Create common db package. Move original message to fetch to db.

db/util.go

@@ -0,0 +1,43 @@
+package db
+
+import (
+	"database/sql"
+	"flag"
+	"fmt"
+
+	_ "github.com/lib/pq"
+)
+
+var (
+	user    = flag.String("dbuser", "gomail", "PostgreSQL user name")
+	name    = flag.String("dbname", "gomail", "PostgreSQL DB name")
+	sslmode = flag.String("dbsslmode", "disable", "PostgreSQL sslmode setting")
+)
+
+type conn struct {
+	*sql.DB
+}
+
+// NewDB creates connection to PostgreSQL DB.  If dsn is empty, the flags
+// -dbuser, -dbname, -dbsslmode are used.
+func NewConn(dsn string) (*conn, error) {
+	if dsn == "" {
+		dsn = fmt.Sprintf("user=%s dbname=%s sslmode=%s", *user, *name,
+			*sslmode)
+	}
+	db, err := sql.Open("postgres", dsn)
+	return &conn{DB: db}, err
+}
+
+func (c *conn) OriginalBlobByHash(hash string, blob *[]byte) error {
+	row := c.QueryRow(`
+SELECT
+    blob
+FROM
+    original
+WHERE
+    hash = $1
+`, hash)
+
+	return row.Scan(blob)
+}