Zlib::Deflate ^(Class)

/*
 * call-seq: Zlib::Deflate.deflate(string[, level])
 *
 * Compresses the given +string+. Valid values of level are
 * <tt>Zlib::NO_COMPRESSION</tt>, <tt>Zlib::BEST_SPEED</tt>,
 * <tt>Zlib::BEST_COMPRESSION</tt>, <tt>Zlib::DEFAULT_COMPRESSION</tt>, and an
 * integer from 0 to 9.
 *
 * This method is almost equivalent to the following code:
 *
 *   def deflate(string, level)
 *     z = Zlib::Deflate.new(level)
 *     dst = z.deflate(string, Zlib::FINISH)
 *     z.close
 *     dst
 *   end
 *
 * TODO: what's default value of +level+?
 *
 */
static VALUE
rb_deflate_s_deflate(argc, argv, klass)
    int argc;
    VALUE *argv;
    VALUE klass;
{
    struct zstream z;
    VALUE src, level, dst;
    int err;

    rb_scan_args(argc, argv, "11", &src, &level);

    zstream_init_deflate(&z);
    err = deflateInit(&z.stream, ARG_LEVEL(level));
    if (err != Z_OK) {
	raise_zlib_error(err, z.stream.msg);
    }
    ZSTREAM_READY(&z);

    StringValue(src);
    zstream_run(&z, RSTRING(src)->ptr, RSTRING(src)->len, Z_FINISH);
    dst = zstream_detach_buffer(&z);
    zstream_end(&z);

    OBJ_INFECT(dst, src);
    return dst;
}

/*
 * call-seq: Zlib::Deflate.new(level=nil, windowBits=nil, memlevel=nil, strategy=nil)
 *
 * Creates a new deflate stream for compression. See zlib.h for details of
 * each argument. If an argument is nil, the default value of that argument is
 * used.
 *
 * TODO: document better!
 */
static VALUE
rb_deflate_initialize(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    struct zstream *z;
    VALUE level, wbits, memlevel, strategy;
    int err;

    rb_scan_args(argc, argv, "04", &level, &wbits, &memlevel, &strategy);
    Data_Get_Struct(obj, struct zstream, z);

    err = deflateInit2(&z->stream, ARG_LEVEL(level), Z_DEFLATED,
		       ARG_WBITS(wbits), ARG_MEMLEVEL(memlevel),
		       ARG_STRATEGY(strategy));
    if (err != Z_OK) {
	raise_zlib_error(err, z->stream.msg);
    }
    ZSTREAM_READY(z);

    return obj;
}

/*
 * call-seq: << string
 *
 * Inputs +string+ into the deflate stream just like Zlib::Deflate#deflate, but
 * returns the Zlib::Deflate object itself.  The output from the stream is
 * preserved in output buffer.
 */
static VALUE
rb_deflate_addstr(obj, src)
    VALUE obj, src;
{
    OBJ_INFECT(obj, src);
    do_deflate(get_zstream(obj), src, Z_NO_FLUSH);
    return obj;
}

/*
 * Duplicates the deflate stream.
 */
static VALUE
rb_deflate_clone(obj)
    VALUE obj;
{
    struct zstream *z = get_zstream(obj);
    struct zstream *z2;
    VALUE clone;
    int err;

    clone = zstream_deflate_new(rb_class_of(obj));
    Data_Get_Struct(clone, struct zstream, z2);

    err = deflateCopy(&z2->stream, &z->stream);
    if (err != Z_OK) {
	raise_zlib_error(err, 0);
    }

    z2->flags = z->flags;
    CLONESETUP(clone, obj);
    OBJ_INFECT(clone, obj);
    return clone;
}

/*
 * call-seq: deflate(string[, flush])
 *
 * Inputs +string+ into the deflate stream and returns the output from the
 * stream.  On calling this method, both the input and the output buffers of
 * the stream are flushed. If +string+ is nil, this method finishes the
 * stream, just like Zlib::ZStream#finish.
 *
 * The value of +flush+ should be either <tt>Zlib::NO_FLUSH</tt>,
 * <tt>Zlib::SYNC_FLUSH</tt>, <tt>Zlib::FULL_FLUSH</tt>, or
 * <tt>Zlib::FINISH</tt>. See zlib.h for details.
 *
 * TODO: document better!
 */
static VALUE
rb_deflate_deflate(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    struct zstream *z = get_zstream(obj);
    VALUE src, flush, dst;

    rb_scan_args(argc, argv, "11", &src, &flush);
    OBJ_INFECT(obj, src);
    do_deflate(z, src, ARG_FLUSH(flush));
    dst = zstream_detach_buffer(z);

    OBJ_INFECT(dst, obj);
    return dst;
}

/*
 * call-seq: flush(flush)
 *
 * This method is equivalent to <tt>deflate('', flush)</tt>.  If flush is omitted,
 * <tt>Zlib::SYNC_FLUSH</tt> is used as flush.  This method is just provided
 * to improve the readability of your Ruby program.
 *
 * TODO: document better!
 */
static VALUE
rb_deflate_flush(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    struct zstream *z = get_zstream(obj);
    VALUE v_flush, dst;
    int flush;

    rb_scan_args(argc, argv, "01", &v_flush);
    flush = FIXNUMARG(v_flush, Z_SYNC_FLUSH);
    if (flush != Z_NO_FLUSH) {  /* prevent Z_BUF_ERROR */
	zstream_run(z, "", 0, flush);
    }
    dst = zstream_detach_buffer(z);

    OBJ_INFECT(dst, obj);
    return dst;
}

/*
 * call-seq: params(level, strategy)
 * 
 * Changes the parameters of the deflate stream. See zlib.h for details. The
 * output from the stream by changing the params is preserved in output
 * buffer.
 *
 * TODO: document better!
 */
static VALUE
rb_deflate_params(obj, v_level, v_strategy)
    VALUE obj, v_level, v_strategy;
{
    struct zstream *z = get_zstream(obj);
    int level, strategy;
    int err;

    level = ARG_LEVEL(v_level);
    strategy = ARG_STRATEGY(v_strategy);

    err = deflateParams(&z->stream, level, strategy);
    while (err == Z_BUF_ERROR) {
	if (RTEST(ruby_debug)) {
	    rb_warning("deflateParams() returned Z_BUF_ERROR");
	}
	zstream_expand_buffer(z);
	err = deflateParams(&z->stream, level, strategy);
    }
    if (err != Z_OK) {
	raise_zlib_error(err, z->stream.msg);
    }

    return Qnil;
}

/*
 * call-seq: set_dictionary(string)
 *
 * Sets the preset dictionary and returns +string+. This method is available
 * just only after Zlib::Deflate.new or Zlib::ZStream#reset method was called.
 * See zlib.h for details.
 *
 * TODO: document better!
 */
static VALUE
rb_deflate_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 = deflateSetDictionary(&z->stream,
			       RSTRING(src)->ptr, RSTRING(src)->len);
    if (err != Z_OK) {
	raise_zlib_error(err, z->stream.msg);
    }

    return dic;
}