Rename pkg/{tagging,lifecycle} to pkg/bucket sub-directory (#8892)

Rename to allow for more such features to come in a more
proper hierarchical manner.

pkg/bucket/lifecycle/lifecycle.go

@@ -0,0 +1,130 @@
+/*
+ * 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
+}