fromfile.hpp

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#pragma once
 
#include <filesystem>
#include <fstream>
#include <memory>
#include <sstream>
#include <string>
 
#include "NumCpp/Core/Internal/Error.hpp"
#include "NumCpp/Core/Internal/StaticAsserts.hpp"
#include "NumCpp/Core/Types.hpp"
#include "NumCpp/Functions/fromstring.hpp"
#include "NumCpp/NdArray.hpp"
 
namespace nc
{
    //============================================================================
    // Method Description:
    template<typename dtype>
    NdArray<dtype> fromfile(const std::string& inFilename)
    {
        if (!std::filesystem::exists(inFilename))
        {
            THROW_INVALID_ARGUMENT_ERROR("input filename does not exist.\n\t" + inFilename);
        }
 
        // read in as binary file
        std::ifstream file(inFilename.c_str(), std::ios::in | std::ios::binary);
        if (!file.is_open())
        {
            THROW_INVALID_ARGUMENT_ERROR("unable to open file\n\t" + inFilename);
        }
 
        file.seekg(0, std::ifstream::end);
        const auto fileSize = static_cast<uint64>(file.tellg());
        file.seekg(0, std::ifstream::beg);
 
        std::vector<char> fileBuffer;
        fileBuffer.reserve(fileSize);
        file.read(fileBuffer.data(), fileSize);
 
        if (file.bad() || file.fail())
        {
            THROW_INVALID_ARGUMENT_ERROR("error occured while reading the file\n");
        }
 
        file.close();
 
        NdArray<dtype> returnArray(reinterpret_cast<dtype*>(fileBuffer.data()), fileSize / sizeof(dtype));
 
        return returnArray;
    }
 
    //============================================================================
    // Method Description:
    template<typename dtype>
    NdArray<dtype> fromfile(const std::string& inFilename, const char inSep)
    {
        std::ifstream file(inFilename.c_str());
        if (!file.is_open())
        {
            THROW_INVALID_ARGUMENT_ERROR("unable to open file\n\t" + inFilename);
        }
 
        std::stringstream buffer;
        buffer << file.rdbuf();
        file.close();
 
        return fromstring<dtype>(buffer.str(), inSep);
    }
} // namespace nc