From 3b005e895839bdd0c5d9e8e05171a2d42e1a74a2 Mon Sep 17 00:00:00 2001
From: Thomas Rudin <thomas@rudin.io>
Date: Wed, 9 Jan 2019 08:44:14 +0100
Subject: [PATCH] sqlite migration

---
 db/sqlite.go      | 41 ++++++++++++++++++++++++++++++++++++++++-
 db/sqlite_test.go |  8 ++++++++
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/db/sqlite.go b/db/sqlite.go
index 4c5cef6..b7138cd 100644
--- a/db/sqlite.go
+++ b/db/sqlite.go
@@ -3,16 +3,55 @@ package db
 import (
 	"database/sql"
 	_ "github.com/mattn/go-sqlite3"
+	"github.com/sirupsen/logrus"
 )
 
 const migrateScript = `
+alter table blocks add mtime timestamp default NULL;
+update blocks set mtime = current_timestamp;
+create index blocks_mtime on blocks(mtime);
+
+CREATE TRIGGER update_blocks_mtime_insert after insert on blocks for each row
+begin
+update blocks set mtime = current_timestamp where pos = new.pos;
+end;
+
+CREATE TRIGGER update_blocks_mtime_update after update on blocks for each row
+begin
+update blocks set mtime = current_timestamp where pos = old.pos;
+end;
 `
 
 type Sqlite3Accessor struct {
 	db *sql.DB
+	filename string
 }
 
 func (db *Sqlite3Accessor) Migrate() error {
+	log := logrus.WithFields(logrus.Fields{"prefix": "db/sqlite.Migrate","filename":db.filename})
+
+	//RW connection
+	rwdb, err := sql.Open("sqlite3", db.filename + "?mode=rw")
+	if err != nil {
+		return err
+	}
+
+	defer rwdb.Close()
+
+	hasMtime := true
+	_, err = rwdb.Query("select max(mtime) from blocks")
+	if err != nil {
+		hasMtime = false
+	}
+
+	if !hasMtime {
+		log.Info("Migrating database")
+		_, err = rwdb.Exec(migrateScript)
+		if err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
@@ -34,6 +73,6 @@ func NewSqliteAccessor(filename string) (*Sqlite3Accessor, error) {
 		return nil, err
 	}
 
-	sq := &Sqlite3Accessor{db: db}
+	sq := &Sqlite3Accessor{db: db, filename: filename}
 	return sq, nil
 }
diff --git a/db/sqlite_test.go b/db/sqlite_test.go
index a322499..f22606c 100644
--- a/db/sqlite_test.go
+++ b/db/sqlite_test.go
@@ -36,4 +36,12 @@ func TestMigrate(t *testing.T){
   }
 
   createEmptyDatabase(tmpfile.Name())
+  a, err := NewSqliteAccessor(tmpfile.Name())
+  if err != nil {
+    panic(err)
+  }
+  err = a.Migrate()
+  if err != nil {
+    panic(err)
+  }
 }