Class: Zlib::Inflate

Inherits:
ZStream show all
Defined in:
zlib.c

Overview

Zlib:Inflate is the class for decompressing compressed data. Unlike Zlib::Deflate, an instance of this class is not able to duplicate (clone, dup) itself.

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from ZStream

#adler, #avail_in, #avail_out, #avail_out=, #close, #closed?, #data_type, #end, #ended?, #finish, #finished?, #flush_next_in, #flush_next_out, #reset, #stream_end?, #total_in, #total_out

Constructor Details

#Zlib::Inflate.new(window_bits) ⇒ Object

Creates a new inflate stream for decompression. See zlib.h for details of the argument. If window_bits is nil, the default value is used.

TODO: document better!




# File 'zlib.c'

/*
 * call-seq: Zlib::Inflate.new(window_bits)
 *
 * Creates a new inflate stream for decompression. See zlib.h for details
 * of the argument.  If +window_bits+ is +nil+, the default value is used.
 *
 * TODO: document better!
 */
static VALUE
rb_inflate_initialize(argc, argv, obj)
    int argc;
    VALUE *argv;
    VALUE obj;
{
    struct zstream *z;
    VALUE wbits;
    int err;

    rb_scan_args(argc, argv, "01", &wbits);
    Data_Get_Struct(obj, struct zstream, z);

    err = inflateInit2(&z->stream, ARG_WBITS(wbits));
    if (err != Z_OK) {
    raise_zlib_error(err, z->stream.msg);
    }
    ZSTREAM_READY(z);

    return obj;
}

Class Method Details

.Zlib::Inflate.inflate(string) ⇒ Object

Decompresses string. Raises a Zlib::NeedDict exception if a preset dictionary is needed for decompression.

This method is almost equivalent to the following code:

def inflate(string)
  zstream = Zlib::Inflate.new
  buf = zstream.inflate(string)
  zstream.finish
  zstream.close
  buf
end




# File 'zlib.c'

/*
 * call-seq: Zlib::Inflate.inflate(string)
 *
 * Decompresses +string+. Raises a Zlib::NeedDict exception if a preset
 * dictionary is needed for decompression.
 *
 * This method is almost equivalent to the following code:
 *
 *   def inflate(string)
 *     zstream = Zlib::Inflate.new
 *     buf = zstream.inflate(string)
 *     zstream.finish
 *     zstream.close
 *     buf
 *   end
 *
 */
static VALUE
rb_inflate_s_inflate(obj, src)
    VALUE obj, src;
{
    struct zstream z;
    VALUE dst, args[2];
    int err;

    StringValue(src);
    zstream_init_inflate(&z);
    err = inflateInit(&z.stream);
    if (err != Z_OK) {
    raise_zlib_error(err, z.stream.msg);
    }
    ZSTREAM_READY(&z);

    args[0] = (VALUE)&z;
    args[1] = src;
    dst = rb_ensure(inflate_run, (VALUE)args, zstream_end, (VALUE)&z);

    OBJ_INFECT(dst, src);
    return dst;
}

Instance Method Details

#<< ⇒ Object

Same as IO.




# File 'zlib.c'

/*
 * call-seq: << string
 *
 * Inputs +string+ into the inflate stream just like Zlib::Inflate#inflate, but
 * returns the Zlib::Inflate object itself.  The output from the stream is
 * preserved in output buffer.
 */
static VALUE
rb_inflate_addstr(obj, src)
    VALUE obj, src;
{
    struct zstream *z = get_zstream(obj);

    OBJ_INFECT(obj, src);

    if (ZSTREAM_IS_FINISHED(z)) {
    if (!NIL_P(src)) {
        StringValue(src);
        zstream_append_buffer2(z, src);
    }
    }
    else {
    do_inflate(z, src);
    if (ZSTREAM_IS_FINISHED(z)) {
        zstream_passthrough_input(z);
    }
    }

    return obj;
}

#inflate(string) ⇒ Object

Inputs string into the inflate stream and returns the output from the stream. Calling this method, both the input and the output buffer of the stream are flushed. If string is nil, this method finishes the stream, just like Zlib::ZStream#finish.

Raises a Zlib::NeedDict exception if a preset dictionary is needed to decompress. Set the dictionary by Zlib::Inflate#set_dictionary and then call this method again with an empty string. (???)

TODO: document better!




# File 'zlib.c'

/*
 * call-seq: inflate(string)
 *
 * Inputs +string+ into the inflate stream and returns the output from the
 * stream.  Calling this method, both the input and the output buffer of the
 * stream are flushed.  If string is +nil+, this method finishes the stream,
 * just like Zlib::ZStream#finish.
 *
 * Raises a Zlib::NeedDict exception if a preset dictionary is needed to
 * decompress.  Set the dictionary by Zlib::Inflate#set_dictionary and then
 * call this method again with an empty string.  (<i>???</i>)
 *
 * TODO: document better!
 */
static VALUE
rb_inflate_inflate(obj, src)
    VALUE obj, src;
{
    struct zstream *z = get_zstream(obj);
    VALUE dst;

    OBJ_INFECT(obj, src);

    if (ZSTREAM_IS_FINISHED(z)) {
    if (NIL_P(src)) {
        dst = zstream_detach_buffer(z);
    }
    else {
        StringValue(src);
        zstream_append_buffer2(z, src);
        dst = rb_str_new(0, 0);
    }
    }
    else {
    do_inflate(z, src);
    dst = zstream_detach_buffer(z);
    if (ZSTREAM_IS_FINISHED(z)) {
        zstream_passthrough_input(z);
    }
    }

    OBJ_INFECT(dst, obj);
    return dst;
}

#set_dictionary ⇒ Object

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!




# File 'zlib.c'

/*
 * 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;
}

#sync(string) ⇒ Object

Inputs string into the end of input buffer and skips data until a full flush point can be found. If the point is found in the buffer, this method flushes the buffer and returns false. Otherwise it returns true and the following data of full flush point is preserved in the buffer.




# File 'zlib.c'

/*
 * call-seq: sync(string)
 *
 * Inputs +string+ into the end of input buffer and skips data until a full
 * flush point can be found.  If the point is found in the buffer, this method
 * flushes the buffer and returns false.  Otherwise it returns +true+ and the
 * following data of full flush point is preserved in the buffer.
 */
static VALUE
rb_inflate_sync(obj, src)
    VALUE obj, src;
{
    struct zstream *z = get_zstream(obj);

    OBJ_INFECT(obj, src);
    StringValue(src);
    return zstream_sync(z, RSTRING(src)->ptr, RSTRING(src)->len);
}

#sync_point? ⇒ Object

Quoted verbatim from original documentation:

What is this?

:)




# File 'zlib.c'

/*
 * Quoted verbatim from original documentation:
 *
 *   What is this?
 *
 * <tt>:)</tt>
 */
static VALUE
rb_inflate_sync_point_p(obj)
    VALUE obj;
{
    struct zstream *z = get_zstream(obj);
    int err;

    err = inflateSyncPoint(&z->stream);
    if (err == 1) {
    return Qtrue;
    }
    if (err != Z_OK) {
    raise_zlib_error(err, z->stream.msg);
    }
    return Qfalse;
}