Zlib.gzip

(::String) -> ::String

(::String, level: ::Integer) -> ::String

(::String, strategy: ::Integer) -> ::String

(::String, level: ::Integer, strategy: ::Integer) -> ::String

Zlib.gzip(src, level: nil, strategy: nil) → String

static VALUE
zlib_s_gzip(int argc, VALUE *argv, VALUE klass)
{
    struct gzfile gz0;
    struct gzfile *gz = &gz0;
    int err;
    VALUE src, opts, level=Qnil, strategy=Qnil, args[2];

    if (OPTHASH_GIVEN_P(opts)) {
        ID keyword_ids[2];
        VALUE kwargs[2];
        keyword_ids[0] = id_level;
        keyword_ids[1] = id_strategy;
        rb_get_kwargs(opts, keyword_ids, 0, 2, kwargs);
        if (kwargs[0] != Qundef) {
            level = kwargs[0];
        }
        if (kwargs[1] != Qundef) {
            strategy = kwargs[1];
        }
    }
    rb_scan_args(argc, argv, "10", &src);
    StringValue(src);
    gzfile_init(gz, &deflate_funcs, zlib_gzip_end);
    gz->level = ARG_LEVEL(level);
    err = deflateInit2(&gz->z.stream, gz->level, Z_DEFLATED,
                       -MAX_WBITS, DEF_MEM_LEVEL, ARG_STRATEGY(strategy));
    if (err != Z_OK) {
        zlib_gzip_end(gz);
        raise_zlib_error(err, gz->z.stream.msg);
    }
    ZSTREAM_READY(&gz->z);
    args[0] = (VALUE)gz;
    args[1] = src;
    return rb_ensure(zlib_gzip_run, (VALUE)args, zlib_gzip_ensure, (VALUE)gz);
}

Gzip the given string. Valid values of level are Zlib::NO_COMPRESSION, Zlib::BEST_SPEED, Zlib::BEST_COMPRESSION, Zlib::DEFAULT_COMPRESSION (default), or an integer from 0 to 9.

This method is almost equivalent to the following code:

Example

def gzip(string, level: nil, strategy: nil)
  sio = StringIO.new
  sio.binmode
  gz = Zlib::GzipWriter.new(sio, level, strategy)
  gz.write(string)
  gz.close
  sio.string
end