minio/pkg/lifecycle/lifecycle.go
2019-08-09 10:02:41 -07:00

131 lines
3.7 KiB
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"
"errors"
"io"
"strings"
"time"
)
var (
errLifecycleTooManyRules = errors.New("Lifecycle configuration allows a maximum of 1000 rules")
errLifecycleNoRule = errors.New("Lifecycle configuration should have at least one rule")
errLifecycleOverlappingPrefix = errors.New("Lifecycle configuration has rules with overlapping prefix")
)
// Action represents a delete action or other transition
// actions that will be implemented later.
type Action int
const (
// NoneAction means no action required after evaluting lifecycle rules
NoneAction Action = iota
// DeleteAction means the object needs to be removed after evaluting lifecycle rules
DeleteAction
)
// Lifecycle - Configuration for bucket lifecycle.
type Lifecycle struct {
XMLName xml.Name `xml:"LifecycleConfiguration"`
Rules []Rule `xml:"Rule"`
}
// IsEmpty - returns whether policy is empty or not.
func (lc Lifecycle) IsEmpty() bool {
return len(lc.Rules) == 0
}
// ParseLifecycleConfig - parses data in given reader to Lifecycle.
func ParseLifecycleConfig(reader io.Reader) (*Lifecycle, error) {
var lc Lifecycle
if err := xml.NewDecoder(reader).Decode(&lc); err != nil {
return nil, err
}
if err := lc.Validate(); err != nil {
return nil, err
}
return &lc, nil
}
// Validate - validates the lifecycle configuration
func (lc Lifecycle) Validate() error {
// Lifecycle config can't have more than 1000 rules
if len(lc.Rules) > 1000 {
return errLifecycleTooManyRules
}
// Lifecycle config should have at least one rule
if len(lc.Rules) == 0 {
return errLifecycleNoRule
}
// Validate all the rules in the lifecycle config
for _, r := range lc.Rules {
if err := r.Validate(); err != nil {
return err
}
}
// Compare every rule's prefix with every other rule's prefix
for i := range lc.Rules {
if i == len(lc.Rules)-1 {
break
}
// N B Empty prefixes overlap with all prefixes
otherRules := lc.Rules[i+1:]
for _, otherRule := range otherRules {
if strings.HasPrefix(lc.Rules[i].Filter.Prefix, otherRule.Filter.Prefix) ||
strings.HasPrefix(otherRule.Filter.Prefix, lc.Rules[i].Filter.Prefix) {
return errLifecycleOverlappingPrefix
}
}
}
return nil
}
// FilterRuleActions returns the expiration and transition from the object name
// after evaluating all rules.
func (lc Lifecycle) FilterRuleActions(objName string) (Expiration, Transition) {
for _, rule := range lc.Rules {
if strings.ToLower(rule.Status) != "enabled" {
continue
}
if strings.HasPrefix(objName, rule.Filter.Prefix) {
return rule.Expiration, Transition{}
}
}
return Expiration{}, Transition{}
}
// ComputeAction returns the action to perform by evaluating all lifecycle rules
// against the object name and its modification time.
func (lc Lifecycle) ComputeAction(objName string, modTime time.Time) Action {
var action = NoneAction
exp, _ := lc.FilterRuleActions(objName)
if !exp.IsDateNull() {
if time.Now().After(exp.Date.Time) {
action = DeleteAction
}
}
if !exp.IsDaysNull() {
if time.Now().After(modTime.Add(time.Duration(exp.Days) * 24 * time.Hour)) {
action = DeleteAction
}
}
return action
}