| |
| #include "map.h" |
| #include <errno.h> |
| |
| |
| static DWORD get_page_size(void) |
| { |
| static DWORD page_size; |
| SYSTEM_INFO sys; |
| |
| if (!page_size) { |
| GetSystemInfo(&sys); |
| page_size = sys.dwAllocationGranularity; |
| } |
| |
| return page_size; |
| } |
| |
| int git__mmap(git_map *out, size_t len, int prot, int flags, int fd, off_t offset) |
| { |
| HANDLE fh = (HANDLE)_get_osfhandle(fd); |
| DWORD page_size = get_page_size(); |
| DWORD fmap_prot = 0; |
| DWORD view_prot = 0; |
| DWORD off_low = 0; |
| DWORD off_hi = 0; |
| off_t page_start; |
| off_t page_offset; |
| |
| assert((out != NULL) && (len > 0)); |
| |
| if ((out == NULL) || (len == 0)) { |
| errno = EINVAL; |
| return GIT_ERROR; |
| } |
| |
| out->data = NULL; |
| out->len = 0; |
| out->fmh = NULL; |
| |
| if (fh == INVALID_HANDLE_VALUE) { |
| errno = EBADF; |
| return GIT_ERROR; |
| } |
| |
| if (prot & GIT_PROT_WRITE) |
| fmap_prot |= PAGE_READWRITE; |
| else if (prot & GIT_PROT_READ) |
| fmap_prot |= PAGE_READONLY; |
| else { |
| errno = EINVAL; |
| return GIT_ERROR; |
| } |
| |
| if (prot & GIT_PROT_WRITE) |
| view_prot |= FILE_MAP_WRITE; |
| if (prot & GIT_PROT_READ) |
| view_prot |= FILE_MAP_READ; |
| |
| if (flags & GIT_MAP_FIXED) { |
| errno = EINVAL; |
| return GIT_ERROR; |
| } |
| |
| page_start = (offset / page_size) * page_size; |
| page_offset = offset - page_start; |
| |
| if (page_offset != 0) { /* offset must be multiple of page size */ |
| errno = EINVAL; |
| return GIT_ERROR; |
| } |
| |
| out->fmh = CreateFileMapping(fh, NULL, fmap_prot, 0, 0, NULL); |
| if (!out->fmh || out->fmh == INVALID_HANDLE_VALUE) { |
| /* errno = ? */ |
| out->fmh = NULL; |
| return GIT_ERROR; |
| } |
| |
| assert(sizeof(off_t) == 8); |
| off_low = (DWORD)(page_start); |
| off_hi = (DWORD)(page_start >> 32); |
| out->data = MapViewOfFile(out->fmh, view_prot, off_hi, off_low, len); |
| if (!out->data) { |
| /* errno = ? */ |
| CloseHandle(out->fmh); |
| out->fmh = NULL; |
| return GIT_ERROR; |
| } |
| out->len = len; |
| |
| return GIT_SUCCESS; |
| } |
| |
| int git__munmap(git_map *map) |
| { |
| assert(map != NULL); |
| |
| if (!map) |
| return GIT_ERROR; |
| |
| if (map->data) { |
| if (!UnmapViewOfFile(map->data)) { |
| /* errno = ? */ |
| CloseHandle(map->fmh); |
| map->data = NULL; |
| map->fmh = NULL; |
| return GIT_ERROR; |
| } |
| map->data = NULL; |
| } |
| |
| if (map->fmh) { |
| if (!CloseHandle(map->fmh)) { |
| /* errno = ? */ |
| map->fmh = NULL; |
| return GIT_ERROR; |
| } |
| map->fmh = NULL; |
| } |
| |
| return GIT_SUCCESS; |
| } |
| |
| |