Add option to use multiple sessions with different stores

README.md

@@ -104,6 +104,56 @@ func main() {
 }
 ```
 
+### multiple sessions with different stores
+
+```go
+package main
+
+import (
+  "github.com/gin-contrib/sessions"
+  "github.com/gin-contrib/sessions/cookie"
+  "github.com/gin-gonic/gin"
+)
+
+func main() {
+  r := gin.Default()
+  cookieStore := cookie.NewStore([]byte("secret"))
+  redisStore, _ := redis.NewStore(10, "tcp", "localhost:6379", "", []byte("secret"))
+  sessionStores := []sessions.SessionStore{
+    {
+      Name:  "a",
+      Store: cookieStore,
+    },
+    {
+      Name:  "b",
+      Store: redisStore,
+    },
+  }
+  r.Use(sessions.SessionsManyStores(sessionStores))
+
+  r.GET("/hello", func(c *gin.Context) {
+    sessionA := sessions.DefaultMany(c, "a")
+    sessionB := sessions.DefaultMany(c, "b")
+
+    if sessionA.Get("hello") != "world!" {
+      sessionA.Set("hello", "world!")
+      sessionA.Save()
+    }
+
+    if sessionB.Get("hello") != "world?" {
+      sessionB.Set("hello", "world?")
+      sessionB.Save()
+    }
+
+    c.JSON(200, gin.H{
+      "a": sessionA.Get("hello"),
+      "b": sessionB.Get("hello"),
+    })
+  })
+  r.Run(":8000")
+}
+```
+
 ## Backend Examples
 
 ### cookie-based

cookie/cookie_test.go

@@ -35,3 +35,7 @@ func TestCookie_SessionOptions(t *testing.T) {
 func TestCookie_SessionMany(t *testing.T) {
 	tester.Many(t, newStore)
 }
+
+func TestCookie_SessionManyStores(t *testing.T) {
+	tester.ManyStores(t, newStore)
+}

memcached/memcached_test.go

@@ -41,6 +41,10 @@ func TestMemcached_SessionMany(t *testing.T) {
 	tester.Many(t, newStore)
 }
 
+func TestMemcached_SessionManyStores(t *testing.T) {
+	tester.ManyStores(t, newStore)
+}
+
 var newBinaryStore = func(_ *testing.T) sessions.Store {
 	store := NewMemcacheStore(
 		mc.NewMC(memcachedTestServer, "", ""), "", []byte("secret"))
@@ -70,3 +74,7 @@ func TestBinaryMemcached_SessionOptions(t *testing.T) {
 func TestBinaryMemcached_SessionMany(t *testing.T) {
 	tester.Many(t, newBinaryStore)
 }
+
+func TestBinaryMemcached_SessionManyStpres(t *testing.T) {
+	tester.ManyStores(t, newBinaryStore)
+}

memstore/memstore_test.go

@@ -35,3 +35,7 @@ func TestCookie_SessionOptions(t *testing.T) {
 func TestCookie_SessionMany(t *testing.T) {
 	tester.Many(t, newStore)
 }
+
+func TestCookie_SessionManyStores(t *testing.T) {
+	tester.ManyStores(t, newStore)
+}

mongo/mongo_test.go

@@ -43,3 +43,7 @@ func TestMongo_SessionOptions(t *testing.T) {
 func TestMongo_SessionMany(t *testing.T) {
 	tester.Many(t, newStore)
 }
+
+func TestMongo_SessionManyStores(t *testing.T) {
+	tester.ManyStores(t, newStore)
+}

postgres/postgres_test.go

@@ -46,3 +46,7 @@ func TestPostgres_SessionOptions(t *testing.T) {
 func TestPostgres_SessionMany(t *testing.T) {
 	tester.Many(t, newStore)
 }
+
+func TestPostgres_SessionManyStores(t *testing.T) {
+	tester.ManyStores(t, newStore)
+}

redis/redis_test.go

@@ -41,6 +41,10 @@ func TestRedis_SessionMany(t *testing.T) {
 	tester.Many(t, newRedisStore)
 }
 
+func TestRedis_SessionManyStores(t *testing.T) {
+	tester.ManyStores(t, newRedisStore)
+}
+
 func TestGetRedisStore(t *testing.T) {
 	t.Run("unmatched type", func(t *testing.T) {
 		type store struct{ Store }

sessions.go

@@ -46,6 +46,12 @@ type Session interface {
 	Save() error
 }
 
+// SessionStore named session stores allow multiple sessions with different store types
+type SessionStore struct {
+	Name  string
+	Store Store
+}
+
 func Sessions(name string, store Store) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		s := &session{name, c.Request, store, nil, false, c.Writer}
@@ -67,6 +73,18 @@ func SessionsMany(names []string, store Store) gin.HandlerFunc {
 	}
 }
 
+func SessionsManyStores(sessionStores []SessionStore) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		sessions := make(map[string]Session, len(sessionStores))
+		for _, sessionStore := range sessionStores {
+			sessions[sessionStore.Name] = &session{sessionStore.Name, c.Request, sessionStore.Store, nil, false, c.Writer}
+		}
+		c.Set(DefaultKey, sessions)
+		defer context.Clear(c.Request)
+		c.Next()
+	}
+}
+
 type session struct {
 	name    string
 	request *http.Request

tester/tester.go

@@ -306,3 +306,54 @@ func Many(t *testing.T, newStore storeFactory) {
 	req2.Header.Set("Cookie", header)
 	r.ServeHTTP(res2, req2)
 }
+
+func ManyStores(t *testing.T, newStore storeFactory) {
+	r := gin.Default()
+
+	store := newStore(t)
+	sessionStores := []sessions.SessionStore{
+		{Name: "a", Store: store},
+		{Name: "b", Store: store},
+	}
+
+	r.Use(sessions.SessionsManyStores(sessionStores))
+
+	r.GET("/set", func(c *gin.Context) {
+		sessionA := sessions.DefaultMany(c, "a")
+		sessionA.Set("hello", "world")
+		_ = sessionA.Save()
+
+		sessionB := sessions.DefaultMany(c, "b")
+		sessionB.Set("foo", "bar")
+		_ = sessionB.Save()
+		c.String(http.StatusOK, ok)
+	})
+
+	r.GET("/get", func(c *gin.Context) {
+		sessionA := sessions.DefaultMany(c, "a")
+		if sessionA.Get("hello") != "world" {
+			t.Error("Session writing failed")
+		}
+		_ = sessionA.Save()
+
+		sessionB := sessions.DefaultMany(c, "b")
+		if sessionB.Get("foo") != "bar" {
+			t.Error("Session writing failed")
+		}
+		_ = sessionB.Save()
+		c.String(http.StatusOK, ok)
+	})
+
+	res1 := httptest.NewRecorder()
+	req1, _ := http.NewRequest("GET", "/set", nil)
+	r.ServeHTTP(res1, req1)
+
+	res2 := httptest.NewRecorder()
+	req2, _ := http.NewRequest("GET", "/get", nil)
+	header := ""
+	for _, x := range res1.Header()["Set-Cookie"] {
+		header += strings.Split(x, ";")[0] + "; \n"
+	}
+	req2.Header.Set("Cookie", header)
+	r.ServeHTTP(res2, req2)
+}