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/errors.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/xml"
+	"fmt"
+)
+
+// IsEventError - checks whether given error is event error or not.
+func IsEventError(err error) bool {
+	switch err.(type) {
+	case ErrInvalidFilterName, *ErrInvalidFilterName:
+		return true
+	case ErrFilterNamePrefix, *ErrFilterNamePrefix:
+		return true
+	case ErrFilterNameSuffix, *ErrFilterNameSuffix:
+		return true
+	case ErrInvalidFilterValue, *ErrInvalidFilterValue:
+		return true
+	case ErrDuplicateEventName, *ErrDuplicateEventName:
+		return true
+	case ErrUnsupportedConfiguration, *ErrUnsupportedConfiguration:
+		return true
+	case ErrDuplicateQueueConfiguration, *ErrDuplicateQueueConfiguration:
+		return true
+	case ErrUnknownRegion, *ErrUnknownRegion:
+		return true
+	case ErrARNNotFound, *ErrARNNotFound:
+		return true
+	case ErrInvalidARN, *ErrInvalidARN:
+		return true
+	case ErrInvalidEventName, *ErrInvalidEventName:
+		return true
+	}
+
+	return false
+}
+
+// ErrInvalidFilterName - invalid filter name error.
+type ErrInvalidFilterName struct {
+	FilterName string
+}
+
+func (err ErrInvalidFilterName) Error() string {
+	return fmt.Sprintf("invalid filter name '%v'", err.FilterName)
+}
+
+// ErrFilterNamePrefix - more than one prefix usage error.
+type ErrFilterNamePrefix struct{}
+
+func (err ErrFilterNamePrefix) Error() string {
+	return fmt.Sprintf("more than one prefix in filter rule")
+}
+
+// ErrFilterNameSuffix - more than one suffix usage error.
+type ErrFilterNameSuffix struct{}
+
+func (err ErrFilterNameSuffix) Error() string {
+	return fmt.Sprintf("more than one suffix in filter rule")
+}
+
+// ErrInvalidFilterValue - invalid filter value error.
+type ErrInvalidFilterValue struct {
+	FilterValue string
+}
+
+func (err ErrInvalidFilterValue) Error() string {
+	return fmt.Sprintf("invalid filter value '%v'", err.FilterValue)
+}
+
+// ErrDuplicateEventName - duplicate event name error.
+type ErrDuplicateEventName struct {
+	EventName Name
+}
+
+func (err ErrDuplicateEventName) Error() string {
+	return fmt.Sprintf("duplicate event name '%v' found", err.EventName)
+}
+
+// ErrUnsupportedConfiguration - unsupported configuration error.
+type ErrUnsupportedConfiguration struct{}
+
+func (err ErrUnsupportedConfiguration) Error() string {
+	return "topic or cloud function configuration is not supported"
+}
+
+// ErrDuplicateQueueConfiguration - duplicate queue configuration error.
+type ErrDuplicateQueueConfiguration struct {
+	Queue Queue
+}
+
+func (err ErrDuplicateQueueConfiguration) Error() string {
+	var message string
+	if data, xerr := xml.Marshal(err.Queue); xerr != nil {
+		message = fmt.Sprintf("%+v", err.Queue)
+	} else {
+		message = string(data)
+	}
+
+	return fmt.Sprintf("duplicate queue configuration %v", message)
+}
+
+// ErrUnknownRegion - unknown region error.
+type ErrUnknownRegion struct {
+	Region string
+}
+
+func (err ErrUnknownRegion) Error() string {
+	return fmt.Sprintf("unknown region '%v'", err.Region)
+}
+
+// ErrARNNotFound - ARN not found error.
+type ErrARNNotFound struct {
+	ARN ARN
+}
+
+func (err ErrARNNotFound) Error() string {
+	return fmt.Sprintf("ARN '%v' not found", err.ARN)
+}
+
+// ErrInvalidARN - invalid ARN error.
+type ErrInvalidARN struct {
+	ARN string
+}
+
+func (err ErrInvalidARN) Error() string {
+	return fmt.Sprintf("invalid ARN '%v'", err.ARN)
+}
+
+// ErrInvalidEventName - invalid event name error.
+type ErrInvalidEventName struct {
+	Name string
+}
+
+func (err ErrInvalidEventName) Error() string {
+	return fmt.Sprintf("invalid event name '%v'", err.Name)
+}