Class: Zlib::GzipFile

Inherits:
Object
  • Object
show all
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 collapse

Instance Method Summary collapse

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.



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# File 'zlib.c', line 3083

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

Instance Method Details

#closeObject

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



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# File 'zlib.c', line 3297

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

    io = gz->io;
    gzfile_close(gz, 1);
    return io;
}

#closed?Boolean

Same as IO#closed?

Returns:

  • (Boolean)


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# File 'zlib.c', line 3332

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;
}

#commentObject

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



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# File 'zlib.c', line 3186

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

#crcObject

Returns CRC value of the uncompressed data.



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# File 'zlib.c', line 3124

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

#finishObject

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.



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# File 'zlib.c', line 3315

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

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

#levelObject

Returns compression level.



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# File 'zlib.c', line 3146

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

#mtimeObject

Returns last modification time recorded in the gzip file header.



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# File 'zlib.c', line 3135

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

#orig_nameObject

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



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# File 'zlib.c', line 3169

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

#os_codeObject

Returns OS code number recorded in the gzip file header.



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# File 'zlib.c', line 3157

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

#syncObject

Same as IO#sync



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# File 'zlib.c', line 3358

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.



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# File 'zlib.c', line 3373

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_ioObject

Same as IO.



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# File 'zlib.c', line 3113

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