CMake/Source/cmFileTime.h
2019-09-03 13:21:26 -04:00

131 lines
3.0 KiB
C++

/* Distributed under the OSI-approved BSD 3-Clause License. See accompanying
file Copyright.txt or https://cmake.org/licensing for details. */
#ifndef cmFileTime_h
#define cmFileTime_h
#include "cmConfigure.h" // IWYU pragma: keep
#include <string>
/** \class cmFileTime
* \brief Abstract file modification time with support for comparison with
* other file modification times.
*/
class cmFileTime
{
public:
using NSC = long long;
static constexpr NSC NsPerS = 1000000000;
cmFileTime() = default;
~cmFileTime() = default;
/**
* @brief Loads the file time of fileName from the file system
* @return true on success
*/
bool Load(std::string const& fileName);
/**
* @brief Return true if this is older than ftm
*/
bool Older(cmFileTime const& ftm) const { return (this->NS - ftm.NS) < 0; }
/**
* @brief Return true if this is newer than ftm
*/
bool Newer(cmFileTime const& ftm) const { return (ftm.NS - this->NS) < 0; }
/**
* @brief Return true if this is the same as ftm
*/
bool Equal(cmFileTime const& ftm) const { return this->NS == ftm.NS; }
/**
* @brief Return true if this is not the same as ftm
*/
bool Differ(cmFileTime const& ftm) const { return this->NS != ftm.NS; }
/**
* @brief Compare file modification times.
* @return -1, 0, +1 for this older, same, or newer than ftm.
*/
int Compare(cmFileTime const& ftm) const
{
NSC const diff = this->NS - ftm.NS;
if (diff == 0) {
return 0;
}
return (diff < 0) ? -1 : 1;
}
// -- Comparison in second resolution
/**
* @brief Return true if this is at least a second older than ftm
*/
bool OlderS(cmFileTime const& ftm) const
{
return (ftm.NS - this->NS) >= cmFileTime::NsPerS;
}
/**
* @brief Return true if this is at least a second newer than ftm
*/
bool NewerS(cmFileTime const& ftm) const
{
return (this->NS - ftm.NS) >= cmFileTime::NsPerS;
}
/**
* @brief Return true if this is within the same second as ftm
*/
bool EqualS(cmFileTime const& ftm) const
{
NSC diff = this->NS - ftm.NS;
if (diff < 0) {
diff = -diff;
}
return (diff < cmFileTime::NsPerS);
}
/**
* @brief Return true if this is older or newer than ftm by at least a second
*/
bool DifferS(cmFileTime const& ftm) const
{
NSC diff = this->NS - ftm.NS;
if (diff < 0) {
diff = -diff;
}
return (diff >= cmFileTime::NsPerS);
}
/**
* @brief Compare file modification times.
* @return -1: this at least a second older, 0: this within the same second
* as ftm, +1: this at least a second newer than ftm.
*/
int CompareS(cmFileTime const& ftm) const
{
NSC const diff = this->NS - ftm.NS;
if (diff <= -cmFileTime::NsPerS) {
return -1;
}
if (diff >= cmFileTime::NsPerS) {
return 1;
}
return 0;
}
/**
* @brief The file modification time in nanoseconds
*/
NSC GetNS() const { return this->NS; }
private:
NSC NS = 0;
};
#endif