package IO::Compress::Zlib::Constants ;

use strict ;
use warnings;
use bytes;

require Exporter;

our ($VERSION, @ISA, @EXPORT);

$VERSION = '2.060';

@ISA = qw(Exporter);

@EXPORT= qw(

ZLIB_HEADER_SIZE
ZLIB_TRAILER_SIZE

ZLIB_CMF_CM_OFFSET
ZLIB_CMF_CM_BITS
ZLIB_CMF_CM_DEFLATED

ZLIB_CMF_CINFO_OFFSET
ZLIB_CMF_CINFO_BITS
ZLIB_CMF_CINFO_MAX

ZLIB_FLG_FCHECK_OFFSET
ZLIB_FLG_FCHECK_BITS

ZLIB_FLG_FDICT_OFFSET
ZLIB_FLG_FDICT_BITS

ZLIB_FLG_LEVEL_OFFSET
ZLIB_FLG_LEVEL_BITS

ZLIB_FLG_LEVEL_FASTEST
ZLIB_FLG_LEVEL_FAST
ZLIB_FLG_LEVEL_DEFAULT
ZLIB_FLG_LEVEL_SLOWEST

ZLIB_FDICT_SIZE

);

# Constant names derived from RFC1950

use constant ZLIB_HEADER_SIZE => 2;
use constant ZLIB_TRAILER_SIZE => 4;

use constant ZLIB_CMF_CM_OFFSET => 0;
use constant ZLIB_CMF_CM_BITS => 0xF ; # 0b1111
use constant ZLIB_CMF_CM_DEFLATED => 8;

use constant ZLIB_CMF_CINFO_OFFSET => 4;
use constant ZLIB_CMF_CINFO_BITS => 0xF ; # 0b1111;
use constant ZLIB_CMF_CINFO_MAX => 7;

use constant ZLIB_FLG_FCHECK_OFFSET => 0;
use constant ZLIB_FLG_FCHECK_BITS => 0x1F ; # 0b11111;

use constant ZLIB_FLG_FDICT_OFFSET => 5;
use constant ZLIB_FLG_FDICT_BITS => 0x1 ; # 0b1;

use constant ZLIB_FLG_LEVEL_OFFSET => 6;
use constant ZLIB_FLG_LEVEL_BITS => 0x3 ; # 0b11;

use constant ZLIB_FLG_LEVEL_FASTEST => 0;
use constant ZLIB_FLG_LEVEL_FAST => 1;
use constant ZLIB_FLG_LEVEL_DEFAULT => 2;
use constant ZLIB_FLG_LEVEL_SLOWEST => 3;

use constant ZLIB_FDICT_SIZE => 4;


1;