Some comments and improvements for migrations

diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index b116e1217642b9c3d713f8191c30d02da46681b0..814564e9af774b1b2688c670f444d95c34d98215 100644 (file)
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -5,7 +5,6 @@
 package migrations
 
 import (
-       "errors"
        "fmt"
        "strings"
        "time"
@@ -17,7 +16,7 @@ import (
        "github.com/gogits/gogs/modules/setting"
 )
 
-const _DB_VER = 1
+const _MIN_DB_VER = 0
 
 type Migration interface {
        Description() string
@@ -48,9 +47,10 @@ type Version struct {
 }
 
 // This is a sequence of migrations. Add new migrations to the bottom of the list.
-// If you want to "retire" a migration, replace it with "expiredMigration"
+// If you want to "retire" a migration, remove it from the top of the list and 
+// update _MIN_VER_DB accordingly 
 var migrations = []Migration{
-       NewMigration("generate collaboration from access", accessToCollaboration),
+       NewMigration("generate collaboration from access", accessToCollaboration), // V0 -> V1
 }
 
 // Migrate database to current version
@@ -64,6 +64,8 @@ func Migrate(x *xorm.Engine) error {
        if err != nil {
                return fmt.Errorf("get: %v", err)
        } else if !has {
+               // If the user table does not exist it is a fresh installation and we
+               // can skip all migrations
                needsMigration, err := x.IsTableExist("user")
                if err != nil {
                        return err
@@ -73,10 +75,12 @@ func Migrate(x *xorm.Engine) error {
                        if err != nil {
                                return err
                        }
+                       // If the user table is empty it is a fresh installation and we can
+                       // skip all migrations
                        needsMigration = !isEmpty
                }
                if !needsMigration {
-                       currentVersion.Version = int64(len(migrations))
+                       currentVersion.Version = int64(_MIN_DB_VER + len(migrations))
                }
 
                if _, err = x.InsertOne(currentVersion); err != nil {
@@ -85,7 +89,7 @@ func Migrate(x *xorm.Engine) error {
        }
 
        v := currentVersion.Version
-       for i, m := range migrations[v:] {
+       for i, m := range migrations[v-_MIN_DB_VER:] {
                log.Info("Migration: %s", m.Description())
                if err = m.Migrate(x); err != nil {
                        return fmt.Errorf("do migrate: %v", err)
@@ -98,10 +102,6 @@ func Migrate(x *xorm.Engine) error {
        return nil
 }
 
-func expiredMigration(x *xorm.Engine) error {
-       return errors.New("You are migrating from a too old gogs version")
-}
-
 func accessToCollaboration(x *xorm.Engine) error {
        type Collaboration struct {
                ID      int64 `xorm:"pk autoincr"`
@@ -118,7 +118,12 @@ func accessToCollaboration(x *xorm.Engine) error {
        }
 
        sess := x.NewSession()
-       defer sess.Close()
+       defer func() {
+               if sess.IsCommitedOrRollbacked {
+                       sess.Rollback()
+               }
+               sess.Close()
+       }()
        if err = sess.Begin(); err != nil {
                return err
        }
@@ -151,7 +156,6 @@ func accessToCollaboration(x *xorm.Engine) error {
 
                results, err := sess.Query("SELECT u.id as `uid`, ou.uid as `memberid` FROM `user` u LEFT JOIN org_user ou ON ou.org_id=u.id WHERE u.lower_name=?", ownerName)
                if err != nil {
-                       sess.Rollback()
                        return err
                }
                if len(results) < 1 {
@@ -189,7 +193,6 @@ func accessToCollaboration(x *xorm.Engine) error {
                }
                has, err := sess.Get(collaboration)
                if err != nil {
-                       sess.Rollback()
                        return err
                } else if has {
                        continue
@@ -197,7 +200,6 @@ func accessToCollaboration(x *xorm.Engine) error {
 
                collaboration.Created = created
                if _, err = sess.InsertOne(collaboration); err != nil {
-                       sess.Rollback()
                        return err
                }
        }