diff options
-rw-r--r-- | src/win32/posix_w32.c | 50 |
1 files changed, 48 insertions, 2 deletions
diff --git a/src/win32/posix_w32.c b/src/win32/posix_w32.c index 835804de4..fcaf77e89 100644 --- a/src/win32/posix_w32.c +++ b/src/win32/posix_w32.c @@ -518,8 +518,54 @@ int p_creat(const char *path, mode_t mode) int p_fallocate(int fd, off_t offset, off_t len) { - error = ENOSYS; - return -1; + HANDLE fh = (HANDLE)_get_osfhandle(fd); + LARGE_INTEGER zero, position, oldsize, newsize; + size_t size; + + if (fh == INVALID_HANDLE_VALUE) { + errno = EBADF; + return -1; + } + + if (offset < 0 || len <= 0) { + errno = EINVAL; + return -1; + } + + if (git__add_sizet_overflow(&size, offset, len)) { + errno = EINVAL; + return -1; + } + + zero.u.LowPart = 0; + zero.u.HighPart = 0; + + newsize.u.LowPart = (size & 0xffffffff); + +#if (SIZE_MAX > UINT32_MAX) + newsize.u.HighPart = size >> 32; +#else + newsize.u.HighPart = 0; +#endif + + if (!GetFileSizeEx(fh, &oldsize)) { + set_errno(); + return -1; + } + + /* POSIX emulation: attempting to shrink the file is ignored */ + if (oldsize.QuadPart >= newsize.QuadPart) + return 0; + + if (!SetFilePointerEx(fh, zero, &position, FILE_CURRENT) || + !SetFilePointerEx(fh, newsize, NULL, FILE_BEGIN) || + !SetEndOfFile(fh) || + !SetFilePointerEx(fh, position, 0, FILE_BEGIN)) { + set_errno(); + return -1; + } + + return 0; } int p_utimes(const char *path, const struct p_timeval times[2]) |