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Diffstat (limited to 'Source/cmFileTimeComparison.cxx')
| -rw-r--r-- | Source/cmFileTimeComparison.cxx | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/Source/cmFileTimeComparison.cxx b/Source/cmFileTimeComparison.cxx new file mode 100644 index 0000000..8b3911e --- /dev/null +++ b/Source/cmFileTimeComparison.cxx @@ -0,0 +1,233 @@ +/* Distributed under the OSI-approved BSD 3-Clause License. See accompanying + file Copyright.txt or https://cmake.org/licensing for details. */ +#include "cmFileTimeComparison.h" + +#include <string> +#include <time.h> +#include <unordered_map> +#include <utility> + +// Use a platform-specific API to get file times efficiently. +#if !defined(_WIN32) || defined(__CYGWIN__) +# include "cm_sys_stat.h" +# define cmFileTimeComparison_Type struct stat +#else +# include "cmsys/Encoding.hxx" +# include <windows.h> +# define cmFileTimeComparison_Type FILETIME +#endif + +class cmFileTimeComparisonInternal +{ +public: + // Internal comparison method. + inline bool FileTimeCompare(const std::string& f1, const std::string& f2, + int* result); + + bool FileTimesDiffer(const std::string& f1, const std::string& f2); + +private: + typedef std::unordered_map<std::string, cmFileTimeComparison_Type> + FileStatsMap; + FileStatsMap Files; + + // Internal methods to lookup and compare modification times. + inline bool Stat(const std::string& fname, cmFileTimeComparison_Type* st); + inline int Compare(cmFileTimeComparison_Type* st1, + cmFileTimeComparison_Type* st2); + inline bool TimesDiffer(cmFileTimeComparison_Type* st1, + cmFileTimeComparison_Type* st2); +}; + +bool cmFileTimeComparisonInternal::Stat(const std::string& fname, + cmFileTimeComparison_Type* st) +{ + // Use the stored time if available. + cmFileTimeComparisonInternal::FileStatsMap::iterator fit = + this->Files.find(fname); + if (fit != this->Files.end()) { + *st = fit->second; + return true; + } + +#if !defined(_WIN32) || defined(__CYGWIN__) + // POSIX version. Use the stat function. + int res = ::stat(fname.c_str(), st); + if (res != 0) { + return false; + } +#else + // Windows version. Get the modification time from extended file + // attributes. + WIN32_FILE_ATTRIBUTE_DATA fdata; + if (!GetFileAttributesExW(cmsys::Encoding::ToWide(fname).c_str(), + GetFileExInfoStandard, &fdata)) { + return false; + } + + // Copy the file time to the output location. + *st = fdata.ftLastWriteTime; +#endif + + // Store the time for future use. + this->Files[fname] = *st; + return true; +} + +cmFileTimeComparison::cmFileTimeComparison() +{ + this->Internals = new cmFileTimeComparisonInternal; +} + +cmFileTimeComparison::~cmFileTimeComparison() +{ + delete this->Internals; +} + +bool cmFileTimeComparison::FileTimeCompare(const std::string& f1, + const std::string& f2, int* result) +{ + return this->Internals->FileTimeCompare(f1, f2, result); +} + +bool cmFileTimeComparison::FileTimesDiffer(const std::string& f1, + const std::string& f2) +{ + return this->Internals->FileTimesDiffer(f1, f2); +} + +int cmFileTimeComparisonInternal::Compare(cmFileTimeComparison_Type* s1, + cmFileTimeComparison_Type* s2) +{ +#if !defined(_WIN32) || defined(__CYGWIN__) +# if CMake_STAT_HAS_ST_MTIM + // Compare using nanosecond resolution. + if (s1->st_mtim.tv_sec < s2->st_mtim.tv_sec) { + return -1; + } + if (s1->st_mtim.tv_sec > s2->st_mtim.tv_sec) { + return 1; + } + if (s1->st_mtim.tv_nsec < s2->st_mtim.tv_nsec) { + return -1; + } + if (s1->st_mtim.tv_nsec > s2->st_mtim.tv_nsec) { + return 1; + } +# elif CMake_STAT_HAS_ST_MTIMESPEC + // Compare using nanosecond resolution. + if (s1->st_mtimespec.tv_sec < s2->st_mtimespec.tv_sec) { + return -1; + } + if (s1->st_mtimespec.tv_sec > s2->st_mtimespec.tv_sec) { + return 1; + } + if (s1->st_mtimespec.tv_nsec < s2->st_mtimespec.tv_nsec) { + return -1; + } + if (s1->st_mtimespec.tv_nsec > s2->st_mtimespec.tv_nsec) { + return 1; + } +# else + // Compare using 1 second resolution. + if (s1->st_mtime < s2->st_mtime) { + return -1; + } + if (s1->st_mtime > s2->st_mtime) { + return 1; + } +# endif + // Files have the same time. + return 0; +#else + // Compare using system-provided function. + return (int)CompareFileTime(s1, s2); +#endif +} + +bool cmFileTimeComparisonInternal::TimesDiffer(cmFileTimeComparison_Type* s1, + cmFileTimeComparison_Type* s2) +{ +#if !defined(_WIN32) || defined(__CYGWIN__) +# if CMake_STAT_HAS_ST_MTIM + // Times are integers in units of 1ns. + long long bil = 1000000000; + long long t1 = s1->st_mtim.tv_sec * bil + s1->st_mtim.tv_nsec; + long long t2 = s2->st_mtim.tv_sec * bil + s2->st_mtim.tv_nsec; + if (t1 < t2) { + return (t2 - t1) >= bil; + } + if (t2 < t1) { + return (t1 - t2) >= bil; + } + return false; +# elif CMake_STAT_HAS_ST_MTIMESPEC + // Times are integers in units of 1ns. + long long bil = 1000000000; + long long t1 = s1->st_mtimespec.tv_sec * bil + s1->st_mtimespec.tv_nsec; + long long t2 = s2->st_mtimespec.tv_sec * bil + s2->st_mtimespec.tv_nsec; + if (t1 < t2) { + return (t2 - t1) >= bil; + } + if (t2 < t1) { + return (t1 - t2) >= bil; + } + return false; +# else + // Times are integers in units of 1s. + if (s1->st_mtime < s2->st_mtime) { + return (s2->st_mtime - s1->st_mtime) >= 1; + } + if (s1->st_mtime > s2->st_mtime) { + return (s1->st_mtime - s2->st_mtime) >= 1; + } + return false; +# endif +#else + // Times are integers in units of 100ns. + LARGE_INTEGER t1; + LARGE_INTEGER t2; + t1.LowPart = s1->dwLowDateTime; + t1.HighPart = s1->dwHighDateTime; + t2.LowPart = s2->dwLowDateTime; + t2.HighPart = s2->dwHighDateTime; + if (t1.QuadPart < t2.QuadPart) { + return (t2.QuadPart - t1.QuadPart) >= static_cast<LONGLONG>(10000000); + } else if (t2.QuadPart < t1.QuadPart) { + return (t1.QuadPart - t2.QuadPart) >= static_cast<LONGLONG>(10000000); + } else { + return false; + } +#endif +} + +bool cmFileTimeComparisonInternal::FileTimeCompare(const std::string& f1, + const std::string& f2, + int* result) +{ + // Get the modification time for each file. + cmFileTimeComparison_Type s1; + cmFileTimeComparison_Type s2; + if (this->Stat(f1, &s1) && this->Stat(f2, &s2)) { + // Compare the two modification times. + *result = this->Compare(&s1, &s2); + return true; + } + // No comparison available. Default to the same time. + *result = 0; + return false; +} + +bool cmFileTimeComparisonInternal::FileTimesDiffer(const std::string& f1, + const std::string& f2) +{ + // Get the modification time for each file. + cmFileTimeComparison_Type s1; + cmFileTimeComparison_Type s2; + if (this->Stat(f1, &s1) && this->Stat(f2, &s2)) { + // Compare the two modification times. + return this->TimesDiffer(&s1, &s2); + } + // No comparison available. Default to different times. + return true; +} |