[#108] Add different expiration header formats

Signed-off-by: Denis Kirillov <denis@nspcc.ru>

uploader/filter.go

@@ -2,7 +2,11 @@ package uploader
 
 import (
 	"bytes"
+	"fmt"
+	"strconv"
+	"time"
 
+	"github.com/nspcc-dev/neofs-api-go/v2/object"
 	"github.com/valyala/fasthttp"
 	"go.uber.org/zap"
 )
@@ -10,6 +14,10 @@ import (
 const (
 	userAttributeHeaderPrefix = "X-Attribute-"
 	systemAttributePrefix     = "__NEOFS__"
+
+	expirationDurationAttr  = systemAttributePrefix + "EXPIRATION_DURATION"
+	expirationTimestampAttr = systemAttributePrefix + "EXPIRATION_TIMESTAMP"
+	expirationRFC3339Attr   = systemAttributePrefix + "EXPIRATION_RFC3339"
 )
 
 var neofsAttributeHeaderPrefixes = [...][]byte{[]byte("Neofs-"), []byte("NEOFS-"), []byte("neofs-")}
@@ -68,3 +76,60 @@ func filterHeaders(l *zap.Logger, header *fasthttp.RequestHeader) map[string]str
 
 	return result
 }
+
+func prepareExpirationHeader(headers map[string]string, epochDurations *epochDurations) error {
+	expirationInEpoch := headers[object.SysAttributeExpEpoch]
+
+	if timeRFC3339, ok := headers[expirationRFC3339Attr]; ok {
+		expTime, err := time.Parse(time.RFC3339, timeRFC3339)
+		if err != nil {
+			return fmt.Errorf("couldn't parse value %s of header %s", timeRFC3339, expirationRFC3339Attr)
+		}
+
+		now := time.Now().UTC()
+		if expTime.Before(now) {
+			return fmt.Errorf("value %s of header %s must be in the future", timeRFC3339, expirationRFC3339Attr)
+		}
+		updateExpirationHeader(headers, epochDurations, expTime.Sub(now))
+		delete(headers, expirationRFC3339Attr)
+	}
+
+	if timestamp, ok := headers[expirationTimestampAttr]; ok {
+		value, err := strconv.ParseInt(timestamp, 10, 64)
+		if err != nil {
+			return fmt.Errorf("couldn't parse value %s of header %s", timestamp, expirationTimestampAttr)
+		}
+		expTime := time.Unix(value, 0)
+
+		now := time.Now()
+		if expTime.Before(now) {
+			return fmt.Errorf("value %s of header %s must be in the future", timestamp, expirationTimestampAttr)
+		}
+		updateExpirationHeader(headers, epochDurations, expTime.Sub(now))
+		delete(headers, expirationTimestampAttr)
+	}
+
+	if duration, ok := headers[expirationDurationAttr]; ok {
+		expDuration, err := time.ParseDuration(duration)
+		if err != nil {
+			return fmt.Errorf("couldn't parse value %s of header %s", duration, expirationDurationAttr)
+		}
+		if expDuration <= 0 {
+			return fmt.Errorf("value %s of header %s must be positive", expDuration, expirationDurationAttr)
+		}
+		updateExpirationHeader(headers, epochDurations, expDuration)
+		delete(headers, expirationDurationAttr)
+	}
+
+	if expirationInEpoch != "" {
+		headers[object.SysAttributeExpEpoch] = expirationInEpoch
+	}
+
+	return nil
+}
+
+func updateExpirationHeader(headers map[string]string, durations *epochDurations, expDuration time.Duration) {
+	epochDuration := durations.msPerBlock * int64(durations.blockPerEpoch)
+	numEpoch := expDuration.Milliseconds() / epochDuration
+	headers[object.SysAttributeExpEpoch] = strconv.FormatInt(int64(durations.currentEpoch)+numEpoch, 10)
+}