src/gromacs/utility/textwriter.h

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  35 /*! \libinternal \file
  36  * \brief
  37  * Declares gmx::TextWriter.
  38  *
  39  * \author Teemu Murtola <teemu.murtola@gmail.com>
  40  * \inlibraryapi
  41  * \ingroup module_utility
  42  */
  43 #ifndef GMX_UTILITY_TEXTWRITER_H
  44 #define GMX_UTILITY_TEXTWRITER_H
  45
  46 #include <cstdio>
  47
  48 #include <string>
  49
  50 #include "gromacs/utility/classhelpers.h"
  51 #include "gromacs/utility/textstream.h"
  52
  53 namespace gmx
  54 {
  55
  56 class TextLineWrapperSettings;
  57
  58 /*! \libinternal \brief
  59  * Writes text into a TextOutputStream.
  60  *
  61  * This class provides more formatting and line-oriented writing capabilities
  62  * than writing raw strings into the stream.
  63  *
  64  * All methods that write to the stream can throw any exceptions that the
  65  * underlying stream throws.
  66  *
  67  * \inlibraryapi
  68  * \ingroup module_utility
  69  */
  70 class TextWriter
  71 {
  72     public:
  73         /*! \brief
  74          * Convenience method for writing a file from a string in a single call.
  75          *
  76          * \param[in] filename  Name of the file to read.
  77          * \param[in] text      String to write to \p filename.
  78          * \throws    std::bad_alloc if out of memory.
  79          * \throws    FileIOError on any I/O error.
  80          *
  81          * If \p filename exists, it is overwritten.
  82          */
  83         static void writeFileFromString(const std::string &filename,
  84                                         const std::string &text);
  85
  86         /*! \brief
  87          * Creates a writer that writes to specified file.
  88          *
  89          * \param[in]  filename  Path to the file to open.
  90          * \throws     std::bad_alloc if out of memory.
  91          * \throws     FileIOError on any I/O error.
  92          *
  93          * This constructor is provided for convenience for writing directly to
  94          * a file, without the need to construct multiple objects.
  95          */
  96         explicit TextWriter(const std::string &filename);
  97         /*! \brief
  98          * Creates a writer that writes to specified file.
  99          *
 100          * \param[in]  fp  File handle to write to.
 101          * \throws     std::bad_alloc if out of memory.
 102          * \throws     FileIOError on any I/O error.
 103          *
 104          * This constructor is provided for interoperability with C-like code
 105          * for writing directly to an already opened file, without the need to
 106          * construct multiple objects.
 107          *
 108          * The caller is responsible of closing \p fp; it is not allowed to
 109          * call close() on the writer.
 110          */
 111         explicit TextWriter(FILE *fp);
 112         /*! \brief
 113          * Creates a writer that writes to specified stream.
 114          *
 115          * \param[in]  stream  Stream to write to.
 116          * \throws     std::bad_alloc if out of memory.
 117          *
 118          * The caller is responsible of the lifetime of the stream (should
 119          * remain in existence as long as the writer exists).
 120          *
 121          * This constructor is provided for convenience for cases where the
 122          * stream is not allocated with `new` and/or not managed by a
 123          * std::shared_ptr (e.g., if the stream is an object on the stack).
 124          */
 125         explicit TextWriter(TextOutputStream *stream);
 126         /*! \brief
 127          * Creates a writer that writes to specified stream.
 128          *
 129          * \param[in]  stream  Stream to write to.
 130          * \throws     std::bad_alloc if out of memory.
 131          *
 132          * The writer keeps a reference to the stream, so the caller can pass
 133          * in a temporary if necessary.
 134          */
 135         explicit TextWriter(const TextOutputStreamPointer &stream);
 136         ~TextWriter();
 137
 138         /*! \brief
 139          * Allows adjusting wrapping settings for the writer.
 140          *
 141          * \todo
 142          * Wrapping is not currently implemented for code that writes partial
 143          * lines with writeString().
 144          */
 145         TextLineWrapperSettings &wrapperSettings();
 146
 147         /*! \brief
 148          * Writes a string to the stream.
 149          *
 150          * \param[in]  str  String to write.
 151          */
 152         void writeString(const char *str);
 153         //! \copydoc writeString(const char *)
 154         void writeString(const std::string &str);
 155         /*! \brief
 156          * Writes a line to the stream.
 157          *
 158          * \param[in]  line  Line to write.
 159          *
 160          * If \p line does not end in a newline, one newline is appended.
 161          * Otherwise, works as writeString().
 162          */
 163         void writeLine(const char *line);
 164         //! \copydoc writeLine(const char *)
 165         void writeLine(const std::string &line);
 166         //! Writes a newline to the stream.
 167         void writeLine();
 168
 169         /*! \brief
 170          * Writes a newline if previous output did not end in one.
 171          *
 172          * If nothing has been written using the writer, this method does
 173          * nothing.
 174          */
 175         void ensureLineBreak();
 176         /*! \brief
 177          * Ensures that the next string written starts after an empty line.
 178          *
 179          * Always terminates the current line (as with ensureLineBreak()), but
 180          * the empty line is only written out when the next line is written,
 181          * so that trailing newlines after final output can be avoided.
 182          *
 183          * If nothing has been written using the writer, this method does
 184          * nothing.
 185          */
 186         void ensureEmptyLine();
 187
 188         /*! \brief
 189          * Closes the underlying stream.
 190          */
 191         void close();
 192
 193     private:
 194         class Impl;
 195
 196         PrivateImplPointer<Impl> impl_;
 197 };
 198
 199 } // namespace gmx
 200
 201 #endif