ext/Compress/IO/Zlib/lib/IO/Compress/Zlib/Constants.pm

   1
   2 package IO::Compress::Zlib::Constants ;
   3
   4 use strict ;
   5 use warnings;
   6 use bytes;
   7
   8 require Exporter;
   9
  10 our ($VERSION, @ISA, @EXPORT);
  11
  12 $VERSION = '2.000_12';
  13
  14 @ISA = qw(Exporter);
  15
  16 @EXPORT= qw(
  17
  18         ZLIB_HEADER_SIZE
  19         ZLIB_TRAILER_SIZE
  20
  21         ZLIB_CMF_CM_OFFSET
  22         ZLIB_CMF_CM_BITS
  23         ZLIB_CMF_CM_DEFLATED
  24
  25         ZLIB_CMF_CINFO_OFFSET
  26         ZLIB_CMF_CINFO_BITS
  27
  28         ZLIB_FLG_FCHECK_OFFSET
  29         ZLIB_FLG_FCHECK_BITS
  30
  31         ZLIB_FLG_FDICT_OFFSET
  32         ZLIB_FLG_FDICT_BITS
  33
  34         ZLIB_FLG_LEVEL_OFFSET
  35         ZLIB_FLG_LEVEL_BITS
  36
  37         ZLIB_FLG_LEVEL_FASTEST
  38         ZLIB_FLG_LEVEL_FAST
  39         ZLIB_FLG_LEVEL_DEFAULT
  40         ZLIB_FLG_LEVEL_SLOWEST
  41
  42         ZLIB_FDICT_SIZE
  43
  44         );
  45
  46 # Constant names derived from RFC1950
  47
  48 use constant ZLIB_HEADER_SIZE       => 2;
  49 use constant ZLIB_TRAILER_SIZE      => 4;
  50
  51 use constant ZLIB_CMF_CM_OFFSET     => 0;
  52 use constant ZLIB_CMF_CM_BITS       => 0xF ; # 0b1111
  53 use constant ZLIB_CMF_CM_DEFLATED   => 8;
  54
  55 use constant ZLIB_CMF_CINFO_OFFSET  => 4;
  56 use constant ZLIB_CMF_CINFO_BITS    => 0xF ; # 0b1111;
  57
  58 use constant ZLIB_FLG_FCHECK_OFFSET => 0;
  59 use constant ZLIB_FLG_FCHECK_BITS   => 0x1F ; # 0b11111;
  60
  61 use constant ZLIB_FLG_FDICT_OFFSET  => 5;
  62 use constant ZLIB_FLG_FDICT_BITS    => 0x1 ; # 0b1;
  63
  64 use constant ZLIB_FLG_LEVEL_OFFSET  => 6;
  65 use constant ZLIB_FLG_LEVEL_BITS    => 0x3 ; # 0b11;
  66
  67 use constant ZLIB_FLG_LEVEL_FASTEST => 0;
  68 use constant ZLIB_FLG_LEVEL_FAST    => 1;
  69 use constant ZLIB_FLG_LEVEL_DEFAULT => 2;
  70 use constant ZLIB_FLG_LEVEL_SLOWEST => 3;
  71
  72 use constant ZLIB_FDICT_SIZE        => 4;
  73
  74
  75 1;