Evaluator cleanups

* Don't use isCurrent anymore; instead look up builds in the previous
  jobset evaluation.  (The isCurrent field is still maintained because
  it's still used in some other places.)

* To determine whether to perform an evaluation, compare the hash of
  the current inputs with the inputs of the previous jobset
  evaluation, rather than checking if there was ever an evaluation
  with those inputs.  This way, if the inputs of an evaluation change
  back to a previous state, we get a new jobset evaluation in the
  database (and thus the latest jobset evaluation correctly represents
  the latest state of the jobset).

* Improve performance by removing some unnecessary operations and
  adding an index.

src/lib/Hydra/Controller/Build.pm

@@ -538,7 +538,7 @@ sub clone_submit : Chained('build') PathPart('clone/submit') Args(0) {
     my %currentBuilds;
     my $newBuild = checkBuild(
         $c->model('DB'), $build->project, $build->jobset,
-        $inputInfo, $nixExprInput, $job, \%currentBuilds);
+        $inputInfo, $nixExprInput, $job, \%currentBuilds, undef);
 
     error($c, "This build has already been performed.") unless $newBuild;
     

src/lib/Hydra/Helper/AddBuilds.pm

@@ -17,6 +17,7 @@ our @ISA = qw(Exporter);
 our @EXPORT = qw(
     fetchInput evalJobs checkBuild inputsToArgs captureStdoutStderr 
     getReleaseName getBuildLog addBuildProducts restartBuild scmPath
+    getPrevJobsetEval
 );
 
 
@@ -787,9 +788,18 @@ sub addBuildProducts {
 }
 
 
+# Return the most recent evaluation of the given jobset that had new
+# builds, or undefined if no such evaluation exists.
+sub getPrevJobsetEval {
+    my ($db, $jobset) = @_;
+    my ($prevEval) = $jobset->jobsetevals({ hasnewbuilds => 1 }, { order_by => "id DESC", rows => 1 });
+    return $prevEval;
+}
+
+
 # Check whether to add the build described by $buildInfo.
 sub checkBuild {
-    my ($db, $project, $jobset, $inputInfo, $nixExprInput, $buildInfo, $currentBuilds) = @_;
+    my ($db, $project, $jobset, $inputInfo, $nixExprInput, $buildInfo, $buildIds, $prevEval) = @_;
 
     my $jobName = $buildInfo->{jobName};
     my $drvPath = $buildInfo->{drvPath};
@@ -822,19 +832,36 @@ sub checkBuild {
         # !!! Checking $outPath doesn't take meta-attributes into
         # account.  For instance, do we want a new build to be
         # scheduled if the meta.maintainers field is changed?
-        my @previousBuilds = $job->builds->search({outPath => $outPath, isCurrent => 1});
+        if (defined $prevEval) {
-        if (scalar(@previousBuilds) > 0) {
+            my ($prevBuild) = $prevEval->builds->search({ job => $job->name, outPath => $outPath }, { rows => 1, columns => ['id'] });
-            print STDERR "already scheduled/built\n";
+            if (defined $prevBuild) {
-            $currentBuilds->{$_->id} = 0 foreach @previousBuilds;
+                print STDERR "    already scheduled/built as build ", $prevBuild->id, "\n";
-            return;
+                $buildIds->{$prevBuild->id} = 0;
+                return;
+            }
         }
         
         my $time = time();
         
         # Nope, so add it.
+        my %extraFlags;
+        if (isValidPath($outPath)) {
+            %extraFlags =
+                ( finished => 1 
+                , iscachedbuild => 1
+                , buildstatus => 0
+                , starttime => $time 
+                , stoptime => $time 
+                , logfile => getBuildLog($drvPath)
+                , errormsg => ""
+                , releasename => getReleaseName($outPath)
+                );
+        } else {
+            %extraFlags = ( finished => 0 );
+        }
+	
         $build = $job->builds->create(
-            { finished => 0
+            { timestamp => $time 
-            , timestamp => $time 
             , description => $buildInfo->{description}
             , longdescription => $buildInfo->{longDescription}
             , license => $buildInfo->{license}
@@ -849,30 +876,19 @@ sub checkBuild {
             , iscurrent => 1
             , nixexprinput => $jobset->nixexprinput
             , nixexprpath => $jobset->nixexprpath
+	    , priority => $priority
+	    , busy => 0
+	    , locker => ""
+	    , %extraFlags
             });
 
-        $currentBuilds->{$build->id} = 1;
+        $buildIds->{$build->id} = 1;
         
-        if (isValidPath($outPath)) {
+        if ($build->iscachedbuild) {
-            print STDERR "marked as cached build ", $build->id, "\n";
+            print STDERR "    marked as cached build ", $build->id, "\n";
-	    $build->update(
-                { finished => 1 
-                , iscachedbuild => 1
-                , buildstatus => 0
-                , starttime => $time 
-                , stoptime => $time 
-                , logfile => getBuildLog($drvPath)
-                , errormsg => ""
-                , releasename => getReleaseName($outPath)
-                });
             addBuildProducts($db, $build);
         } else {
-            print STDERR "added to queue as build ", $build->id, "\n";
+            print STDERR "    added to queue as build ", $build->id, "\n";
-	    $build->update(
-		{ priority => $priority
-                , busy => 0
-                , locker => ""
-                });
         }
 
         my %inputs;

src/lib/Hydra/Schema/JobsetEvals.pm

@@ -161,5 +161,4 @@ __PACKAGE__->has_many(
 
 __PACKAGE__->many_to_many(builds => 'buildIds', 'build');
 
-# You can replace this text with custom content, and it will be preserved on regeneration
 1;

src/script/hydra-evaluator

@@ -80,11 +80,12 @@ sub sendJobsetErrorNotification() {
     );
     $email->body_set($body);
 
-    print $email->as_string if $ENV{'HYDRA_MAIL_TEST'};
+    print STDERR $email->as_string if $ENV{'HYDRA_MAIL_TEST'};
 
     sendmail($email);
 }
 
+
 sub permute {
     my @list = @_;
     for (my $n = scalar @list - 1; $n > 0; $n--) {
@@ -105,13 +106,13 @@ sub checkJobset {
     my $checkoutStop = time;
 
     # Hash the arguments to hydra-eval-jobs and check the
-    # JobsetInputHashes to see if we've already evaluated this set of
+    # JobsetInputHashes to see if the previous evaluation had the same
     # inputs.  If so, bail out.
     my @args = ($jobset->nixexprinput, $jobset->nixexprpath, inputsToArgs($inputInfo));
     my $argsHash = sha256_hex("@args");
-
+    my $prevEval = getPrevJobsetEval($db, $jobset);
-    if (scalar($jobset->jobsetevals->search({hash => $argsHash})) > 0) {
+    if ($prevEval->hash eq $argsHash) {
-        print "  already evaluated, skipping\n";
+        print STDERR "  jobset is unchanged, skipping\n";
         txn_do($db, sub {
             $jobset->update({lastcheckedtime => time});
         });
@@ -125,12 +126,17 @@ sub checkJobset {
 
     txn_do($db, sub {
         
+        # Clear the "current" flag on all builds.  Since we're in a
+        # transaction this will only become visible after the new
+        # current builds have been added.
+        $jobset->builds->search({iscurrent => 1})->update({iscurrent => 0});
+
         # Schedule each successfully evaluated job.
-        my %currentBuilds;
+        my %buildIds;
         foreach my $job (permute @{$jobs->{job}}) {
             next if $job->{jobName} eq "";
-            print "considering job " . $job->{jobName} . "\n";
+            print STDERR "  considering job " . $project->name, ":", $jobset->name, ":", $job->{jobName} . "\n";
-            checkBuild($db, $project, $jobset, $inputInfo, $nixExprInput, $job, \%currentBuilds);
+            checkBuild($db, $project, $jobset, $inputInfo, $nixExprInput, $job, \%buildIds, $prevEval);
         }
 
         # Update the last checked times and error messages for each
@@ -140,22 +146,11 @@ sub checkJobset {
 
         $jobset->update({lastcheckedtime => time});
         
-        foreach my $job ($jobset->jobs->all) {
+        $_->update({ errormsg => $failedJobNames{$_->name} ? join '\n', @{$failedJobNames{$_->name}} : undef })
-            if ($failedJobNames{$job->name}) {
+            foreach $jobset->jobs->all;
-                $job->update({errormsg => join '\n', @{$failedJobNames{$job->name}}});
-            } else {
-                $job->update({errormsg => undef});
-            }
-        }
-
-        # Clear the "current" flag on all builds that are no longer
-        # current.
-        foreach my $build ($jobset->builds->search({iscurrent => 1})) {
-            $build->update({iscurrent => 0}) unless defined $currentBuilds{$build->id};
-        }
 
         my $hasNewBuilds = 0;
-        while (my ($id, $new) = each %currentBuilds) {
+        while (my ($id, $new) = each %buildIds) {
             $hasNewBuilds = 1 if $new;
         }
 
@@ -168,13 +163,13 @@ sub checkJobset {
             });
 
         if ($hasNewBuilds) {
-            while (my ($id, $new) = each %currentBuilds) {
+            while (my ($id, $new) = each %buildIds) {
                 $ev->jobsetevalmembers->create({ build => $id, isnew => $new });
             }
         }
     });
        
-    # Store the errors messages for jobs that failed to evaluate.
+    # Store the error messages for jobs that failed to evaluate.
     my $msg = "";
     foreach my $error (@{$jobs->{error}}) {
         my $bindings = "";
@@ -197,7 +192,7 @@ sub checkJobset {
 sub checkJobsetWrapped {
     my ($project, $jobset) = @_;
     
-    print "considering jobset ", $jobset->name, " in ", $project->name, "\n";
+    print STDERR "considering jobset ", $project->name, ":", $jobset->name, "\n";
     
     eval {
         checkJobset($project, $jobset);
@@ -205,7 +200,7 @@ sub checkJobsetWrapped {
     
     if ($@) {
         my $msg = $@;
-        print "error evaluating jobset ", $jobset->name, ": $msg";
+        print STDERR "error evaluating jobset ", $jobset->name, ": $msg";
         txn_do($db, sub {
             $jobset->update({lastcheckedtime => time});
             setJobsetError($jobset, $msg);
@@ -216,7 +211,7 @@ sub checkJobsetWrapped {
 
 sub checkProjects {
     foreach my $project ($db->resultset('Projects')->search({enabled => 1})) {
-        print "considering project ", $project->name, "\n";
+        print STDERR "considering project ", $project->name, "\n";
         checkJobsetWrapped($project, $_)
             foreach $project->jobsets->search({enabled => 1});
     }
@@ -237,7 +232,7 @@ while (1) {
     eval {
         checkProjects;
     };
-    if ($@) { print "$@"; }
+    if ($@) { print STDERR "$@"; }
-    print "sleeping...\n";
+    print STDERR "sleeping...\n";
     sleep 30;
 }

src/sql/hydra.sql

@@ -493,6 +493,7 @@ create table BuildMachineSystemTypes (
 
 
 -- Some indices.
+
 create index IndexBuildInputsOnBuild on BuildInputs(build);
 create index IndexBuildInputsOnDependency on BuildInputs(dependency);
 create index IndexBuildProducstOnBuildAndType on BuildProducts(build, type);
@@ -517,8 +518,6 @@ create index IndexBuildsOnJobsetFinishedTimestamp on Builds(project, jobset, fin
 create index IndexBuildsOnJobFinishedId on builds(project, jobset, job, system, finished, id DESC);
 create index IndexBuildsOnJobSystemCurrent on Builds(project, jobset, job, system, isCurrent);
 create index IndexBuildsOnDrvPath on Builds(drvPath);
-create index IndexBuildsOnKeep on Builds(keep); -- used by hydra-update-gc-roots
-create index IndexMostRecentSuccessfulBuilds on Builds(project, jobset, job, system, finished, buildStatus, id desc); -- used by hydra-update-gc-roots
 create index IndexCachedHgInputsOnHash on CachedHgInputs(uri, branch, sha256hash);
 create index IndexCachedGitInputsOnHash on CachedGitInputs(uri, branch, sha256hash);
 create index IndexCachedSubversionInputsOnUriRevision on CachedSubversionInputs(uri, revision);
@@ -528,3 +527,10 @@ create index IndexJobsetInputAltsOnInput on JobsetInputAlts(project, jobset, inp
 create index IndexJobsetInputAltsOnJobset on JobsetInputAlts(project, jobset);
 create index IndexProjectsOnEnabled on Projects(enabled);
 create index IndexReleaseMembersOnBuild on ReleaseMembers(build);
+
+--  For hydra-update-gc-roots.
+create index IndexBuildsOnKeep on Builds(keep);
+create index IndexMostRecentSuccessfulBuilds on Builds(project, jobset, job, system, finished, buildStatus, id desc);
+
+-- To get the most recent eval for a jobset.
+create index IndexJobsetEvalsOnJobsetId on JobsetEvals(project, jobset, hasNewBuilds, id desc);

src/sql/upgrade-4.sql

@@ -0,0 +1 @@
+create index IndexJobsetEvalsOnJobsetId on JobsetEvals(project, jobset, hasNewBuilds, id desc);