From ed00f0b25e5cee10a434f170d18f62a6692681a1 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Sat, 11 May 2019 00:41:13 +0200
Subject: [PATCH] Cache flake-based jobset evaluations

---
 src/lib/Hydra/Schema/JobsetEvals.pm | 11 +++++++++--
 src/script/hydra-eval-jobset        | 15 +++++++++++++--
 src/sql/hydra.sql                   |  2 ++
 src/sql/upgrade-57.sql              |  1 +
 4 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/src/lib/Hydra/Schema/JobsetEvals.pm b/src/lib/Hydra/Schema/JobsetEvals.pm
index 0bd21da2..ef0b1523 100644
--- a/src/lib/Hydra/Schema/JobsetEvals.pm
+++ b/src/lib/Hydra/Schema/JobsetEvals.pm
@@ -88,6 +88,11 @@ __PACKAGE__->table("JobsetEvals");
   data_type: 'integer'
   is_nullable: 1
 
+=head2 flake
+
+  data_type: 'text'
+  is_nullable: 1
+
 =cut
 
 __PACKAGE__->add_columns(
@@ -111,6 +116,8 @@ __PACKAGE__->add_columns(
   { data_type => "integer", is_nullable => 1 },
   "nrsucceeded",
   { data_type => "integer", is_nullable => 1 },
+  "flake",
+  { data_type => "text", is_nullable => 1 },
 );
 
 =head1 PRIMARY KEY
@@ -188,8 +195,8 @@ __PACKAGE__->belongs_to(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.07033 @ 2013-06-13 01:54:50
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:SlEiF8oN6FBK262uSiMKiw
+# Created by DBIx::Class::Schema::Loader v0.07049 @ 2019-05-11 00:16:10
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:XwlJFCJiS0LHsLg2fFqfUg
 
 __PACKAGE__->has_many(
   "buildIds",
diff --git a/src/script/hydra-eval-jobset b/src/script/hydra-eval-jobset
index 1e5c81e7..71d24a83 100755
--- a/src/script/hydra-eval-jobset
+++ b/src/script/hydra-eval-jobset
@@ -607,6 +607,16 @@ sub checkJobsetWrapped {
     };
     my $fetchError = $@;
 
+    my $flakeRef = $jobset->flake;
+    if (defined $flakeRef) {
+        (my $res, my $json, my $stderr) = captureStdoutStderr(
+            600, "nix", "flake", "info", "--tarball-ttl", 0, "--json", "--", $flakeRef);
+        die "'nix flake info' returned " . ($res & 127 ? "signal $res" : "exit code " . ($res >> 8))
+            . ":\n" . ($stderr ? decode("utf-8", $stderr) : "(no output)\n")
+            if $res;
+        $flakeRef = decode_json($json)->{'uri'};
+    }
+
     Net::Statsd::increment("hydra.evaluator.checkouts");
     my $checkoutStop = clock_gettime(CLOCK_MONOTONIC);
     Net::Statsd::timing("hydra.evaluator.checkout_time", int(($checkoutStop - $checkoutStart) * 1000));
@@ -626,7 +636,7 @@ sub checkJobsetWrapped {
     my @args = ($jobset->nixexprinput, $jobset->nixexprpath, inputsToArgs($inputInfo, $exprType));
     my $argsHash = sha256_hex("@args");
     my $prevEval = getPrevJobsetEval($db, $jobset, 0);
-    if (defined $prevEval && $prevEval->hash eq $argsHash && !$dryRun && !$jobset->forceeval) {
+    if (defined $prevEval && $prevEval->hash eq $argsHash && !$dryRun && !$jobset->forceeval && $prevEval->flake eq $flakeRef) {
         print STDERR "  jobset is unchanged, skipping\n";
         Net::Statsd::increment("hydra.evaluator.unchanged_checkouts");
         txn_do($db, sub {
@@ -637,7 +647,7 @@ sub checkJobsetWrapped {
 
     # Evaluate the job expression.
     my $evalStart = clock_gettime(CLOCK_MONOTONIC);
-    my $jobs = evalJobs($inputInfo, $exprType, $jobset->nixexprinput, $jobset->nixexprpath, $jobset->flake);
+    my $jobs = evalJobs($inputInfo, $exprType, $jobset->nixexprinput, $jobset->nixexprpath, $flakeRef);
     my $evalStop = clock_gettime(CLOCK_MONOTONIC);
 
     if ($jobsetsJobset) {
@@ -697,6 +707,7 @@ sub checkJobsetWrapped {
             , evaltime => abs(int($evalStop - $evalStart))
             , hasnewbuilds => $jobsetChanged ? 1 : 0
             , nrbuilds => $jobsetChanged ? scalar(keys %buildMap) : undef
+            , flake => $flakeRef
             });
 
         if ($jobsetChanged) {
diff --git a/src/sql/hydra.sql b/src/sql/hydra.sql
index 8998fd57..f81bbad4 100644
--- a/src/sql/hydra.sql
+++ b/src/sql/hydra.sql
@@ -527,6 +527,8 @@ create table JobsetEvals (
     nrBuilds      integer,
     nrSucceeded   integer, -- set lazily when all builds are finished
 
+    flake         text, -- immutable flake reference
+
     foreign key   (project) references Projects(name) on delete cascade on update cascade,
     foreign key   (project, jobset) references Jobsets(project, name) on delete cascade on update cascade
 );
diff --git a/src/sql/upgrade-57.sql b/src/sql/upgrade-57.sql
index 15553beb..b59ee949 100644
--- a/src/sql/upgrade-57.sql
+++ b/src/sql/upgrade-57.sql
@@ -4,3 +4,4 @@ alter table Jobsets add column type integer default 0;
 alter table Jobsets add column flake text;
 alter table Jobsets add check ((type = 0) = (nixExprInput is not null and nixExprPath is not null));
 alter table Jobsets add check ((type = 1) = (flake is not null));
+alter table JobsetEvals add column flake text;