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Commit | Line | Data |
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bb742ede | 1 | /* |
359fc2d2 | 2 | * Copyright (C) the libgit2 contributors. All rights reserved. |
bb742ede VM |
3 | * |
4 | * This file is part of libgit2, distributed under the GNU GPL v2 with | |
5 | * a Linking Exception. For full terms see the included COPYING file. | |
6 | */ | |
79ca2edc RJ |
7 | |
8 | #include "map.h" | |
9 | #include <errno.h> | |
10 | ||
11 | ||
12 | static DWORD get_page_size(void) | |
13 | { | |
14 | static DWORD page_size; | |
15 | SYSTEM_INFO sys; | |
16 | ||
17 | if (!page_size) { | |
18 | GetSystemInfo(&sys); | |
19 | page_size = sys.dwAllocationGranularity; | |
20 | } | |
21 | ||
22 | return page_size; | |
23 | } | |
24 | ||
f79026b4 | 25 | int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, git_off_t offset) |
79ca2edc RJ |
26 | { |
27 | HANDLE fh = (HANDLE)_get_osfhandle(fd); | |
28 | DWORD page_size = get_page_size(); | |
29 | DWORD fmap_prot = 0; | |
30 | DWORD view_prot = 0; | |
31 | DWORD off_low = 0; | |
87d9869f | 32 | DWORD off_hi = 0; |
f0bde7fa AB |
33 | git_off_t page_start; |
34 | git_off_t page_offset; | |
79ca2edc | 35 | |
e3c47510 | 36 | GIT_MMAP_VALIDATE(out, len, prot, flags); |
79ca2edc RJ |
37 | |
38 | out->data = NULL; | |
39 | out->len = 0; | |
40 | out->fmh = NULL; | |
41 | ||
42 | if (fh == INVALID_HANDLE_VALUE) { | |
43 | errno = EBADF; | |
e1de726c RB |
44 | giterr_set(GITERR_OS, "Failed to mmap. Invalid handle value"); |
45 | return -1; | |
79ca2edc RJ |
46 | } |
47 | ||
48 | if (prot & GIT_PROT_WRITE) | |
49 | fmap_prot |= PAGE_READWRITE; | |
50 | else if (prot & GIT_PROT_READ) | |
51 | fmap_prot |= PAGE_READONLY; | |
79ca2edc RJ |
52 | |
53 | if (prot & GIT_PROT_WRITE) | |
54 | view_prot |= FILE_MAP_WRITE; | |
55 | if (prot & GIT_PROT_READ) | |
56 | view_prot |= FILE_MAP_READ; | |
57 | ||
79ca2edc RJ |
58 | page_start = (offset / page_size) * page_size; |
59 | page_offset = offset - page_start; | |
60 | ||
87d9869f | 61 | if (page_offset != 0) { /* offset must be multiple of page size */ |
79ca2edc | 62 | errno = EINVAL; |
e1de726c RB |
63 | giterr_set(GITERR_OS, "Failed to mmap. Offset must be multiple of page size"); |
64 | return -1; | |
79ca2edc RJ |
65 | } |
66 | ||
67 | out->fmh = CreateFileMapping(fh, NULL, fmap_prot, 0, 0, NULL); | |
68 | if (!out->fmh || out->fmh == INVALID_HANDLE_VALUE) { | |
e1de726c | 69 | giterr_set(GITERR_OS, "Failed to mmap. Invalid handle value"); |
79ca2edc | 70 | out->fmh = NULL; |
e1de726c | 71 | return -1; |
79ca2edc RJ |
72 | } |
73 | ||
f0bde7fa | 74 | assert(sizeof(git_off_t) == 8); |
e1de726c | 75 | |
79ca2edc | 76 | off_low = (DWORD)(page_start); |
90d4d2f0 | 77 | off_hi = (DWORD)(page_start >> 32); |
79ca2edc RJ |
78 | out->data = MapViewOfFile(out->fmh, view_prot, off_hi, off_low, len); |
79 | if (!out->data) { | |
e1de726c | 80 | giterr_set(GITERR_OS, "Failed to mmap. No data written"); |
79ca2edc RJ |
81 | CloseHandle(out->fmh); |
82 | out->fmh = NULL; | |
e1de726c | 83 | return -1; |
79ca2edc RJ |
84 | } |
85 | out->len = len; | |
86 | ||
e1de726c | 87 | return 0; |
79ca2edc RJ |
88 | } |
89 | ||
f79026b4 | 90 | int p_munmap(git_map *map) |
79ca2edc | 91 | { |
e1de726c | 92 | int error = 0; |
79ca2edc | 93 | |
e1de726c | 94 | assert(map != NULL); |
79ca2edc RJ |
95 | |
96 | if (map->data) { | |
97 | if (!UnmapViewOfFile(map->data)) { | |
e1de726c RB |
98 | giterr_set(GITERR_OS, "Failed to munmap. Could not unmap view of file"); |
99 | error = -1; | |
79ca2edc RJ |
100 | } |
101 | map->data = NULL; | |
102 | } | |
103 | ||
104 | if (map->fmh) { | |
105 | if (!CloseHandle(map->fmh)) { | |
e1de726c RB |
106 | giterr_set(GITERR_OS, "Failed to munmap. Could not close handle"); |
107 | error = -1; | |
79ca2edc RJ |
108 | } |
109 | map->fmh = NULL; | |
110 | } | |
111 | ||
e1de726c | 112 | return error; |
79ca2edc RJ |
113 | } |
114 | ||
115 |