First attempt at the manifest-less substituter

.gitignore

@@ -60,6 +60,7 @@ Makefile.in
 /scripts/GeneratePatches.pm
 /scripts/download-using-manifests.pl
 /scripts/copy-from-other-stores.pl
+/scripts/download-from-binary-cache.pl
 /scripts/find-runtime-roots.pl
 /scripts/build-remote.pl
 /scripts/nix-reduce-build

perl/lib/Nix/Config.pm.in

@@ -6,6 +6,7 @@ $stateDir = $ENV{"NIX_STATE_DIR"} || "@localstatedir@/nix";
 $manifestDir = $ENV{"NIX_MANIFESTS_DIR"} || "@localstatedir@/nix/manifests";
 $logDir = $ENV{"NIX_LOG_DIR"} || "@localstatedir@/log/nix";
 $confDir = $ENV{"NIX_CONF_DIR"} || "@sysconfdir@/nix";
+$storeDir = $ENV{"NIX_STORE_DIR"} || "@storedir@";
 
 $bzip2 = "@bzip2@";
 $xz = "@xz@";

scripts/Makefile.am

@@ -7,17 +7,14 @@ noinst_SCRIPTS = nix-profile.sh \
   find-runtime-roots.pl build-remote.pl nix-reduce-build \
   copy-from-other-stores.pl nix-http-export.cgi
 
-nix-pull nix-push: download-using-manifests.pl
+install-exec-local: download-using-manifests.pl copy-from-other-stores.pl download-from-binary-cache.pl find-runtime-roots.pl
-
-install-exec-local: download-using-manifests.pl copy-from-other-stores.pl find-runtime-roots.pl
 	$(INSTALL) -d $(DESTDIR)$(sysconfdir)/profile.d
 	$(INSTALL_DATA) nix-profile.sh $(DESTDIR)$(sysconfdir)/profile.d/nix.sh
 	$(INSTALL) -d $(DESTDIR)$(libexecdir)/nix
 	$(INSTALL_PROGRAM) find-runtime-roots.pl $(DESTDIR)$(libexecdir)/nix 
 	$(INSTALL_PROGRAM) build-remote.pl $(DESTDIR)$(libexecdir)/nix 
 	$(INSTALL) -d $(DESTDIR)$(libexecdir)/nix/substituters
-	$(INSTALL_PROGRAM) download-using-manifests.pl $(DESTDIR)$(libexecdir)/nix/substituters
+	$(INSTALL_PROGRAM) download-using-manifests.pl copy-from-other-stores.pl download-from-binary-cache.pl $(DESTDIR)$(libexecdir)/nix/substituters
-	$(INSTALL_PROGRAM) copy-from-other-stores.pl $(DESTDIR)$(libexecdir)/nix/substituters
 	$(INSTALL) -d $(DESTDIR)$(sysconfdir)/nix
 
 include ../substitute.mk
@@ -29,6 +26,7 @@ EXTRA_DIST = nix-collect-garbage.in \
   nix-build.in \
   download-using-manifests.pl.in \
   copy-from-other-stores.pl.in \
+  download-from-binary-cache.pl.in \
   nix-copy-closure.in \
   find-runtime-roots.pl.in \
   build-remote.pl.in \

scripts/download-from-binary-cache.pl.in

@@ -0,0 +1,118 @@
+#! @perl@ -w @perlFlags@
+
+use strict;
+use Nix::Config;
+use Nix::Store;
+
+my @binaryCacheUrls = ("file:///tmp/binary-cache");
+
+sub getInfoFrom {
+    my ($storePath, $pathHash, $binaryCacheUrl) = @_;
+    my $infoUrl = "$binaryCacheUrl/$pathHash.narinfo";
+    #print STDERR "checking $infoUrl...\n";
+    my $s = `$Nix::Config::curl --fail --silent --location ${infoUrl}`;
+    if ($? != 0) {
+        print STDERR "GOT CURL REPLY ", $? >> 8, "\n";
+        return undef;
+    }
+    my ($storePath2, $url, $fileHash, $fileSize, $narHash, $narSize, $deriver);
+    my @refs;
+    foreach my $line (split "\n", $s) {
+        $line =~ /^(.*): (.*)$/ or return undef;
+        if ($1 eq "StorePath") { $storePath2 = $2; }
+        elsif ($1 eq "URL") { $url = $2; }
+        elsif ($1 eq "CompressedHash") { $fileHash = $2; }
+        elsif ($1 eq "CompressedSize") { $fileSize = int($2); }
+        elsif ($1 eq "NarHash") { $narHash = $2; }
+        elsif ($1 eq "NarSize") { $narSize = int($2); }
+        elsif ($1 eq "References") { @refs = split / /, $2; }
+        elsif ($1 eq "Deriver") { $deriver = $2; }
+    }
+    if ($storePath ne $storePath2 || !defined $url || !defined $narHash || !defined $narSize) {
+        print STDERR "bad NAR info file ‘$infoUrl’\n";
+        return undef
+    }
+    return
+        { url => $url
+        , fileHash => $fileHash
+        , fileSize => $fileSize
+        , narHash => $narHash
+        , narSize => $narSize
+        , refs => [ map { "$Nix::Config::storeDir/$_" } @refs ]
+        , deriver => "$Nix::Config::storeDir/$deriver"
+        }
+}
+
+sub getInfo {
+    my ($storePath) = @_;
+
+    my $pathHash = hashString("sha256", 1, $storePath);
+
+    cache: foreach my $binaryCacheUrl (@binaryCacheUrls) {
+        my $info = getInfoFrom($storePath, $pathHash, $binaryCacheUrl);
+        return $info if defined $info;
+    }
+
+    return undef;
+}
+
+sub downloadBinary {
+    my ($storePath) = @_;
+    
+    my $pathHash = hashString("sha256", 1, $storePath);
+
+    cache: foreach my $binaryCacheUrl (@binaryCacheUrls) {
+        my $info = getInfoFrom($storePath, $pathHash, $binaryCacheUrl);
+        if (defined $info) {
+            if (system("$Nix::Config::curl --fail --location $binaryCacheUrl/$info->{url} | $Nix::Config::xz -d | $Nix::Config::binDir/nix-store --restore $storePath") == 0) {
+                return 1;
+            }
+        }
+    }
+
+    return 0;
+}
+
+if ($ARGV[0] eq "--query") {
+
+    while (<STDIN>) {
+        my $cmd = $_; chomp $cmd;
+
+        if ($cmd eq "have") {
+            my $storePath = <STDIN>; chomp $storePath;
+            # FIXME: want to give correct info here, but it's too slow.
+            print "0\n";
+            #my $info = getInfo($storePath);
+            #if (defined $info) { print "1\n"; } else { print "0\n"; }
+        }
+
+        elsif ($cmd eq "info") {
+            my $storePath = <STDIN>; chomp $storePath;
+            my $info = getInfo($storePath);
+            if (defined $info) {
+                print "1\n";
+                print $info->{deriver} || "", "\n";
+                print scalar @{$info->{refs}}, "\n";
+                print "$_\n" foreach @{$info->{refs}};
+                print $info->{fileSize} || 0, "\n";
+                print $info->{narSize}, "\n";
+            } else {
+                print "0\n";
+            }
+        }
+
+        else { die "unknown command `$cmd'"; }
+
+        flush STDOUT;
+    }
+
+}
+
+elsif ($ARGV[0] eq "--substitute") {
+    my $storePath = $ARGV[1] or die;
+    exit 1 unless downloadBinary($storePath);
+}
+
+else {
+    die;
+}