ImageLoader.cpp

//
// Created by Arkadiy on 20/03/2016.
//

#include <assert.h>
#include <regex>
#include <iomanip>
#include <sstream>
#include <future>
#include <iostream>
#include "ImageLoader.h"
//#include "cbf.h"
#include "CBFDataReader.h"
#include "Hdf5HelperFuncitons.h"

ImageLoader::ImageLoader(ReconstructionParameters par) :
    current_frame_number(par.first_image),
    filename_template(par.data_filename_template),
    last_frame_number(par.last_image),
    frame_increment(par.frame_increment),
    mask_is_defined(false)
{
    //get file size
    CBFDataReader first_frame(current_frame_filename());
    current_frame_number-=frame_increment;

    //allocate memory
    m_dim1=first_frame.dim1();
    m_dim2=first_frame.dim2();

    data = (int *)malloc(sizeof(int)*m_dim1*m_dim2);
    buffer = (int *)malloc(sizeof(int)*m_dim1*m_dim2); //Tick-tock buffer.

    if(par.mask_filename != "") {
        // load mask
        if(!file_exists(par.mask_filename)) {
            throw FileNotFound(par.mask_filename);
        }

        H5File file(par.mask_filename, H5F_ACC_RDONLY);
        auto sz = getDatasetDimensions(file, "data");
        if(sz[0]!=m_dim2 || sz[1]!=m_dim1) {
            std::stringstream message;
            message << "Error with input mask dimensions. Expected " << m_dim1 << "x" << m_dim2 << " found " << sz[0] <<"x" << sz[1] << "." << endl;
            throw MaskError(message.str());
        }
        mask = readVector<int>(file, "data");
        mask_is_defined = true;
    }

    load_frame_to_buffer();
}

void ImageLoader::load_frame_to_buffer() {
    next_frame_f = async(launch::async, //async|deferred
            [=](int current_frame_number)
            {
                CBFDataReader frame(format_template(filename_template, current_frame_number + frame_increment));
                assert(frame.dim1() == ny() and frame.dim2() == nx());
                frame.read_data(buffer);
    }, current_frame_number);
}

template <typename T>
void swap_a_for_b(T& a, T& b) {
    T t=a;
    a=b;
    b=t;
}


// TODO: check this works with stepping over some frames
bool ImageLoader::load_next_frame() {
    current_frame_number+=frame_increment;
    if (current_frame_number > last_frame_number)
        return false;

    next_frame_f.get();
    swap_a_for_b(data, buffer);

    if (current_frame_number+frame_increment <= last_frame_number)
        load_frame_to_buffer();

    return true;
}