Initial Commit

database/perl/lib/IO/Compress/Gzip/Constants.pm

@@ -0,0 +1,148 @@
+package IO::Compress::Gzip::Constants;
+
+use strict ;
+use warnings;
+use bytes;
+
+require Exporter;
+
+our ($VERSION, @ISA, @EXPORT, %GZIP_OS_Names);
+our ($GZIP_FNAME_INVALID_CHAR_RE, $GZIP_FCOMMENT_INVALID_CHAR_RE);
+
+$VERSION = '2.100';
+
+@ISA = qw(Exporter);
+
+@EXPORT= qw(
+
+    GZIP_ID_SIZE
+    GZIP_ID1
+    GZIP_ID2
+
+    GZIP_FLG_DEFAULT
+    GZIP_FLG_FTEXT
+    GZIP_FLG_FHCRC
+    GZIP_FLG_FEXTRA
+    GZIP_FLG_FNAME
+    GZIP_FLG_FCOMMENT
+    GZIP_FLG_RESERVED
+
+    GZIP_CM_DEFLATED
+
+    GZIP_MIN_HEADER_SIZE
+    GZIP_TRAILER_SIZE
+
+    GZIP_MTIME_DEFAULT
+    GZIP_XFL_DEFAULT
+    GZIP_FEXTRA_HEADER_SIZE
+    GZIP_FEXTRA_MAX_SIZE
+    GZIP_FEXTRA_SUBFIELD_HEADER_SIZE
+    GZIP_FEXTRA_SUBFIELD_ID_SIZE
+    GZIP_FEXTRA_SUBFIELD_LEN_SIZE
+    GZIP_FEXTRA_SUBFIELD_MAX_SIZE
+
+    $GZIP_FNAME_INVALID_CHAR_RE
+    $GZIP_FCOMMENT_INVALID_CHAR_RE
+
+    GZIP_FHCRC_SIZE
+
+    GZIP_ISIZE_MAX
+    GZIP_ISIZE_MOD_VALUE
+
+
+    GZIP_NULL_BYTE
+
+    GZIP_OS_DEFAULT
+
+    %GZIP_OS_Names
+
+    GZIP_MINIMUM_HEADER
+
+    );
+
+# Constant names derived from RFC 1952
+
+use constant GZIP_ID_SIZE                     => 2 ;
+use constant GZIP_ID1                         => 0x1F;
+use constant GZIP_ID2                         => 0x8B;
+
+use constant GZIP_MIN_HEADER_SIZE             => 10 ;# minimum gzip header size
+use constant GZIP_TRAILER_SIZE                => 8 ;
+
+
+use constant GZIP_FLG_DEFAULT                 => 0x00 ;
+use constant GZIP_FLG_FTEXT                   => 0x01 ;
+use constant GZIP_FLG_FHCRC                   => 0x02 ; # called CONTINUATION in gzip
+use constant GZIP_FLG_FEXTRA                  => 0x04 ;
+use constant GZIP_FLG_FNAME                   => 0x08 ;
+use constant GZIP_FLG_FCOMMENT                => 0x10 ;
+#use constant GZIP_FLG_ENCRYPTED              => 0x20 ; # documented in gzip sources
+use constant GZIP_FLG_RESERVED                => (0x20 | 0x40 | 0x80) ;
+
+use constant GZIP_XFL_DEFAULT                 => 0x00 ;
+
+use constant GZIP_MTIME_DEFAULT               => 0x00 ;
+
+use constant GZIP_FEXTRA_HEADER_SIZE          => 2 ;
+use constant GZIP_FEXTRA_MAX_SIZE             => 0xFFFF ;
+use constant GZIP_FEXTRA_SUBFIELD_ID_SIZE     => 2 ;
+use constant GZIP_FEXTRA_SUBFIELD_LEN_SIZE    => 2 ;
+use constant GZIP_FEXTRA_SUBFIELD_HEADER_SIZE => GZIP_FEXTRA_SUBFIELD_ID_SIZE +
+                                                 GZIP_FEXTRA_SUBFIELD_LEN_SIZE;
+use constant GZIP_FEXTRA_SUBFIELD_MAX_SIZE    => GZIP_FEXTRA_MAX_SIZE -
+                                                 GZIP_FEXTRA_SUBFIELD_HEADER_SIZE ;
+
+
+if (ord('A') == 193)
+{
+    # EBCDIC
+    $GZIP_FNAME_INVALID_CHAR_RE = '[\x00-\x3f\xff]';
+    $GZIP_FCOMMENT_INVALID_CHAR_RE = '[\x00-\x0a\x11-\x14\x16-\x3f\xff]';
+
+}
+else
+{
+    $GZIP_FNAME_INVALID_CHAR_RE       =  '[\x00-\x1F\x7F-\x9F]';
+    $GZIP_FCOMMENT_INVALID_CHAR_RE    =  '[\x00-\x09\x11-\x1F\x7F-\x9F]';
+}
+
+use constant GZIP_FHCRC_SIZE        => 2 ; # aka CONTINUATION in gzip
+
+use constant GZIP_CM_DEFLATED       => 8 ;
+
+use constant GZIP_NULL_BYTE         => "\x00";
+use constant GZIP_ISIZE_MAX         => 0xFFFFFFFF ;
+use constant GZIP_ISIZE_MOD_VALUE   => GZIP_ISIZE_MAX + 1 ;
+
+# OS Names sourced from http://www.gzip.org/format.txt
+
+use constant GZIP_OS_DEFAULT=> 0xFF ;
+%GZIP_OS_Names = (
+    0   => 'MS-DOS',
+    1   => 'Amiga',
+    2   => 'VMS',
+    3   => 'Unix',
+    4   => 'VM/CMS',
+    5   => 'Atari TOS',
+    6   => 'HPFS (OS/2, NT)',
+    7   => 'Macintosh',
+    8   => 'Z-System',
+    9   => 'CP/M',
+    10  => 'TOPS-20',
+    11  => 'NTFS (NT)',
+    12  => 'SMS QDOS',
+    13  => 'Acorn RISCOS',
+    14  => 'VFAT file system (Win95, NT)',
+    15  => 'MVS',
+    16  => 'BeOS',
+    17  => 'Tandem/NSK',
+    18  => 'THEOS',
+    GZIP_OS_DEFAULT()   => 'Unknown',
+    ) ;
+
+use constant GZIP_MINIMUM_HEADER =>   pack("C4 V C C",
+        GZIP_ID1, GZIP_ID2, GZIP_CM_DEFLATED, GZIP_FLG_DEFAULT,
+        GZIP_MTIME_DEFAULT, GZIP_XFL_DEFAULT, GZIP_OS_DEFAULT) ;
+
+
+1;