Create DB session provider(based on xorm) (#13031)

* Create Xorm session provider

This PR creates a Xorm session provider which creates
the appropriate Session table for macaron/session.

Fix #7137

Signed-off-by: Andrew Thornton <art27@cantab.net>

* extraneous l

Signed-off-by: Andrew Thornton <art27@cantab.net>

* fix lint

Signed-off-by: Andrew Thornton <art27@cantab.net>

* use key instead of ID to be compatible with go-macaron/session

Signed-off-by: Andrew Thornton <art27@cantab.net>

* And change the migration too.

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Update spacing of imports

Co-authored-by: 6543 <6543@obermui.de>

* Update modules/session/xorm.go

Co-authored-by: techknowlogick <matti@mdranta.net>

* add xorm provider to the virtual provider

Signed-off-by: Andrew Thornton <art27@cantab.net>

* prep for master merge

* prep for merge master

* As per @lunny

* move migration out of the way

* Move to call this db session as per @lunny

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: techknowlogick <matti@mdranta.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

4 files changed, 145 insertions, 0 deletions

diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index 66a44a27f8..740e8cb3ee 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -290,6 +290,8 @@ var migrations = []Migration{
 	NewMigration("Add Dismissed to Review table", addDismissedReviewColumn),
 	// v171 -> v172
 	NewMigration("Add Sorting to ProjectBoard table", addSortingColToProjectBoard),
+	// v172 -> v173
+	NewMigration("Add sessions table for go-chi/session", addSessionTable),
 }
 
 // GetCurrentDBVersion returns the current db version
diff --git a/models/migrations/v172.go b/models/migrations/v172.go
new file mode 100644
index 0000000000..51f83bcc91
--- /dev/null
+++ b/models/migrations/v172.go
@@ -0,0 +1,20 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package migrations
+
+import (
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"xorm.io/xorm"
+)
+
+func addSessionTable(x *xorm.Engine) error {
+	type Session struct {
+		Key         string `xorm:"pk CHAR(16)"`
+		Data        []byte `xorm:"BLOB"`
+		CreatedUnix timeutil.TimeStamp
+	}
+	return x.Sync2(new(Session))
+}
diff --git a/models/models.go b/models/models.go
index 1bfe75b7fc..de50793fe7 100644
--- a/models/models.go
+++ b/models/models.go
@@ -132,6 +132,7 @@ func init() {
 		new(Project),
 		new(ProjectBoard),
 		new(ProjectIssue),
+		new(Session),
 	)
 
 	gonicNames := []string{"SSL", "UID"}
diff --git a/models/session.go b/models/session.go
new file mode 100644
index 0000000000..fe363ee487
--- /dev/null
+++ b/models/session.go
@@ -0,0 +1,122 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+import (
+	"fmt"
+
+	"code.gitea.io/gitea/modules/timeutil"
+)
+
+// Session represents a session compatible for go-chi session
+type Session struct {
+	Key    string             `xorm:"pk CHAR(16)"` // has to be Key to match with go-chi/session
+	Data   []byte             `xorm:"BLOB"`
+	Expiry timeutil.TimeStamp // has to be Expiry to match with go-chi/session
+}
+
+// UpdateSession updates the session with provided id
+func UpdateSession(key string, data []byte) error {
+	_, err := x.ID(key).Update(&Session{
+		Data:   data,
+		Expiry: timeutil.TimeStampNow(),
+	})
+	return err
+}
+
+// ReadSession reads the data for the provided session
+func ReadSession(key string) (*Session, error) {
+	session := Session{
+		Key: key,
+	}
+	sess := x.NewSession()
+	defer sess.Close()
+	if err := sess.Begin(); err != nil {
+		return nil, err
+	}
+
+	if has, err := sess.Get(&session); err != nil {
+		return nil, err
+	} else if !has {
+		session.Expiry = timeutil.TimeStampNow()
+		_, err := sess.Insert(&session)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &session, sess.Commit()
+}
+
+// ExistSession checks if a session exists
+func ExistSession(key string) (bool, error) {
+	session := Session{
+		Key: key,
+	}
+	return x.Get(&session)
+}
+
+// DestroySession destroys a session
+func DestroySession(key string) error {
+	_, err := x.Delete(&Session{
+		Key: key,
+	})
+	return err
+}
+
+// RegenerateSession regenerates a session from the old id
+func RegenerateSession(oldKey, newKey string) (*Session, error) {
+	sess := x.NewSession()
+	defer sess.Close()
+	if err := sess.Begin(); err != nil {
+		return nil, err
+	}
+
+	if has, err := sess.Get(&Session{
+		Key: newKey,
+	}); err != nil {
+		return nil, err
+	} else if has {
+		return nil, fmt.Errorf("session Key: %s already exists", newKey)
+	}
+
+	if has, err := sess.Get(&Session{
+		Key: oldKey,
+	}); err != nil {
+		return nil, err
+	} else if !has {
+		_, err := sess.Insert(&Session{
+			Key:    oldKey,
+			Expiry: timeutil.TimeStampNow(),
+		})
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if _, err := sess.Exec("UPDATE "+sess.Engine().TableName(&Session{})+" SET `key` = ? WHERE `key`=?", newKey, oldKey); err != nil {
+		return nil, err
+	}
+
+	s := Session{
+		Key: newKey,
+	}
+	if _, err := sess.Get(&s); err != nil {
+		return nil, err
+	}
+
+	return &s, sess.Commit()
+}
+
+// CountSessions returns the number of sessions
+func CountSessions() (int64, error) {
+	return x.Count(&Session{})
+}
+
+// CleanupSessions cleans up expired sessions
+func CleanupSessions(maxLifetime int64) error {
+	_, err := x.Where("created_unix <= ?", timeutil.TimeStampNow().Add(-maxLifetime)).Delete(&Session{})
+	return err
+}