[#96] Support ranges for GetObject

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

api/handler/get.go

@@ -2,9 +2,11 @@ package handler
 
 import (
 	"context"
+	"fmt"
 	"io"
 	"net/http"
 	"strconv"
+	"strings"
 	"sync"
 
 	"github.com/gorilla/mux"
@@ -39,7 +41,14 @@ func (d *detector) Write(data []byte) (int, error) {
 }
 
 func (h *handler) contentTypeFetcher(ctx context.Context, w io.Writer, info *layer.ObjectInfo) (string, error) {
+	return h.contentTypeFetcherWithRange(ctx, w, info, nil)
+}
+
+func (h *handler) contentTypeFetcherWithRange(ctx context.Context, w io.Writer, info *layer.ObjectInfo, rangeParams *layer.RangeParams) (string, error) {
 	if info.IsDir() {
+		if rangeParams != nil {
+			return "", fmt.Errorf("it is forbidden to request for a range in the directory")
+		}
 		return info.ContentType, nil
 	}
 
@@ -49,6 +58,7 @@ func (h *handler) contentTypeFetcher(ctx context.Context, w io.Writer, info *lay
 		Bucket: info.Bucket,
 		Object: info.Name,
 		Writer: writer,
+		Range:  rangeParams,
 	}
 
 	// params.Length = inf.Size
@@ -60,6 +70,42 @@ func (h *handler) contentTypeFetcher(ctx context.Context, w io.Writer, info *lay
 	return writer.contentType, nil
 }
 
+func fetchRangeHeader(headers http.Header, fullSize uint64) (*layer.RangeParams, error) {
+	const prefix = "bytes="
+	rangeHeader := headers.Get("Range")
+	if len(rangeHeader) == 0 {
+		return nil, nil
+	}
+	if !strings.HasPrefix(rangeHeader, prefix) {
+		return nil, fmt.Errorf("unknown unit in range header")
+	}
+	arr := strings.Split(strings.TrimPrefix(rangeHeader, prefix), "-")
+	if len(arr) != 2 || (len(arr[0]) == 0 && len(arr[1]) == 0) {
+		return nil, fmt.Errorf("unknown byte-range-set")
+	}
+
+	var end, start uint64
+	var err0, err1 error
+	base, bitSize := 10, 64
+
+	if len(arr[0]) == 0 {
+		end, err1 = strconv.ParseUint(arr[1], base, bitSize)
+		start = fullSize - end
+		end = fullSize - 1
+	} else if len(arr[1]) == 0 {
+		start, err0 = strconv.ParseUint(arr[0], base, bitSize)
+		end = fullSize - 1
+	} else {
+		start, err0 = strconv.ParseUint(arr[0], base, bitSize)
+		end, err1 = strconv.ParseUint(arr[1], base, bitSize)
+	}
+
+	if err0 != nil || err1 != nil || start > end {
+		return nil, fmt.Errorf("invalid Range header")
+	}
+	return &layer.RangeParams{Start: start, End: end}, nil
+}
+
 func writeHeaders(h http.Header, info *layer.ObjectInfo) {
 	h.Set("Content-Type", info.ContentType)
 	h.Set("Last-Modified", info.Created.Format(http.TimeFormat))
@@ -74,6 +120,7 @@ func (h *handler) GetObjectHandler(w http.ResponseWriter, r *http.Request) {
 	var (
 		err    error
 		inf    *layer.ObjectInfo
+		params *layer.RangeParams
 
 		req = mux.Vars(r)
 		bkt = req["bucket"]
@@ -82,34 +129,40 @@ func (h *handler) GetObjectHandler(w http.ResponseWriter, r *http.Request) {
 	)
 
 	if inf, err = h.obj.GetObjectInfo(r.Context(), bkt, obj); err != nil {
-		h.log.Error("could not find object",
+		writeError(w, r, h.log, "could not find object", rid, bkt, obj, err)
-			zap.String("request_id", rid),
-			zap.String("bucket_name", bkt),
-			zap.String("object_name", obj),
-			zap.Error(err))
-
-		api.WriteErrorResponse(r.Context(), w, api.Error{
-			Code:           api.GetAPIError(api.ErrInternalError).Code,
-			Description:    err.Error(),
-			HTTPStatusCode: http.StatusInternalServerError,
-		}, r.URL)
-
 		return
-	} else if inf.ContentType, err = h.contentTypeFetcher(r.Context(), w, inf); err != nil {
+	}
-		h.log.Error("could not get object",
+	if params, err = fetchRangeHeader(r.Header, uint64(inf.Size)); err != nil {
-			zap.String("request_id", rid),
+		writeError(w, r, h.log, "could not parse range header", rid, bkt, obj, err)
-			zap.String("bucket_name", bkt),
+		return
-			zap.String("object_name", obj),
+	}
-			zap.Error(err))
+	if inf.ContentType, err = h.contentTypeFetcherWithRange(r.Context(), w, inf, params); err != nil {
-
+		writeError(w, r, h.log, "could not get object", rid, bkt, obj, err)
-		api.WriteErrorResponse(r.Context(), w, api.Error{
-			Code:           api.GetAPIError(api.ErrInternalError).Code,
-			Description:    err.Error(),
-			HTTPStatusCode: http.StatusInternalServerError,
-		}, r.URL)
-
 		return
 	}
 
 	writeHeaders(w.Header(), inf)
+	if params != nil {
+		writeRangeHeaders(w, params, inf.Size)
+	}
+}
+
+func writeRangeHeaders(w http.ResponseWriter, params *layer.RangeParams, size int64) {
+	w.Header().Set("Accept-Ranges", "bytes")
+	w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", params.Start, params.End, size))
+	w.WriteHeader(http.StatusPartialContent)
+}
+
+func writeError(w http.ResponseWriter, r *http.Request, log *zap.Logger, msg, rid, bkt, obj string, err error) {
+	log.Error(msg,
+		zap.String("request_id", rid),
+		zap.String("bucket_name", bkt),
+		zap.String("object_name", obj),
+		zap.Error(err))
+
+	api.WriteErrorResponse(r.Context(), w, api.Error{
+		Code:           api.GetAPIError(api.ErrInternalError).Code,
+		Description:    err.Error(),
+		HTTPStatusCode: http.StatusInternalServerError,
+	}, r.URL)
 }

api/handler/get_test.go

@@ -0,0 +1,41 @@
+package handler
+
+import (
+	"net/http"
+	"testing"
+
+	"github.com/nspcc-dev/neofs-s3-gw/api/layer"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFetchRangeHeader(t *testing.T) {
+	for _, tc := range []struct {
+		header   string
+		expected *layer.RangeParams
+		fullSize uint64
+		err      bool
+	}{
+		{header: "bytes=0-256", expected: &layer.RangeParams{Start: 0, End: 256}, err: false},
+		{header: "bytes=0-0", expected: &layer.RangeParams{Start: 0, End: 0}, err: false},
+		{header: "bytes=0-", expected: &layer.RangeParams{Start: 0, End: 99}, fullSize: 100, err: false},
+		{header: "bytes=-10", expected: &layer.RangeParams{Start: 90, End: 99}, fullSize: 100, err: false},
+		{header: "", err: false},
+		{header: "bytes=-1-256", err: true},
+		{header: "bytes=256-0", err: true},
+		{header: "bytes=string-0", err: true},
+		{header: "bytes=0-string", err: true},
+		{header: "bytes:0-256", err: true},
+		{header: "bytes:-", err: true},
+	} {
+		h := make(http.Header)
+		h.Add("Range", tc.header)
+		params, err := fetchRangeHeader(h, tc.fullSize)
+		if tc.err {
+			require.Error(t, err)
+			continue
+		}
+
+		require.NoError(t, err)
+		require.Equal(t, tc.expected, params)
+	}
+}

api/layer/layer.go

@@ -38,6 +38,7 @@ type (
 
 	// GetObjectParams stores object get request parameters.
 	GetObjectParams struct {
+		Range  *RangeParams
 		Bucket string
 		Object string
 		Offset int64
@@ -45,6 +46,12 @@ type (
 		Writer io.Writer
 	}
 
+	// RangeParams stores range header request parameters.
+	RangeParams struct {
+		Start uint64
+		End   uint64
+	}
+
 	// PutObjectParams stores object put request parameters.
 	PutObjectParams struct {
 		Bucket string
@@ -274,14 +281,23 @@ func (n *layer) GetObject(ctx context.Context, p *GetObjectParams) error {
 	addr.SetObjectID(oid)
 	addr.SetContainerID(bkt.CID)
 
-	_, err = n.objectGet(ctx, &getParams{
+	params := &getParams{
 		Writer:  p.Writer,
-
 		address: addr,
-
 		offset:  p.Offset,
 		length:  p.Length,
-	})
+	}
+
+	if p.Range != nil {
+		objRange := object.NewRange()
+		objRange.SetOffset(p.Range.Start)
+		// Range header is inclusive
+		objRange.SetLength(p.Range.End - p.Range.Start + 1)
+		params.Range = objRange
+		_, err = n.objectRange(ctx, params)
+	} else {
+		_, err = n.objectGet(ctx, params)
+	}
 
 	if err != nil {
 		return fmt.Errorf("couldn't get object, cid: %s : %w", bkt.CID, err)

api/layer/object.go

@@ -24,6 +24,7 @@ type (
 
 	getParams struct {
 		io.Writer
+		*object.Range
 
 		offset  int64
 		length  int64
@@ -73,6 +74,13 @@ func (n *layer) objectGet(ctx context.Context, p *getParams) (*object.Object, er
 	return n.pool.GetObject(ctx, ops, n.BearerOpt(ctx))
 }
 
+// objectRange gets object range and writes it into provided io.Writer.
+func (n *layer) objectRange(ctx context.Context, p *getParams) ([]byte, error) {
+	w := newWriter(p.Writer, p.offset, p.length)
+	ops := new(client.RangeDataParams).WithAddress(p.address).WithDataWriter(w).WithRange(p.Range)
+	return n.pool.ObjectPayloadRangeData(ctx, ops, n.BearerOpt(ctx))
+}
+
 // objectPut into NeoFS, took payload from io.Reader.
 func (n *layer) objectPut(ctx context.Context, p *PutObjectParams) (*ObjectInfo, error) {
 	var (