guix/scripts/nix-pull.in

116 lines
2.9 KiB
Perl

#! /usr/bin/perl -w
use strict;
use IPC::Open2;
my $tmpfile = "@localstatedir@/nix/pull.tmp";
my $conffile = "@sysconfdir@/nix/prebuilts.conf";
my @ids;
my @subs;
my @sucs;
my $fullexpr = "[";
my $first = 1;
open CONFFILE, "<$conffile";
while (<CONFFILE>) {
chomp;
if (/^\s*(\S+)\s*(\#.*)?$/) {
my $url = $1;
print "obtaining list of Nix archives at $url...\n";
system "wget '$url' -O '$tmpfile' 2> /dev/null"; # !!! escape
if ($?) { die "`wget' failed"; }
open INDEX, "<$tmpfile";
while (<INDEX>) {
# Get all links to prebuilts, that is, file names of the
# form foo-HASH-HASH.tar.bz2.
next unless (/HREF=\"([^\"]*)\"/);
my $fn = $1;
next if $fn =~ /\.\./;
next if $fn =~ /\//;
next unless $fn =~ /^([0-9a-z]{32})-([0-9a-z]{32})(.*)\.nar\.bz2$/;
my $hash = $1;
my $id = $2;
my $outname = $3;
my $fsid;
if ($outname =~ /^-/) {
next unless $outname =~ /^-((s-([0-9a-z]{32}))?.*)$/;
$outname = $1;
$fsid = $3;
} else {
$outname = "unnamed";
}
print STDERR "$id ($outname)\n";
# Construct a Fix expression that fetches and unpacks a
# Nix archive from the network.
my $fetch =
"App(IncludeFix(\"fetchurl/fetchurl.fix\"), " .
"[(\"url\", \"$url/$fn\"), (\"md5\", \"$hash\")])";
my $fixexpr =
"App(IncludeFix(\"nar/unnar.fix\"), " .
"[ (\"nar\", $fetch)" .
", (\"name\", \"$outname\")" .
", (\"id\", \"$id\")" .
"])";
if (!$first) { $fullexpr .= "," };
$first = 0;
$fullexpr .= $fixexpr; # !!! O(n^2)?
push @ids, $id;
# Does the name encode a successor relation?
if (defined $fsid) {
push @sucs, $fsid;
push @sucs, $id;
}
}
close INDEX;
unlink $tmpfile;
}
}
$fullexpr .= "]";
# Instantiate Nix expressions from the Fix expressions we created above.
print STDERR "running fix...\n";
my $pid = open2(\*READ, \*WRITE, "fix -") or die "cannot run fix";
print WRITE $fullexpr;
close WRITE;
my $i = 0;
while (<READ>) {
chomp;
die unless /^([0-9a-z]{32})$/;
my $nid = $1;
die unless ($i < scalar @ids);
my $id = $ids[$i++];
push @subs, $id;
push @subs, $nid;
}
waitpid $pid, 0;
$? == 0 or die "fix failed";
# Register all substitutes.
print STDERR "registering substitutes...\n";
system "nix --substitute @subs";
if ($?) { die "`nix --substitute' failed"; }
# Register all successors.
print STDERR "registering successors...\n";
system "nix --successor @sucs";
if ($?) { die "`nix --successor' failed"; }