Using FindFirstFile and FindNextFile in win32 allows us to
use the directory information that is returned, instead of
us having to get the file attributes all over again, which
is a distinct cost savings on win32.
Changed win32/path_w32.c to utilize NTFS' FindFirst..FindNext data instead of doing an lstat per file. Avoiding unnecessary directory opens and file scans reduces IO, improving overall performance. Effect is magnified due to NTFS being a kernel mode file system (as opposed to user mode).
Win32 DLLs have four fields for the version number (major, minor,
teeny, patch). If a consumer wants to build a custom DLL, it may
be useful to set the patchlevel version number in the DLL.
This value only affects the DLL version number, it does not affect
the resultant "version number", which remains major.minor.teeny.
Make our overflow checking look more like gcc and clang's, so that
we can substitute it out with the compiler instrinsics on platforms
that support it. This means dropping the ability to pass `NULL` as
an out parameter.
As a result, the macros also get updated to reflect this as well.
Win32 generally ignores Unix-like mode bits that don't make any
sense on the platform (eg `0644` makes no sense to Windows). But
WINE complains loudly when presented with POSIXy bits. Remove them.
(Thanks @phkelley)
Introduce git__reallocarray that checks the product of the number
of elements and element size for overflow before allocation. Also
introduce git__mallocarray that behaves like calloc, but without the
`c`. (It does not zero memory, for those truly worried about every
cycle.)
`p_stat` calls `git_win32_path_from_utf8`, which canonicalizes the
path. Do not further try to modify the path, else we trim the
trailing slash from a root directory and try to access `C:` instead
of `C:/`.
Disallow:
1. paths with trailing dot
2. paths with trailing space
3. paths with trailing colon
4. paths that are 8.3 short names of .git folders ("GIT~1")
5. paths that are reserved path names (COM1, LPT1, etc).
6. paths with reserved DOS characters (colons, asterisks, etc)
These paths would (without \\?\ syntax) be elided to other paths - for
example, ".git." would be written as ".git". As a result, writing these
paths literally (using \\?\ syntax) makes them hard to operate with from
the shell, Windows Explorer or other tools. Disallow these.
When turning UTF-8 paths into UCS-2 paths for Windows, always use
the \\?\-prefixed paths. Because this bypasses the system's
path canonicalization, handle the canonicalization functions ourselves.
We must:
1. always use a backslash as a directory separator
2. only use a single backslash between directories
3. not rely on the system to translate "." and ".." in paths
4. remove trailing backslashes, except at the drive root (C:\)
A reparse point that is an IO_REPARSE_TAG_MOUNT_POINT could be
a junction or an actual filesystem mount point. (Who knew?)
If it's the latter, its reparse point will report the actual
volume information \??\Volume{GUID}\ and we should not attempt
to dereference that further, instead readlink should report
EINVAL since it's not a symlink / junction and its original
path was canonical.
Yes, really.
* Removes mingw-compat.h
* Cleans up separation of compiler/platform idiosyncrasies
* Unifies mingw/msvc stat structures and functions
* (Tries to) hide more compiler specific implementation details (even in our internal API)
When renaming a lock file to its final location, we need to make sure
that it is replaced atomically.
We currently have a workaround for Windows by removing the target file.
This means that the target file, which may be a ref or a packfile, may
cease to exist for a short wile, which shold be avoided.
Implement the workaround only in Windows, by making sure that the file
we want to replace is writable.
Use size_t for page size, instead of long. Check result of sysconf.
Use size_t for page offset so no cast to size_t (second arg to p_mmap).
Use mod instead div/mult pair, so no cast to size_t is necessary.
Windows has its own ftruncate() called _chsize_s().
p_mkstemp() is changed to use p_open() so we can make sure we open for
writing; the addition of exclusive create is a good thing to do
regardless, as we want a temporary path for ourselves.
Lastly, MSVC doesn't quite know how to add two numbers if one of them is a
void pointer, so let's alias it to unsigned char.C
Some OSs cannot keep their ideas about file content straight when mixing
standard IO with file mapping. As we use mmap for reading from the
packfile, let's make writing to the pack file use mmap.
