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35 /*! \libinternal \file
37 * Declares gmx::IFileOutputRedirector.
39 * \author Teemu Murtola <teemu.murtola@gmail.com>
41 * \ingroup module_utility
43 #ifndef GMX_UTILITY_FILEREDIRECTOR_H
44 #define GMX_UTILITY_FILEREDIRECTOR_H
48 #include "gromacs/utility/textstream.h"
53 /*! \libinternal \brief
54 * Allows overriding file existence checks from code that supports it.
56 * The calling code should take in this interface and use the methods in it
57 * all file system operations that need to support this redirection.
59 * This allows tests to override the file existence checks without actually
60 * using the file system. See IFileOutputRedirector for notes on
61 * a typical usage pattern.
63 * With some further refactoring of the File class, this could also support
64 * redirecting input files from in-memory buffers as well, but for now the
65 * current capabilities are sufficient.
68 * \ingroup module_utility
70 class IFileInputRedirector
73 virtual ~IFileInputRedirector();
76 * Checks whether the provided path exists (and is a file).
78 virtual bool fileExists(const char *filename) const = 0;
80 //! Convenience method to check file existence using an std::string path.
81 bool fileExists(const std::string &filename) const
83 return fileExists(filename.c_str());
87 /*! \libinternal \brief
88 * Allows capturing `stdout` and file output from code that supports it.
90 * The calling code should take in this interface and use the stream objects
91 * it returns for all output that needs to support this redirection.
93 * Currently, the (nearly) only purpose for this interface is for unit tests to
94 * capture the file output without duplicating the knowledge of which files are
95 * actually produced. The tests can also replace actual files with in-memory
96 * streams (e.g., a StringOutputStream), and test the output without actually
97 * accessing the file system and managing actual files.
99 * As the main user for non-default implementation of this interface is tests,
100 * code using this interface generally uses a pattern where the redirector is
101 * initialized to defaultFileOutputRedirector(), and a separate setter is
102 * provided for tests to change the default. This allows code outside the
103 * tests (and outside the code actually calling the redirector) to be written
104 * as if this interface did not exist (i.e., they do not need to pass the
107 * Also, the interface only supports text files, but can be generalized if/when
108 * there is a need for binary streams (see also TextOutputStream).
111 * \ingroup module_utility
113 class IFileOutputRedirector
116 virtual ~IFileOutputRedirector();
119 * Returns a stream to use for `stdout` output.
121 virtual TextOutputStream &standardOutput() = 0;
123 * Returns a stream to use for output to a file at a given path.
125 * \param[in] filename Requested file name.
127 virtual TextOutputStreamPointer openTextOutputFile(const char *filename) = 0;
129 //! Convenience method to open a stream using an std::string path.
130 TextOutputStreamPointer openTextOutputFile(const std::string &filename)
132 return openTextOutputFile(filename.c_str());
138 * Returns default implementation for IFileInputRedirector.
140 * The returned implementation does not redirect anything, but just uses the
141 * file system normally.
145 * \ingroup module_utility
147 IFileInputRedirector &defaultFileInputRedirector();
149 * Returns default implementation for IFileOutputRedirector.
151 * The returned implementation does not redirect anything, but just opens the
152 * files at requested locations.
156 * \ingroup module_utility
158 IFileOutputRedirector &defaultFileOutputRedirector();