io/CFileGZOutputStream.h

Go to the documentation of this file.

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */
#pragma once

#include <mrpt/core/optional_ref.h>
#include <mrpt/core/pimpl.h>
#include <mrpt/io/CStream.h>

namespace mrpt::io
{
/** Saves data to a file and transparently compress the data using the given
 * compression level.
 *   The generated files are in gzip format ("file.gz").
 *  This class requires compiling MRPT with wxWidgets. If wxWidgets is not
 * available then the class is actually mapped to the standard CFileOutputStream
 *
 * \sa CFileOutputStream
 * \ingroup mrpt_io_grp
 */
class CFileGZOutputStream : public CStream
{
   private:
    struct Impl;
    mrpt::pimpl<Impl> m_f;

   public:
    /** Constructor: opens an output file with compression level = 1 (minimum,
     * fastest).
     * \param fileName The file to be open in this stream
     * \sa open
     */
    CFileGZOutputStream(const std::string& fileName);

    /** Constructor, without opening the file.
     * \sa open
     */
    CFileGZOutputStream();

    CFileGZOutputStream(const CFileGZOutputStream&) = delete;
    CFileGZOutputStream& operator=(const CFileGZOutputStream&) = delete;

    /** Destructor */
    ~CFileGZOutputStream() override;

    /** Open a file for write, choosing the compression level
     * \param fileName The file to be open in this stream
     * \param compress_level 0:no compression, 1:fastest, 9:best
     * \return true on success, false on any error.
     */
    bool open(
        const std::string& fileName, int compress_level = 1,
        mrpt::optional_ref<std::string> error_msg = std::nullopt);
    /** Close the file */
    void close();
    /** Returns true if the file was open without errors. */
    bool fileOpenCorrectly() const;
    /** Returns true if the file was open without errors. */
    bool is_open() { return fileOpenCorrectly(); }
    /** Method for getting the current cursor position, where 0 is the first
     * byte and TotalBytesCount-1 the last one. */
    uint64_t getPosition() const override;

    /** This method is not implemented in this class */
    uint64_t Seek(int64_t, CStream::TSeekOrigin = sFromBeginning) override;
    /** This method is not implemented in this class */
    uint64_t getTotalBytesCount() const override;
    size_t Read(void* Buffer, size_t Count) override;
    size_t Write(const void* Buffer, size_t Count) override;
};  // End of class def.
static_assert(
    !std::is_copy_constructible_v<CFileGZOutputStream> &&
        !std::is_copy_assignable_v<CFileGZOutputStream>,
    "Copy Check");
}  // namespace mrpt::io