC_NEW(teca_programmable_reduce)
    TECA_ALGORITHM_DELETE_COPY_ASSIGN(teca_programmable_reduce)
    ~teca_programmable_reduce(){}
 
    // set the implementation name, this is used in logging to
    // identify the specific instance of programmable redeuce
    int set_name(const std::string &name);
 
    const char *get_class_name() const override
    { return this->class_name; }
 
    // set the callback that initializes the output metadata during
    // report phase of the pipeline. The callback must be a callable
    // with the signature:
    //
    // teca_metadata report_callback(unsigned int port,
    //    const std::vector<teca_metadata> &input_md);
    //
    // the default implementation forwards downstream
    TECA_ALGORITHM_CALLBACK_PROPERTY(report_callback_t, report_callback)
 
    // set the callback that initializes the upstream request.
    // The callback must be a callable with the signature:
    //
    // std::vector<teca_metadata> request(
    //    unsigned int port, const std::vector<teca_metadata> &input_md,
    //    const teca_metadata &request) override;
    //
    // the default implementation forwards upstream
    TECA_ALGORITHM_CALLBACK_PROPERTY(request_callback_t, request_callback)
 
    // set the callback that performs the reduction on 2 datasets
    // returning the reduced dataset. The callback must be a callable
    // with the signature:
    //
    // p_teca_dataset reduce(const const_p_teca_dataset &left,
    //    const const_p_teca_dataset &right);
    //
    // the default implementation returns a nullptr
    TECA_ALGORITHM_CALLBACK_PROPERTY(reduce_callback_t, reduce_callback)
 
    // set the callback that finalizes the reduction.
    // The callback must be a callable with the signature:
    //
    // p_teca_dataset reduce(const const_p_teca_dataset &ds);
    //
    // the default implementation passes the input dataset
    // through
    TECA_ALGORITHM_CALLBACK_PROPERTY(finalize_callback_t, finalize_callback)
 
protected:
    teca_programmable_reduce();
 
    // overrides
    p_teca_dataset reduce(const const_p_teca_dataset &left,
        const const_p_teca_dataset &right) override;
 
    p_teca_dataset finalize(const const_p_teca_dataset &input) override;
 
    std::vector<teca_metadata> initialize_upstream_request(
        unsigned int port, const std::vector<teca_metadata> &input_md,
        const teca_metadata &request) override;
 
    teca_metadata initialize_output_metadata(unsigned int port,
        const std::vector<teca_metadata> &input_md) override;
 
private:
    reduce_callback_t reduce_callback;
    finalize_callback_t finalize_callback;
    request_callback_t request_callback;
    report_callback_t report_callback;
    char class_name[64];
};
 
#endif