[#76] Refactor HeadObject logic

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

README.md

@@ -262,6 +262,8 @@ $ neofs-cli -r 192.168.130.72:8080 -k 6PYLKJhiSub5imt6WCVy6Quxtd9xu176omev1vWYov
 
 #### Requests
 
+The following requests support GET/HEAD methods. 
+
 ##### By IDs
 
 Basic downloading involves container ID and object ID and is done via GET
@@ -311,7 +313,7 @@ $ wget http://localhost:8082/get/Dxhf4PNprrJHWWTG5RGLdfLkJiSQ3AQqit1MSnEPRkDZ/2m
 
 #### Replies
 
-You get object contents in the reply body, but at the same time you also get a
+You get object contents in the reply body (if GET method was used), but at the same time you also get a
 set of reply headers generated using the following rules:
  * `Content-Length` is set to the length of the object
  * `Content-Type` is autodetected dynamically by gateway

downloader/download.go

@@ -47,8 +47,6 @@ type (
 
 var errObjectNotFound = errors.New("object not found")
 
-const sizeToDetectType = 512
-
 func newReader(data []byte, err error) *errReader {
 	return &errReader{data: data, err: err}
 }
@@ -198,69 +196,6 @@ func bearerOpts(ctx context.Context) client.CallOption {
 	return client.WithBearer(nil)
 }
 
-func (r request) headObject(clnt client.Object, objectAddress *object.Address) {
-	var start = time.Now()
-	if err := tokens.StoreBearerToken(r.RequestCtx); err != nil {
-		r.log.Error("could not fetch and store bearer token", zap.Error(err))
-		r.Error("could not fetch and store bearer token", fasthttp.StatusBadRequest)
-		return
-	}
-
-	options := new(client.ObjectHeaderParams).WithAddress(objectAddress)
-	bearerOpt := bearerOpts(r.RequestCtx)
-	obj, err := clnt.GetObjectHeader(r.RequestCtx, options, bearerOpt)
-	if err != nil {
-		r.handleNeoFSErr(err, start)
-		return
-	}
-
-	r.Response.Header.Set("Content-Length", strconv.FormatUint(obj.PayloadSize(), 10))
-	var contentType string
-	for _, attr := range obj.Attributes() {
-		key := attr.Key()
-		val := attr.Value()
-		if !isValidToken(key) || !isValidValue(val) {
-			continue
-		}
-		r.Response.Header.Set("X-Attribute-"+key, val)
-		switch key {
-		case object.AttributeTimestamp:
-			value, err := strconv.ParseInt(val, 10, 64)
-			if err != nil {
-				r.log.Info("couldn't parse creation date",
-					zap.String("key", key),
-					zap.String("val", val),
-					zap.Error(err))
-				continue
-			}
-			r.Response.Header.Set("Last-Modified", time.Unix(value, 0).UTC().Format(http.TimeFormat))
-		case object.AttributeContentType:
-			contentType = val
-		}
-	}
-	r.Response.Header.Set("x-object-id", obj.ID().String())
-	r.Response.Header.Set("x-owner-id", obj.OwnerID().String())
-	r.Response.Header.Set("x-container-id", obj.ContainerID().String())
-
-	if len(contentType) == 0 {
-		objRange := object.NewRange()
-		objRange.SetOffset(0)
-		if sizeToDetectType < obj.PayloadSize() {
-			objRange.SetLength(sizeToDetectType)
-		} else {
-			objRange.SetLength(obj.PayloadSize())
-		}
-		ops := new(client.RangeDataParams).WithAddress(objectAddress).WithRange(objRange)
-		data, err := clnt.ObjectPayloadRangeData(r.RequestCtx, ops, bearerOpt)
-		if err != nil {
-			r.handleNeoFSErr(err, start)
-			return
-		}
-		contentType = http.DetectContentType(data)
-	}
-	r.SetContentType(contentType)
-}
-
 func (r *request) handleNeoFSErr(err error, start time.Time) {
 	r.log.Error(
 		"could not receive object",
@@ -320,11 +255,6 @@ func (d *Downloader) DownloadByAddress(c *fasthttp.RequestCtx) {
 	d.byAddress(c, request.receiveFile)
 }
 
-// HeadByAddress handles head requests using simple cid/oid format.
-func (d *Downloader) HeadByAddress(c *fasthttp.RequestCtx) {
-	d.byAddress(c, request.headObject)
-}
-
 // byAddress is wrapper for function (e.g. request.headObject, request.receiveFile) that
 // prepares request and object address to it.
 func (d *Downloader) byAddress(c *fasthttp.RequestCtx, f func(request, client.Object, *object.Address)) {
@@ -349,11 +279,6 @@ func (d *Downloader) DownloadByAttribute(c *fasthttp.RequestCtx) {
 	d.byAttribute(c, request.receiveFile)
 }
 
-// HeadByAttribute handles attribute-based head requests.
-func (d *Downloader) HeadByAttribute(c *fasthttp.RequestCtx) {
-	d.byAttribute(c, request.headObject)
-}
-
 // byAttribute is wrapper similar to byAddress.
 func (d *Downloader) byAttribute(c *fasthttp.RequestCtx, f func(request, client.Object, *object.Address)) {
 	var (

downloader/head.go

@@ -0,0 +1,88 @@
+package downloader
+
+import (
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/nspcc-dev/neofs-api-go/pkg/client"
+	"github.com/nspcc-dev/neofs-api-go/pkg/object"
+	"github.com/nspcc-dev/neofs-http-gw/tokens"
+	"github.com/valyala/fasthttp"
+	"go.uber.org/zap"
+)
+
+const sizeToDetectType = 512
+
+func (r request) headObject(clnt client.Object, objectAddress *object.Address) {
+	var start = time.Now()
+	if err := tokens.StoreBearerToken(r.RequestCtx); err != nil {
+		r.log.Error("could not fetch and store bearer token", zap.Error(err))
+		r.Error("could not fetch and store bearer token", fasthttp.StatusBadRequest)
+		return
+	}
+
+	options := new(client.ObjectHeaderParams).WithAddress(objectAddress)
+	bearerOpt := bearerOpts(r.RequestCtx)
+	obj, err := clnt.GetObjectHeader(r.RequestCtx, options, bearerOpt)
+	if err != nil {
+		r.handleNeoFSErr(err, start)
+		return
+	}
+
+	r.Response.Header.Set("Content-Length", strconv.FormatUint(obj.PayloadSize(), 10))
+	var contentType string
+	for _, attr := range obj.Attributes() {
+		key := attr.Key()
+		val := attr.Value()
+		if !isValidToken(key) || !isValidValue(val) {
+			continue
+		}
+		r.Response.Header.Set("X-Attribute-"+key, val)
+		switch key {
+		case object.AttributeTimestamp:
+			value, err := strconv.ParseInt(val, 10, 64)
+			if err != nil {
+				r.log.Info("couldn't parse creation date",
+					zap.String("key", key),
+					zap.String("val", val),
+					zap.Error(err))
+				continue
+			}
+			r.Response.Header.Set("Last-Modified", time.Unix(value, 0).UTC().Format(http.TimeFormat))
+		case object.AttributeContentType:
+			contentType = val
+		}
+	}
+	r.Response.Header.Set("x-object-id", obj.ID().String())
+	r.Response.Header.Set("x-owner-id", obj.OwnerID().String())
+	r.Response.Header.Set("x-container-id", obj.ContainerID().String())
+
+	if len(contentType) == 0 {
+		objRange := object.NewRange()
+		objRange.SetOffset(0)
+		if sizeToDetectType < obj.PayloadSize() {
+			objRange.SetLength(sizeToDetectType)
+		} else {
+			objRange.SetLength(obj.PayloadSize())
+		}
+		ops := new(client.RangeDataParams).WithAddress(objectAddress).WithRange(objRange)
+		data, err := clnt.ObjectPayloadRangeData(r.RequestCtx, ops, bearerOpt)
+		if err != nil {
+			r.handleNeoFSErr(err, start)
+			return
+		}
+		contentType = http.DetectContentType(data)
+	}
+	r.SetContentType(contentType)
+}
+
+// HeadByAddress handles head requests using simple cid/oid format.
+func (d *Downloader) HeadByAddress(c *fasthttp.RequestCtx) {
+	d.byAddress(c, request.headObject)
+}
+
+// HeadByAttribute handles attribute-based head requests.
+func (d *Downloader) HeadByAttribute(c *fasthttp.RequestCtx) {
+	d.byAttribute(c, request.headObject)
+}