Added automated database migration script

app/lib/dal/fileDAL.js

@@ -33,6 +33,7 @@ function FileDAL(params) {
 
   // DALs
   this.confDAL = new ConfDAL(rootPath, myFS, null, that, CFSStorage);
+  this.metaDAL = new (require('./sqliteDAL/MetaDAL'))(sqlite);
   this.peerDAL = new (require('./sqliteDAL/PeerDAL'))(sqlite);
   this.blockDAL = new (require('./sqliteDAL/BlockDAL'))(sqlite);
   this.sourcesDAL = new (require('./sqliteDAL/SourcesDAL'))(sqlite);
@@ -45,6 +46,7 @@ function FileDAL(params) {
   this.msDAL = new (require('./sqliteDAL/MembershipDAL'))(sqlite);
 
   this.newDals = {
+    'metaDAL': that.metaDAL,
     'blockDAL': that.blockDAL,
     'certDAL': that.certDAL,
     'msDAL': that.msDAL,
@@ -77,8 +79,11 @@ function FileDAL(params) {
 
   this.init = () => co(function *() {
     yield _.values(that.newDals).map((dal) => dal.init());
+    yield that.metaDAL.upgradeDatabase();
   });
   
+  this.getDBVersion = () => that.metaDAL.getVersion();
+
   this.getCurrency = function() {
     return currency;
   };

app/lib/dal/sqliteDAL/MetaDAL.js

+/**
+ * Created by cgeek on 22/08/15.
+ */
+
+var co = require('co');
+var logger = require('../../../../app/lib/logger')('linksDAL');
+var AbstractSQLite = require('./AbstractSQLite');
+
+module.exports = MetaDAL;
+
+function MetaDAL(db) {
+
+  "use strict";
+
+  AbstractSQLite.call(this, db);
+
+  let that = this;
+
+  this.table = 'meta';
+  this.fields = [
+    'id',
+    'version'
+  ];
+  this.arrays = [];
+  this.booleans = [];
+  this.pkFields = ['version'];
+  this.translated = {};
+
+  let migrations = {
+    0: 'BEGIN; COMMIT;',
+    1: 'BEGIN; COMMIT;'
+  };
+
+  this.init = () => co(function *() {
+    return that.exec('BEGIN;' +
+      'CREATE TABLE IF NOT EXISTS ' + that.table + ' (' +
+      'id INTEGER NOT NULL,' +
+      'version INTEGER NOT NULL,' +
+      'PRIMARY KEY (id)' +
+      ');' +
+      'INSERT INTO ' + that.table + ' VALUES (1,0);' +
+      'COMMIT;', []);
+  });
+
+  this.upgradeDatabase = () => co(function *() {
+    let version = yield that.getVersion();
+    while(migrations[version]) {
+      yield that.exec(migrations[version]);
+      // Automated increment
+      yield that.exec('UPDATE meta SET version = version + 1');
+      version++;
+    }
+  });
+
+  this.getRow = () => that.sqlFindOne({ id: 1 });
+
+  this.getVersion = () => co(function *() {
+    let row = yield that.getRow();
+    return row.version;
+  });
+}

test/dal/dal.js

@@ -170,6 +170,12 @@ describe("DAL", function(){
     return fileDAL.saveConf({ currency: "meta_brouzouf" });
   }));
 
+  it('should have DB version 2', () => co(function *() {
+    let version = yield fileDAL.getDBVersion();
+    should.exist(version);
+    version.should.equal(2);
+  }));
+
   it('should have no peer in a first time', function(){
     return fileDAL.listAllPeers().then(function(peers){
       peers.should.have.length(0);