Class: Zlib::GzipFile

Inherits:

Object

• Object
• Zlib::GzipFile

Defined in:

zlib.c,
zlib.c

Overview

Zlib::GzipFile is an abstract class for handling a gzip formatted compressed file. The operations are defined in the subclasses, Zlib::GzipReader for reading, and Zlib::GzipWriter for writing.

GzipReader should be used by associating an IO, or IO-like, object.

Method Catalogue

• ::wrap

• ::open (Zlib::GzipReader::open and Zlib::GzipWriter::open)

• #close

• #closed?

• #comment

• comment= (Zlib::GzipWriter#comment=)

• #crc

• eof? (Zlib::GzipReader#eof?)

• #finish

• #level

• lineno (Zlib::GzipReader#lineno)

• lineno= (Zlib::GzipReader#lineno=)

• #mtime

• mtime= (Zlib::GzipWriter#mtime=)

• #orig_name

• orig_name (Zlib::GzipWriter#orig_name=)

• #os_code

• path (when the underlying IO supports #path)

• #sync

• #sync=

• #to_io

(due to internal structure, documentation may appear under Zlib::GzipReader or Zlib::GzipWriter)

Direct Known Subclasses

GzipReader, GzipWriter

Defined Under Namespace

Classes: CRCError, Error, LengthError, NoFooter

Class Method Summary

• .wrap(*args) ⇒ Object

  call-seq: Zlib::GzipReader.wrap(io, …) { |gz| … } Zlib::GzipWriter.wrap(io, …) { |gz| … }.

Instance Method Summary

• #close ⇒ Object

  Closes the GzipFile object.

• #closed? ⇒ Boolean

  Same as IO#closed?.

• #comment ⇒ Object

  Returns comments recorded in the gzip file header, or nil if the comments is not present.

• #crc ⇒ Object

  Returns CRC value of the uncompressed data.

• #finish ⇒ Object

  Closes the GzipFile object.

• #level ⇒ Object

  Returns compression level.

• #mtime ⇒ Object

  Returns last modification time recorded in the gzip file header.

• #orig_name ⇒ Object

  Returns original filename recorded in the gzip file header, or nil if original filename is not present.

• #os_code ⇒ Object

  Returns OS code number recorded in the gzip file header.

• #sync ⇒ Object

  Same as IO#sync.

• #sync=(mode) ⇒ Object

  call-seq: sync = flag.

• #to_io ⇒ Object

  Same as IO.

Class Method Details

.wrap(*args) ⇒ Object

call-seq:

Zlib::GzipReader.wrap(io, ...) { |gz| ... }
Zlib::GzipWriter.wrap(io, ...) { |gz| ... }

Creates a GzipReader or GzipWriter associated with io, passing in any necessary extra options, and executes the block with the newly created object just like File.open.

The GzipFile object will be closed automatically after executing the block. If you want to keep the associated IO object open, you may call Zlib::GzipFile#finish method in the block.

# File 'zlib.c', line 3223

static VALUE
rb_gzfile_s_wrap(int argc, VALUE *argv, VALUE klass)
{
    return gzfile_wrap(argc, argv, klass, 0);
}

Instance Method Details

#close ⇒ Object

Closes the GzipFile object. This method calls close method of the associated IO object. Returns the associated IO object.

# File 'zlib.c', line 3447

static VALUE
rb_gzfile_close(VALUE obj)
{
    struct gzfile *gz;
    VALUE io;

    TypedData_Get_Struct(obj, struct gzfile, &gzfile_data_type, gz);
    if (!ZSTREAM_IS_READY(&gz->z)) {
        return Qnil;
    }
    io = gz->io;
    gzfile_close(gz, 1);
    return io;
}

#closed? ⇒ Boolean

Same as IO#closed?

Returns:

• (Boolean)

# File 'zlib.c', line 3486

static VALUE
rb_gzfile_closed_p(VALUE obj)
{
    struct gzfile *gz;
    TypedData_Get_Struct(obj, struct gzfile, &gzfile_data_type, gz);
    return NIL_P(gz->io) ? Qtrue : Qfalse;
}

#comment ⇒ Object

Returns comments recorded in the gzip file header, or nil if the comments is not present.

# File 'zlib.c', line 3323

static VALUE
rb_gzfile_comment(VALUE obj)
{
    VALUE str = get_gzfile(obj)->comment;
    if (!NIL_P(str)) {
  str = rb_str_dup(str);
    }
    return str;
}

#crc ⇒ Object

Returns CRC value of the uncompressed data.

# File 'zlib.c', line 3262

static VALUE
rb_gzfile_crc(VALUE obj)
{
    return rb_uint2inum(get_gzfile(obj)->crc);
}

#finish ⇒ Object

Closes the GzipFile object. Unlike Zlib::GzipFile#close, this method never calls the close method of the associated IO object. Returns the associated IO object.

# File 'zlib.c', line 3469

static VALUE
rb_gzfile_finish(VALUE obj)
{
    struct gzfile *gz = get_gzfile(obj);
    VALUE io;

    io = gz->io;
    gzfile_close(gz, 0);
    return io;
}

#level ⇒ Object

Returns compression level.

# File 'zlib.c', line 3284

static VALUE
rb_gzfile_level(VALUE obj)
{
    return INT2FIX(get_gzfile(obj)->level);
}

#mtime ⇒ Object

Returns last modification time recorded in the gzip file header.

# File 'zlib.c', line 3273

static VALUE
rb_gzfile_mtime(VALUE obj)
{
    return rb_time_new(get_gzfile(obj)->mtime, (time_t)0);
}

#orig_name ⇒ Object

Returns original filename recorded in the gzip file header, or nil if original filename is not present.

# File 'zlib.c', line 3307

static VALUE
rb_gzfile_orig_name(VALUE obj)
{
    VALUE str = get_gzfile(obj)->orig_name;
    if (!NIL_P(str)) {
  str = rb_str_dup(str);
    }
    return str;
}

#os_code ⇒ Object

Returns OS code number recorded in the gzip file header.

# File 'zlib.c', line 3295

static VALUE
rb_gzfile_os_code(VALUE obj)
{
    return INT2FIX(get_gzfile(obj)->os_code);
}

#sync ⇒ Object

Same as IO#sync

# File 'zlib.c', line 3515

static VALUE
rb_gzfile_sync(VALUE obj)
{
    return (get_gzfile(obj)->z.flags & GZFILE_FLAG_SYNC) ? Qtrue : Qfalse;
}

#sync=(mode) ⇒ Object

call-seq: sync = flag

Same as IO. If flag is true, the associated IO object must respond to the flush method. While sync mode is true, the compression ratio decreases sharply.

# File 'zlib.c', line 3530

static VALUE
rb_gzfile_set_sync(VALUE obj, VALUE mode)
{
    struct gzfile *gz = get_gzfile(obj);

    if (RTEST(mode)) {
  gz->z.flags |= GZFILE_FLAG_SYNC;
    }
    else {
  gz->z.flags &= ~GZFILE_FLAG_SYNC;
    }
    return mode;
}

#to_io ⇒ Object

Same as IO.

# File 'zlib.c', line 3251

static VALUE
rb_gzfile_to_io(VALUE obj)
{
    return get_gzfile(obj)->io;
}