[backend] speed up changed2lookat by using a new reverse-dependency hash

Otherwise having lots of prps slows down the function too much. Creating
the reverse-dependency hash will also take some time, but we do this
only when updating the project data and not when we check a prp.
Found by profiling.

src/backend/BSSched/Lookat.pm

@@ -102,23 +102,38 @@ sub changed2lookat {
   my $changed_med  = $gctx->{'changed_med'};
   my $changed_high = $gctx->{'changed_high'};
 
-  # add all changed_high entries to changed_med to make things simpler
-  for (keys %$changed_high) {
-    $changed_med->{$_} = $changed_high->{$_} unless ($changed_med->{$_} || 0) == 2;
+  if (%$changed_high) {
+    # add all changed_high entries to changed_med to make things simpler
+    for (keys %$changed_high) {
+      $changed_med->{$_} = $changed_high->{$_} unless ($changed_med->{$_} || 0) == 2;
+    }
+    push @$lookat_high, grep {$changed_high->{$_}} sort keys %$changed_med;
+    push @$lookat_med, grep {!$changed_high->{$_}} sort keys %$changed_med;
+  } else {
+    push @$lookat_med, sort keys %$changed_med;
   }
-  push @$lookat_high, grep {$changed_high->{$_}} sort keys %$changed_med;
-  push @$lookat_med, grep {!$changed_high->{$_}} sort keys %$changed_med;
   @$lookat_high = BSUtil::unify(@$lookat_high);
   @$lookat_med = BSUtil::unify(@$lookat_med);
   my %lookat_high = map {$_ => 1} @$lookat_high;
   @$lookat_med = grep {!$lookat_high{$_}} @$lookat_med;
-  my $prpdeps = $gctx->{'prpdeps'};
-  for my $prp (@{$gctx->{'prps'}}) {
-    if (!$changed_low->{$prp} && !$changed_med->{$prp}) {
-      next unless grep {$changed_med->{$_}} @{$prpdeps->{$prp}};
-    }
+
+  for my $prp (keys %$changed_low) {
     $lookat_next->{$prp} = 1;
   }
+  my $rprpdeps = $gctx->{'rprpdeps'};
+  for my $prp (keys %$changed_med) {
+    $lookat_next->{$prp} = 1;
+    $lookat_next->{$_} = 1 for @{$rprpdeps->{$prp} || []};
+  }
+
+  #my $prpdeps = $gctx->{'prpdeps'};
+  #for my $prp (@{$gctx->{'prps'}}) {
+  #  if (!$changed_low->{$prp} && !$changed_med->{$prp}) {
+  #    next unless grep {$changed_med->{$_}} @{$prpdeps->{$prp}};
+  #  }
+  #  $lookat_next->{$prp} = 1;
+  #}
+
   %$changed_low = ();
   %$changed_med = ();
   %$changed_high = ();

src/backend/BSSched/ProjPacks.pm

@@ -807,7 +807,7 @@ sub calc_prps {
       # map searchpath to internal prp representation
       my @sp = map {"$_->{'project'}/$_->{'repository'}"} @searchpath;
       $prpsearchpath{$prp} = \@sp;
-      $prpdeps{"$projid/$repo->{'name'}"} = \@sp;
+      $prpdeps{$prp} = \@sp;
 
       # Find extra dependencies due to aggregate/kiwi description files
       my @xsp;
@@ -852,12 +852,17 @@ sub calc_prps {
       for (@{$prpdeps{$prp}}) {
 	$prpnoleaf{$_} = 1 if $_ ne $prp;
       }
+    }
+    # check for inter-repository project dependencies
+    for my $prp (keys %myprps) {
       $haveinterrepodep{$projid} = 1 if grep {$myprps{$_} && $_ ne $prp} @{$prpdeps{$prp}};
     }
   }
   # good bye no longer used entries!
   delete $newchanneldata{''};
   %{$gctx->{'channeldata'}} = %newchanneldata;
+
+  # print statistics
   print "have ".scalar(keys %newchanneldata)." unique channel configs\n" if %newchanneldata;
   print "have ".scalar(keys %haveinterrepodep)." inter-repo dependencies\n" if %haveinterrepodep;
 
@@ -869,9 +874,16 @@ sub calc_prps {
     print "cycle: ".join(' -> ', @$_)."\n" for @cycs;
   }
 
+  # create reverse deps to speed up changed2lookat
+  my %rprpdeps;
+  for my $prp (keys %prpdeps) {
+    push @{$rprpdeps{$_}}, $prp for @{$prpdeps{$prp}};
+  }
+
   $gctx->{'prps'} = \@prps;
   $gctx->{'prpsearchpath'} = \%prpsearchpath;
   $gctx->{'prpdeps'} = \%prpdeps;
+  $gctx->{'rprpdeps'} = \%rprpdeps;
   $gctx->{'prpnoleaf'} = \%prpnoleaf;
   $gctx->{'haveinterrepodep'} = \%haveinterrepodep;
 }

src/backend/bs_sched

@@ -422,6 +422,7 @@ my $gctx = {
   'projpacks_linked' => {},		# data of all linked sources
   'prps' => [],				# sorted list of all local prps (project repos)
   'prpdeps' => {},			# searchpath plus aggregate deps plus kiwi deps
+  'rprpdeps' => {},			# reverse prpdeps
 					# maps prp => [ prp, prp ... ], used for sorting
   'prpnoleaf' => {},			# is this prp referenced by another prp?
   'prpsearchpath' => {},		# which prps to use for building