FileTools.cpp

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#include "FileTools.h"
 
#include <spdlog/fmt/bundled/core.h>
 
#include <boost/algorithm/string/predicate.hpp>
#include <boost/endian/conversion.hpp>
#include <boost/interprocess/file_mapping.hpp>
#include <boost/interprocess/mapped_region.hpp>
#include <filesystem>
#include <fstream>
#include <typeindex>
#include <unordered_map>
 
#include "BaseLib/Logging.h"
#include "Error.h"
 
namespace
{
std::string project_directory;
 
bool project_directory_is_set = false;
}  // anonymous namespace
 
namespace BaseLib
{
bool isProjectDirectorySet()
{
    return project_directory_is_set;
}
 
bool IsFileExisting(const std::string& strFilename)
{
    return std::filesystem::exists(std::filesystem::path(strFilename));
}
 
std::tuple<std::string, std::string::size_type, std::string::size_type>
getParenthesizedString(std::string const& in,
                       char const open_char,
                       char const close_char,
                       std::string::size_type pos)
{
    auto const pos_curly_brace_open = in.find_first_of(open_char, pos);
    if (pos_curly_brace_open == std::string::npos)
    {
        return std::make_tuple("", std::string::npos, std::string::npos);
    }
    auto const pos_curly_brace_close =
        in.find_first_of(close_char, pos_curly_brace_open);
    if (pos_curly_brace_close == std::string::npos)
    {
        return std::make_tuple("", std::string::npos, std::string::npos);
    }
    return std::make_tuple(
        in.substr(pos_curly_brace_open + 1,
                  pos_curly_brace_close - (pos_curly_brace_open + 1)),
        pos_curly_brace_open, pos_curly_brace_close);
}
 
std::string containsKeyword(std::string const& str, std::string const& keyword)
{
    auto const position = str.find(keyword);
    if (position != std::string::npos)
    {
        return str.substr(0, position);
    }
    return "";
}
 
template <typename T>
bool substituteKeyword(std::string& result,
                       std::string const& parenthesized_string,
                       std::string::size_type const begin,
                       std::string::size_type const end,
                       std::string const& keyword, T& data)
{
    std::string precision_specification =
        containsKeyword(parenthesized_string, keyword);
 
    if (precision_specification.empty())
    {
        return false;
    }
 
    std::unordered_map<std::type_index, char> type_specification;
    type_specification[std::type_index(typeid(int))] = 'd';
    type_specification[std::type_index(typeid(double))] = 'f';  // default
    type_specification[std::type_index(typeid(std::string))] = 's';
 
    auto const& b = precision_specification.back();
    // see https://fmt.dev/latest/syntax/#format-specification-mini-language
    if (b == 'e' || b == 'E' || b == 'f' || b == 'F' || b == 'g' || b == 'G')
    {
        type_specification[std::type_index(typeid(double))] = b;
        precision_specification.pop_back();
    }
 
    std::string const generated_fmt_string =
        "{" + precision_specification +
        type_specification[std::type_index(typeid(data))] + "}";
    result.replace(
        begin, end - begin + 1,
        fmt::vformat(generated_fmt_string, fmt::make_format_args(data)));
 
    return true;
}
 
std::string constructFormattedFileName(std::string const& format_specification,
                                       std::string const& mesh_name,
                                       int const timestep,
                                       double const t,
                                       int const iteration)
{
    char const open_char = '{';
    char const close_char = '}';
    std::string::size_type begin = 0;
    std::string::size_type end = std::string::npos;
    std::string result = format_specification;
 
    while (begin != std::string::npos)
    {
        auto length_before_substitution = result.length();
        // find next parenthesized string
        std::string str = "";
        std::tie(str, begin, end) =
            getParenthesizedString(result, open_char, close_char, begin);
        if (!substituteKeyword(result, str, begin, end, "timestep", timestep) &&
            !substituteKeyword(result, str, begin, end, "time", t) &&
            !substituteKeyword(result, str, begin, end, "iteration", iteration))
        {
            substituteKeyword(result, str, begin, end, "meshname", mesh_name);
        }
        begin = end - (length_before_substitution - result.length());
    }
 
    return result;
}
 
double swapEndianness(double const& v)
{
    union
    {
        double v;
        char c[sizeof(double)];
    } a{}, b{};
 
    a.v = v;
    for (unsigned short i = 0; i < sizeof(double) / 2; i++)
    {
        b.c[i] = a.c[sizeof(double) / 2 - i - 1];
    }
 
    for (unsigned short i = sizeof(double) / 2; i < sizeof(double); i++)
    {
        b.c[i] = a.c[sizeof(double) + sizeof(double) / 2 - i - 1];
    }
 
    return b.v;
}
 
std::string dropFileExtension(std::string const& filename)
{
    auto const filename_path = std::filesystem::path(filename);
    return (filename_path.parent_path() / filename_path.stem()).string();
}
 
std::string extractBaseName(std::string const& pathname)
{
    return std::filesystem::path(pathname).filename().string();
}
 
std::string extractBaseNameWithoutExtension(std::string const& pathname)
{
    std::string basename = extractBaseName(pathname);
    return dropFileExtension(basename);
}
 
std::string getFileExtension(const std::string& path)
{
    return std::filesystem::path(path).extension().string();
}
 
bool hasFileExtension(std::string const& extension, std::string const& filename)
{
    return boost::iequals(extension, getFileExtension(filename));
}
 
std::string extractPath(std::string const& pathname)
{
    return std::filesystem::path(pathname).parent_path().string();
}
 
std::string joinPaths(std::string const& pathA, std::string const& pathB)
{
    return (std::filesystem::path(pathA) /= std::filesystem::path(pathB))
        .string();
}
 
std::string const& getProjectDirectory()
{
    if (!project_directory_is_set)
    {
        OGS_FATAL("The project directory has not yet been set.");
    }
    return project_directory;
}
 
void setProjectDirectory(std::string const& dir)
{
    if (project_directory_is_set)
    {
        OGS_FATAL("The project directory has already been set.");
    }
    // TODO Remove these global vars. They are a possible source of errors when
    // invoking OGS from Python multiple times within a single session.
    project_directory = dir;
    project_directory_is_set = true;
}
 
void unsetProjectDirectory()
{
    project_directory.clear();
    project_directory_is_set = false;
}
 
void removeFile(std::string const& filename)
{
    bool const success =
        std::filesystem::remove(std::filesystem::path(filename));
    if (success)
    {
        DBUG("Removed '{:s}'", filename);
    }
}
 
void removeFiles(std::vector<std::string> const& files)
{
    for (auto const& file : files)
    {
        removeFile(file);
    }
}
 
bool createOutputDirectory(std::string const& dir)
{
    if (dir.empty())
    {
        return false;
    }
 
    std::error_code mkdir_err;
    if (std::filesystem::create_directories(dir, mkdir_err))
    {
        INFO("Output directory {:s} created.", dir);
    }
    else if (mkdir_err.value() != 0)
    {
        WARN("Could not create output directory {:s}. Error code {:d}, {:s}",
             dir, mkdir_err.value(), mkdir_err.message());
        return false;
    }
    return true;
}
 
std::vector<double> readDoublesFromBinaryFile(const std::string& filename)
{
    auto prj_dir = BaseLib::getProjectDirectory();
    std::string path_to_file = BaseLib::joinPaths(prj_dir, filename);
    std::string file_extension = BaseLib::getFileExtension(filename);
    if (file_extension != ".bin")
    {
        OGS_FATAL(
            "Currently only binary files with extension '.bin' supported. The "
            "specified file has extension {:s}.",
            file_extension)
    }
    return BaseLib::readBinaryVector<double>(path_to_file);
}
 
template <typename T>
T readBinaryValue(std::istream& in)
{
    T v;
    in.read(reinterpret_cast<char*>(&v), sizeof(T));
    return v;
}
 
// explicit template instantiation
template float readBinaryValue<float>(std::istream&);
template double readBinaryValue<double>(std::istream&);
 
template <typename T>
std::vector<T> readBinaryVector(std::string const& filename,
                                std::size_t const start_element,
                                std::size_t const num_elements)
{
    if (!IsFileExisting(filename))
    {
        OGS_FATAL("File {:s} not found", filename);
    }
 
    // Determine file size
    std::uintmax_t file_size = std::filesystem::file_size(filename);
    std::size_t total_elements = file_size / sizeof(T);
 
    if (start_element >= total_elements)
    {
        OGS_FATAL("Start element is beyond file size");
    }
 
    // Calculate the number of elements to read
    std::size_t const elements_to_read =
        std::min(num_elements, total_elements - start_element);
 
    // Calculate offset and size to map
    std::size_t const offset = start_element * sizeof(T);
    std::size_t const size_to_map = elements_to_read * sizeof(T);
 
    // Create a file mapping
    boost::interprocess::file_mapping file(filename.c_str(),
                                           boost::interprocess::read_only);
 
    // Map the specified region
    boost::interprocess::mapped_region region(
        file, boost::interprocess::read_only, offset, size_to_map);
 
    // Get the address of the mapped region
    auto* addr = region.get_address();
 
    // Create vector and copy data
    std::vector<T> result(elements_to_read);
    std::memcpy(result.data(), addr, size_to_map);
 
    if constexpr (std::endian::native != std::endian::little)
    {
        boost::endian::endian_reverse_inplace(result);
    }
 
    return result;
}
 
// explicit template instantiation
template std::vector<float> readBinaryVector<float>(std::string const&,
                                                    std::size_t const,
                                                    std::size_t const);
template std::vector<double> readBinaryVector<double>(std::string const&,
                                                      std::size_t const,
                                                      std::size_t const);
 
template <typename T>
void writeValueBinary(std::ostream& out, T const& val)
{
    out.write(reinterpret_cast<const char*>(&val), sizeof(T));
}
 
// explicit template instantiation
template void writeValueBinary<std::size_t>(std::ostream&, std::size_t const&);
 
}  // end namespace BaseLib