src/gromacs/utility/filestream.h

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
   3  *
   4  * Copyright (c) 2015,2018, by the GROMACS development team, led by
   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
   6  * and including many others, as listed in the AUTHORS file in the
   7  * top-level source directory and at http://www.gromacs.org.
   8  *
   9  * GROMACS is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public License
  11  * as published by the Free Software Foundation; either version 2.1
  12  * of the License, or (at your option) any later version.
  13  *
  14  * GROMACS is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with GROMACS; if not, see
  21  * http://www.gnu.org/licenses, or write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA.
  23  *
  24  * If you want to redistribute modifications to GROMACS, please
  25  * consider that scientific software is very special. Version
  26  * control is crucial - bugs must be traceable. We will be happy to
  27  * consider code for inclusion in the official distribution, but
  28  * derived work must not be called official GROMACS. Details are found
  29  * in the README & COPYING files - if they are missing, get the
  30  * official version at http://www.gromacs.org.
  31  *
  32  * To help us fund GROMACS development, we humbly ask that you cite
  33  * the research papers on the package. Check out http://www.gromacs.org.
  34  */
  35 /*! \libinternal \file
  36  * \brief
  37  * Declares implementations for textstream.h interfaces for file input/output.
  38  *
  39  * \author Teemu Murtola <teemu.murtola@gmail.com>
  40  * \inlibraryapi
  41  * \ingroup module_utility
  42  */
  43 #ifndef GMX_UTILITY_FILESTREAM_H
  44 #define GMX_UTILITY_FILESTREAM_H
  45
  46 #include <cstdio>
  47
  48 #include <string>
  49
  50 #include "gromacs/utility/classhelpers.h"
  51 #include "gromacs/utility/fileptr.h"
  52 #include "gromacs/utility/textstream.h"
  53
  54 namespace gmx
  55 {
  56
  57 namespace internal
  58 {
  59 class FileStreamImpl;
  60 }
  61
  62 /*! \libinternal \brief
  63  * Text input stream implementation for reading from `stdin`.
  64  *
  65  * Implementations for the TextInputStream methods throw FileIOError on any
  66  * I/O error.
  67  *
  68  * \inlibraryapi
  69  * \ingroup module_utility
  70  */
  71 class StandardInputStream : public TextInputStream
  72 {
  73     public:
  74         /*! \brief
  75          * Returns whether `stdin` is an interactive terminal.
  76          *
  77          * Only works on Unix, otherwise always returns true.
  78          *
  79          * Does not throw.
  80          */
  81         bool isInteractive() const;
  82
  83         // From TextInputStream
  84         bool readLine(std::string *line) override;
  85         void close() override {}
  86
  87         /*! \brief
  88          * Returns a stream for accessing `stdin`.
  89          *
  90          * Does not throw.
  91          */
  92         static StandardInputStream &instance();
  93 };
  94
  95 /*! \libinternal \brief
  96  * Text input stream implementation for reading from a file.
  97  *
  98  * Implementations for the TextInputStream methods throw FileIOError on any
  99  * I/O error.
 100  *
 101  * \inlibraryapi
 102  * \ingroup module_utility
 103  */
 104 class TextInputFile : public TextInputStream
 105 {
 106     public:
 107         /*! \brief
 108          * Opens a file and returns an RAII-style `FILE` handle.
 109          *
 110          * \param[in] filename  Path of the file to open.
 111          * \throws    FileIOError on any I/O error.
 112          *
 113          * Instead of returning `NULL` on errors, throws an exception with
 114          * additional details (including the file name and `errno`).
 115          */
 116         static FilePtr openRawHandle(const char *filename);
 117         //! \copydoc openRawHandle(const char *)
 118         static FilePtr openRawHandle(const std::string &filename);
 119
 120         /*! \brief
 121          * Opens a text file as a stream.
 122          *
 123          * \param[in]  filename  Path to the file to open.
 124          * \throws     std::bad_alloc if out of memory.
 125          * \throws     FileIOError on any I/O error.
 126          */
 127         explicit TextInputFile(const std::string &filename);
 128         /*! \brief
 129          * Initializes file object from an existing file handle.
 130          *
 131          * \param[in]  fp     File handle to use.
 132          * \throws     std::bad_alloc if out of memory.
 133          *
 134          * The caller is responsible of closing the file; close() does nothing
 135          * for an object constructed this way.
 136          */
 137         explicit TextInputFile(FILE *fp);
 138         ~TextInputFile() override;
 139
 140         /*! \brief
 141          * Returns a raw handle to the input file.
 142          *
 143          * This is provided for interoperability with older C-like code.
 144          */
 145         FILE *handle();
 146
 147         // From TextInputStream
 148         bool readLine(std::string *line) override;
 149         void close() override;
 150
 151     private:
 152         PrivateImplPointer<internal::FileStreamImpl> impl_;
 153 };
 154
 155 /*! \libinternal \brief
 156  * Text output stream implementation for writing to a file.
 157  *
 158  * Implementations for the TextOutputStream methods throw FileIOError on any
 159  * I/O error.
 160  *
 161  * \inlibraryapi
 162  * \ingroup module_utility
 163  */
 164 class TextOutputFile : public TextOutputStream
 165 {
 166     public:
 167         //! \copydoc TextInputFile::TextInputFile(const std::string &)
 168         explicit TextOutputFile(const std::string &filename);
 169         //! \copydoc TextInputFile::TextInputFile(FILE *)
 170         explicit TextOutputFile(FILE *fp);
 171         ~TextOutputFile() override;
 172
 173         // From TextOutputStream
 174         void write(const char *text) override;
 175         void close() override;
 176
 177         /*! \brief
 178          * Returns a stream for accessing `stdout`.
 179          *
 180          * \throws    std::bad_alloc if out of memory (only on first call).
 181          */
 182         static TextOutputFile &standardOutput();
 183         /*! \brief
 184          * Returns a stream for accessing `stderr`.
 185          *
 186          * \throws    std::bad_alloc if out of memory (only on first call).
 187          */
 188         static TextOutputFile &standardError();
 189
 190     private:
 191         PrivateImplPointer<internal::FileStreamImpl> impl_;
 192 };
 193
 194 } // namespace gmx
 195
 196 #endif