make notification as separate package (#5294)

* Remove old notification files

* Add net package

* Add event package

* Modify minio to take new notification system

pkg/event/name.go

@@ -0,0 +1,152 @@
+/*
+ * Minio Cloud Storage, (C) 2018 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package event
+
+import (
+	"encoding/json"
+	"encoding/xml"
+)
+
+// Name - event type enum.
+// Refer http://docs.aws.amazon.com/AmazonS3/latest/dev/NotificationHowTo.html#notification-how-to-event-types-and-destinations
+type Name int
+
+// Values of Name
+const (
+	ObjectAccessedAll Name = 1 + iota
+	ObjectAccessedGet
+	ObjectAccessedHead
+	ObjectCreatedAll
+	ObjectCreatedCompleteMultipartUpload
+	ObjectCreatedCopy
+	ObjectCreatedPost
+	ObjectCreatedPut
+	ObjectRemovedAll
+	ObjectRemovedDelete
+)
+
+// Expand - returns expanded values of abbreviated event type.
+func (name Name) Expand() []Name {
+	switch name {
+	case ObjectAccessedAll:
+		return []Name{ObjectAccessedGet, ObjectAccessedHead}
+	case ObjectCreatedAll:
+		return []Name{ObjectCreatedCompleteMultipartUpload, ObjectCreatedCopy, ObjectCreatedPost, ObjectCreatedPut}
+	case ObjectRemovedAll:
+		return []Name{ObjectRemovedDelete}
+	default:
+		return []Name{name}
+	}
+}
+
+// String - returns string representation of event type.
+func (name Name) String() string {
+	switch name {
+	case ObjectAccessedAll:
+		return "s3:ObjectAccessed:*"
+	case ObjectAccessedGet:
+		return "s3:ObjectAccessed:Get"
+	case ObjectAccessedHead:
+		return "s3:ObjectAccessed:Head"
+	case ObjectCreatedAll:
+		return "s3:ObjectCreated:*"
+	case ObjectCreatedCompleteMultipartUpload:
+		return "s3:ObjectCreated:CompleteMultipartUpload"
+	case ObjectCreatedCopy:
+		return "s3:ObjectCreated:Copy"
+	case ObjectCreatedPost:
+		return "s3:ObjectCreated:Post"
+	case ObjectCreatedPut:
+		return "s3:ObjectCreated:Put"
+	case ObjectRemovedAll:
+		return "s3:ObjectRemoved:*"
+	case ObjectRemovedDelete:
+		return "s3:ObjectRemoved:Delete"
+	}
+
+	return ""
+}
+
+// MarshalXML - encodes to XML data.
+func (name Name) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
+	return e.EncodeElement(name.String(), start)
+}
+
+// UnmarshalXML - decodes XML data.
+func (name *Name) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
+	var s string
+	if err := d.DecodeElement(&s, &start); err != nil {
+		return err
+	}
+
+	eventName, err := ParseName(s)
+	if err != nil {
+		return err
+	}
+
+	*name = eventName
+	return nil
+}
+
+// MarshalJSON - encodes to JSON data.
+func (name Name) MarshalJSON() ([]byte, error) {
+	return json.Marshal(name.String())
+}
+
+// UnmarshalJSON - decodes JSON data.
+func (name *Name) UnmarshalJSON(data []byte) error {
+	var s string
+	if err := json.Unmarshal(data, &s); err != nil {
+		return err
+	}
+
+	eventName, err := ParseName(s)
+	if err != nil {
+		return err
+	}
+
+	*name = eventName
+	return nil
+}
+
+// ParseName - parses string to Name.
+func ParseName(s string) (Name, error) {
+	switch s {
+	case "s3:ObjectAccessed:*":
+		return ObjectAccessedAll, nil
+	case "s3:ObjectAccessed:Get":
+		return ObjectAccessedGet, nil
+	case "s3:ObjectAccessed:Head":
+		return ObjectAccessedHead, nil
+	case "s3:ObjectCreated:*":
+		return ObjectCreatedAll, nil
+	case "s3:ObjectCreated:CompleteMultipartUpload":
+		return ObjectCreatedCompleteMultipartUpload, nil
+	case "s3:ObjectCreated:Copy":
+		return ObjectCreatedCopy, nil
+	case "s3:ObjectCreated:Post":
+		return ObjectCreatedPost, nil
+	case "s3:ObjectCreated:Put":
+		return ObjectCreatedPut, nil
+	case "s3:ObjectRemoved:*":
+		return ObjectRemovedAll, nil
+	case "s3:ObjectRemoved:Delete":
+		return ObjectRemovedDelete, nil
+	default:
+		return 0, &ErrInvalidEventName{s}
+	}
+}