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author | Edward Thomson <ethomson@edwardthomson.com> | 2021-11-14 16:43:53 -0500 |
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committer | Edward Thomson <ethomson@edwardthomson.com> | 2022-02-22 22:07:44 -0500 |
commit | c3b7ace9cf3216928a31886b32c264e0cd3cde75 (patch) | |
tree | d7575e38bef62714b99f4b2dd8bbb44ec7bb6534 /src/util/win32/map.c | |
parent | ef4ab2988320005cbcb3db920e6b41f10b3c60cf (diff) | |
download | libgit2-c3b7ace9cf3216928a31886b32c264e0cd3cde75.tar.gz |
refactor: make util an object library
Instead of simply including the utility files directly, make them a
cmake object library for easy reusability between other projects within
libgit2.
Now the top-level `src` is responsible for platform selection, while the
next-level `libgit2` and `util` configurations are responsible for
identifying what objects they include.
Diffstat (limited to 'src/util/win32/map.c')
-rw-r--r-- | src/util/win32/map.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/src/util/win32/map.c b/src/util/win32/map.c new file mode 100644 index 000000000..52e1363ea --- /dev/null +++ b/src/util/win32/map.c @@ -0,0 +1,141 @@ +/* + * Copyright (C) the libgit2 contributors. All rights reserved. + * + * This file is part of libgit2, distributed under the GNU GPL v2 with + * a Linking Exception. For full terms see the included COPYING file. + */ + +#include "git2_util.h" + +#include "map.h" +#include <errno.h> + +#ifndef NO_MMAP + +static DWORD get_page_size(void) +{ + static DWORD page_size; + SYSTEM_INFO sys; + + if (!page_size) { + GetSystemInfo(&sys); + page_size = sys.dwPageSize; + } + + return page_size; +} + +static DWORD get_allocation_granularity(void) +{ + static DWORD granularity; + SYSTEM_INFO sys; + + if (!granularity) { + GetSystemInfo(&sys); + granularity = sys.dwAllocationGranularity; + } + + return granularity; +} + +int git__page_size(size_t *page_size) +{ + *page_size = get_page_size(); + return 0; +} + +int git__mmap_alignment(size_t *page_size) +{ + *page_size = get_allocation_granularity(); + return 0; +} + +int p_mmap(git_map *out, size_t len, int prot, int flags, int fd, off64_t offset) +{ + HANDLE fh = (HANDLE)_get_osfhandle(fd); + DWORD alignment = get_allocation_granularity(); + DWORD fmap_prot = 0; + DWORD view_prot = 0; + DWORD off_low = 0; + DWORD off_hi = 0; + off64_t page_start; + off64_t page_offset; + + GIT_MMAP_VALIDATE(out, len, prot, flags); + + out->data = NULL; + out->len = 0; + out->fmh = NULL; + + if (fh == INVALID_HANDLE_VALUE) { + errno = EBADF; + git_error_set(GIT_ERROR_OS, "failed to mmap. Invalid handle value"); + return -1; + } + + if (prot & GIT_PROT_WRITE) + fmap_prot |= PAGE_READWRITE; + else if (prot & GIT_PROT_READ) + fmap_prot |= PAGE_READONLY; + + if (prot & GIT_PROT_WRITE) + view_prot |= FILE_MAP_WRITE; + if (prot & GIT_PROT_READ) + view_prot |= FILE_MAP_READ; + + page_start = (offset / alignment) * alignment; + page_offset = offset - page_start; + + if (page_offset != 0) { /* offset must be multiple of the allocation granularity */ + errno = EINVAL; + git_error_set(GIT_ERROR_OS, "failed to mmap. Offset must be multiple of allocation granularity"); + return -1; + } + + out->fmh = CreateFileMapping(fh, NULL, fmap_prot, 0, 0, NULL); + if (!out->fmh || out->fmh == INVALID_HANDLE_VALUE) { + git_error_set(GIT_ERROR_OS, "failed to mmap. Invalid handle value"); + out->fmh = NULL; + return -1; + } + + 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) { + git_error_set(GIT_ERROR_OS, "failed to mmap. No data written"); + CloseHandle(out->fmh); + out->fmh = NULL; + return -1; + } + out->len = len; + + return 0; +} + +int p_munmap(git_map *map) +{ + int error = 0; + + GIT_ASSERT_ARG(map); + + if (map->data) { + if (!UnmapViewOfFile(map->data)) { + git_error_set(GIT_ERROR_OS, "failed to munmap. Could not unmap view of file"); + error = -1; + } + map->data = NULL; + } + + if (map->fmh) { + if (!CloseHandle(map->fmh)) { + git_error_set(GIT_ERROR_OS, "failed to munmap. Could not close handle"); + error = -1; + } + map->fmh = NULL; + } + + return error; +} + +#endif |