Source/cmFileTimeComparison.cxx

   1 /*=========================================================================
   2
   3   Program:   CMake - Cross-Platform Makefile Generator
   4   Module:    $RCSfile: cmFileTimeComparison.cxx,v $
   5   Language:  C++
   6   Date:      $Date: 2008-01-03 05:01:38 $
   7   Version:   $Revision: 1.7 $
   8
   9   Copyright (c) 2002 Kitware, Inc., Insight Consortium.  All rights reserved.
  10   See Copyright.txt or http://www.cmake.org/HTML/Copyright.html for details.
  11
  12      This software is distributed WITHOUT ANY WARRANTY; without even
  13      the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  14      PURPOSE.  See the above copyright notices for more information.
  15
  16 =========================================================================*/
  17 #include "cmFileTimeComparison.h"
  18
  19 // Use a hash table to avoid duplicate file time checks from disk.
  20 #if defined(CMAKE_BUILD_WITH_CMAKE)
  21 # include <cmsys/hash_map.hxx>
  22 #endif
  23
  24 // Use a platform-specific API to get file times efficiently.
  25 #if !defined(_WIN32) || defined(__CYGWIN__)
  26 #  define cmFileTimeComparison_Type struct stat
  27 #  include <ctype.h>
  28 #  include <sys/stat.h>
  29 #else
  30 #  define cmFileTimeComparison_Type FILETIME
  31 #  include <windows.h>
  32 #endif
  33
  34 //----------------------------------------------------------------------------
  35 class cmFileTimeComparisonInternal
  36 {
  37 public:
  38   // Internal comparison method.
  39   inline bool FileTimeCompare(const char* f1, const char* f2, int* result);
  40
  41   bool FileTimesDiffer(const char* f1, const char* f2);
  42
  43 private:
  44 #if defined(CMAKE_BUILD_WITH_CMAKE)
  45   // Use a hash table to efficiently map from file name to modification time.
  46   class HashString
  47     {
  48   public:
  49     size_t operator()(const cmStdString& s) const
  50       {
  51       return h(s.c_str());
  52       }
  53     cmsys::hash<const char*> h;
  54     };
  55   typedef cmsys::hash_map<cmStdString,
  56                           cmFileTimeComparison_Type, HashString> FileStatsMap;
  57   FileStatsMap Files;
  58 #endif
  59
  60   // Internal methods to lookup and compare modification times.
  61   inline bool Stat(const char* fname, cmFileTimeComparison_Type* st);
  62   inline int Compare(cmFileTimeComparison_Type* st1,
  63                      cmFileTimeComparison_Type* st2);
  64   inline bool TimesDiffer(cmFileTimeComparison_Type* st1,
  65                           cmFileTimeComparison_Type* st2);
  66 };
  67
  68 //----------------------------------------------------------------------------
  69 bool cmFileTimeComparisonInternal::Stat(const char* fname,
  70                                         cmFileTimeComparison_Type* st)
  71 {
  72 #if defined(CMAKE_BUILD_WITH_CMAKE)
  73   // Use the stored time if available.
  74   cmFileTimeComparisonInternal::FileStatsMap::iterator fit =
  75     this->Files.find(fname);
  76   if ( fit != this->Files.end() )
  77     {
  78     *st = fit->second;
  79     return true;
  80     }
  81 #endif
  82
  83 #if !defined(_WIN32) || defined(__CYGWIN__)
  84   // POSIX version.  Use the stat function.
  85   int res = ::stat(fname, st);
  86   if ( res != 0 )
  87     {
  88     return false;
  89     }
  90 #else
  91   // Windows version.  Get the modification time from extended file
  92   // attributes.
  93   WIN32_FILE_ATTRIBUTE_DATA fdata;
  94   if(!GetFileAttributesEx(fname, GetFileExInfoStandard, &fdata))
  95     {
  96     return false;
  97     }
  98
  99   // Copy the file time to the output location.
 100   *st = fdata.ftLastWriteTime;
 101 #endif
 102
 103 #if defined(CMAKE_BUILD_WITH_CMAKE)
 104   // Store the time for future use.
 105   this->Files[fname] = *st;
 106 #endif
 107
 108   return true;
 109 }
 110
 111 //----------------------------------------------------------------------------
 112 cmFileTimeComparison::cmFileTimeComparison()
 113 {
 114   this->Internals = new cmFileTimeComparisonInternal;
 115 }
 116
 117 //----------------------------------------------------------------------------
 118 cmFileTimeComparison::~cmFileTimeComparison()
 119 {
 120   delete this->Internals;
 121 }
 122
 123 //----------------------------------------------------------------------------
 124 bool cmFileTimeComparison::FileTimeCompare(const char* f1,
 125                                            const char* f2, int* result)
 126 {
 127   return this->Internals->FileTimeCompare(f1, f2, result);
 128 }
 129
 130 //----------------------------------------------------------------------------
 131 bool cmFileTimeComparison::FileTimesDiffer(const char* f1, const char* f2)
 132 {
 133   return this->Internals->FileTimesDiffer(f1, f2);
 134 }
 135
 136 //----------------------------------------------------------------------------
 137 int cmFileTimeComparisonInternal::Compare(cmFileTimeComparison_Type* s1,
 138                                           cmFileTimeComparison_Type* s2)
 139 {
 140 #if !defined(_WIN32) || defined(__CYGWIN__)
 141 # if cmsys_STAT_HAS_ST_MTIM
 142   // Compare using nanosecond resolution.
 143   if(s1->st_mtim.tv_sec < s2->st_mtim.tv_sec)
 144     {
 145     return -1;
 146     }
 147   else if(s1->st_mtim.tv_sec > s2->st_mtim.tv_sec)
 148     {
 149     return 1;
 150     }
 151   else if(s1->st_mtim.tv_nsec < s2->st_mtim.tv_nsec)
 152     {
 153     return -1;
 154     }
 155   else if(s1->st_mtim.tv_nsec > s2->st_mtim.tv_nsec)
 156     {
 157     return 1;
 158     }
 159 # else
 160   // Compare using 1 second resolution.
 161   if(s1->st_mtime < s2->st_mtime)
 162     {
 163     return -1;
 164     }
 165   else if(s1->st_mtime > s2->st_mtime)
 166     {
 167     return 1;
 168     }
 169 # endif
 170   // Files have the same time.
 171   return 0;
 172 #else
 173   // Compare using system-provided function.
 174   return (int)CompareFileTime(s1, s2);
 175 #endif
 176 }
 177
 178 //----------------------------------------------------------------------------
 179 bool cmFileTimeComparisonInternal::TimesDiffer(cmFileTimeComparison_Type* s1,
 180                                                cmFileTimeComparison_Type* s2)
 181 {
 182 #if !defined(_WIN32) || defined(__CYGWIN__)
 183 # if cmsys_STAT_HAS_ST_MTIM
 184   // Times are integers in units of 1ns.
 185   long long bil = 1000000000;
 186   long long t1 = s1->st_mtim.tv_sec * bil + s1->st_mtim.tv_nsec;
 187   long long t2 = s2->st_mtim.tv_sec * bil + s2->st_mtim.tv_nsec;
 188   if(t1 < t2)
 189     {
 190     return (t2 - t1) >= bil;
 191     }
 192   else if(t2 < t1)
 193     {
 194     return (t1 - t2) >= bil;
 195     }
 196   else
 197     {
 198     return false;
 199     }
 200 # else
 201   // Times are integers in units of 1s.
 202   if(s1->st_mtime < s2->st_mtime)
 203     {
 204     return (s2->st_mtime - s1->st_mtime) >= 1;
 205     }
 206   else if(s1->st_mtime > s2->st_mtime)
 207     {
 208     return (s1->st_mtime - s2->st_mtime) >= 1;
 209     }
 210   else
 211     {
 212     return false;
 213     }
 214 # endif
 215 #else
 216   // Times are integers in units of 100ns.
 217   LARGE_INTEGER t1;
 218   LARGE_INTEGER t2;
 219   t1.LowPart = s1->dwLowDateTime;
 220   t1.HighPart = s1->dwHighDateTime;
 221   t2.LowPart = s2->dwLowDateTime;
 222   t2.HighPart = s2->dwHighDateTime;
 223   if(t1.QuadPart < t2.QuadPart)
 224     {
 225     return (t2.QuadPart - t1.QuadPart) >= static_cast<LONGLONG>(10000000);
 226     }
 227   else if(t2.QuadPart < t1.QuadPart)
 228     {
 229     return (t1.QuadPart - t2.QuadPart) >= static_cast<LONGLONG>(10000000);
 230     }
 231   else
 232     {
 233     return false;
 234     }
 235 #endif
 236 }
 237
 238 //----------------------------------------------------------------------------
 239 bool cmFileTimeComparisonInternal::FileTimeCompare(const char* f1,
 240                                                    const char* f2,
 241                                                    int* result)
 242 {
 243   // Get the modification time for each file.
 244   cmFileTimeComparison_Type s1;
 245   cmFileTimeComparison_Type s2;
 246   if(this->Stat(f1, &s1) &&
 247      this->Stat(f2, &s2))
 248     {
 249     // Compare the two modification times.
 250     *result = this->Compare(&s1, &s2);
 251     return true;
 252     }
 253   else
 254     {
 255     // No comparison available.  Default to the same time.
 256     *result = 0;
 257     return false;
 258     }
 259 }
 260
 261 //----------------------------------------------------------------------------
 262 bool cmFileTimeComparisonInternal::FileTimesDiffer(const char* f1,
 263                                                    const char* f2)
 264 {
 265   // Get the modification time for each file.
 266   cmFileTimeComparison_Type s1;
 267   cmFileTimeComparison_Type s2;
 268   if(this->Stat(f1, &s1) &&
 269      this->Stat(f2, &s2))
 270     {
 271     // Compare the two modification times.
 272     return this->TimesDiffer(&s1, &s2);
 273     }
 274   else
 275     {
 276     // No comparison available.  Default to different times.
 277     return true;
 278     }
 279 }