path: root/e-util/e-db3-utils.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

#include "config.h"

#include "e-db3-utils.h"

#include <db.h>

#include <errno.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <libgnome/gnome-util.h>

#if DB_VERSION_MAJOR != 3 || \
    DB_VERSION_MINOR != 1 || \
    DB_VERSION_PATCH != 17
#error Including wrong DB3.  Need libdb 3.1.17.
#endif

static char *
get_check_filename (const char *filename)
{
    return g_strdup_printf ("%s-upgrading", filename);
}

static char *
get_copy_filename (const char *filename)
{
    return g_strdup_printf ("%s-copy", filename);
}

static int
cp_file (const char *src, const char *dest)
{
    int i;
    int o;
    char buffer[1024];
    int length;
    int place;

    i = open (src, O_RDONLY);
    if (i == -1)
        return -1;
    o = creat (dest, S_IREAD | S_IWRITE);
    if (o == -1) {
        close (i);
        return -1;
    }
    while (1) {
        length = read (i, &buffer, sizeof (buffer));

        if (length == 0)
            break;

        if (length == -1) {
            if (errno == EINTR)
                continue;
            else {
                close (i);
                close (o);
                unlink (dest);
                return -1;
            }
        }

        place = 0;
        while (length != 0) {
            int count;
            count = write (o, buffer + place, length);
            if (count == -1) {
                if (errno == EINTR)
                    continue;
                else {
                    close (i);
                    close (o);
                    unlink (dest);
                    return -1;
                }
            }

            length -= count;
            place += count;
        }
    }
    if (close (i))
        return -1;
    if (close (o))
        return -1;
    return 0;
}

static int
touch_file (const char *file)
{
    int o;
    o = creat (file, S_IREAD | S_IWRITE);
    if (o == -1)
        return -1;

    if (close (o) == -1)
        return -1;

    return 0;
}

static int
resume_upgrade (const char *filename, const char *copy_filename, const char *check_filename)
{
    DB *db;
    int ret_val;

    ret_val = db_create (&db, NULL, 0);

    if (ret_val == 0)
        ret_val = cp_file (copy_filename, filename);

    if (ret_val == 0)
        ret_val = db->upgrade (db, filename, 0);

    if (ret_val == 0)
        ret_val = unlink (check_filename);
    if (ret_val == 0)
        ret_val = unlink (copy_filename);

    db->close (db, 0);

    return ret_val;
}

int
e_db3_utils_maybe_recover (const char *filename)
{
    int ret_val = 0;
    char *copy_filename;
    char *check_filename;

    copy_filename = get_copy_filename (filename);
    check_filename = get_check_filename (filename);

    if (g_file_exists (check_filename)) {
        ret_val = resume_upgrade(filename, copy_filename, check_filename);
    } else if (g_file_exists (copy_filename)) {
        unlink (copy_filename);
    }

    g_free (copy_filename);
    g_free (check_filename);
    return ret_val;
}

int
e_db3_utils_upgrade_format (const char *filename)
{
    char *copy_filename;
    char *check_filename;
    DB *db;
    int ret_val;

    ret_val = db_create (&db, NULL, 0);
    if (ret_val != 0)
        return ret_val;

    copy_filename = get_copy_filename (filename);
    check_filename = get_check_filename (filename);

    ret_val = cp_file (filename, copy_filename);

    if (ret_val == 0)
        ret_val = touch_file (check_filename);
    if (ret_val == 0)
        ret_val = db->upgrade (db, filename, 0);
    if (ret_val == 0)
        ret_val = unlink (check_filename);

    if (ret_val == 0)
        ret_val = unlink (copy_filename);

    db->close (db, 0);

    g_free (check_filename);
    g_free (copy_filename);
    return ret_val;
}