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In Files

  • zlib/zlib.c

Zlib::Inflate

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.

Public Class Methods

Zlib::Inflate.inflate(string) click to toggle source

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(VALUE obj, VALUE 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;
}
            
Zlib::Inflate.new(window_bits) click to toggle source

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(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;
}
            

Public Instance Methods

<<(p1) click to toggle source

Same as IO.

 
               static VALUE
rb_inflate_addstr(VALUE obj, VALUE 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) click to toggle source

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 #set_dictionary and then call this method again with an empty string. (???)

TODO: document better!

 
               static VALUE
rb_inflate_inflate(VALUE obj, VALUE 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(p1) click to toggle source

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(VALUE obj, VALUE dic)
{
    struct zstream *z = get_zstream(obj);
    VALUE src = dic;
    int err;

    OBJ_INFECT(obj, dic);
    StringValue(src);
    err = inflateSetDictionary(&z->stream,
                               (Bytef*)RSTRING_PTR(src), RSTRING_LEN(src));
    if (err != Z_OK) {
        raise_zlib_error(err, z->stream.msg);
    }

    return dic;
}
            
sync(string) click to toggle source

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(VALUE obj, VALUE src)
{
    struct zstream *z = get_zstream(obj);

    OBJ_INFECT(obj, src);
    StringValue(src);
    return zstream_sync(z, (Bytef*)RSTRING_PTR(src), RSTRING_LEN(src));
}
            
sync_point?() click to toggle source

Quoted verbatim from original documentation:

What is this?

:)

 
               static VALUE
rb_inflate_sync_point_p(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;
}
            

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