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##- 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.
#- This package provides functions to use Compress::Zlib instead of gzip.
package Packdrakeng::zlib;
use strict;
use Compress::Zlib;
(our $VERSION) = q($Id$) =~ /(\d+\.\d+)/;
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 $sourcefh is not set, this means we want a flush(), for end_block()
# EOF, flush compress stream, adding crc
if (!defined($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 does not create a 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);
my $wres = syswrite($pack->{handle}, $cbuf) || 0;
$wres == length($cbuf) or do {
warn "Can't push all data to compressor\n";
return 0, 0;
};
$outsize += $wres;
$insize += $lenght;
}
($insize, $outsize)
}
sub gzip_uncompress {
my ($pack, $destfh, $fileinfo) = @_;
if (!defined $fileinfo) {
$pack->{ustream_data} = undef;
return 0;
}
if (defined($pack->{ustream_data}) && ($fileinfo->{coff} != $pack->{ustream_data}{coff} || $fileinfo->{off} < $pack->{ustream_data}{off})) {
$pack->{ustream_data} = undef;
}
if (!defined($pack->{ustream_data})) {
$pack->{ustream_data}{coff} = $fileinfo->{coff};
$pack->{ustream_data}{read} = 0; # uncompressed data read
$pack->{ustream_data}{x} = inflateInit(
-WindowBits => - MAX_WBITS(),
);
$pack->{ustream_data}{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 && $magic[1] == Compress::Zlib::MAGIC2 or do {
warn("Wrong magic header found\n");
return -1;
};
} else {
warn("Unexpected end of file while reading magic\n");
return -1;
}
my ($method, $flags);
if (sysread($pack->{handle}, $buf, 2) == 2) {
($method, $flags) = unpack("C2", $buf);
} else {
warn("Unexpected end of file while reading flags\n");
return -1;
}
if (sysread($pack->{handle}, $buf, 6) != 6) {
warn("Unexpected end of file while reading gzip header\n");
return -1;
}
$pack->{ustream_data}{cread} += 12; #Gzip header fixed size is already read
if ($flags & 0x04) {
if (sysread($pack->{handle}, $buf, 2) == 2) {
my $len = unpack("I", $buf);
$pack->{ustream_data}{cread} += $len;
if (sysread($pack->{handle}, $buf, $len) != $len) {
warn("Unexpected end of file while reading gzip header\n");
return -1;
}
} else {
warn("Unexpected end of file while reading gzip header\n");
return -1;
}
}
}
} else {
sysseek($pack->{handle}, $pack->{ustream_data}{cread} - 2, 1);
}
$pack->{ustream_data}{off} = $fileinfo->{off};
my $byteswritten = 0;
while ($byteswritten < $fileinfo->{size}) {
my ($l, $out, $status) = (0, $pack->{ustream_data}{buf});
$pack->{ustream_data}{buf} = undef;
if (!defined($out)) {
my $cl=sysread($pack->{handle}, my $buf,
$pack->{ustream_data}{cread} + $pack->{bufsize} > $fileinfo->{csize} ?
$fileinfo->{csize} - $pack->{ustream_data}{cread} :
$pack->{bufsize}) or do {
warn("Unexpected end of file\n");
return -1;
};
$pack->{ustream_data}{cread} += $cl;
($out, $status) = $pack->{ustream_data}{x}->inflate(\$buf);
$status == Z_OK || $status == Z_STREAM_END or do {
warn("Unable to uncompress data\n");
return -1;
};
}
$l = length($out) or next;
if ($pack->{ustream_data}{read} < $fileinfo->{off} && $pack->{ustream_data}{read} + $l > $fileinfo->{off}) {
$out = substr($out, $fileinfo->{off} - $pack->{ustream_data}{read});
}
$pack->{ustream_data}{read} += $l;
if ($pack->{ustream_data}{read} <= $fileinfo->{off}) { next }
my $bw;
if ($byteswritten + length($out) > $fileinfo->{size}) {
$bw = $fileinfo->{size} - $byteswritten;
$pack->{ustream_data}{buf} = substr($out, $bw); # keeping track of unwritten uncompressed data
$pack->{ustream_data}{read} -= length($pack->{ustream_data}{buf});
} else {
$bw = length($out);
}
syswrite($destfh, $out, $bw) == $bw or do {
warn "Can't write data into dest\n";
return -1;
};
$byteswritten += $bw;
}
$byteswritten
}
1;
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