minio/pkg/bucket/lifecycle/and.go

/*
 * MinIO Cloud Storage, (C) 2019 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 lifecycle

import (
	"encoding/xml"
)

var errDuplicateTagKey = Errorf("Duplicate Tag Keys are not allowed")

// And - a tag to combine a prefix and multiple tags for lifecycle configuration rule.
type And struct {
	XMLName xml.Name `xml:"And"`
	Prefix  Prefix   `xml:"Prefix,omitempty"`
	Tags    []Tag    `xml:"Tag,omitempty"`
}

// isEmpty returns true if Tags field is null
func (a And) isEmpty() bool {
	return len(a.Tags) == 0 && !a.Prefix.set
}

// Validate - validates the And field
func (a And) Validate() error {
	emptyPrefix := !a.Prefix.set
	emptyTags := len(a.Tags) == 0

	if emptyPrefix && emptyTags {
		return nil
	}

	if emptyPrefix && !emptyTags || !emptyPrefix && emptyTags {
		return errXMLNotWellFormed
	}

	if a.ContainsDuplicateTag() {
		return errDuplicateTagKey
	}
	for _, t := range a.Tags {
		if err := t.Validate(); err != nil {
			return err
		}
	}
	return nil
}

// ContainsDuplicateTag - returns true if duplicate keys are present in And
func (a And) ContainsDuplicateTag() bool {
	x := make(map[string]struct{}, len(a.Tags))

	for _, t := range a.Tags {
		if _, has := x[t.Key]; has {
			return true
		}
		x[t.Key] = struct{}{}
	}

	return false
}