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bdca8b01d2
#pragma once is a widely supported compiler pragma, even though it is not part of the C++ standard. Many of the issues keeping #pragma once from being standardized (distributed filesystems, build farms, hard links, etc.) do not apply to CMake - it is easy to build CMake on a single machine. CMake also does not install any header files which can be consumed by other projects (though cmCPluginAPI.h has been deliberately omitted from this conversion in case anyone is still using it.) Finally, #pragma once has been required to build CMake since at least August 2017 (7f29bbe6 enabled server mode unconditionally, which had been using #pragma once since September 2016 (b13d3e0d)). The fact that we now require C++11 filters out old compilers, and it is unlikely that there is a compiler which supports C++11 but does not support #pragma once.
55 lines
1.5 KiB
C++
55 lines
1.5 KiB
C++
/* Distributed under the OSI-approved BSD 3-Clause License. See accompanying
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file Copyright.txt or https://cmake.org/licensing for details. */
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#pragma once
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#include "cmConfigure.h" // IWYU pragma: keep
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#include <string>
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#include <unordered_map>
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#include "cmFileTime.h" // IWYU pragma: keep
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/** \class cmFileTimeCache
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* \brief Caches file modification times in an internal map for fast lookups.
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*/
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class cmFileTimeCache
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{
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public:
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cmFileTimeCache();
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~cmFileTimeCache();
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cmFileTimeCache(const cmFileTimeCache&) = delete;
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cmFileTimeCache& operator=(const cmFileTimeCache&) = delete;
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/**
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* @brief Loads the file time from the cache or the file system.
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* @return true on success
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*/
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bool Load(std::string const& fileName, cmFileTime& fileTime);
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/**
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* @brief Removes a file time from the cache
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* @return true if the file was found in the cache and removed
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*/
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bool Remove(std::string const& fileName);
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/**
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* @brief Compare file modification times.
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* @return true for successful comparison and false for error.
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*
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* When true is returned, result has -1, 0, +1 for
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* f1 older, same, or newer than f2.
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*/
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bool Compare(std::string const& f1, std::string const& f2, int* result);
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/**
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* @brief Compare file modification times.
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* @return true unless both files exist and have modification times less
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* than 1 second apart.
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*/
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bool DifferS(std::string const& f1, std::string const& f2);
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private:
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std::unordered_map<std::string, cmFileTime> Cache;
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};
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