file.c

/****************************************************************************/
/*          pfixtools: a collection of postfix related tools                */
/*          ~~~~~~~~~                                                       */
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/****************************************************************************/

#include <sys/mman.h>
#include <sys/stat.h>

#include "file.h"

file_map_t *file_map_new(const char *file, bool memlock)
{
    file_map_t *map = p_new(file_map_t, 1);
    if (!file_map_open(map, file, memlock)) {
        p_delete(&map);
        return NULL;
    }
    return map;
}

void file_map_delete(file_map_t **map)
{
    if (*map) {
        file_map_close(*map);
        p_delete(map);
    }
}

bool file_map_open(file_map_t *map, const char *file, bool memlock)
{
    int fd;

    fd = open(file, O_RDONLY, 0000);
    if (fd < 0) {
        UNIXERR("open");
        return false;
    }

    if (fstat(fd, &map->st) < 0) {
        UNIXERR("fstat");
        close(fd);
        return false;
    }

    map->map = mmap(NULL, map->st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
    if (map->map == MAP_FAILED) {
        UNIXERR("mmap");
        close(fd);
        map->map = NULL;
        return false;
    }
    close(fd);

    map->end = map->map + map->st.st_size;
    map->locked = memlock && mlock(map->map, map->st.st_size) == 0;
    return true;
}

void file_map_close(file_map_t *map)
{
    if (!map->map) {
        return;
    }
    if (map->locked) {
        munlock(map->map, map->end - map->map);
    }
    munmap((void*)map->map, map->end - map->map);
    map->map = NULL;
    map->end = NULL;
    map->locked = false;
}

/* vim:set et sw=4 sts=4 sws=4: */