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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/path.h"
49 #include "gromacs/utility/textstream.h"
54 /*! \libinternal \brief
55 * Allows overriding file existence checks from code that supports it.
57 * The calling code should take in this interface and use the methods in it
58 * all file system operations that need to support this redirection.
60 * This allows tests to override the file existence checks without actually
61 * using the file system. See IFileOutputRedirector for notes on
62 * a typical usage pattern.
64 * With some further refactoring of the File class, this could also support
65 * redirecting input files from in-memory buffers as well, but for now the
66 * current capabilities are sufficient.
69 * \ingroup module_utility
71 class IFileInputRedirector
74 virtual ~IFileInputRedirector();
77 * Checks whether the provided path exists (and is a file).
79 * The \p onNotFound can be used to influence the behavior on error
80 * conditions. Functions to pass as this parameter are provided as
81 * members of gmx::File.
83 virtual bool fileExists(const char* filename, File::NotFoundHandler onNotFound) const = 0;
85 //! Convenience method to check file existence using an std::string path.
86 bool fileExists(const std::string& filename, File::NotFoundHandler onNotFound) const
88 return fileExists(filename.c_str(), onNotFound);
92 /*! \libinternal \brief
93 * Allows capturing `stdout` and file output from code that supports it.
95 * The calling code should take in this interface and use the stream objects
96 * it returns for all output that needs to support this redirection.
98 * Currently, the (nearly) only purpose for this interface is for unit tests to
99 * capture the file output without duplicating the knowledge of which files are
100 * actually produced. The tests can also replace actual files with in-memory
101 * streams (e.g., a StringOutputStream), and test the output without actually
102 * accessing the file system and managing actual files.
104 * As the main user for non-default implementation of this interface is tests,
105 * code using this interface generally uses a pattern where the redirector is
106 * initialized to defaultFileOutputRedirector(), and a separate setter is
107 * provided for tests to change the default. This allows code outside the
108 * tests (and outside the code actually calling the redirector) to be written
109 * as if this interface did not exist (i.e., they do not need to pass the
112 * Also, the interface only supports text files, but can be generalized if/when
113 * there is a need for binary streams (see also TextOutputStream).
116 * \ingroup module_utility
118 class IFileOutputRedirector
121 virtual ~IFileOutputRedirector();
124 * Returns a stream to use for `stdout` output.
126 virtual TextOutputStream& standardOutput() = 0;
128 * Returns a stream to use for output to a file at a given path.
130 * \param[in] filename Requested file name.
132 virtual TextOutputStreamPointer openTextOutputFile(const char* filename) = 0;
134 //! Convenience method to open a stream using an std::string path.
135 TextOutputStreamPointer openTextOutputFile(const std::string& filename)
137 return openTextOutputFile(filename.c_str());
143 * Returns default implementation for IFileInputRedirector.
145 * The returned implementation does not redirect anything, but just uses the
146 * file system normally.
150 * \ingroup module_utility
152 IFileInputRedirector& defaultFileInputRedirector();
154 * Returns default implementation for IFileOutputRedirector.
156 * The returned implementation does not redirect anything, but just opens the
157 * files at requested locations.
161 * \ingroup module_utility
163 IFileOutputRedirector& defaultFileOutputRedirector();