* Get rid of the substitutes database table (NIX-47). Instead, if we

  need any info on substitutable paths, we just call the substituters
  (such as download-using-manifests.pl) directly.  This means that
  it's no longer necessary for nix-pull to register substitutes or for
  nix-channel to clear them, which makes those operations much faster
  (NIX-95).  Also, we don't have to worry about keeping nix-pull
  manifests (in /nix/var/nix/manifests) and the database in sync with
  each other.

  The downside is that there is some overhead in calling an external
  program to get the substitutes info.  For instance, "nix-env -qas"
  takes a bit longer.

  Abolishing the substitutes table also makes the logic in
  local-store.cc simpler, as we don't need to store info for invalid
  paths.  On the downside, you cannot do things like "nix-store -qR"
  on a substitutable but invalid path (but nobody did that anyway).

* Never catch interrupts (the Interrupted exception).

3 files changed, 48 insertions, 52 deletions

diff --git a/scripts/download-using-manifests.pl.in b/scripts/download-using-manifests.pl.in
index 65ab36084ab9..f963eead19ab 100644
--- a/scripts/download-using-manifests.pl.in
+++ b/scripts/download-using-manifests.pl.in
@@ -22,16 +22,6 @@ my $tmpNar2 = "$tmpDir/nar2";
 END { unlink $tmpNar; unlink $tmpNar2; rmdir $tmpDir; }
 
 
-# Check the arguments.
-die unless scalar @ARGV == 1;
-my $targetPath = $ARGV[0];
-
-my $date = strftime ("%F %H:%M:%S UTC", gmtime (time));
-print LOGFILE "$$ get $targetPath $date\n";
-
-print "\n*** Trying to download/patch `$targetPath'\n";
-
-
 # Load all manifests.
 my %narFiles;
 my %localPaths;
@@ -46,6 +36,54 @@ for my $manifest (glob "$manifestDir/*.nixmanifest") {
 }
 
 
+# Parse the arguments.
+
+if ($ARGV[0] eq "--query-paths") {
+    foreach my $storePath (keys %narFiles) { print "$storePath\n"; }
+    foreach my $storePath (keys %localPaths) { print "$storePath\n"; }
+    exit 0;
+}
+
+elsif ($ARGV[0] eq "--query-info") {
+    shift @ARGV;
+    foreach my $storePath (@ARGV) {
+        my $info;
+        if (defined $narFiles{$storePath}) {
+            $info = @{$narFiles{$storePath}}[0];
+        }
+        elsif (defined $localPaths{$storePath}) {
+            $info = @{$localPaths{$storePath}}[0];
+        }
+        else {
+            next; # not an error
+        }
+        print "$storePath\n";
+        print "$info->{deriver}\n";
+        my @references = split " ", $info->{references};
+        my $count = scalar @references;
+        print "$count\n";
+        foreach my $reference (@references) {
+            print "$reference\n";
+        }
+    }
+    exit 0;
+}
+
+elsif ($ARGV[0] ne "--substitute") {
+    die "syntax: $0 [--query-paths | --query-info PATHS... | --substitute PATH]\n";
+}
+
+
+die unless scalar @ARGV == 2;
+my $targetPath = $ARGV[1];
+
+
+my $date = strftime ("%F %H:%M:%S UTC", gmtime (time));
+print LOGFILE "$$ get $targetPath $date\n";
+
+print "\n*** Trying to download/patch `$targetPath'\n";
+
+
 # If we can copy from a local path, do that.
 my $localPathList = $localPaths{$targetPath};
 foreach my $localPath (@{$localPathList}) {
diff --git a/scripts/nix-channel.in b/scripts/nix-channel.in
index 6a4603976fb9..1ef9c58447b3 100644
--- a/scripts/nix-channel.in
+++ b/scripts/nix-channel.in
@@ -76,10 +76,6 @@ sub removeChannel {
 sub update {
     readChannels;
 
-    # Get rid of all the old substitutes.
-    system("@bindir@/nix-store", "--clear-substitutes") == 0
-        or die "cannot clear substitutes";
-
     # Remove all the old manifests.
     for my $manifest (glob "$stateDir/manifests/*.nixmanifest") {
         unlink $manifest or die "cannot remove `$manifest': $!";
diff --git a/scripts/nix-pull.in b/scripts/nix-pull.in
index ff83f2857c9d..378d9a363e98 100644
--- a/scripts/nix-pull.in
+++ b/scripts/nix-pull.in
@@ -108,41 +108,3 @@ while (@ARGV) {
 
 my $size = scalar (keys %narFiles) + scalar (keys %localPaths);
 print "$size store paths in manifest\n";
-
-
-# Register all substitutes.
-print STDERR "registering substitutes...\n";
-
-my $pid = open(WRITE, "|$binDir/nix-store --register-substitutes")
-    or die "cannot run nix-store";
-
-sub writeRegistration {
-    my $storePath = shift;
-    my $object = shift;
-    print WRITE "$storePath\n";
-    print WRITE "$object->{deriver}\n";
-    print WRITE "$libexecDir/nix/download-using-manifests.pl\n";
-    print WRITE "0\n";
-    my @references = split " ", $object->{references};
-    my $count = scalar @references;
-    print WRITE "$count\n";
-    foreach my $reference (@references) {
-        print WRITE "$reference\n";
-    }
-}
-
-foreach my $storePath (keys %narFiles) {
-    my $narFileList = $narFiles{$storePath};
-    foreach my $narFile (@{$narFileList}) {
-        writeRegistration $storePath, $narFile;
-    }
-}
-
-foreach my $storePath (keys %localPaths) {
-    my $localPathList = $localPaths{$storePath};
-    foreach my $localPath (@{$localPathList}) {
-        writeRegistration $storePath, $localPath;
-    }
-}
-
-close WRITE or die "nix-store failed: $?";