Put object on successful write returns full metadata, to avoid subsequent GetObjectMetadata() calls in driver

pkg/storage/donut/bucket.go

@@ -217,19 +217,19 @@ func (b bucket) ReadObject(objectName string) (reader io.ReadCloser, size int64,
 }
 
 // WriteObject - write a new object into bucket
-func (b bucket) WriteObject(objectName string, objectData io.Reader, expectedMD5Sum string, metadata map[string]string) (string, error) {
+func (b bucket) WriteObject(objectName string, objectData io.Reader, expectedMD5Sum string, metadata map[string]string) (ObjectMetadata, error) {
 	b.lock.Lock()
 	defer b.lock.Unlock()
 	if objectName == "" || objectData == nil {
-		return "", iodine.New(InvalidArgument{}, nil)
+		return ObjectMetadata{}, iodine.New(InvalidArgument{}, nil)
 	}
 	writers, err := b.getDiskWriters(normalizeObjectName(objectName), "data")
 	if err != nil {
-		return "", iodine.New(err, nil)
+		return ObjectMetadata{}, iodine.New(err, nil)
 	}
 	sumMD5 := md5.New()
 	sum512 := sha512.New()
-	objMetadata := new(ObjectMetadata)
+	objMetadata := ObjectMetadata{}
 	objMetadata.Version = objectMetadataVersion
 	objMetadata.Created = time.Now().UTC()
 	// if total writers are only '1' do not compute erasure
@@ -238,19 +238,19 @@ func (b bucket) WriteObject(objectName string, objectData io.Reader, expectedMD5
 		mw := io.MultiWriter(writers[0], sumMD5, sum512)
 		totalLength, err := io.Copy(mw, objectData)
 		if err != nil {
-			return "", iodine.New(err, nil)
+			return ObjectMetadata{}, iodine.New(err, nil)
 		}
 		objMetadata.Size = totalLength
 	case false:
 		// calculate data and parity dictated by total number of writers
 		k, m, err := b.getDataAndParity(len(writers))
 		if err != nil {
-			return "", iodine.New(err, nil)
+			return ObjectMetadata{}, iodine.New(err, nil)
 		}
 		// encoded data with k, m and write
 		chunkCount, totalLength, err := b.writeEncodedData(k, m, writers, objectData, sumMD5, sum512)
 		if err != nil {
-			return "", iodine.New(err, nil)
+			return ObjectMetadata{}, iodine.New(err, nil)
 		}
 		/// donutMetadata section
 		objMetadata.BlockSize = blockSize
@@ -271,20 +271,19 @@ func (b bucket) WriteObject(objectName string, objectData io.Reader, expectedMD5
 	// Verify if the written object is equal to what is expected, only if it is requested as such
 	if strings.TrimSpace(expectedMD5Sum) != "" {
 		if err := b.isMD5SumEqual(strings.TrimSpace(expectedMD5Sum), objMetadata.MD5Sum); err != nil {
-			return "", iodine.New(err, nil)
+			return ObjectMetadata{}, iodine.New(err, nil)
 		}
 	}
-
 	objMetadata.Metadata = metadata
 	// write object specific metadata
 	if err := b.writeObjectMetadata(normalizeObjectName(objectName), objMetadata); err != nil {
-		return "", iodine.New(err, nil)
+		return ObjectMetadata{}, iodine.New(err, nil)
 	}
 	// close all writers, when control flow reaches here
 	for _, writer := range writers {
 		writer.Close()
 	}
-	return objMetadata.MD5Sum, nil
+	return objMetadata, nil
 }
 
 // isMD5SumEqual - returns error if md5sum mismatches, other its `nil`
@@ -307,8 +306,8 @@ func (b bucket) isMD5SumEqual(expectedMD5Sum, actualMD5Sum string) error {
 }
 
 // writeObjectMetadata - write additional object metadata
-func (b bucket) writeObjectMetadata(objectName string, objMetadata *ObjectMetadata) error {
-	if objMetadata == nil {
+func (b bucket) writeObjectMetadata(objectName string, objMetadata ObjectMetadata) error {
+	if objMetadata.Object == "" {
 		return iodine.New(InvalidArgument{}, nil)
 	}
 	objMetadataWriters, err := b.getDiskWriters(objectName, objectMetadataConfig)
@@ -320,7 +319,7 @@ func (b bucket) writeObjectMetadata(objectName string, objMetadata *ObjectMetada
 	}
 	for _, objMetadataWriter := range objMetadataWriters {
 		jenc := json.NewEncoder(objMetadataWriter)
-		if err := jenc.Encode(objMetadata); err != nil {
+		if err := jenc.Encode(&objMetadata); err != nil {
 			return iodine.New(err, nil)
 		}
 	}

pkg/storage/donut/donut.go

@@ -175,7 +175,7 @@ func (dt donut) ListObjects(bucket, prefix, marker, delimiter string, maxkeys in
 }
 
 // PutObject - put object
-func (dt donut) PutObject(bucket, object, expectedMD5Sum string, reader io.Reader, metadata map[string]string) (string, error) {
+func (dt donut) PutObject(bucket, object, expectedMD5Sum string, reader io.Reader, metadata map[string]string) (ObjectMetadata, error) {
 	dt.lock.Lock()
 	defer dt.lock.Unlock()
 	errParams := map[string]string{
@@ -183,33 +183,33 @@ func (dt donut) PutObject(bucket, object, expectedMD5Sum string, reader io.Reade
 		"object": object,
 	}
 	if bucket == "" || strings.TrimSpace(bucket) == "" {
-		return "", iodine.New(InvalidArgument{}, errParams)
+		return ObjectMetadata{}, iodine.New(InvalidArgument{}, errParams)
 	}
 	if object == "" || strings.TrimSpace(object) == "" {
-		return "", iodine.New(InvalidArgument{}, errParams)
+		return ObjectMetadata{}, iodine.New(InvalidArgument{}, errParams)
 	}
 	if err := dt.listDonutBuckets(); err != nil {
-		return "", iodine.New(err, errParams)
+		return ObjectMetadata{}, iodine.New(err, errParams)
 	}
 	if _, ok := dt.buckets[bucket]; !ok {
-		return "", iodine.New(BucketNotFound{Bucket: bucket}, nil)
+		return ObjectMetadata{}, iodine.New(BucketNotFound{Bucket: bucket}, nil)
 	}
 	bucketMeta, err := dt.getDonutBucketMetadata()
 	if err != nil {
-		return "", iodine.New(err, errParams)
+		return ObjectMetadata{}, iodine.New(err, errParams)
 	}
 	if _, ok := bucketMeta.Buckets[bucket].BucketObjects[object]; ok {
-		return "", iodine.New(ObjectExists{Object: object}, errParams)
+		return ObjectMetadata{}, iodine.New(ObjectExists{Object: object}, errParams)
 	}
-	md5sum, err := dt.buckets[bucket].WriteObject(object, reader, expectedMD5Sum, metadata)
+	objMetadata, err := dt.buckets[bucket].WriteObject(object, reader, expectedMD5Sum, metadata)
 	if err != nil {
-		return "", iodine.New(err, errParams)
+		return ObjectMetadata{}, iodine.New(err, errParams)
 	}
 	bucketMeta.Buckets[bucket].BucketObjects[object] = 1
 	if err := dt.setDonutBucketMetadata(bucketMeta); err != nil {
-		return "", iodine.New(err, errParams)
+		return ObjectMetadata{}, iodine.New(err, errParams)
 	}
-	return md5sum, nil
+	return objMetadata, nil
 }
 
 // GetObject - get object

pkg/storage/donut/donut_test.go

@@ -195,13 +195,9 @@ func (s *MySuite) TestNewObjectMetadata(c *C) {
 	err = donut.MakeBucket("foo", "private")
 	c.Assert(err, IsNil)
 
-	calculatedMd5Sum, err := donut.PutObject("foo", "obj", expectedMd5Sum, reader, metadata)
+	objectMetadata, err := donut.PutObject("foo", "obj", expectedMd5Sum, reader, metadata)
 	c.Assert(err, IsNil)
-	c.Assert(calculatedMd5Sum, Equals, expectedMd5Sum)
-
-	objectMetadata, err := donut.GetObjectMetadata("foo", "obj")
-	c.Assert(err, IsNil)
-
+	c.Assert(objectMetadata.MD5Sum, Equals, expectedMd5Sum)
 	c.Assert(objectMetadata.Metadata["contentType"], Equals, metadata["contentType"])
 	c.Assert(objectMetadata.Metadata["foo"], Equals, metadata["foo"])
 	c.Assert(objectMetadata.Metadata["hello"], Equals, metadata["hello"])
@@ -240,9 +236,9 @@ func (s *MySuite) TestNewObjectCanBeWritten(c *C) {
 	reader := ioutil.NopCloser(bytes.NewReader([]byte(data)))
 	metadata["contentLength"] = strconv.Itoa(len(data))
 
-	calculatedMd5Sum, err := donut.PutObject("foo", "obj", expectedMd5Sum, reader, metadata)
+	actualMetadata, err := donut.PutObject("foo", "obj", expectedMd5Sum, reader, metadata)
 	c.Assert(err, IsNil)
-	c.Assert(calculatedMd5Sum, Equals, expectedMd5Sum)
+	c.Assert(actualMetadata.MD5Sum, Equals, expectedMd5Sum)
 
 	reader, size, err := donut.GetObject("foo", "obj")
 	c.Assert(err, IsNil)
@@ -253,7 +249,7 @@ func (s *MySuite) TestNewObjectCanBeWritten(c *C) {
 	c.Assert(err, IsNil)
 	c.Assert(actualData.Bytes(), DeepEquals, []byte(data))
 
-	actualMetadata, err := donut.GetObjectMetadata("foo", "obj")
+	actualMetadata, err = donut.GetObjectMetadata("foo", "obj")
 	c.Assert(err, IsNil)
 	c.Assert(expectedMd5Sum, Equals, actualMetadata.MD5Sum)
 	c.Assert(int64(len(data)), Equals, actualMetadata.Size)

pkg/storage/donut/interfaces.go

@@ -40,7 +40,7 @@ type ObjectStorage interface {
 	// Object operations
 	GetObject(bucket, object string) (io.ReadCloser, int64, error)
 	GetObjectMetadata(bucket, object string) (ObjectMetadata, error)
-	PutObject(bucket, object, expectedMD5Sum string, reader io.Reader, metadata map[string]string) (string, error)
+	PutObject(bucket, object, expectedMD5Sum string, reader io.Reader, metadata map[string]string) (ObjectMetadata, error)
 }
 
 // Management is a donut management system interface

pkg/storage/drivers/donut/donut.go

@@ -528,6 +528,10 @@ func (d donutDriver) CreateObject(bucketName, objectName, contentType, expectedM
 		"objectName":  objectName,
 		"contentType": contentType,
 	}
+	if d.donut == nil {
+		return "", iodine.New(drivers.InternalError{}, errParams)
+	}
+	// TODO - Should be able to write bigger than cache
 	if size > int64(d.maxSize) {
 		generic := drivers.GenericObjectError{Bucket: bucketName, Object: objectName}
 		return "", iodine.New(drivers.EntityTooLarge{
@@ -536,9 +540,6 @@ func (d donutDriver) CreateObject(bucketName, objectName, contentType, expectedM
 			MaxSize:            strconv.FormatUint(d.maxSize, 10),
 		}, nil)
 	}
-	if d.donut == nil {
-		return "", iodine.New(drivers.InternalError{}, errParams)
-	}
 	if !drivers.IsValidBucket(bucketName) {
 		return "", iodine.New(drivers.BucketNameInvalid{Bucket: bucketName}, nil)
 	}
@@ -565,7 +566,7 @@ func (d donutDriver) CreateObject(bucketName, objectName, contentType, expectedM
 		expectedMD5Sum = hex.EncodeToString(expectedMD5SumBytes)
 	}
 	newReader := newProxyReader(reader)
-	calculatedMD5Sum, err := d.donut.PutObject(bucketName, objectName, expectedMD5Sum, newReader, metadata)
+	objMetadata, err := d.donut.PutObject(bucketName, objectName, expectedMD5Sum, newReader, metadata)
 	if err != nil {
 		switch iodine.ToError(err).(type) {
 		case donut.BadDigest:
@@ -577,20 +578,16 @@ func (d donutDriver) CreateObject(bucketName, objectName, contentType, expectedM
 	// free up
 	newReader.readBytes = nil
 	go debug.FreeOSMemory()
-	objectMetadata, err := d.donut.GetObjectMetadata(bucketName, objectName)
-	if err != nil {
-		return "", iodine.New(err, nil)
-	}
 	newObject := drivers.ObjectMetadata{
 		Bucket: bucketName,
 		Key:    objectName,
 
-		ContentType: objectMetadata.Metadata["contentType"],
-		Created:     objectMetadata.Created,
-		Md5:         calculatedMD5Sum,
-		Size:        objectMetadata.Size,
+		ContentType: objMetadata.Metadata["contentType"],
+		Created:     objMetadata.Created,
+		Md5:         objMetadata.MD5Sum,
+		Size:        objMetadata.Size,
 	}
 	storedBucket.objectMetadata[objectKey] = newObject
 	d.storedBuckets[bucketName] = storedBucket
-	return calculatedMD5Sum, nil
+	return newObject.Md5, nil
 }