377 lines
10 KiB
Perl
Executable file
377 lines
10 KiB
Perl
Executable file
#! @perl@ -w -I@libexecdir@/nix
|
|
|
|
use strict;
|
|
use POSIX qw(tmpnam);
|
|
use readmanifest;
|
|
|
|
die unless scalar @ARGV == 5;
|
|
|
|
my $hashAlgo = "sha256";
|
|
|
|
my $cacheDir = $ARGV[0];
|
|
my $patchesDir = $ARGV[1];
|
|
my $patchesURL = $ARGV[2];
|
|
my $srcDir = $ARGV[3];
|
|
my $dstDir = $ARGV[4];
|
|
|
|
my $tmpdir;
|
|
do { $tmpdir = tmpnam(); }
|
|
until mkdir $tmpdir, 0777;
|
|
|
|
print "TEMP = $tmpdir\n";
|
|
|
|
#END { rmdir $tmpdir; }
|
|
|
|
my %srcNarFiles;
|
|
my %srcPatches;
|
|
my %srcSuccessors;
|
|
|
|
my %dstNarFiles;
|
|
my %dstPatches;
|
|
my %dstSuccessors;
|
|
|
|
readManifest "$srcDir/MANIFEST",
|
|
\%srcNarFiles, \%srcPatches, \%srcSuccessors;
|
|
|
|
readManifest "$dstDir/MANIFEST",
|
|
\%dstNarFiles, \%dstPatches, \%dstSuccessors;
|
|
|
|
|
|
sub findOutputPaths {
|
|
my $narFiles = shift;
|
|
my $successors = shift;
|
|
|
|
my %outPaths;
|
|
|
|
foreach my $p (keys %{$narFiles}) {
|
|
|
|
# Ignore store expressions.
|
|
next if ($p =~ /\.store$/);
|
|
next if ($p =~ /\.drv$/);
|
|
|
|
# Ignore builders (too much ambiguity -- they're all called
|
|
# `builder.sh').
|
|
next if ($p =~ /\.sh$/);
|
|
next if ($p =~ /\.patch$/);
|
|
|
|
# Don't bother including tar files etc.
|
|
next if ($p =~ /\.tar\.(gz|bz2)$/ || $p =~ /\.zip$/ || $p =~ /\.bin$/);
|
|
|
|
$outPaths{$p} = 1;
|
|
}
|
|
|
|
return %outPaths;
|
|
}
|
|
|
|
print "finding src output paths...\n";
|
|
my %srcOutPaths = findOutputPaths \%srcNarFiles, \%srcSuccessors;
|
|
|
|
print "finding dst output paths...\n";
|
|
my %dstOutPaths = findOutputPaths \%dstNarFiles, \%dstSuccessors;
|
|
|
|
|
|
sub getNameVersion {
|
|
my $p = shift;
|
|
$p =~ /\/[0-9a-z]+((?:-[a-zA-Z][^\/-]*)+)([^\/]*)$/;
|
|
my $name = $1;
|
|
my $version = $2;
|
|
$name =~ s/^-//;
|
|
$version =~ s/^-//;
|
|
return ($name, $version);
|
|
}
|
|
|
|
|
|
# A quick hack to get a measure of the `distance' between two
|
|
# versions: it's just the position of the first character that differs
|
|
# (or 999 if they are the same).
|
|
sub versionDiff {
|
|
my $s = shift;
|
|
my $t = shift;
|
|
my $i;
|
|
return 999 if $s eq $t;
|
|
for ($i = 0; $i < length $s; $i++) {
|
|
return $i if $i >= length $t or
|
|
substr($s, $i, 1) ne substr($t, $i, 1);
|
|
}
|
|
return $i;
|
|
}
|
|
|
|
|
|
sub getNarBz2 {
|
|
my $narFiles = shift;
|
|
my $storePath = shift;
|
|
|
|
my $narFileList = $$narFiles{$storePath};
|
|
die "missing store expression $storePath" unless defined $narFileList;
|
|
|
|
my $narFile = @{$narFileList}[0];
|
|
die unless defined $narFile;
|
|
|
|
$narFile->{url} =~ /\/([^\/]+)$/;
|
|
die unless defined $1;
|
|
return "$cacheDir/$1";
|
|
}
|
|
|
|
|
|
sub containsPatch {
|
|
my $patches = shift;
|
|
my $storePath = shift;
|
|
my $basePath = shift;
|
|
my $patchList = $$patches{$storePath};
|
|
return 0 if !defined $patchList;
|
|
my $found = 0;
|
|
foreach my $patch (@{$patchList}) {
|
|
# !!! baseHash might differ
|
|
return 1 if $patch->{basePath} eq $basePath;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
# Compute the "weighted" number of uses of a path in the build graph.
|
|
sub computeUses {
|
|
my $narFiles = shift;
|
|
my $path = shift;
|
|
|
|
# Find the deriver of $path.
|
|
return 1 unless defined $$narFiles{$path};
|
|
my $deriver = @{$$narFiles{$path}}[0]->{deriver};
|
|
return 1 unless defined $deriver && $deriver ne "";
|
|
|
|
# print " DERIVER $deriver\n";
|
|
|
|
# Optimisation: build the referers graph from the references
|
|
# graph.
|
|
my %referers;
|
|
foreach my $q (keys %{$narFiles}) {
|
|
my @refs = split " ", @{$$narFiles{$q}}[0]->{references};
|
|
foreach my $r (@refs) {
|
|
$referers{$r} = [] unless defined $referers{$r};
|
|
push @{$referers{$r}}, $q;
|
|
}
|
|
}
|
|
|
|
# Determine the shortest path from $deriver to all other reachable
|
|
# paths in the `referers' graph.
|
|
|
|
my %dist;
|
|
$dist{$deriver} = 0;
|
|
|
|
my @queue = ($deriver);
|
|
my $pos = 0;
|
|
|
|
while ($pos < scalar @queue) {
|
|
my $p = $queue[$pos];
|
|
$pos++;
|
|
|
|
foreach my $q (@{$referers{$p}}) {
|
|
if (!defined $dist{$q}) {
|
|
$dist{$q} = $dist{$p} + 1;
|
|
# print " $q $dist{$q}\n";
|
|
push @queue, $q;
|
|
}
|
|
}
|
|
}
|
|
|
|
my $wuse = 1.0;
|
|
foreach my $user (keys %dist) {
|
|
next if $user eq $deriver;
|
|
# print " $user $dist{$user}\n";
|
|
$wuse += 1.0 / 2.0**$dist{$user};
|
|
}
|
|
|
|
# print " XXX $path $wuse\n";
|
|
|
|
return $wuse;
|
|
}
|
|
|
|
|
|
# For each output path in the destination, see if we need to / can
|
|
# create a patch.
|
|
|
|
print "creating patches...\n";
|
|
|
|
foreach my $p (keys %dstOutPaths) {
|
|
|
|
# If exactly the same path already exists in the source, skip it.
|
|
next if defined $srcOutPaths{$p};
|
|
|
|
print " $p\n";
|
|
|
|
# If not, then we should find the paths in the source that are
|
|
# `most' likely to be present on a system that wants to install
|
|
# this path.
|
|
|
|
(my $name, my $version) = getNameVersion $p;
|
|
|
|
my @closest = ();
|
|
my $closestVersion;
|
|
my $minDist = -1; # actually, larger means closer
|
|
|
|
# Find all source paths with the same name.
|
|
|
|
foreach my $q (keys %srcOutPaths) {
|
|
(my $name2, my $version2) = getNameVersion $q;
|
|
if ($name eq $name2) {
|
|
|
|
# If the sizes differ too much, then skip. This
|
|
# disambiguates between, e.g., a real component and a
|
|
# wrapper component (cf. Firefox in Nixpkgs).
|
|
my $srcSize = @{$srcNarFiles{$q}}[0]->{size};
|
|
my $dstSize = @{$dstNarFiles{$p}}[0]->{size};
|
|
my $ratio = $srcSize / $dstSize;
|
|
$ratio = 1 / $ratio if $ratio < 1;
|
|
# print " SIZE $srcSize $dstSize $ratio $q\n";
|
|
|
|
if ($ratio >= 3) {
|
|
print " SKIPPING $q due to size ratio $ratio ($srcSize $dstSize)\n";
|
|
next;
|
|
}
|
|
|
|
# If the numbers of weighted uses differ too much, then
|
|
# skip. This disambiguates between, e.g., the bootstrap
|
|
# GCC and the final GCC in Nixpkgs.
|
|
my $srcUses = computeUses \%srcNarFiles, $q;
|
|
my $dstUses = computeUses \%dstNarFiles, $p;
|
|
$ratio = $srcUses / $dstUses;
|
|
$ratio = 1 / $ratio if $ratio < 1;
|
|
print " USE $srcUses $dstUses $ratio $q\n";
|
|
|
|
if ($ratio >= 2) {
|
|
print " SKIPPING $q due to use ratio $ratio ($srcUses $dstUses)\n";
|
|
next;
|
|
}
|
|
|
|
# If there are multiple matching names, include the ones
|
|
# with the closest version numbers.
|
|
my $dist = versionDiff $version, $version2;
|
|
if ($dist > $minDist) {
|
|
$minDist = $dist;
|
|
@closest = ($q);
|
|
$closestVersion = $version2;
|
|
} elsif ($dist == $minDist) {
|
|
push @closest, $q;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (scalar(@closest) == 0) {
|
|
print " NO BASE: $p\n";
|
|
next;
|
|
}
|
|
|
|
foreach my $closest (@closest) {
|
|
|
|
# Generate a patch between $closest and $p.
|
|
print " $p <- $closest\n";
|
|
|
|
# If the patch already exists, skip it.
|
|
if (containsPatch(\%srcPatches, $p, $closest) ||
|
|
containsPatch(\%dstPatches, $p, $closest))
|
|
{
|
|
print " skipping, already exists\n";
|
|
next;
|
|
}
|
|
|
|
# next;
|
|
|
|
my $srcNarBz2 = getNarBz2 \%srcNarFiles, $closest;
|
|
my $dstNarBz2 = getNarBz2 \%dstNarFiles, $p;
|
|
|
|
system("@bunzip2@ < $srcNarBz2 > $tmpdir/A") == 0
|
|
or die "cannot unpack $srcNarBz2";
|
|
|
|
system("@bunzip2@ < $dstNarBz2 > $tmpdir/B") == 0
|
|
or die "cannot unpack $dstNarBz2";
|
|
|
|
system("@libexecdir@/bsdiff $tmpdir/A $tmpdir/B $tmpdir/DIFF") == 0
|
|
or die "cannot compute binary diff";
|
|
|
|
my $baseHash = `@bindir@/nix-hash --flat --type $hashAlgo --base32 $tmpdir/A` or die;
|
|
chomp $baseHash;
|
|
|
|
my $narHash = `@bindir@/nix-hash --flat --type $hashAlgo --base32 $tmpdir/B` or die;
|
|
chomp $narHash;
|
|
|
|
my $narDiffHash = `@bindir@/nix-hash --flat --type $hashAlgo --base32 $tmpdir/DIFF` or die;
|
|
chomp $narDiffHash;
|
|
|
|
my $narDiffSize = (stat "$tmpdir/DIFF")[7];
|
|
my $dstNarBz2Size = (stat $dstNarBz2)[7];
|
|
|
|
if ($narDiffSize >= $dstNarBz2Size) {
|
|
print " rejecting; patch bigger than full archive\n";
|
|
next;
|
|
}
|
|
|
|
my $finalName =
|
|
"$narDiffHash.nar-bsdiff";
|
|
|
|
print " size $narDiffSize; full size $dstNarBz2Size\n";
|
|
|
|
if (-e "$patchesDir/$finalName") {
|
|
print " not copying, already exists\n";
|
|
}
|
|
|
|
else {
|
|
|
|
system("cp '$tmpdir/DIFF' '$patchesDir/$finalName.tmp'") == 0
|
|
or die "cannot copy diff";
|
|
|
|
rename("$patchesDir/$finalName.tmp", "$patchesDir/$finalName")
|
|
or die "cannot rename $patchesDir/$finalName.tmp";
|
|
|
|
}
|
|
|
|
# Add the patch to the manifest.
|
|
addPatch \%dstPatches, $p,
|
|
{ url => "$patchesURL/$finalName", hash => "$hashAlgo:$narDiffHash"
|
|
, size => $narDiffSize, basePath => $closest, baseHash => "$hashAlgo:$baseHash"
|
|
, narHash => "$hashAlgo:$narHash", patchType => "nar-bsdiff"
|
|
};
|
|
}
|
|
}
|
|
|
|
|
|
# Add in any potentially useful patches in the source (namely, those
|
|
# patches that produce either paths in the destination or paths that
|
|
# can be used as the base for other useful patches).
|
|
|
|
my $changed;
|
|
do {
|
|
# !!! we repeat this to reach the transitive closure; inefficient
|
|
$changed = 0;
|
|
|
|
foreach my $p (keys %srcPatches) {
|
|
my $patchList = $srcPatches{$p};
|
|
|
|
my $include = 0;
|
|
|
|
# Is path $p included in the destination? If so, include
|
|
# patches that produce it.
|
|
$include = 1 if (defined $dstNarFiles{$p});
|
|
|
|
# Is path $p a path that serves as a base for paths in the
|
|
# destination? If so, include patches that produce it.
|
|
foreach my $q (keys %dstPatches) {
|
|
foreach my $patch (@{$dstPatches{$q}}) {
|
|
# !!! check baseHash
|
|
$include = 1 if ($p eq $patch->{basePath});
|
|
}
|
|
}
|
|
|
|
if ($include) {
|
|
foreach my $patch (@{$patchList}) {
|
|
$changed = 1 if addPatch \%dstPatches, $p, $patch;
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
} while $changed;
|
|
|
|
|
|
# Rewrite the manifest of the destination (with the new patches).
|
|
writeManifest "$dstDir/MANIFEST",
|
|
\%dstNarFiles, \%dstPatches, \%dstSuccessors;
|