multipart: remove proper MD5, rather create MD5 based on parts to be s3 compatible.

This increases the performance phenominally.

api-response.go

@@ -218,6 +218,11 @@ type CompleteMultipartUploadResponse struct {
 	ETag     string
 }
 
+// getLocation get URL location.
+func getLocation(r *http.Request) string {
+	return r.URL.Path
+}
+
 // takes an array of Bucketmetadata information for serialization
 // input:
 // array of bucket metadata

bucket-handlers.go

@@ -291,7 +291,7 @@ func (api storageAPI) PutBucketHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	// Make sure to add Location information here only for bucket
-	w.Header().Set("Location", "/"+bucket)
+	w.Header().Set("Location", getLocation(r))
 	writeSuccessResponse(w, nil)
 }
 

object-handlers.go

@@ -798,7 +798,10 @@ func (api storageAPI) CompleteMultipartUploadHandler(w http.ResponseWriter, r *h
 		}
 		return
 	}
-	response := generateCompleteMultpartUploadResponse(bucket, object, r.URL.String(), metadata.MD5)
+	// get object location.
+	location := getLocation(r)
+	// Generate complete multipart response.
+	response := generateCompleteMultpartUploadResponse(bucket, object, location, metadata.MD5)
 	encodedSuccessResponse := encodeSuccessResponse(response)
 	// write headers
 	setCommonHeaders(w)

pkg/fs/api_suite_nix_test.go

@@ -66,7 +66,6 @@ func testMultipartObjectCreation(c *check.C, create func() Filesystem) {
 
 	completedParts := CompleteMultipartUpload{}
 	completedParts.Part = make([]CompletePart, 0)
-	finalHasher := md5.New()
 	for i := 1; i <= 10; i++ {
 		randomPerm := rand.Perm(10)
 		randomString := ""
@@ -75,7 +74,6 @@ func testMultipartObjectCreation(c *check.C, create func() Filesystem) {
 		}
 
 		hasher := md5.New()
-		finalHasher.Write([]byte(randomString))
 		hasher.Write([]byte(randomString))
 		expectedmd5Sum := base64.StdEncoding.EncodeToString(hasher.Sum(nil))
 		expectedmd5Sumhex := hex.EncodeToString(hasher.Sum(nil))
@@ -87,12 +85,11 @@ func testMultipartObjectCreation(c *check.C, create func() Filesystem) {
 		c.Assert(calculatedmd5sum, check.Equals, expectedmd5Sumhex)
 		completedParts.Part = append(completedParts.Part, CompletePart{PartNumber: i, ETag: calculatedmd5sum})
 	}
-	finalExpectedmd5SumHex := hex.EncodeToString(finalHasher.Sum(nil))
 	completedPartsBytes, e := xml.Marshal(completedParts)
 	c.Assert(e, check.IsNil)
 	objectMetadata, err := fs.CompleteMultipartUpload("bucket", "key", uploadID, bytes.NewReader(completedPartsBytes), nil)
 	c.Assert(err, check.IsNil)
-	c.Assert(objectMetadata.MD5, check.Equals, finalExpectedmd5SumHex)
+	c.Assert(objectMetadata.MD5, check.Equals, "9b7d6f13ba00e24d0b02de92e814891b-10")
 }
 
 func testMultipartObjectAbort(c *check.C, create func() Filesystem) {

pkg/fs/api_suite_windows_test.go

@@ -65,7 +65,6 @@ func testMultipartObjectCreation(c *check.C, create func() Filesystem) {
 
 	completedParts := CompleteMultipartUpload{}
 	completedParts.Part = make([]CompletePart, 0)
-	finalHasher := md5.New()
 	for i := 1; i <= 10; i++ {
 		randomPerm := rand.Perm(10)
 		randomString := ""
@@ -74,7 +73,6 @@ func testMultipartObjectCreation(c *check.C, create func() Filesystem) {
 		}
 
 		hasher := md5.New()
-		finalHasher.Write([]byte(randomString))
 		hasher.Write([]byte(randomString))
 		expectedmd5Sum := base64.StdEncoding.EncodeToString(hasher.Sum(nil))
 		expectedmd5Sumhex := hex.EncodeToString(hasher.Sum(nil))
@@ -86,12 +84,11 @@ func testMultipartObjectCreation(c *check.C, create func() Filesystem) {
 		c.Assert(calculatedmd5sum, check.Equals, expectedmd5Sumhex)
 		completedParts.Part = append(completedParts.Part, CompletePart{PartNumber: i, ETag: calculatedmd5sum})
 	}
-	finalExpectedmd5SumHex := hex.EncodeToString(finalHasher.Sum(nil))
 	completedPartsBytes, e := xml.Marshal(completedParts)
 	c.Assert(e, check.IsNil)
 	objectMetadata, err := fs.CompleteMultipartUpload("bucket", "key", uploadID, bytes.NewReader(completedPartsBytes), nil)
 	c.Assert(err, check.IsNil)
-	c.Assert(objectMetadata.MD5, check.Equals, finalExpectedmd5SumHex)
+	c.Assert(objectMetadata.MD5, check.Equals, "9b7d6f13ba00e24d0b02de92e814891b-10")
 }
 
 func testMultipartObjectAbort(c *check.C, create func() Filesystem) {

pkg/fs/fs-multipart.go

@@ -141,6 +141,22 @@ func doPartsMatch(parts []CompletePart, savedParts []PartMetadata) bool {
 	return true
 }
 
+// Create an s3 compatible MD5sum for complete multipart transaction.
+func makeS3MD5(md5Strs ...string) (string, *probe.Error) {
+	var finalMD5Bytes []byte
+	for _, md5Str := range md5Strs {
+		md5Bytes, e := hex.DecodeString(md5Str)
+		if e != nil {
+			return "", probe.NewError(e)
+		}
+		finalMD5Bytes = append(finalMD5Bytes, md5Bytes...)
+	}
+	md5Hasher := md5.New()
+	md5Hasher.Write(finalMD5Bytes)
+	s3MD5 := fmt.Sprintf("%s-%d", hex.EncodeToString(md5Hasher.Sum(nil)), len(md5Strs))
+	return s3MD5, nil
+}
+
 type multiCloser struct {
 	Closers []io.Closer
 }
@@ -177,7 +193,9 @@ func saveParts(partPathPrefix string, mw io.Writer, parts []CompletePart) *probe
 	var partReaders []io.Reader
 	var partClosers []io.Closer
 	for _, part := range parts {
+		// Trim prefix
 		md5Sum := strings.TrimPrefix(part.ETag, "\"")
+		// Trim suffix
 		md5Sum = strings.TrimSuffix(md5Sum, "\"")
 		partFile, e := os.OpenFile(partPathPrefix+md5Sum+fmt.Sprintf("$%d-$multiparts", part.PartNumber), os.O_RDONLY, 0600)
 		if e != nil {
@@ -199,7 +217,8 @@ func saveParts(partPathPrefix string, mw io.Writer, parts []CompletePart) *probe
 	defer closer.Close()
 
 	reader := io.MultiReader(partReaders...)
-	readBuffer := make([]byte, 4*1024*1024)
+	readBufferSize := 8 * 1024 * 1024          // 8MiB
+	readBuffer := make([]byte, readBufferSize) // Allocate 8MiB buffer.
 	if _, e := io.CopyBuffer(mw, reader, readBuffer); e != nil {
 		return probe.NewError(e)
 	}
@@ -465,16 +484,14 @@ func (fs Filesystem) CompleteMultipartUpload(bucket, object, uploadID string, da
 	}
 
 	objectPath := filepath.Join(bucketPath, object)
-	file, e := atomic.FileCreateWithPrefix(objectPath, "$tmpobject")
+	objectWriter, e := atomic.FileCreateWithPrefix(objectPath, "$tmpobject")
 	if e != nil {
 		return ObjectMetadata{}, probe.NewError(e)
 	}
-	md5Hasher := md5.New()
-	objectWriter := io.MultiWriter(file, md5Hasher)
 
 	partBytes, e := ioutil.ReadAll(data)
 	if e != nil {
-		file.CloseAndPurge()
+		objectWriter.CloseAndPurge()
 		return ObjectMetadata{}, probe.NewError(e)
 	}
 	if signature != nil {
@@ -482,21 +499,21 @@ func (fs Filesystem) CompleteMultipartUpload(bucket, object, uploadID string, da
 		sh.Write(partBytes)
 		ok, err := signature.DoesSignatureMatch(hex.EncodeToString(sh.Sum(nil)))
 		if err != nil {
-			file.CloseAndPurge()
+			objectWriter.CloseAndPurge()
 			return ObjectMetadata{}, err.Trace()
 		}
 		if !ok {
-			file.CloseAndPurge()
+			objectWriter.CloseAndPurge()
 			return ObjectMetadata{}, probe.NewError(SignDoesNotMatch{})
 		}
 	}
 	completeMultipartUpload := &CompleteMultipartUpload{}
 	if e = xml.Unmarshal(partBytes, completeMultipartUpload); e != nil {
-		file.CloseAndPurge()
+		objectWriter.CloseAndPurge()
 		return ObjectMetadata{}, probe.NewError(MalformedXML{})
 	}
 	if !sort.IsSorted(completedParts(completeMultipartUpload.Part)) {
-		file.CloseAndPurge()
+		objectWriter.CloseAndPurge()
 		return ObjectMetadata{}, probe.NewError(InvalidPartOrder{})
 	}
 
@@ -509,28 +526,42 @@ func (fs Filesystem) CompleteMultipartUpload(bucket, object, uploadID string, da
 	fs.rwLock.RUnlock()
 
 	if !doPartsMatch(parts, savedParts) {
-		file.CloseAndPurge()
+		objectWriter.CloseAndPurge()
 		return ObjectMetadata{}, probe.NewError(InvalidPart{})
 	}
 
 	// Parts successfully validated, save all the parts.
 	partPathPrefix := objectPath + uploadID
 	if err := saveParts(partPathPrefix, objectWriter, parts); err != nil {
-		file.CloseAndPurge()
+		objectWriter.CloseAndPurge()
 		return ObjectMetadata{}, err.Trace(partPathPrefix)
 	}
-	// Successfully saved, remove all parts.
+	var md5Strs []string
-	removeParts(partPathPrefix, savedParts)
+	for _, part := range savedParts {
+		md5Strs = append(md5Strs, part.ETag)
+	}
+	// Save the s3 md5.
+	s3MD5, err := makeS3MD5(md5Strs...)
+	if err != nil {
+		objectWriter.CloseAndPurge()
+		return ObjectMetadata{}, err.Trace(md5Strs...)
+	}
+
+	// Successfully saved multipart, remove all parts in a routine.
+	go removeParts(partPathPrefix, savedParts)
 
 	// Critical region requiring write lock.
 	fs.rwLock.Lock()
 	delete(fs.multiparts.ActiveSession, uploadID)
 	if err := saveMultipartsSession(*fs.multiparts); err != nil {
 		fs.rwLock.Unlock()
-		file.CloseAndPurge()
+		objectWriter.CloseAndPurge()
 		return ObjectMetadata{}, err.Trace(partPathPrefix)
 	}
-	file.Close()
+	if e = objectWriter.Close(); e != nil {
+		fs.rwLock.Unlock()
+		return ObjectMetadata{}, probe.NewError(e)
+	}
 	fs.rwLock.Unlock()
 
 	// Send stat again to get object metadata.
@@ -538,6 +569,7 @@ func (fs Filesystem) CompleteMultipartUpload(bucket, object, uploadID string, da
 	if e != nil {
 		return ObjectMetadata{}, probe.NewError(e)
 	}
+
 	contentType := "application/octet-stream"
 	if objectExt := filepath.Ext(objectPath); objectExt != "" {
 		content, ok := mimedb.DB[strings.ToLower(strings.TrimPrefix(objectExt, "."))]
@@ -551,7 +583,7 @@ func (fs Filesystem) CompleteMultipartUpload(bucket, object, uploadID string, da
 		LastModified: st.ModTime(),
 		Size:         st.Size(),
 		ContentType:  contentType,
-		MD5:          hex.EncodeToString(md5Hasher.Sum(nil)),
+		MD5:          s3MD5,
 	}
 	return newObject, nil
 }