#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) Guido Draheim, use under copyleft (LGPL,MPL)
 */

#ifdef _USE_MMAP
#if defined ZZIP_HAVE_SYS_MMAN_H && ! defined WIN32
#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 had used the plugin->sys variable for (user) but not anymore */

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);
        HANDLE fileMapping = NULL;
        if (hFile)
            fileMapping = CreateFileMapping(hFile, 0, PAGE_READONLY, 0, 0, NULL);
        if (fileMapping != NULL) {
            char* p = MapViewOfFile(fileMapping, FILE_MAP_READ, 0, offs, len);
            CloseHandle(fileMapping);
            *user = 1;
            if (p)
                return p;
        }
        return MAP_FAILED;
    }
}
static void
win32_munmap(long* user, char* fd_map, size_t len)
{
    UnmapViewOfFile(fd_map);
}

#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
