provider: dynamo-db support added

server/db/providers/dynamodb/shared.go

@@ -0,0 +1,46 @@
+package dynamodb
+
+import (
+	"github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute"
+	"github.com/guregu/dynamo"
+)
+
+// As updpate all item not supported so set manually via Set and SetNullable for empty field
+func UpdateByHashKey(table dynamo.Table, hashKey string, hashValue string, item interface{}) error {
+	existingValue, err := dynamo.MarshalItem(item)
+	var i interface{}
+
+	if err != nil {
+		return err
+	}
+
+	nullableValue, err := dynamodbattribute.MarshalMap(item)
+	if err != nil {
+		return err
+	}
+
+	u := table.Update(hashKey, hashValue)
+	for k, v := range existingValue {
+		if k == hashKey {
+			continue
+		}
+		u = u.Set(k, v)
+	}
+
+	for k, v := range nullableValue {
+		if k == hashKey {
+			continue
+		}
+		dynamodbattribute.Unmarshal(v, &i)
+		if i == nil {
+			u = u.SetNullable(k, v)
+		}
+	}
+
+	err = u.Run()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}