=begin
#
# zlib.rd.src
#
#   Copyright (C) UENO Katsuhiro 2000-2002
#
#   $Id: zlib.rd.src,v 1.14 2002/03/13 19:13:14 katsu Exp $
#


= Ruby/zlib version 0.5.0

Ruby/zlib is an extension library to use zlib from Ruby.
Ruby/zlib also provides the features for accessing gzipped files.

You can modify or redistribute Ruby/zlib in the same manner of Ruby
interpreter. The latest version of Ruby/zlib would be found at
((<URL:http://www.blue.sky.or.jp/>)).

Any comments and suggestions are always welcome. Please send them to
ruby-list ML, ruby-ext ML, ruby-talk ML, or the author's mail address
((<URL:mailto:katsu@blue.sky.or.jp>)).

This document is experimental and broken English version.
If you find some mistakes or strange expressions (including kidding
or unnatural ones) in this document, please let me know for my study.

  * ((<Zlib>))
        * ((<Zlib::Error>))
        * ((<Zlib::ZStream>))
        * ((<Zlib::Deflate>))
        * ((<Zlib::Inflate>))
        * ((<Zlib::GzipFile>))
          * ((<Zlib::GzipFile::Error>))
        * ((<Zlib::GzipWriter>))
        * ((<Zlib::GzipReader>))
  * ((<Changes from 0.4.0>))



== Zlib

Zlib is the module which provides the other features in zlib C
library. See zlib.h for detail of each module function.

=== Module Functions:

--- Zlib.version
        Returns the string which represents the version of zlib
        library.

--- Zlib.adlar32([string[, adlar]])
        Calculates Alder-32 checksum for ((|string|)),
        and returns updated value of ((|alder|)).
        If ((|string|)) is omitted, it returns the Adler-32 initial
        value. If ((|alder|)) is omitted, it assumes that the initial
        value is given to ((|alder|)).

--- Zlib.crc32([string[, crc]])
        Calculates CRC checksum for ((|string|)), and returns
        updated value of ((|crc|)). If ((|string|)) is omitted,
        it returns the CRC initial value. ((|crc|)) is omitted,
        it assumes that the initial value is given to ((|crc|)).


--- Zlib.crc_table
        Returns the table for calculating CRC checksum as an array.

=== Constants:

--- Zlib::VERSION
        The string which represents the version of zlib.h.

--- Zlib::BINARY
--- Zlib::ASCII
--- Zlib::UNKNOWN
        The integers representing data types which
        ((<Zlib::ZStream#data_type>)) method returns.

--- Zlib::NO_COMPRESSION
--- Zlib::BEST_SPEED
--- Zlib::BEST_COMPRESSION
--- Zlib::DEFAULT_COMPRESSION
        The integers representing compression levels which are
        an argument for ((<Zlib::Deflate.new>)),
        ((<Zlib::Deflate#deflate>)), and so on.

--- Zlib::FILTERED
--- Zlib::HUFFMAN_ONLY
--- Zlib::DEFAULT_STRATEGY
        The integers representing compression methods which are
        an argument for ((<Zlib::Deflate.new>)) and
        ((<Zlib::Deflate#params>)).

--- Zlib::DEF_MEM_LEVEL
--- Zlib::MAX_MEM_LEVEL
        The integers representing memory levels which are an
        argument for ((<Zlib::Deflate.new>)),
        ((<Zlib::Deflate#params>)), and so on.

--- Zlib::MAX_WBITS
        The default value of ((|windowBits|)) which is an argument for
        ((<Zlib::Deflate.new>)) and ((<Zlib::Inflate.new>)).

--- Zlib::NO_FLUSH
--- Zlib::SYNC_FLUSH
--- Zlib::FULL_FLUSH
--- Zlib::FINISH
        The integers to control the output of the deflate stream,
        which are an argument for ((<Zlib::Deflate#deflate>)) and so on.

--- Zlib::OS_CODE
--- Zlib::OS_MSDOS
--- Zlib::OS_AMIGA
--- Zlib::OS_VMS
--- Zlib::OS_UNIX
--- Zlib::OS_ATARI
--- Zlib::OS_OS
--- Zlib::OS_MACOS
--- Zlib::OS_TOPS
--- Zlib::OS_WIN
        The return values of ((<Zlib::GzipFile#os_code>)) method.



== Zlib::Error

The superclass for all excpetions raised by Ruby/zlib.

The following exceptions are defined as subclasses of Zlib::Error.
These exceptions are raised when zlib library functions return
with an error status.

  * Zlib::StreamEnd
  * Zlib::NeedDict
  * Zlib::DataError
  * Zlib::StreamError
  * Zlib::MemError
  * Zlib::BufError
  * Zlib::VersionError

=== SuperClass:

* StandardError



== Zlib::ZStream

The abstruct class for the stream which handles the compressed data.
The operations are defined in the subclasses, ((<Zlib::Deflate>))
for compression, and ((<Zlib::Inflate>)) for decpmpression.

An instance of Zlib::ZStream has one stream (struct zstream) and
two variable-length buffers which associated to the input (next_in)
of the stream and the output (next_out) of the stream. In this document,
"input buffer" means the buffer for input, and "output buffer" means
the buffer for output.

Data inputed into an instance of Zlib::ZStream are temporally
stored into the end of input buffer, and then data in input buffer
are processed from the beginning of the buffer until no more
output from the stream is produced (i.e. until avail_out > 0
after processing). During processing, output buffer is allocated
and expanded automatically to hold all output data.

Some paticular instance methods consume the data in output buffer
and return them as a String.

Here is an ascii art for describing above:

     +================ an instance of Zlib::ZStream ================+
     ||                                                            ||
     ||     +--------+          +-------+          +--------+      ||
     ||  +--| output |<---------|zstream|<---------| input  |<--+  ||
     ||  |  | buffer |  next_out+-------+next_in   | buffer |   |  ||
     ||  |  +--------+                             +--------+   |  ||
     ||  |                                                      |  ||
     +===|======================================================|===+
         |                                                      |
         v                                                      |
     "output data"                                         "input data"

If an error is occured during processing input buffer,
an exception which is a subclass of ((<Zlib::Error>)) is raised.
At that time, both input and output buffer keeps their conditions
at the time when the error is occured.

=== SuperClass:

* Object

=== Class Methods:

--- Zlib::ZStream.new
        See ((<Zlib::Deflate.new>)) and ((<Zlib::Inflate.new>)).

=== Methods:

--- Zlib::ZStream#avail_in
        Returns bytes of data in input buffer.
        Normally, returns 0.

--- Zlib::ZStream#avail_out
        Returns bytes of free spaces in output buffer.
        Because the free spaces are allocated automatically,
        this method returns 0 normally.

--- Zlib::ZStream#avail_out = size
        Allocates free spaces of ((|size|)) bytes in output buffer.
        If there are more than ((|size|)) bytes spaces in the buffer,
        the buffer is truncated.
        Because the free spaces are allocated automatically,
        you usually need not to use this method.

--- Zlib::ZStream#flush_next_in
        Flushes input buffer and returns all data in that buffer.

--- Zlib::ZStream#flush_next_out
        Flushes output buffer and returns all data in that buffer.

--- Zlib::ZStream#total_in
        Returns the total bytes of the input data to the stream.

--- Zlib::ZStream#total_out
        Returns the total bytes of the output data from the stream.

--- Zlib::ZStream#data_type
        Guesses the type of the data which have been inputed into
        the stream. The returned value is either ((<Zlib::BINARY>)),
        ((<Zlib::ASCII>)), or ((<Zlib::UNKNOWN>)).

--- Zlib::ZStream#adler
        Returns the alder-32 checksum.

--- Zlib::ZStream#reset
        Resets and initializes the stream. All data in both
        input and output buffer are discarded.

--- Zlib::ZStream#finish
        Finishes the stream and flushes output buffer.
        See ((<Zlib::Deflate#finish>)) and ((<Zlib::Inflate#finish>))
        for detail of the behavior.

--- Zlib::ZStream#finished?
--- Zlib::ZStream#stream_end?
        Returns true if the stream is finished.

--- Zlib::ZStream#close
--- Zlib::ZStream#end
        Closes the stream. All operations on the closed stream
        will raise an exception.

--- Zlib::ZStream#closed?
--- Zlib::ZStream#ended?
        Returns true if the stream closed.



== Zlib::Deflate

The class for compressing string data.

=== SuperClass:

* ((<Zlib::ZStream>))

=== Class Methods:

--- Zlib::Deflate.deflate(string[, level])
        Compresses ((|string|)). The avail values of ((|level|)) are
        ((<Zlib::NO_COMPRESSION>)), ((<Zlib::BEST_SPEED>)),
        ((<Zlib::BEST_COMPRESSION>)), ((<Zlib::DEFAULT_COMPRESSION>)),
        and the integer from 0 to 9.

        This method is almostly equivalant to the following code:

                def deflate(string, level)
                  z = Zlib::Deflate.new(level)
                  dst = z.deflate(string, Zlib::FINISH)
                  z.close
                  dst
                end

--- Zlib::Deflate.new([level[, windowBits[, memlevel[, strategy]]]])
        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.

=== Methods:

--- Zlib::Deflate#clone
        Duplicates the deflate stream.

--- Zlib::Deflate#deflate(string[, flush])
        Inputs ((|string|)) into the deflate stream and returns
        the output from the stream. Calling this method,
        both input and output buffer 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 ((<Zlib::NO_FLUSH>)),
        ((<Zlib::SYNC_FLUSH>)), ((<Zlib::FULL_FLUSH>)), or
        ((<Zlib::FINISH>)).
        See zlib.h for details.

--- Zlib::Deflate#<< string
        Inputs ((|string|)) into the deflate stream just like
        ((<Zlib::Deflate#deflate>)), but returns Zlib::Deflate object
        itself. The output from the stream is preserved in output
        buffer.

--- Zlib::Deflate#flush([flush])
        This method is equivalant to (({deflate('', ((|flush|)))})).
        If ((|flush|)) is omitted, ((<Zlib::SYNC_FLUSH>)) is used
        as ((|flush|)). This method is just provided for
        readability of your Ruby script.

--- Zlib::Deflate#finish
        Finishes the stream. This method is equivalant to
        (({deflate('', Zlib::FINISH)})).

--- Zlib::Deflate#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.

--- Zlib::Deflate#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.



== Zlib::Inflate

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

=== SuperClass:

* ((<Zlib::ZStream>))

=== Class Methods:

--- Zlib::Inflate.inflate(string)
        Decompresses ((|string|)). Raises a ((<Zlib::NeedDict>))
        exception if a preset dictionary is needed for decompression.

        This method is almostly equivalant to the following code:

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

--- Zlib::Inflate.new([windowBits])
        Creates a new inflate stream for decompression.
        See zlib.h for details of the argument.
        If ((|windowBits|)) is nil, the default value is used.

=== Methods:

--- Zlib::Inflate#inflate(string)
        Inputs ((|string|)) into the inflate stream and returns
        the output from the stream. Calling this method,
        both input and 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.

--- Zlib::Inflate#<< string
        Inputs ((|string|)) into the inflate stream just like
        ((<Zlib::Inflate#inflate>)), but returns Zlib::Inflate object
        itself. The output from the stream is preserved in output
        buffer.

--- Zlib::Inflate#finish
        Finishes the inflate stream and returns the garbage
        following the compressed data. Raises an exception
        if the stream is not finished
        (i.e. ((<Zlib::ZStream#finished?>)) doesn't returns true).

        The inflate stream finishes itself as soon as it meets
        the end code of the compressed data, you need not to call
        thisd method explicitly. However, this method is useful
        for checking whether the data is correctly ended or not.

--- Zlib::Inflate#set_dictionary(string)
        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.

--- Zlib::Inflate#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.

--- Zlib::Inflate#sync_point?
        What is this?



== Zlib::GzipFile

The abstruct 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 with associating an instance of IO class
(or an object which has the same methods as IO has).

=== SuperClass:

* Object

=== Class Methods:

--- Zlib::GzipFile.new(io)
        See ((<Zlib::GzipReader.new>)) and ((<Zlib::GzipWriter.new>)).

=== Methods:

--- Zlib::GzipFile#closed?
--- Zlib::GzipFile#to_io
        Same as IO.

--- Zlib::GzipFile#close([dont_close_io])
        Closes the GzipReader object. If ((|dont_close_io|)) is
        ommited or not true, close method of the associated IO object
        is called. Returns the associated IO object.

--- Zlib::GzipFile#crc
        Returns CRC value of the uncompressed data.

--- Zlib::GzipFile#level
        Returns compression level.

--- Zlib::GzipFile#mtime
        Returns last modification time recorded in the gzip
        file header.

--- Zlib::GzipFile#os_code
        Returns OS code number recorded in the gzip file header.

--- Zlib::GzipFile#orig_name
        Returns original filename recorded in the gzip file header,
        or nil if original filename is not present.

--- Zlib::GzipFile#comment
        Returns comments recorded in the gzip file header, or
        nil if the comments is not present.

--- Zlib::GzipFile#sync
--- Zlib::GzipFile#sync= flag
        Same as IO. If ((|flag|)) is true, the associated IO object
        must respond to flush method. While `sync' mode is true,
        the compression ratio decreases sharply.



== Zlib::GzipFile::Error

The superclass for all exceptions raised during processing a gzip
file.

The following exceptions are defined as subclasses of
Zlib::GzipFile::Error.

  : Zlib::GzipFile::NoFooter
        Raised when gzip file footer has not found.

  : Zlib::GzipFile::CRCError
        Raised when the CRC checksum recorded in gzip file footer
        is not equivalant to CRC checksum of the actually
        uncompressed data.

  : Zlib::GzipFile::LengthError
        Raised when the data length recorded in gzip file footer
        is not equivalant to length of the actually uncompressed data.

=== SuperClass:

* ((<Zlib::Error>))



== Zlib::GzipReader

The class for reading a gzipped file. GzipReader should be used with
associating an instance of IO class (or an object which has the same
methods as IO has).

	Zlib::GzipReader.open('hoge.gz') {|gz|
	  print gz.read
	}

        f = File.open('hoge.gz')
        gz = Zlib::GzipReader.new(f)
        print gz.read
        gz.close

=== SuperClass:

* ((<Zlib::GzipFile>))

=== Included Module:

* Enumerable

=== Class Methods:

--- Zlib::GzipReader.new(io)
--- Zlib::GzipReader.new(io) {|gz| ... }
        Creates a GzipReader object associated with ((|io|)).
        The GzipReader object reads gzipped data from ((|io|)),
        and parses/decompresses them. At least, ((|io|)) must have
        read method that behaves same as read method in IO class.

        If the gzip file header is incorrect, raises an
        ((<Zlib::GzipFile::Error>)) exception.

        If this method is called with a block, the block will be
        executed with a newly created GzipReader object, just like
        File.open. The GzipReader object will be closed
        automatically after executing the block. If you want to keep
        the associated IO object opening, you may call explicitly
        ((<Zlib::GzipFile#close>)) method with an argument in the block.

--- Zlib::GzipReader.open(filename)
--- Zlib::GzipReader.open(filename) {|gz| ... }
        Opens a file specified by ((|filename|)) as a gzipped file,
        and returns a GzipReader object associated with that file.
        Further details of this method are same as
        ((<Zlib::GzipReader.new>)).

=== Methods:

--- Zlib::GzipReader#eof
--- Zlib::GzipReader#eof?
        Returns true if the object reaches the end of ompressed data.
        Note that eof? does ((*not*)) return true when reaches the
        end of ((*file*)).

--- Zlib::GzipReader#pos
--- Zlib::GzipReader#tell
        Returns the total bytes of data decompressed until now.
        Not that it does ((*not*)) the position of file pointer.

--- Zlib::GzipReader#each([rs])
--- Zlib::GzipReader#each_line([rs])
--- Zlib::GzipReader#each_byte([rs])
--- Zlib::GzipReader#gets([rs])
--- Zlib::GzipReader#getc
--- Zlib::GzipReader#lineno
--- Zlib::GzipReader#lineno=
--- Zlib::GzipReader#read([length])
--- Zlib::GzipReader#readchar
--- Zlib::GzipReader#readline([rs])
--- Zlib::GzipReader#readlines([rs])
--- Zlib::GzipReader#ungetc(char)
        Same as IO, but raises ((<Zlib::Error>)) or
        ((<Zlib::GzipFile::Error>)) exception if an error was found
        in the gzip file.

        Be careful of the footer of gzip file. A gzip file has
        the checksum of pre-compressed data in its footer.
        GzipReader checks all uncompressed data against that checksum
        at the following cases, and if failed, raises
        ((<Zlib::GzipFile::NoFooter>)), ((<Zlib::GzipFile::CRCError>)),
        or ((<Zlib::GzipFile::LengthError>)) exception.

         * When an reading request is received beyond the end of file
           (the end of compressed data).
           That is, when ((<Zlib::GzipReader#read>)),
           ((<Zlib::GzipReader#gets>)), or some other methods for reading
           returns nil.
         * When ((<Zlib::GzipFile#close>)) method is called after
           the object reaches the end of file.
         * When ((<Zlib::GzipReader#unused>)) method is called after
           the object reaches the end of file.

--- Zlib::GzipReader#rewind
        Resets the position of the file pointer to the point
        created the GzipReader object.
        The associated IO object need to respond to seek method.

--- Zlib::GzipReader#unused
        Returns the rest of the data which had read for parsing gzip
        format, or nil if the whole gzip file is not parsed yet.



== Zlib::GzipWriter

The class for writing a gzipped file. GzipWriter should be used with
associate with an instance of IO class (or an object which has
the same methods as IO has).

	Zlib::GzipWriter.open('hoge.gz') {|gz|
	  gz.write 'jugemu jugemu gokou no surikire...'
	}

        f = File.open('hoge.gz', 'w')
        gz = Zlib::GzipWriter.new(f)
        gz.write 'jugemu jugemu gokou no surikire...'
        gz.close

NOTE: Due to the limitation in finalizer of Ruby, you must close
explicitly GzipWriter object by ((<Zlib::GzipWriter#close>)) etc.
Otherwise, GzipWriter should be not able to write gzip footer and
generate broken gzip file.

=== SuperClass:

* ((<Zlib::GzipFile>))

=== Class Methods:

--- Zlib::GzipWriter.new(io[, level[, strategy]])
--- Zlib::GzipWriter.new(io[, level[, strategy]]) {|gz| ... }
        Creates a GzipWriter object associated with ((|io|)).
        ((|level|)) and ((|strategy|)) should be same as the
        arguments of ((<Zlib::Deflate.new>)). The GzipWriter object
        writes gzipped data to ((|io|)). At least, ((|io|)) must
        respond to write method that behaves same as write method
        in IO class.

        If new is called with a block, the block will be executed
        with a newly created GzipWriter object, just like File.open.
        The GzipWriter object will be closed automatically after
        executing the block. If you want to keep the associated IO
        object opening, you may call explicitly
        ((<Zlib::GzipFile#close>)) method with an argument
        in the block explicitly.

--- Zlib::GzipWriter.open(filename[, level[, strategy]])
--- Zlib::GzipWriter.open(filename[, level[, strategy]]) {|gz| ... }
        Opens a file specified by ((|filename|)) for writing
        gzip compressed data, and returns a GzipWriter object
        associated with that file. Further details of this method
        are same as ((<Zlib::GzipWriter.new>)).

=== Methods:

--- Zlib::GzipWriter#close([dont_close_io])
        Writes the gzip file footer and closes the GzipWriter object.

        ((*NOTE: Due to the limitation in finalizer of Ruby, you must
        close GzipWriter object explicitly. Otherwise, GzipWriter
        should be not able to write gzip footer and generate broken
        gzip file.*))

--- Zlib::GzipWriter#pos
--- Zlib::GzipWriter#tell
        Returns the total bytes of data compressed until now.
        Note that it does ((*not*)) the position of file pointer.

--- Zlib::GzipWriter#<< str
--- Zlib::GzipWriter#putc(ch)
--- Zlib::GzipWriter#puts(obj...)
--- Zlib::GzipWriter#print(arg...)
--- Zlib::GzipWriter#printf(format, arg...)
--- Zlib::GzipWriter#write(str)
        Same as IO.

--- Zlib::GzipWriter#flush([flush])
        Flushes all the internal buffers of the GzipWriter object.
        The meaning of ((|flush|)) is same as one of the argument of
        ((<Zlib::Deflate#deflate>)).
        ((<Zlib::SYNC_FLUSH>)) is used if ((|flush|)) is omitted.
        It is no use giving ((|flush|)) ((<Zlib::NO_FLUSH>)).

--- Zlib::GzipWriter#mtime= time
        Sets last modification time to be stored in the gzip file
        header. ((<Zlib::GzipFile::Error>)) exception will be raised
        if this method is called after writing method (like
        ((<Zlib::GzipWriter#write>))) was called.

--- Zlib::GzipWriter#orig_name= filename
        Sets original filename to be stored in the gzip file header.
        ((<Zlib::GzipFile::Error>)) exception will be raised
        if this method is called after writing method (like
        ((<Zlib::GzipWriter#write>))) was called.

--- Zlib::GzipWriter#comment= string
        Sets comments to be stored in the gzip file header.
        ((<Zlib::GzipFile::Error>)) exception will be raised
        if this method is called after writing method (like
        ((<Zlib::GzipWriter#write>))) was called.



== Changes from 0.4.0

Almost all the code are rewritten.
I hope all changes are enumerated below :-)

 * The names of almost classes and some methods are changed.
   All classes and constants are now defined under module ((<Zlib>)).
   The obsoleted names are also available for backward compatibility.

   * Classes
        * Deflate -> ((<Zlib::Deflate>))
        * Inflate -> ((<Zlib::Inflate>))
        * Zlib::Gzip -> ((<Zlib::GzipFile>))
        * GzipReader -> ((<Zlib::GzipReader>))
        * GzipWriter -> ((<Zlib::GzipWriter>))
        * Zlib::Gzip::Error -> ((<Zlib::GzipFile::Error>))
        * Zlib::GzipReader::NoFooter -> ((<Zlib::GzipFile::NoFooter>))
        * Zlib::GzipReader::CRCError -> ((<Zlib::GzipFile::CRCError>))
        * Zlib::GzipReader::LengthError -> ((<Zlib::GzipFile::LengthError>))
   * Constants
        * Zlib::ZStream::BINARY -> ((<Zlib::BINARY>))
        * Zlib::ZStream::ASCII -> ((<Zlib::ASCII>))
        * Zlib::ZStream::UNKNOWN -> ((<Zlib::UNKNOWN>))
        * Zlib::Deflate::NO_COMPRESSION -> ((<Zlib::NO_COMPRESSION>))
        * Zlib::Deflate::BEST_SPEED -> ((<Zlib::BEST_SPEED>))
        * Zlib::Deflate::BEST_COMPRESSION -> ((<Zlib::BEST_COMPRESSION>))
        * Zlib::Deflate::DEFAULT_COMPRESSION -> ((<Zlib::DEFAULT_COMPRESSION>))
        * Zlib::Deflate::FILTERED -> ((<Zlib::FILTERED>))
        * Zlib::Deflate::HUFFMAN_ONLY -> ((<Zlib::HUFFMAN_ONLY>))
        * Zlib::Deflate::DEFAULT_STRATEGY -> ((<Zlib::DEFAULT_STRATEGY>))
        * Zlib::Deflate::MAX_WBITS -> ((<Zlib::MAX_WBITS>))
        * Zlib::Deflate::DEF_MEM_LEVEL -> ((<Zlib::DEF_MEM_LEVEL>))
        * Zlib::Deflate::MAX_MEM_LEVEL -> ((<Zlib::MAX_MEM_LEVEL>))
        * Zlib::Deflate::NO_FLUSH -> ((<Zlib::NO_FLUSH>))
        * Zlib::Deflate::SYNC_FLUSH -> ((<Zlib::SYNC_FLUSH>))
        * Zlib::Deflate::FULL_FLUSH -> ((<Zlib::FULL_FLUSH>))
        * Zlib::Inflate::MAX_WBITS -> ((<Zlib::MAX_WBITS>))
        * Zlib::GzipReader::OS_* -> ((<Zlib::OS_*|Zlib::OS_CODE>))
   * Methods
        * Zlib::ZStream#flush_out -> ((<Zlib::ZStream#flush_next_out>))

 * ((<Zlib::Error#next_in>)) method is added.
 * Made buffer for input (next_in).
 * Process NeedDict error specially.
 * ((<Zlib::GzipReader#unused>)) returns nil after closing.
 * Now you are up to call ((<Zlib::GzipWriter#close>)) explicitly
   to avoid segv in finalizer. ((<[ruby-dev:11915]|URL:http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-dev/11915>))
 * divided intialize from new.
 * remove sanity checks for arguments for deflateInit2 and inflateInit2.
 * adapted the behavior of ((<Zlib::GzipWriter#puts>)) to Ruby-1.7.
 * Made all functions static.


=end
