diff options
| -rw-r--r-- | Packdrakeng/zlib.pm | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/Packdrakeng/zlib.pm b/Packdrakeng/zlib.pm new file mode 100644 index 0000000..d541a67 --- /dev/null +++ b/Packdrakeng/zlib.pm @@ -0,0 +1,150 @@ +##- Nanar <nanardon@mandrake.org> +##- +##- This program is free software; you can redistribute it and/or modify +##- it under the terms of the GNU General Public License as published by +##- the Free Software Foundation; either version 2, or (at your option) +##- any later version. +##- +##- This program is distributed in the hope that it will be useful, +##- but WITHOUT ANY WARRANTY; without even the implied warranty of +##- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +##- GNU General Public License for more details. +##- +##- You should have received a copy of the GNU General Public License +##- along with this program; if not, write to the Free Software +##- Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +##- $Id$ + +##- This package provide functions to use Zlib::Compress instead gzip. + +package Packdrakeng::zlib; + +use strict; +use warnings; +use Compress::Zlib; + +my $gzip_header = pack("C" . Compress::Zlib::MIN_HDR_SIZE, + Compress::Zlib::MAGIC1, Compress::Zlib::MAGIC2, + Compress::Zlib::Z_DEFLATED(), 0,0,0,0,0,0, Compress::Zlib::OSCODE); + +sub gzip_compress { + my ($pack, $sourcefh) = @_; + my ($insize, $outsize) = (0, 0); # aka uncompressed / compressed data length + + # If $sourcefh is not set, this mean we want a flush(), for end_block() + # EOF, flush compress stream, adding crc + if (!defined($sourcefh)) { + if (defined($pack->{cstream_data}{object})) { + my ($cbuf, $status) = $pack->{cstream_data}{object}->flush(); + $outsize += syswrite($pack->{handle}, $cbuf); + $outsize += syswrite($pack->{handle}, pack("V V", $pack->{cstream_data}{crc}, $pack->{cstream_data}{object}->total_in())); + } + $pack->{cstream_data} = undef; + return(undef, $outsize); + } + + if (!defined $pack->{cstream_data}{object}) { + # Writing gzip header file + $outsize += syswrite($pack->{handle}, $gzip_header); + $pack->{cstream_data}{object} = deflateInit( + -Level => $pack->{level}, + # Zlib do not create gzip header, except with this flag + -WindowBits => - MAX_WBITS(), + ); + } + + binmode $sourcefh; + + while (my $lenght = sysread($sourcefh, my $buf, $pack->{bufsize})) { + $pack->{cstream_data}{crc} = crc32($buf, $pack->{cstream_data}{crc}); + my ($cbuf, $status) = $pack->{cstream_data}{object}->deflate($buf); + $outsize += syswrite($pack->{handle}, $cbuf); + $insize += $lenght; + } + + ($insize, $outsize) +} + +sub gzip_uncompress { + my ($pack, $destfh, $fileinfo) = @_; + my $x = inflateInit( + -WindowBits => - MAX_WBITS(), + ); + my $cread = 0; # Compressed data read + { + my $buf; + # get magic + if (sysread($pack->{handle}, $buf, 2) == 2) { + my @magic = unpack("C*", $buf); + $magic[0] == Compress::Zlib::MAGIC1 && $magic[1] == Compress::Zlib::MAGIC2 or do { + warn("Wrong magic header found"); + return -1; + }; + } else { + warn("Unexpect end of file while reading magic"); + return -1; + } + my ($method, $flags); + if (sysread($pack->{handle}, $buf, 2) == 2) { + ($method, $flags) = unpack("C2", $buf); + } else { + warn("Unexpect end of file while reading flags"); + return -1; + } + + if (sysread($pack->{handle}, $buf, 6) != 6) { + warn("Unexpect end of file while reading gzip header"); + return -1; + } + + $cread += 12; #Gzip header fixed size is already read + if ($flags & 0x04) { + if (sysread($pack->{handle}, $buf, 2) == 2) { + my $len = unpack("I", $buf); + $cread += $len; + if (sysread($pack->{handle}, $buf, $len) != $len) { + warn("Unexpect end of file while reading gzip header"); + return -1; + } + } else { + warn("Unexpect end of file while reading gzip header"); + return -1; + } + } + } + my $byteswritten = 0; + my $read = 0; # uncompressed data read + while ($byteswritten < $fileinfo->{size}) { + my $cl=sysread($pack->{handle}, my $buf, + $cread + $pack->{bufsize} > $fileinfo->{csize} ? + $fileinfo->{csize} - $cread : + $pack->{bufsize}) or do { + warn("Enexpected end of file"); + return -1; + }; + $cread += $cl; + my ($out, $status) = $x->inflate(\$buf); + $status == Z_OK || $status == Z_STREAM_END or do { + warn("Unable to uncompress data"); + return -1; + }; + my $l = length($out) or next; + if ($read < $fileinfo->{off} && $read + $l > $fileinfo->{off}) { + $out = substr($out, $fileinfo->{off} - $read); + } + $read += $l; + if ($read <= $fileinfo->{off}) { next } + + my $bw = $byteswritten + length($out) > $fileinfo->{size} ? $fileinfo->{size} - $byteswritten : length($out); + syswrite($destfh, $out, $bw) == $bw or do { + warn "Can't write data into dest"; + return -1; + }; + $byteswritten += $bw; + + } + $byteswritten +} + + |