schema: Separate "Derivations" from "Evaluations".

* src/schema.sql (Derivations): New table.
(Evaluations): Remove 'derivation' and 'job_name' columns.  Add 'id'
column.
* src/cuirass/database.scm (db-add-evaluation): Adapt.
(db-get-derivation, db-add-derivation): New procedures.
(evaluation-exists?, db-get-evaluation): Delete.
* bin/evaluate.in (main): Adapt.
* tests/database.scm ("sqlite-exec"): Likewise.
("db-add-derivation", "db-get-derivation"): New tests.
("db-add-evaluation", "db-get-evaluation"): Delete.

4 files changed, 38 insertions, 36 deletions

diff --git a/bin/evaluate.in b/bin/evaluate.in
index 878732f..6c5a53f 100644
--- a/bin/evaluate.in
+++ b/bin/evaluate.in
@@ -57,17 +57,17 @@ exec ${GUILE:-@GUILE@} --no-auto-compile -e main -s "$0" "$@"
                  (exit 1)))
          (parameterize ((%package-database database))
            ;; Call the entry point of FILE and print the resulting job sexp.
-           (let* ((proc   (module-ref %user-module 'hydra-jobs))
-                  (thunks (proc store (assq-ref spec #:arguments)))
-                  (db     (db-open))
-                  (spec-id (assq-ref spec #:id)))
+           (let* ((proc    (module-ref %user-module 'hydra-jobs))
+                  (thunks  (proc store (assq-ref spec #:arguments)))
+                  (db      (db-open))
+                  (spec-id (assq-ref spec #:id))
+                  (eval-id (db-add-evaluation db spec-id)))
              (pretty-print
               (map (λ (thunk)
                      (let* ((job  (call-with-time-display thunk))
                             ;; Keep track of SPEC id in the returned jobs.
-                            (job* (acons #:spec-id spec-id job)))
-                       (or (evaluation-exists? db job*)
-                           (db-add-evaluation db job*))
+                            (job* (acons #:eval-id eval-id job)))
+                       (db-add-derivation db job*)
                        job*))
                    thunks)
               stdout)
diff --git a/src/cuirass/database.scm b/src/cuirass/database.scm
index 13362a5..a314704 100644
--- a/src/cuirass/database.scm
+++ b/src/cuirass/database.scm
@@ -31,9 +31,9 @@
             db-get-specifications
             db-add-stamp
             db-get-stamp
-            evaluation-exists?
             db-add-evaluation
-            db-get-evaluation
+            db-add-derivation
+            db-get-derivation
             db-add-build
             read-sql-file
             read-quoted-string
@@ -142,25 +142,23 @@ INSERT INTO Specifications\
                      (#:commit . ,(if (string=? rev "NULL") #f rev)))
                    specs))))))
 
-(define (evaluation-exists? db job)
-  "Check if JOB is already added to DB."
-  (let ((primary-key (assq-ref job #:derivation)))
-    (not (null? (sqlite-exec db "\
-SELECT * FROM Evaluations WHERE derivation='~A';"
-                             primary-key)))))
-
-(define (db-add-evaluation db job)
+(define (db-add-derivation db job)
   "Store a derivation result in database DB and return its ID."
   (sqlite-exec db "\
-INSERT INTO Evaluations (derivation, job_name, specification)\
+INSERT INTO Derivations (derivation, job_name, evaluation)\
   VALUES ('~A', '~A', '~A');"
                (assq-ref job #:derivation)
                (assq-ref job #:job-name)
-               (assq-ref job #:spec-id)))
+               (assq-ref job #:eval-id)))
 
-(define (db-get-evaluation db id)
+(define (db-get-derivation db id)
   "Retrieve a job in database DB which corresponds to ID."
-  (car (sqlite-exec db "SELECT * FROM Evaluations WHERE derivation='~A';" id)))
+  (car (sqlite-exec db "SELECT * FROM Derivations WHERE derivation='~A';" id)))
+
+(define (db-add-evaluation db spec-id)
+  (sqlite-exec db "INSERT INTO Evaluations (specification) VALUES ('~A');"
+               spec-id)
+  (last-insert-rowid db))
 
 (define-syntax-rule (with-database db body ...)
   "Run BODY with a connection to the database which is bound to DB in BODY."
diff --git a/src/schema.sql b/src/schema.sql
index d5c1f00..248f9d2 100644
--- a/src/schema.sql
+++ b/src/schema.sql
@@ -21,12 +21,19 @@ CREATE TABLE Stamps (
 );
 
 CREATE TABLE Evaluations (
-  derivation    TEXT NOT NULL PRIMARY KEY,
-  job_name      TEXT NOT NULL,
+  id            INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
   specification INTEGER NOT NULL,
   FOREIGN KEY (specification) REFERENCES Specifications (id)
 );
 
+CREATE TABLE Derivations (
+  derivation    TEXT NOT NULL,
+  evaluation    INTEGER NOT NULL,
+  job_name      TEXT NOT NULL,
+  PRIMARY KEY (derivation, evaluation),
+  FOREIGN KEY (evaluation) REFERENCES Evaluations (id)
+);
+
 CREATE TABLE Builds (
   id              INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
   derivation      TEXT NOT NULL,
diff --git a/tests/database.scm b/tests/database.scm
index 29a1e50..7fa9f1b 100644
--- a/tests/database.scm
+++ b/tests/database.scm
@@ -57,15 +57,12 @@
 
       (test-assert "sqlite-exec"
         (begin
-          (sqlite-exec (%db) "\
-INSERT INTO Evaluations (derivation, job_name, specification)\
-  VALUES ('drv1', 'job1', 1);")
-          (sqlite-exec (%db) "\
-INSERT INTO Evaluations (derivation, job_name, specification)\
-  VALUES ('drv2', 'job2', 2);")
-          (sqlite-exec (%db) "\
-INSERT INTO Evaluations (derivation, job_name, specification)\
-  VALUES ('drv3', 'job3', 3);")
+          (sqlite-exec (%db)
+                       "INSERT INTO Evaluations (specification) VALUES (1);")
+          (sqlite-exec (%db)
+                       "INSERT INTO Evaluations (specification) VALUES (2);")
+          (sqlite-exec (%db)
+                       "INSERT INTO Evaluations (specification) VALUES (3);")
           (sqlite-exec (%db) "SELECT * FROM Evaluations;")))
 
       (test-equal "db-add-specification"
@@ -74,14 +71,14 @@ INSERT INTO Evaluations (derivation, job_name, specification)\
           (db-add-specification (%db) example-spec)
           (car (db-get-specifications (%db)))))
 
-      (test-assert "db-add-evaluation"
+      (test-assert "db-add-derivation"
         (let* ((job (make-dummy-job))
                (key (assq-ref job #:derivation)))
-          (db-add-evaluation (%db) job)
+          (db-add-derivation (%db) job)
           (%id key)))
 
-      (test-assert "db-get-evaluation"
-        (db-get-evaluation (%db) (%id)))
+      (test-assert "db-get-derivation"
+        (db-get-derivation (%db) (%id)))
 
       (test-assert "db-close"
         (db-close (%db))))