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git/compat/cygwin.h

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cygwin: Use native Win32 API for stat lstat/stat functions in Cygwin are very slow, because they try to emulate some *nix things that Git does not actually need. This patch adds Win32 specific implementation of these functions for Cygwin. This implementation handles most situation directly but in some rare cases it falls back on the implementation provided for Cygwin. This is necessary for two reasons: - Cygwin has its own file hierarchy, so absolute paths used in Cygwin is not suitable to be used Win32 API. cygwin_conv_to_win32_path can not be used because it automatically dereference Cygwin symbol links, also it causes extra syscall. Fortunately Git rarely use absolute paths, so we always use Cygwin implementation for absolute paths. - Support of symbol links. Cygwin stores symbol links as ordinary using one of two possible formats. Therefore, the fast implementation falls back to Cygwin functions if it detects potential use of symbol links. The speed of this implementation should be the same as mingw_lstat for common cases, but it is considerable slower when the specified file name does not exist. Despite all efforts to make the fast implementation as robust as possible, it may not work well for some very rare situations. I am aware only one situation: use Cygwin mount to bind unrelated paths inside repository together. Therefore, the core.ignoreCygwinFSTricks configuration option is provided, which controls whether native or Cygwin version of stat is used. Signed-off-by: Dmitry Potapov <dpotapov@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-09-30 15:53:47 +02:00
#include <sys/types.h>
#include <sys/stat.h>
typedef int (*stat_fn_t)(const char*, struct stat*);
extern stat_fn_t cygwin_stat_fn;
extern stat_fn_t cygwin_lstat_fn;
Make core.sharedRepository work under cygwin 1.7 When core.sharedRepository is used, set_shared_perm() in path.c needs lstat() to return the correct POSIX permissions. The default for cygwin is core.ignoreCygwinFSTricks = false, which means that the fast implementation in do_stat() is used instead of lstat(). lstat() under cygwin uses the Windows security model to implement POSIX-like permissions. The user, group or everyone bits can be set individually. do_stat() simplifes the file permission bits, and may return a wrong value. The read-only attribute of a file is used to calculate the permissions, resulting in either rw-r--r-- or r--r--r-- One effect of the simplified do_stat() is that t1301 fails. Add a function cygwin_get_st_mode_bits() which returns the POSIX permissions. When not compiling for cygwin, true_mode_bits() in path.c is used. Side note: t1301 passes under cygwin 1.5. The "user write" bit is synchronized with the "read only" attribute of a file: $ chmod 444 x $ attrib x A R C:\temp\pt\x cygwin 1.7 would show A C:\temp\pt\x Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-23 13:40:29 +01:00
int cygwin_get_st_mode_bits(const char *path, int *mode);
cygwin: Use native Win32 API for stat lstat/stat functions in Cygwin are very slow, because they try to emulate some *nix things that Git does not actually need. This patch adds Win32 specific implementation of these functions for Cygwin. This implementation handles most situation directly but in some rare cases it falls back on the implementation provided for Cygwin. This is necessary for two reasons: - Cygwin has its own file hierarchy, so absolute paths used in Cygwin is not suitable to be used Win32 API. cygwin_conv_to_win32_path can not be used because it automatically dereference Cygwin symbol links, also it causes extra syscall. Fortunately Git rarely use absolute paths, so we always use Cygwin implementation for absolute paths. - Support of symbol links. Cygwin stores symbol links as ordinary using one of two possible formats. Therefore, the fast implementation falls back to Cygwin functions if it detects potential use of symbol links. The speed of this implementation should be the same as mingw_lstat for common cases, but it is considerable slower when the specified file name does not exist. Despite all efforts to make the fast implementation as robust as possible, it may not work well for some very rare situations. I am aware only one situation: use Cygwin mount to bind unrelated paths inside repository together. Therefore, the core.ignoreCygwinFSTricks configuration option is provided, which controls whether native or Cygwin version of stat is used. Signed-off-by: Dmitry Potapov <dpotapov@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-09-30 15:53:47 +02:00
Make core.sharedRepository work under cygwin 1.7 When core.sharedRepository is used, set_shared_perm() in path.c needs lstat() to return the correct POSIX permissions. The default for cygwin is core.ignoreCygwinFSTricks = false, which means that the fast implementation in do_stat() is used instead of lstat(). lstat() under cygwin uses the Windows security model to implement POSIX-like permissions. The user, group or everyone bits can be set individually. do_stat() simplifes the file permission bits, and may return a wrong value. The read-only attribute of a file is used to calculate the permissions, resulting in either rw-r--r-- or r--r--r-- One effect of the simplified do_stat() is that t1301 fails. Add a function cygwin_get_st_mode_bits() which returns the POSIX permissions. When not compiling for cygwin, true_mode_bits() in path.c is used. Side note: t1301 passes under cygwin 1.5. The "user write" bit is synchronized with the "read only" attribute of a file: $ chmod 444 x $ attrib x A R C:\temp\pt\x cygwin 1.7 would show A C:\temp\pt\x Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-23 13:40:29 +01:00
#define get_st_mode_bits(p,m) cygwin_get_st_mode_bits((p),(m))
#ifndef CYGWIN_C
/* cygwin.c needs the original lstat() */
cygwin: Use native Win32 API for stat lstat/stat functions in Cygwin are very slow, because they try to emulate some *nix things that Git does not actually need. This patch adds Win32 specific implementation of these functions for Cygwin. This implementation handles most situation directly but in some rare cases it falls back on the implementation provided for Cygwin. This is necessary for two reasons: - Cygwin has its own file hierarchy, so absolute paths used in Cygwin is not suitable to be used Win32 API. cygwin_conv_to_win32_path can not be used because it automatically dereference Cygwin symbol links, also it causes extra syscall. Fortunately Git rarely use absolute paths, so we always use Cygwin implementation for absolute paths. - Support of symbol links. Cygwin stores symbol links as ordinary using one of two possible formats. Therefore, the fast implementation falls back to Cygwin functions if it detects potential use of symbol links. The speed of this implementation should be the same as mingw_lstat for common cases, but it is considerable slower when the specified file name does not exist. Despite all efforts to make the fast implementation as robust as possible, it may not work well for some very rare situations. I am aware only one situation: use Cygwin mount to bind unrelated paths inside repository together. Therefore, the core.ignoreCygwinFSTricks configuration option is provided, which controls whether native or Cygwin version of stat is used. Signed-off-by: Dmitry Potapov <dpotapov@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-09-30 15:53:47 +02:00
#define stat(path, buf) (*cygwin_stat_fn)(path, buf)
#define lstat(path, buf) (*cygwin_lstat_fn)(path, buf)
Make core.sharedRepository work under cygwin 1.7 When core.sharedRepository is used, set_shared_perm() in path.c needs lstat() to return the correct POSIX permissions. The default for cygwin is core.ignoreCygwinFSTricks = false, which means that the fast implementation in do_stat() is used instead of lstat(). lstat() under cygwin uses the Windows security model to implement POSIX-like permissions. The user, group or everyone bits can be set individually. do_stat() simplifes the file permission bits, and may return a wrong value. The read-only attribute of a file is used to calculate the permissions, resulting in either rw-r--r-- or r--r--r-- One effect of the simplified do_stat() is that t1301 fails. Add a function cygwin_get_st_mode_bits() which returns the POSIX permissions. When not compiling for cygwin, true_mode_bits() in path.c is used. Side note: t1301 passes under cygwin 1.5. The "user write" bit is synchronized with the "read only" attribute of a file: $ chmod 444 x $ attrib x A R C:\temp\pt\x cygwin 1.7 would show A C:\temp\pt\x Signed-off-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-03-23 13:40:29 +01:00
#endif
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