Function dav_get_resource_state

modules/dav/main/util_lock.c:686–743

** dav_get_resource_state: Returns the state of the resource ** r->filename: DAV_RESOURCE_NULL, DAV_RESOURCE_LOCK_NULL, ** or DAV_RESOURCE_EXIST. ** ** Returns DAV_RESOURCE_ERROR if an error occurs. */

**    Returns DAV_RESOURCE_ERROR if an error occurs.
*/
DAV_DECLARE(int) dav_get_resource_state(request_rec *r,
                                        const dav_resource *resource)
{
    const dav_hooks_locks *hooks = DAV_GET_HOOKS_LOCKS(r);

    if (resource->exists)
        return DAV_RESOURCE_EXISTS;

    if (hooks != NULL) {
        dav_error *err;
        dav_lockdb *lockdb;
        int locks_present;

        /*
        ** A locknull resource has the form:
        **
        **   known-dir "/" locknull-file
        **
        ** It would be nice to look into <resource> to verify this form,
        ** but it does not have enough information for us. Instead, we
        ** can look at the path_info. If the form does not match, then
        ** there is no way we could have a locknull resource -- it must
        ** be a plain, null resource.
        **
        ** Apache sets r->filename to known-dir/unknown-file and r->path_info
        ** to "" for the "proper" case. If anything is in path_info, then
        ** it can't be a locknull resource.
        **
        ** ### I bet this path_info hack doesn't work for repositories.
        ** ### Need input from repository implementors! What kind of
        ** ### restructure do we need? New provider APIs?
        */
        if (r->path_info != NULL && *r->path_info != '\0') {
            return DAV_RESOURCE_NULL;
        }

        if ((err = (*hooks->open_lockdb)(r, 1, 1, &lockdb)) == NULL) {
            /* note that we might see some expired locks... *shrug* */
            err = (*hooks->has_locks)(lockdb, resource, &locks_present);
            (*hooks->close_lockdb)(lockdb);
        }

        if (err != NULL) {
            /* ### don't log an error. return err. add higher-level desc. */

            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(00623)
                          "Failed to query lock-null status for %s",
                          r->filename);

            return DAV_RESOURCE_ERROR;
        }

        if (locks_present)
            return DAV_RESOURCE_LOCK_NULL;
    }

    return DAV_RESOURCE_NULL;
}