ENH: Improved file modification time comparison on Windows to use GetFileAttributesEx instead of CreateFile/GetFileTime/CloseHandle to get file times. This results in a 30% reduction in time to do a build system check.

This commit is contained in:
Brad King 2005-10-27 13:57:48 -04:00
parent 6b0c50e824
commit 946c9a2cc6
2 changed files with 56 additions and 57 deletions

View File

@ -9,22 +9,19 @@
Copyright (c) 2002 Kitware, Inc., Insight Consortium. All rights reserved.
See Copyright.txt or http://www.cmake.org/HTML/Copyright.html for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notices for more information.
=========================================================================*/
#include "cmFileTimeComparison.h"
#include <cmsys/Directory.hxx>
#include <cmsys/RegularExpression.hxx>
#include <cmsys/SystemTools.hxx>
// Use a hash table to avoid duplicate file time checks from disk.
#if defined(CMAKE_BUILD_WITH_CMAKE)
# include <cmsys/hash_map.hxx>
#endif
// Use a platform-specific API to get file times efficiently.
#if !defined(_WIN32) || defined(__CYGWIN__)
# define cmFileTimeComparison_Type struct stat
# include <ctype.h>
@ -34,13 +31,16 @@
# include <windows.h>
#endif
//----------------------------------------------------------------------------
class cmFileTimeComparisonInternal
{
public:
// Internal comparison method.
inline bool FileTimeCompare(const char* f1, const char* f2, int* result);
private:
#if defined(CMAKE_BUILD_WITH_CMAKE)
// Use a hash table to efficiently map from file name to modification time.
class HashString
{
public:
@ -50,67 +50,78 @@ private:
}
cmsys::hash<const char*> h;
};
typedef cmsys::hash_map<cmStdString, cmFileTimeComparison_Type, HashString> FileStatsMap;
typedef cmsys::hash_map<cmStdString,
cmFileTimeComparison_Type, HashString> FileStatsMap;
FileStatsMap Files;
#endif
// Internal methods to lookup and compare modification times.
inline bool Stat(const char* fname, cmFileTimeComparison_Type* st);
inline int Compare(cmFileTimeComparison_Type* st1, cmFileTimeComparison_Type* st2);
inline int Compare(cmFileTimeComparison_Type* st1,
cmFileTimeComparison_Type* st2);
};
bool cmFileTimeComparisonInternal::Stat(const char* fname, cmFileTimeComparison_Type* st)
//----------------------------------------------------------------------------
bool cmFileTimeComparisonInternal::Stat(const char* fname,
cmFileTimeComparison_Type* st)
{
#if defined(CMAKE_BUILD_WITH_CMAKE)
cmFileTimeComparisonInternal::FileStatsMap::iterator fit = this->Files.find(fname);
// Use the stored time if available.
cmFileTimeComparisonInternal::FileStatsMap::iterator fit =
this->Files.find(fname);
if ( fit != this->Files.end() )
{
*st = fit->second;
return true;
}
#endif
#if !defined(_WIN32) || defined(__CYGWIN__)
// POSIX version. Use the stat function.
int res = ::stat(fname, st);
if ( res != 0 )
{
return false;
}
#else
// Windows version. Create file handles and get the modification times.
HANDLE hf1 = CreateFile(fname, GENERIC_READ, FILE_SHARE_READ,
NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS,
NULL);
if(hf1 == INVALID_HANDLE_VALUE)
// Windows version. Get the modification time from extended file attributes.
WIN32_FILE_ATTRIBUTE_DATA fdata;
if(!GetFileAttributesEx(fname, GetFileExInfoStandard, &fdata))
{
return false;
}
if(!GetFileTime(hf1, 0, 0, st))
{
CloseHandle(hf1);
return false;
}
CloseHandle(hf1);
// Copy the file time to the output location.
*st = fdata.ftLastWriteTime;
#endif
#if defined(CMAKE_BUILD_WITH_CMAKE)
// Store the time for future use.
this->Files[fname] = *st;
#endif
return true;
}
//----------------------------------------------------------------------------
cmFileTimeComparison::cmFileTimeComparison()
{
m_Internals = new cmFileTimeComparisonInternal;
}
//----------------------------------------------------------------------------
cmFileTimeComparison::~cmFileTimeComparison()
{
delete m_Internals;
}
//----------------------------------------------------------------------------
bool cmFileTimeComparison::FileTimeCompare(const char* f1, const char* f2, int* result)
{
return m_Internals->FileTimeCompare(f1, f2, result);
}
//----------------------------------------------------------------------------
int cmFileTimeComparisonInternal::Compare(cmFileTimeComparison_Type* s1, cmFileTimeComparison_Type* s2)
{
#if !defined(_WIN32) || defined(__CYGWIN__)
@ -143,27 +154,33 @@ int cmFileTimeComparisonInternal::Compare(cmFileTimeComparison_Type* s1, cmFileT
return 1;
}
# endif
// Files have the same time.
return 0;
#else
// Compare using system-provided function.
return (int)CompareFileTime(s1, s2);
#endif
}
bool cmFileTimeComparisonInternal::FileTimeCompare(const char* f1, const char* f2, int* result)
//----------------------------------------------------------------------------
bool cmFileTimeComparisonInternal::FileTimeCompare(const char* f1,
const char* f2,
int* result)
{
// Default to same time.
*result = 0;
// Get the modification time for each file.
cmFileTimeComparison_Type s1;
if(!this->Stat(f1, &s1))
{
return false;
}
cmFileTimeComparison_Type s2;
if(!this->Stat(f2, &s2))
if(this->Stat(f1, &s1) &&
this->Stat(f2, &s2))
{
// Compare the two modification times.
*result = this->Compare(&s1, &s2);
return true;
}
else
{
// No comparison available. Default to the same time.
*result = 0;
return false;
}
*result = this->Compare(&s1, &s2);
return true;
}

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@ -786,38 +786,20 @@ bool SystemTools::FileTimeCompare(const char* f1, const char* f2,
}
# endif
#else
// Windows version. Create file handles and get the modification times.
HANDLE hf1 = CreateFile(f1, GENERIC_READ, FILE_SHARE_READ,
NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS,
NULL);
if(hf1 == INVALID_HANDLE_VALUE)
// Windows version. Get the modification time from extended file attributes.
WIN32_FILE_ATTRIBUTE_DATA f1d;
WIN32_FILE_ATTRIBUTE_DATA f2d;
if(!GetFileAttributesEx(f1, GetFileExInfoStandard, &f1d))
{
return false;
}
FILETIME tf1;
if(!GetFileTime(hf1, 0, 0, &tf1))
{
CloseHandle(hf1);
return false;
}
CloseHandle(hf1);
HANDLE hf2 = CreateFile(f2, GENERIC_READ, FILE_SHARE_READ,
NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS,
NULL);
if(hf2 == INVALID_HANDLE_VALUE)
if(!GetFileAttributesEx(f2, GetFileExInfoStandard, &f2d))
{
return false;
}
FILETIME tf2;
if(!GetFileTime(hf2, 0, 0, &tf2))
{
CloseHandle(hf2);
return false;
}
CloseHandle(hf2);
// Compare the file times using resolution provided by system call.
*result = (int)CompareFileTime(&tf1, &tf2);
*result = (int)CompareFileTime(&f1d.ftLastWriteTime, &f2d.ftLastWriteTime);
#endif
return true;
}