Update frontend; Cache MetaData

frontend

@@ -1 +1 @@
-Subproject commit 1000e51693662be6c7c4faf19302f76279c6e0c1
+Subproject commit 184a5079bd53a89442664c28c5cebb733557f1f1

repository/job.go

@@ -26,7 +26,7 @@ type JobRepository struct {
 
 func (r *JobRepository) Init() error {
 	r.stmtCache = sq.NewStmtCache(r.DB)
-	r.cache = lrucache.New(100)
+	r.cache = lrucache.New(1024 * 1024)
 	return nil
 }
 
@@ -59,6 +59,12 @@ func scanJob(row interface{ Scan(...interface{}) error }) (*schema.Job, error) {
 }
 
 func (r *JobRepository) FetchMetadata(job *schema.Job) (map[string]string, error) {
+	cachekey := fmt.Sprintf("metadata:%d", job.ID)
+	if cached := r.cache.Get(cachekey, nil); cached != nil {
+		job.MetaData = cached.(map[string]string)
+		return job.MetaData, nil
+	}
+
 	if err := sq.Select("job.meta_data").From("job").Where("job.id = ?", job.ID).
 		RunWith(r.stmtCache).QueryRow().Scan(&job.RawMetaData); err != nil {
 		return nil, err
@@ -72,9 +78,42 @@ func (r *JobRepository) FetchMetadata(job *schema.Job) (map[string]string, error
 		return nil, err
 	}
 
+	r.cache.Put(cachekey, job.MetaData, len(job.RawMetaData), 24*time.Hour)
 	return job.MetaData, nil
 }
 
+func (r *JobRepository) UpdateMetadata(job *schema.Job, key, val string) (err error) {
+	cachekey := fmt.Sprintf("metadata:%d", job.ID)
+	r.cache.Del(cachekey)
+	if job.MetaData == nil {
+		if _, err = r.FetchMetadata(job); err != nil {
+			return err
+		}
+	}
+
+	if job.MetaData != nil {
+		cpy := make(map[string]string, len(job.MetaData)+1)
+		for k, v := range job.MetaData {
+			cpy[k] = v
+		}
+		cpy[key] = val
+		job.MetaData = cpy
+	} else {
+		job.MetaData = map[string]string{key: val}
+	}
+
+	if job.RawMetaData, err = json.Marshal(job.MetaData); err != nil {
+		return err
+	}
+
+	if _, err = sq.Update("job").Set("meta_data", job.RawMetaData).Where("job.id = ?", job.ID).RunWith(r.stmtCache).Exec(); err != nil {
+		return err
+	}
+
+	r.cache.Put(cachekey, job.MetaData, len(job.RawMetaData), 24*time.Hour)
+	return nil
+}
+
 // Find executes a SQL query to find a specific batch job.
 // The job is queried using the batch job id, the cluster name,
 // and the start time of the job in UNIX epoch time seconds.