projects / libgit2.git / blame
| Commit | Line | Data |
|---|---|---|
| 79ca2edc RJ |
1 | |
| 2 | #include "map.h" | |
| 3 | #include <errno.h> | |
| 4 | ||
| 5 | ||
| 6 | static DWORD get_page_size(void) | |
| 7 | { | |
| 8 | static DWORD page_size; | |
| 9 | SYSTEM_INFO sys; | |
| 10 | ||
| 11 | if (!page_size) { | |
| 12 | GetSystemInfo(&sys); | |
| 13 | page_size = sys.dwAllocationGranularity; | |
| 14 | } | |
| 15 | ||
| 16 | return page_size; | |
| 17 | } | |
| 18 | ||
| 19 | int git__mmap(git_map *out, size_t len, int prot, int flags, int fd, off_t offset) | |
| 20 | { | |
| 21 | HANDLE fh = (HANDLE)_get_osfhandle(fd); | |
| 22 | DWORD page_size = get_page_size(); | |
| 23 | DWORD fmap_prot = 0; | |
| 24 | DWORD view_prot = 0; | |
| 25 | DWORD off_low = 0; | |
| 26 | DWORD off_hi = 0; | |
| 27 | off_t page_start; | |
| 28 | off_t page_offset; | |
| 29 | ||
| 30 | assert((out != NULL) && (len > 0)); | |
| 31 | ||
| 32 | if ((out == NULL) || (len == 0)) { | |
| 33 | errno = EINVAL; | |
| 34 | return GIT_ERROR; | |
| 35 | } | |
| 36 | ||
| 37 | out->data = NULL; | |
| 38 | out->len = 0; | |
| 39 | out->fmh = NULL; | |
| 40 | ||
| 41 | if (fh == INVALID_HANDLE_VALUE) { | |
| 42 | errno = EBADF; | |
| 43 | return GIT_ERROR; | |
| 44 | } | |
| 45 | ||
| 46 | if (prot & GIT_PROT_WRITE) | |
| 47 | fmap_prot |= PAGE_READWRITE; | |
| 48 | else if (prot & GIT_PROT_READ) | |
| 49 | fmap_prot |= PAGE_READONLY; | |
| 50 | else { | |
| 51 | errno = EINVAL; | |
| 52 | return GIT_ERROR; | |
| 53 | } | |
| 54 | ||
| 55 | if (prot & GIT_PROT_WRITE) | |
| 56 | view_prot |= FILE_MAP_WRITE; | |
| 57 | if (prot & GIT_PROT_READ) | |
| 58 | view_prot |= FILE_MAP_READ; | |
| 59 | ||
| 60 | if (flags & GIT_MAP_FIXED) { | |
| 61 | errno = EINVAL; | |
| 62 | return GIT_ERROR; | |
| 63 | } | |
| 64 | ||
| 65 | page_start = (offset / page_size) * page_size; | |
| 66 | page_offset = offset - page_start; | |
| 67 | ||
| 68 | if (page_offset != 0) { /* offset must be multiple of page size */ | |
| 69 | errno = EINVAL; | |
| 70 | return GIT_ERROR; | |
| 71 | } | |
| 72 | ||
| 73 | out->fmh = CreateFileMapping(fh, NULL, fmap_prot, 0, 0, NULL); | |
| 74 | if (!out->fmh || out->fmh == INVALID_HANDLE_VALUE) { | |
| 75 | /* errno = ? */ | |
| 76 | out->fmh = NULL; | |
| 77 | return GIT_ERROR; | |
| 78 | } | |
| 79 | ||
| 80 | off_low = (DWORD)(page_start); | |
| 81 | if (sizeof(off_t) > 4) | |
| 82 | off_hi = (DWORD)(page_start >> 32); | |
| 83 | out->data = MapViewOfFile(out->fmh, view_prot, off_hi, off_low, len); | |
| 84 | if (!out->data) { | |
| 85 | /* errno = ? */ | |
| 86 | CloseHandle(out->fmh); | |
| 87 | out->fmh = NULL; | |
| 88 | return GIT_ERROR; | |
| 89 | } | |
| 90 | out->len = len; | |
| 91 | ||
| 92 | return GIT_SUCCESS; | |
| 93 | } | |
| 94 | ||
| 95 | int git__munmap(git_map *map) | |
| 96 | { | |
| 97 | assert(map != NULL); | |
| 98 | ||
| 99 | if (!map) | |
| 100 | return GIT_ERROR; | |
| 101 | ||
| 102 | if (map->data) { | |
| 103 | if (!UnmapViewOfFile(map->data)) { | |
| 104 | /* errno = ? */ | |
| 105 | CloseHandle(map->fmh); | |
| 106 | map->data = NULL; | |
| 107 | map->fmh = NULL; | |
| 108 | return GIT_ERROR; | |
| 109 | } | |
| 110 | map->data = NULL; | |
| 111 | } | |
| 112 | ||
| 113 | if (map->fmh) { | |
| 114 | if (!CloseHandle(map->fmh)) { | |
| 115 | /* errno = ? */ | |
| 116 | map->fmh = NULL; | |
| 117 | return GIT_ERROR; | |
| 118 | } | |
| 119 | map->fmh = NULL; | |
| 120 | } | |
| 121 | ||
| 122 | return GIT_SUCCESS; | |
| 123 | } | |
| 124 | ||
| 125 |