temporary_file.h

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#pragma once
 
#include <liboscar/utilities/temporary_file_parameters.h>
 
#include <filesystem>
#include <fstream>
 
namespace osc
{
    // `TemporaryFile` securely creates and manages a temporary file.
    //
    // The implementation guarantees that:
    //
    // - The file is created in the operating system's temporary directory, throwing otherwise.
    // - The name of the file begins with `prefix`, ends with `suffix`, and the characters
    //   between the prefix and suffix are chosen to result in a new, unique, filename, throwing
    //   otherwise.
    // - The file will be deleted from the filesystem upon destruction of the `TemporaryFile` object.
    class TemporaryFile final {
    public:
        // Constructs a `TemporaryFile` with the given parameters.
        //
        // The file is created on-disk and opened by the constructor.
        explicit TemporaryFile(const TemporaryFileParameters& = {});
        TemporaryFile(const TemporaryFile&) = delete;
        TemporaryFile(TemporaryFile&&) noexcept;
        TemporaryFile& operator=(const TemporaryFile&) = delete;
        TemporaryFile& operator=(TemporaryFile&&) noexcept;
        ~TemporaryFile() noexcept;
 
        // Returns the name of the temporary file.
        std::filesystem::path filename() const { return absolute_path_.filename(); }
 
        // Returns the absolute path to the temporary file.
        const std::filesystem::path& absolute_path() const { return absolute_path_; }
 
        // Returns the underlying stream that is connected to the temporary file.
        std::fstream& stream() { return handle_; }
 
        // Closes the handle that this `TemporaryFile` has to the underlying file, but does not delete
        // the underlying file (the destructor still deletes it, though)
        void close() { handle_.close(); }
 
    private:
        std::filesystem::path absolute_path_;
        std::fstream handle_;
        bool should_delete_ = true;
    };
}