use block lists instead of vm swap space

instead of copying packages into the swap space for exchange with
the host write the block lists there so the host can directly fetch
the data from the disk image.

1 files changed, 86 insertions, 54 deletions

diff --git a/extractbuild b/extractbuild
index 02652d0..5b5da86 100755
--- a/extractbuild
+++ b/extractbuild
@@ -2,68 +2,100 @@
 
 use strict;
 
-sub ls {
-  local *D;
-  opendir(D, $_[0]) || return ();
-  my @r = grep {$_ ne '.' && $_ ne '..'} readdir(D);
-  closedir D;
-  return @r;
+# buffer size for reading
+my $bufsize = 4*1024*1024;
+
+my ($opt_skip, $opt_disk, $opt_input, $opt_verbose);
+
+while (@ARGV)  {
+  if ($ARGV[0] eq '--skip') {
+    shift @ARGV;
+    $opt_skip = shift @ARGV;
+    next;
+  }
+  if ($ARGV[0] eq '--disk') {
+    shift @ARGV;
+    $opt_disk = shift @ARGV;
+    next;
+  }
+  if ($ARGV[0] eq '--input') {
+    shift @ARGV;
+    $opt_input = shift @ARGV;
+    next;
+  }
+  if ($ARGV[0] eq '--verbose' || $ARGV[0] eq '-v') {
+    shift @ARGV;
+    $opt_verbose = 1;
+    next;
+  }
+  last;
 }
 
-my $xenswap = $ARGV[0] || die "please specify output file";
+die "need to specify disk image\n" unless $opt_disk;
 
-die("$xenswap: $!\n") unless -e $xenswap;
-open(S, '>', $xenswap) || die("$xenswap: $!\n");
-# placeholder for buildstatus information
-syswrite(S, 'x'x512);
+open(F, '<', $opt_disk) || die "$opt_disk: $!\n";
 
-my $topdir = '/.build.packages';
-if (-l $topdir) {
-  $topdir = '/'.readlink($topdir) || die("readlink: $!");
+if($opt_input) {
+  open(S, '<', $opt_input) || die "$opt_input: $!\n";
+} else {
+  open(S, '<&STDIN') || die "can't dup stdin: $!\n";
 }
-my @dirs = map {"$topdir/RPMS/$_"} ls("$topdir/RPMS");
-unshift @dirs, "$topdir/SRPMS";
-unshift @dirs, "$topdir/DEBS";
-unshift @dirs, "$topdir/KIWI";
 
-my @packs;
-for my $dir (@dirs) {
-  push @packs, map {"$dir/$_"} grep {-f "$dir/$_"} ls($dir);
+# skip build status
+if($opt_skip) {
+  seek(S, $opt_skip, 0) || die "$!\n";
 }
-#unshift @packs, '/.build.log';
 
-my $cpio = '';
-for my $pack (@packs) {
-  print "$pack\n";
-  my @s = stat($pack);
-  my $n = $pack;
-  $n =~ s/.*\///;
-  $n = 'logfile' if $n eq '.build.log';
-  die("$pack: $!\n") unless @s;
-  $cpio .= "07070100000000000081a4000000000000000000000001";
-  $cpio .= sprintf("%08x%08x", $s[9], $s[7]);
-  $cpio .= "00000000000000000000000000000000";
-  $cpio .= sprintf("%08x", length($n) + 1);
-  $cpio .= "00000000";
-  $cpio .= "$n\0";
-  $cpio .= substr("\0\0\0\0", (length($cpio) & 3)) if length($cpio) & 3;
-  open(F, '<', $pack) || die("$pack: $!\n");
-  my $l = $s[7];
-  while ($l) {
-    my $ll = sysread(F, $cpio, $l > 8192 ? 8192 : $l, length($cpio));
-    die("$pack: $!\n") unless $ll;
-    die if $ll > $l;
-    $l -= $ll;
-    while (length($cpio) > 4096) {
-      (syswrite(S, $cpio, 4096) || 0) == 4096 || die("swap write: $!\n");
-      $cpio = substr($cpio, 4096);
+while(<S>) {
+  chomp;
+  last unless length $_;
+  my ($file, $filesize, $blksize, @blocks) = split(/ /);
+  if($#blocks == -1) {
+    die "invalid input\n";
+  }
+  $filesize = int($filesize);
+  $blksize = int($blksize);
+  die "invalid block size" unless ($blksize > 0 && $blksize <= $bufsize);
+  my $maxblocks = int($bufsize/$blksize);
+  $file =~ s/.*\///; # ensure basename, also stops directory traversal
+  $file =~ s/[^[:print:]]/_/g; # no binary junk in file names
+  print "$file\n" if $opt_verbose;
+  open (O, '>', $file) or die "$file: $!";
+  for my $block (@blocks) {
+    my ($block, $end) = split(/-/, $block);
+    $block = int($block);
+
+    if($block == 0) { # a hole!
+      seek(O, $blksize, 1);
+      $filesize -= $blksize;
+      next;
+    }
+
+    $end = $block unless $end;
+    $end = int($end);
+    seek(F, $block*$blksize, 0) || die "$file: seek: $!\n";
+    while($block <= $end && $filesize) {
+      my $size;
+      if($end == $block) {
+	$size = $blksize;
+	++$block;
+      } elsif($maxblocks >= $end-$block) {
+	$size = ($end-$block)*$blksize;
+	$block += $end-$block;
+      } else {
+	$size = $maxblocks*$blksize;
+	$block += $maxblocks;
+      }
+      $size = $filesize if $size > $filesize;
+      my $buf;
+      if((sysread(F, $buf, $size) || 0) != $size) {
+	die "$file: read: $!\n";
+      }
+      $filesize -= $size;
+      print O $buf;
     }
   }
-  $cpio .= substr("\0\0\0\0", (length($cpio) & 3)) if length($cpio) & 3;
-}
-$cpio .= "07070100000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000b00000000TRAILER!!!\0\0\0\0";
-$cpio .= "\0" x (4096 - length($cpio) % 4096) if length($cpio) % 4096;
-while (length($cpio)) {
-  (syswrite(S, $cpio, 4096) || 0) == 4096 || die("swap write: $!\n");
-  $cpio = substr($cpio, 4096);
+  close O;
+  # sanity check
+  die "$file: invalid file size ($filesize byes left)\n" if $filesize != 0;
 }