* Make the creation of user environments much faster and more storage

efficient by creating only a single symlink to entire directory
  trees unless a collission occurs.
This commit is contained in:
Eelco Dolstra 2004-04-06 11:42:28 +00:00
parent bf3863b546
commit 2be8ac48bb

View file

@ -2,71 +2,92 @@
use strict;
use Cwd;
use IO::Handle;
STDOUT->autoflush(1);
my $out = $ENV{"out"};
mkdir "$out", 0755 || die "error creating $out";
my $selfdir = $ENV{"out"};
mkdir "$selfdir", 0755 || die "error creating $selfdir";
# For each activated package, create symlinks.
sub createLinks {
my $srcdir = shift;
my $dstdir = shift;
my $srcDir = shift;
my $dstDir = shift;
my @srcfiles = glob("$srcdir/*");
my @srcFiles = glob("$srcDir/*");
foreach my $srcfile (@srcfiles) {
my $basename = $srcfile;
$basename =~ s/^.*\///g; # strip directory
my $dstfile = "$dstdir/$basename";
if ($srcfile =~ /\/propagated-build-inputs$/) {
} elsif (-d $srcfile) {
# !!! hack for resolving name clashes
if (!-e $dstfile) {
mkdir $dstfile, 0755 ||
die "error creating directory $dstfile";
foreach my $srcFile (@srcFiles) {
my $baseName = $srcFile;
$baseName =~ s/^.*\///g; # strip directory
my $dstFile = "$dstDir/$baseName";
if ($srcFile =~ /\/propagated-build-inputs$/ ||
$srcFile =~ /\/nix-support$/)
{
# Do noting.
}
elsif (-d $srcFile) {
lstat $dstFile;
if (-d _) {
createLinks($srcFile, $dstFile);
}
-d $dstfile or die "$dstfile is not a directory";
createLinks($srcfile, $dstfile);
} elsif (-l $dstfile) {
my $target = readlink($dstfile);
die "collission between $srcfile and $target";
} else {
# print "linking $dstfile to $srcfile\n";
symlink($srcfile, $dstfile) ||
die "error creating link $dstfile";
elsif (-l _) {
my $target = readlink $dstFile or die;
if (!-d $target) {
die "collission between directory `$srcFile' and non-directory `$target'";
}
unlink $dstFile or die "error unlinking `$dstFile': $!";
mkdir $dstFile, 0755 ||
die "error creating directory `$dstFile': $!";
createLinks($target, $dstFile);
createLinks($srcFile, $dstFile);
}
else {
symlink($srcFile, $dstFile) ||
die "error creating link `$dstFile': $!";
}
}
elsif (-l $dstFile) {
my $target = readlink $dstFile;
die "collission between `$srcFile' and `$target'";
}
else {
# print "linking $dstFile to $srcFile\n";
symlink($srcFile, $dstFile) ||
die "error creating link `$dstFile': $!";
}
}
}
my %done;
sub addPkg {
my $pkgdir = shift;
my $pkgDir = shift;
return if (defined $done{$pkgdir});
$done{$pkgdir} = 1;
return if (defined $done{$pkgDir});
$done{$pkgDir} = 1;
# print "merging $pkgdir\n";
createLinks("$pkgdir", "$selfdir");
# if (-f "$pkgdir/envpkgs") {
# my $envpkgs = `cat $pkgdir/envpkgs`;
# chomp $envpkgs;
# my @envpkgs = split / +/, $envpkgs;
# foreach my $envpkg (@envpkgs) {
# addPkg($envpkg);
# }
# }
createLinks("$pkgDir", "$out");
}
my @args = split ' ', $ENV{"derivations"};
while (scalar @args > 0) {
my $drvpath = shift @args;
print "adding $drvpath\n";
addPkg($drvpath);
my $drvPath = shift @args;
print "adding $drvPath\n";
addPkg($drvPath);
}
symlink($ENV{"manifest"}, "$selfdir/manifest") or die "cannot create manifest";
symlink($ENV{"manifest"}, "$out/manifest") or die "cannot create manifest";