/src/zziplib/zzip/__mmap.h
https://bitbucket.org/cabalistic/ogredeps/ · C++ Header · 107 lines · 72 code · 15 blank · 20 comment · 7 complexity · 58172afad5f2e53c9535fb2037e0b7b6 MD5 · raw file
- #ifndef __ZZIP_INTERNAL_MMAP_H
- #define __ZZIP_INTERNAL_MMAP_H
- #include <zzip/types.h>
- /*
- * DO NOT USE THIS CODE.
- *
- * It is an internal header file for zziplib that carries some inline
- * functions (or just static members) and a few defines, simply to be
- * able to reuse these across - and have everything in a specific place.
- *
- * Copyright (c) 2002,2003 Guido Draheim
- * All rights reserved,
- * use under the restrictions of the
- * Lesser GNU General Public License
- * or alternatively the restrictions
- * of the Mozilla Public License 1.1
- */
- #ifdef _USE_MMAP
- #if defined ZZIP_HAVE_SYS_MMAN_H
- #include <sys/mman.h>
- #define USE_POSIX_MMAP 1
- #elif defined ZZIP_HAVE_WINBASE_H || defined WIN32
- #include <windows.h>
- #define USE_WIN32_MMAP 1
- #else
- #undef _USE_MMAP
- #endif
- #endif
- /* -------------- specify MMAP function imports --------------------------- */
- #if defined USE_POSIX_MMAP
- #define USE_MMAP 1
- #define _zzip_mmap(user, fd, offs, len) \
- mmap (0, len, PROT_READ, MAP_SHARED, fd, offs)
- #define _zzip_munmap(user, ptr, len) \
- munmap (ptr, len)
- #define _zzip_getpagesize(user) getpagesize()
- #ifndef MAP_FAILED /* hpux10.20 does not have it */
- #define MAP_FAILED ((void*)(-1))
- #endif
- #elif defined USE_WIN32_MMAP
- #define USE_MMAP 1
- #ifndef MAP_FAILED
- #define MAP_FAILED 0
- #endif
- /* we (ab)use the "*user" variable to store the FileMapping handle */
- /* which assumes (sizeof(long) == sizeof(HANDLE)) */
- static size_t win32_getpagesize (void)
- {
- SYSTEM_INFO si; GetSystemInfo (&si);
- return si.dwAllocationGranularity;
- }
- static void* win32_mmap (long* user, int fd, zzip_off_t offs, size_t len)
- {
- if (! user || *user != 1) /* || offs % getpagesize() */
- return 0;
- {
- HANDLE hFile = (HANDLE)_get_osfhandle(fd);
- if (hFile)
- *user = (int) CreateFileMapping (hFile, 0, PAGE_READONLY, 0, 0, NULL);
- if (*user)
- {
- char* p = 0;
- p = MapViewOfFile(*(HANDLE*)user, FILE_MAP_READ, 0, offs, len);
- if (p) return p + offs;
- CloseHandle (*(HANDLE*)user); *user = 1;
- }
- return MAP_FAILED;
- }
- }
- static void win32_munmap (long* user, char* fd_map, size_t len)
- {
- UnmapViewOfFile (fd_map);
- CloseHandle (*(HANDLE*)user); *user = 1;
- }
- #define _zzip_mmap(user, fd, offs, len) \
- win32_mmap ((long*) &(user), fd, offs, len)
- #define _zzip_munmap(user, ptr, len) \
- win32_munmap ((long*) &(user), ptr, len)
- #define _zzip_getpagesize(user) win32_getpagesize()
- #else /* disable */
- #define USE_MMAP 0
- /* USE_MAP is intentional: we expect the compiler to do some "code removal"
- * on any source code enclosed in if (USE_MMAP) {...} i.e. the unreachable
- * branch of an if (0) {....} is not emitted to the final object binary. */
- #ifndef MAP_FAILED
- #define MAP_FAILED 0
- #endif
- #define _zzip_mmap(user, fd, offs, len) (MAP_FAILED)
- #define _zzip_munmap(user, ptr, len) {}
- #define _zzip_getpagesize(user) 1
- #endif /* USE_MMAP defines */
- #endif