rename all remaining packages to internal/ (#12418)

This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`

internal/bucket/lifecycle/transition.go

@@ -0,0 +1,165 @@
+// Copyright (c) 2015-2021 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package lifecycle
+
+import (
+	"encoding/xml"
+	"time"
+)
+
+var (
+	errTransitionInvalidDays     = Errorf("Days must be 0 or greater when used with Transition")
+	errTransitionInvalidDate     = Errorf("Date must be provided in ISO 8601 format")
+	errTransitionInvalid         = Errorf("Exactly one of Days (0 or greater) or Date (positive ISO 8601 format) should be present inside Expiration.")
+	errTransitionDateNotMidnight = Errorf("'Date' must be at midnight GMT")
+)
+
+// TransitionDate is a embedded type containing time.Time to unmarshal
+// Date in Transition
+type TransitionDate struct {
+	time.Time
+}
+
+// UnmarshalXML parses date from Transition and validates date format
+func (tDate *TransitionDate) UnmarshalXML(d *xml.Decoder, startElement xml.StartElement) error {
+	var dateStr string
+	err := d.DecodeElement(&dateStr, &startElement)
+	if err != nil {
+		return err
+	}
+	// While AWS documentation mentions that the date specified
+	// must be present in ISO 8601 format, in reality they allow
+	// users to provide RFC 3339 compliant dates.
+	trnDate, err := time.Parse(time.RFC3339, dateStr)
+	if err != nil {
+		return errTransitionInvalidDate
+	}
+	// Allow only date timestamp specifying midnight GMT
+	hr, min, sec := trnDate.Clock()
+	nsec := trnDate.Nanosecond()
+	loc := trnDate.Location()
+	if !(hr == 0 && min == 0 && sec == 0 && nsec == 0 && loc.String() == time.UTC.String()) {
+		return errTransitionDateNotMidnight
+	}
+
+	*tDate = TransitionDate{trnDate}
+	return nil
+}
+
+// MarshalXML encodes expiration date if it is non-zero and encodes
+// empty string otherwise
+func (tDate TransitionDate) MarshalXML(e *xml.Encoder, startElement xml.StartElement) error {
+	if tDate.Time.IsZero() {
+		return nil
+	}
+	return e.EncodeElement(tDate.Format(time.RFC3339), startElement)
+}
+
+// TransitionDays is a type alias to unmarshal Days in Transition
+type TransitionDays int
+
+// UnmarshalXML parses number of days from Transition and validates if
+// >= 0
+func (tDays *TransitionDays) UnmarshalXML(d *xml.Decoder, startElement xml.StartElement) error {
+	var numDays int
+	err := d.DecodeElement(&numDays, &startElement)
+	if err != nil {
+		return err
+	}
+	if numDays < 0 {
+		return errTransitionInvalidDays
+	}
+	*tDays = TransitionDays(numDays)
+	return nil
+}
+
+// MarshalXML encodes number of days to expire if it is non-zero and
+// encodes empty string otherwise
+func (tDays TransitionDays) MarshalXML(e *xml.Encoder, startElement xml.StartElement) error {
+	if tDays == 0 {
+		return nil
+	}
+	return e.EncodeElement(int(tDays), startElement)
+}
+
+// Transition - transition actions for a rule in lifecycle configuration.
+type Transition struct {
+	XMLName      xml.Name       `xml:"Transition"`
+	Days         TransitionDays `xml:"Days,omitempty"`
+	Date         TransitionDate `xml:"Date,omitempty"`
+	StorageClass string         `xml:"StorageClass,omitempty"`
+
+	set bool
+}
+
+// MarshalXML encodes transition field into an XML form.
+func (t Transition) MarshalXML(enc *xml.Encoder, start xml.StartElement) error {
+	if !t.set {
+		return nil
+	}
+	type transitionWrapper Transition
+	return enc.EncodeElement(transitionWrapper(t), start)
+}
+
+// UnmarshalXML decodes transition field from the XML form.
+func (t *Transition) UnmarshalXML(d *xml.Decoder, startElement xml.StartElement) error {
+	type transitionWrapper Transition
+	var trw transitionWrapper
+	err := d.DecodeElement(&trw, &startElement)
+	if err != nil {
+		return err
+	}
+	*t = Transition(trw)
+	t.set = true
+	return nil
+}
+
+// Validate - validates the "Transition" element
+func (t Transition) Validate() error {
+	if !t.set {
+		return nil
+	}
+
+	if t.IsDaysNull() && t.IsDateNull() {
+		return errXMLNotWellFormed
+	}
+
+	// Both transition days and date are specified
+	if !t.IsDaysNull() && !t.IsDateNull() {
+		return errTransitionInvalid
+	}
+	if t.StorageClass == "" {
+		return errXMLNotWellFormed
+	}
+	return nil
+}
+
+// IsDaysNull returns true if days field is null
+func (t Transition) IsDaysNull() bool {
+	return t.Days == TransitionDays(0)
+}
+
+// IsDateNull returns true if date field is null
+func (t Transition) IsDateNull() bool {
+	return t.Date.Time.IsZero()
+}
+
+// IsNull returns true if both date and days fields are null
+func (t Transition) IsNull() bool {
+	return t.IsDaysNull() && t.IsDateNull()
+}