1 2package IO::Compress::Zlib::Constants ; 3 4use strict ; 5use warnings; 6use bytes; 7 8require Exporter; 9 10our ($VERSION, @ISA, @EXPORT); 11 12$VERSION = '2.101'; 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 ZLIB_CMF_CINFO_MAX 28 29 ZLIB_FLG_FCHECK_OFFSET 30 ZLIB_FLG_FCHECK_BITS 31 32 ZLIB_FLG_FDICT_OFFSET 33 ZLIB_FLG_FDICT_BITS 34 35 ZLIB_FLG_LEVEL_OFFSET 36 ZLIB_FLG_LEVEL_BITS 37 38 ZLIB_FLG_LEVEL_FASTEST 39 ZLIB_FLG_LEVEL_FAST 40 ZLIB_FLG_LEVEL_DEFAULT 41 ZLIB_FLG_LEVEL_SLOWEST 42 43 ZLIB_FDICT_SIZE 44 45 ); 46 47# Constant names derived from RFC1950 48 49use constant ZLIB_HEADER_SIZE => 2; 50use constant ZLIB_TRAILER_SIZE => 4; 51 52use constant ZLIB_CMF_CM_OFFSET => 0; 53use constant ZLIB_CMF_CM_BITS => 0xF ; # 0b1111 54use constant ZLIB_CMF_CM_DEFLATED => 8; 55 56use constant ZLIB_CMF_CINFO_OFFSET => 4; 57use constant ZLIB_CMF_CINFO_BITS => 0xF ; # 0b1111; 58use constant ZLIB_CMF_CINFO_MAX => 7; 59 60use constant ZLIB_FLG_FCHECK_OFFSET => 0; 61use constant ZLIB_FLG_FCHECK_BITS => 0x1F ; # 0b11111; 62 63use constant ZLIB_FLG_FDICT_OFFSET => 5; 64use constant ZLIB_FLG_FDICT_BITS => 0x1 ; # 0b1; 65 66use constant ZLIB_FLG_LEVEL_OFFSET => 6; 67use constant ZLIB_FLG_LEVEL_BITS => 0x3 ; # 0b11; 68 69use constant ZLIB_FLG_LEVEL_FASTEST => 0; 70use constant ZLIB_FLG_LEVEL_FAST => 1; 71use constant ZLIB_FLG_LEVEL_DEFAULT => 2; 72use constant ZLIB_FLG_LEVEL_SLOWEST => 3; 73 74use constant ZLIB_FDICT_SIZE => 4; 75 76 771; 78