field_io.h

#ifndef FIELD_IO_H_
#define FIELD_IO_H_
 
//////////////////////////////////////////////////////////////////////
// This file collects Field<> I/O routines
 
#include "plumbing/field.h"
 
namespace hila {
// Define this as template, in order to avoid code generation if the function is not needed -
// a bit crazy
template <typename IS, std::enable_if_t<std::is_same<IS, std::ifstream>::value, int> = 0>
bool open_input_file(const std::string &filename, IS &inputfile) {
    bool ok = true;
    if (hila::myrank() == 0) {
        inputfile.open(filename, std::ios::in | std::ios::binary);
        if (inputfile.fail()) {
            hila::out0 << "ERROR in opening file " << filename << '\n';
            ok = false;
        }
    }
    hila::broadcast(ok);
    if (!ok)
        hila::terminate(5);
 
    return ok;
}
 
template <typename OS, std::enable_if_t<std::is_same<OS, std::ofstream>::value, int> = 0>
bool open_output_file(const std::string &filename, OS &outputfile, bool binary = true,
                      int precision = 8) {
    bool ok = true;
    if (hila::myrank() == 0) {
        std::ios::openmode mode = std::ios::out | std::ios::trunc;
        if (binary)
            mode |= std::ios::binary;
 
        outputfile.open(filename, mode);
        outputfile.precision(precision);
        if (outputfile.fail()) {
            hila::out0 << "ERROR in opening file " << filename << '\n';
            ok = false;
        }
    }
    hila::broadcast(ok);
    if (!ok)
        hila::terminate(4);
 
    return ok;
}
 
 
template <typename S, std::enable_if_t<std::is_same<S, std::ofstream>::value ||
                                           std::is_same<S, std::ifstream>::value,
                                       int> = 0>
bool close_file(const std::string &filename, S &fstream) {
    bool error = false;
    if (hila::myrank() == 0) {
        fstream.close();
        if (fstream.fail()) {
            hila::out0 << "ERROR in reading/writing file " << filename << '\n';
            error = true;
        }
    }
    hila::broadcast(error);
 
    if (error)
        hila::terminate(3);
 
    return !error;
}
 
} // namespace hila
 
//////////////////////////////////////////////////////////////////////////////////
 
/// Write the field to a file stream
template <typename T>
void Field<T>::write(std::ofstream &outputfile, bool binary, int precision) const {
    constexpr size_t sites_per_write = WRITE_BUFFER_SIZE / sizeof(T);
    constexpr size_t write_size = sites_per_write * sizeof(T);
 
    if (!binary)
        outputfile.precision(precision);
 
    std::vector<CoordinateVector> coord_list(sites_per_write);
    T *buffer = (T *)memalloc(write_size);
    CoordinateVector size = lattice.size();
 
    for (size_t i = 0; i < lattice.volume(); i += sites_per_write) {
        size_t sites = std::min(sites_per_write, lattice.volume() - i);
        for (size_t j = 0; j < sites; j++)
            coord_list[j] = lattice.global_coordinates(i + j);
 
        if (sites < sites_per_write)
            coord_list.resize(sites);
 
        fs->gather_elements(buffer, coord_list);
        if (hila::myrank() == 0) {
            if (binary) {
                outputfile.write((char *)buffer, sites * sizeof(T));
            } else {
                for (size_t j = 0; j < sites; j++) {
                    outputfile << buffer[j] << '\n';
                }
            }
        }
    }
 
    std::free(buffer);
}
 
/// Write the Field to a named file replacing the file
template <typename T>
void Field<T>::write(const std::string &filename, bool binary, int precision) const {
    std::ofstream outputfile;
    hila::open_output_file(filename, outputfile, binary);
    write(outputfile, binary, precision);
    hila::close_file(filename, outputfile);
}
 
/// Write a list of fields into an output stream
template <typename T>
static void write_fields(std::ofstream &outputfile, Field<T> &last) {
    last.write(outputfile);
}
 
template <typename T, typename... fieldtypes>
static void write_fields(std::ofstream &outputfile, Field<T> &next, fieldtypes &...fields) {
    next.write(outputfile);
    write_fields(outputfile, fields...);
}
 
/// Write a list of fields to a file
template <typename... fieldtypes>
static void write_fields(const std::string &filename, fieldtypes &...fields) {
    std::ofstream outputfile;
    hila::open_output_file(filename, outputfile);
    write_fields(outputfile, fields...);
    hila::close_file(filename, outputfile);
}
 
/////////////////////////////////////////////////////////////////////////////////
 
/// Read the Field from a stream
template <typename T>
void Field<T>::read(std::ifstream &inputfile) {
    constexpr size_t sites_per_read = WRITE_BUFFER_SIZE / sizeof(T);
    constexpr size_t read_size = sites_per_read * sizeof(T);
 
    if (!this->is_allocated())
        this->allocate();
 
    mark_changed(ALL);
 
    std::vector<CoordinateVector> coord_list(sites_per_read);
    T *buffer = (T *)memalloc(read_size);
    CoordinateVector size = lattice.size();
 
    for (size_t i = 0; i < lattice.volume(); i += sites_per_read) {
        size_t sites = std::min(sites_per_read, lattice.volume() - i);
        for (size_t j = 0; j < sites; j++)
            coord_list[j] = lattice.global_coordinates(i + j);
 
        if (sites < sites_per_read)
            coord_list.resize(sites);
 
        if (hila::myrank() == 0)
            inputfile.read((char *)buffer, sites * sizeof(T));
 
        fs->scatter_elements(buffer, coord_list);
    }
 
    std::free(buffer);
}
 
// Read Field contents from the beginning of a file
template <typename T>
void Field<T>::read(const std::string &filename) {
    std::ifstream inputfile;
    hila::open_input_file(filename, inputfile);
    read(inputfile);
    hila::close_file(filename, inputfile);
}
 
// Read a list of fields from an input stream
template <typename T>
static void read_fields(std::ifstream &inputfile, Field<T> &last) {
    last.read_from_stream(inputfile);
}
 
template <typename T, typename... fieldtypes>
static void read_fields(std::ifstream &inputfile, Field<T> &next, fieldtypes &...fields) {
    next.read_from_stream(inputfile);
    read_fields(inputfile, fields...);
}
 
// Read a list of fields from a file
template <typename... fieldtypes>
static void read_fields(const std::string &filename, fieldtypes &...fields) {
    std::ifstream inputfile;
    hila::open_input_file(filename, inputfile);
    read_fields(inputfile, fields...);
    hila::close_file(filename, inputfile);
}
 
 
///////////////////////////////////////////////////////////////////////////////
 
/// Write a "subspace" of the original lattice
/// Each element is written on a single line
/// TODO: more formatting?
 
template <typename T>
void Field<T>::write_subvolume(std::ofstream &outputfile, const CoordinateVector &cmin,
                               const CoordinateVector &cmax, int precision) const {
 
    constexpr size_t sites_per_write = WRITE_BUFFER_SIZE / sizeof(T);
 
    size_t sites = 1;
    int line_len = 1; // number of elements on 1st non-trivial dimension
    foralldir(d) {
        assert(cmin[d] >= 0 && cmax[d] >= cmin[d] && cmax[d] < lattice.size(d) &&
               "subvolume size mismatch");
        sites *= cmax[d] - cmin[d] + 1;
 
        if (line_len == 1)
            line_len = sites;
    }
 
    size_t n_write = std::min(sites_per_write, sites);
 
    std::vector<CoordinateVector> coord_list(n_write);
    T *buffer = (T *)memalloc(n_write * sizeof(T));
 
    CoordinateVector c;
 
    size_t i = 0, j = 0;
 
    if (hila::myrank() == 0) {
        outputfile.precision(precision);
    }
 
    forcoordinaterange(c, cmin, cmax) {
        coord_list[i] = c;
        i++;
        j++;
        if (i == n_write || j == sites) {
            if (i < n_write)
                coord_list.resize(i);
 
            fs->gather_elements(buffer, coord_list);
 
            if (hila::myrank() == 0) {
                for (size_t k = 0; k < i; k++) {
                    for (int l = 0; l < sizeof(T) / sizeof(hila::arithmetic_type<T>); l++) {
                        outputfile << hila::get_number_in_var(buffer[k], l) << ' ';
                    }
                    outputfile << '\n';
                }
            }
            i = 0;
        }
    }
}
 
 
template <typename T>
void Field<T>::write_subvolume(const std::string &filename, const CoordinateVector &cmin,
                               const CoordinateVector &cmax, int precision) const {
 
    std::ofstream out;
    hila::open_output_file(filename, out, false);
    write_subvolume(out, cmin, cmax, precision);
    hila::close_file(filename, out);
}
 
// Write a subspace (slice) of the original lattice.  Here
// slice[d] = fixed coordinate value, or < 0: run the dimension through.
// For example, slice = {5,2,-1,0}; prints the line along z-axis at (x,y,t) = (5,2,0)
// Outf is either filename or ofstream
 
template <typename T>
template <typename outf_type>
void Field<T>::write_slice(outf_type &outf, const CoordinateVector &slice, int precision) const {
 
    static_assert(std::is_same<outf_type, std::string>::value ||
                      std::is_same<outf_type, std::ofstream>::value,
                  "file name / output stream argument in write_slice()?");
 
    CoordinateVector cmin, cmax;
    foralldir(d) {
        if (slice[d] < 0) {
            cmin[d] = 0;
            cmax[d] = lattice.size(d) - 1;
        } else {
            cmin[d] = cmax[d] = slice[d];
        }
    }
    write_subvolume(outf, cmin, cmax, precision);
}
 
 
#endif