set_dictionary

/*
 * Sets the preset dictionary and returns +string+.  This method is available just
 * only after a Zlib::NeedDict exception was raised.  See zlib.h for details.
 *
 * TODO: document better!
 */
static VALUE
rb_inflate_set_dictionary(obj, dic)
    VALUE obj, dic;
{
    struct zstream *z = get_zstream(obj);
    VALUE src = dic;
    int err;

    OBJ_INFECT(obj, dic);
    StringValue(src);
    err = inflateSetDictionary(&z->stream,
                               RSTRING(src)->ptr, RSTRING(src)->len);
    if (err != Z_OK) {
        raise_zlib_error(err, z->stream.msg);
    }

    return dic;
}