From 9f740b9683d578409ed4480347b5e88ec01048fc Mon Sep 17 00:00:00 2001
From: Denis Kirillov <denis@nspcc.ru>
Date: Wed, 29 Jun 2022 13:51:05 +0300
Subject: [PATCH] [#289] Add detect mimetype by extension

Signed-off-by: Denis Kirillov <denis@nspcc.ru>
---
 api/handler/head.go | 24 +++++++++++++-----------
 api/layer/object.go | 21 ++++++++++++++++++---
 2 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/api/handler/head.go b/api/handler/head.go
index 2e11696b..f4bfaf4d 100644
--- a/api/handler/head.go
+++ b/api/handler/head.go
@@ -69,18 +69,20 @@ func (h *handler) HeadObjectHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if len(info.ContentType) == 0 {
-		buffer := bytes.NewBuffer(make([]byte, 0, sizeToDetectType))
-		getParams := &layer.GetObjectParams{
-			ObjectInfo: info,
-			Writer:     buffer,
-			Range:      getRangeToDetectContentType(info.Size),
-			BucketInfo: bktInfo,
+		if info.ContentType = layer.MimeByFileName(info.Name); len(info.ContentType) == 0 {
+			buffer := bytes.NewBuffer(make([]byte, 0, sizeToDetectType))
+			getParams := &layer.GetObjectParams{
+				ObjectInfo: info,
+				Writer:     buffer,
+				Range:      getRangeToDetectContentType(info.Size),
+				BucketInfo: bktInfo,
+			}
+			if err = h.obj.GetObject(r.Context(), getParams); err != nil {
+				h.logAndSendError(w, "could not get object", reqInfo, err, zap.Stringer("oid", info.ID))
+				return
+			}
+			info.ContentType = http.DetectContentType(buffer.Bytes())
 		}
-		if err = h.obj.GetObject(r.Context(), getParams); err != nil {
-			h.logAndSendError(w, "could not get object", reqInfo, err, zap.Stringer("oid", info.ID))
-			return
-		}
-		info.ContentType = http.DetectContentType(buffer.Bytes())
 	}
 
 	if err = h.setLockingHeaders(r.Context(), bktInfo, info, w.Header()); err != nil {
diff --git a/api/layer/object.go b/api/layer/object.go
index b2e3bc16..f73206b2 100644
--- a/api/layer/object.go
+++ b/api/layer/object.go
@@ -7,6 +7,8 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"mime"
+	"path/filepath"
 	"sort"
 	"strings"
 	"time"
@@ -155,6 +157,15 @@ func (n *layer) objectGet(ctx context.Context, bktInfo *data.BucketInfo, objID o
 	return res.Head, nil
 }
 
+// MimeByFileName detect mime type by filename extension.
+func MimeByFileName(name string) string {
+	ext := filepath.Ext(name)
+	if len(ext) == 0 {
+		return ""
+	}
+	return mime.TypeByExtension(ext)
+}
+
 // PutObject stores object into NeoFS, took payload from io.Reader.
 func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.ObjectInfo, error) {
 	own := n.Owner(ctx)
@@ -169,11 +180,15 @@ func (n *layer) PutObject(ctx context.Context, p *PutObjectParams) (*data.Object
 	r := p.Reader
 	if r != nil {
 		if len(p.Header[api.ContentType]) == 0 {
-			d := newDetector(r)
-			if contentType, err := d.Detect(); err == nil {
+			if contentType := MimeByFileName(p.Object); len(contentType) == 0 {
+				d := newDetector(r)
+				if contentType, err = d.Detect(); err == nil {
+					p.Header[api.ContentType] = contentType
+				}
+				r = d.MultiReader()
+			} else {
 				p.Header[api.ContentType] = contentType
 			}
-			r = d.MultiReader()
 		}
 	}