CMake/Source/cmFileTimeCache.h
2019-03-27 18:09:53 +01:00

57 lines
1.5 KiB
C++

/* Distributed under the OSI-approved BSD 3-Clause License. See accompanying
file Copyright.txt or https://cmake.org/licensing for details. */
#ifndef cmFileTimeCache_h
#define cmFileTimeCache_h
#include "cmConfigure.h" // IWYU pragma: keep
#include "cmFileTime.h" // IWYU pragma: keep
#include <string>
#include <unordered_map>
/** \class cmFileTimeCache
* \brief Caches file modification times in an internal map for fast lookups.
*/
class cmFileTimeCache
{
public:
cmFileTimeCache();
~cmFileTimeCache();
cmFileTimeCache(const cmFileTimeCache&) = delete;
cmFileTimeCache& operator=(const cmFileTimeCache&) = delete;
/**
* @brief Loads the file time from the cache or the file system.
* @return true on success
*/
bool Load(std::string const& fileName, cmFileTime& fileTime);
/**
* @brief Removes a file time from the cache
* @return true if the file was found in the cache and removed
*/
bool Remove(std::string const& fileName);
/**
* @brief Compare file modification times.
* @return true for successful comparison and false for error.
*
* When true is returned, result has -1, 0, +1 for
* f1 older, same, or newer than f2.
*/
bool Compare(std::string const& f1, std::string const& f2, int* result);
/**
* @brief Compare file modification times.
* @return true unless both files exist and have modification times less
* than 1 second apart.
*/
bool DifferS(std::string const& f1, std::string const& f2);
private:
std::unordered_map<std::string, cmFileTime> Cache;
};
#endif