Merge pull request #670 from harshavardhana/pr_out_go_vet_fixes_for_donut

pkg/erasure/erasure_encode.go

@@ -47,8 +47,8 @@ const (
 	SIMDAlign = 32
 )
 
-// ErasureParams is a configuration set for building an encoder. It is created using ValidateParams().
+// Params is a configuration set for building an encoder. It is created using ValidateParams().
-type ErasureParams struct {
+type Params struct {
 	K         uint8
 	M         uint8
 	Technique Technique // cauchy or vandermonde matrix (RS)
@@ -56,18 +56,18 @@ type ErasureParams struct {
 
 // Erasure is an object used to encode and decode data.
 type Erasure struct {
-	params                   *ErasureParams
+	params                   *Params
 	encodeMatrix, encodeTbls *C.uchar
 	decodeMatrix, decodeTbls *C.uchar
 	decodeIndex              *C.uint32_t
 }
 
-// ValidateParams creates an ErasureParams object.
+// ValidateParams creates an Params object.
 //
 // k and m represent the matrix size, which corresponds to the protection level
 // technique is the matrix type. Valid inputs are Cauchy (recommended) or Vandermonde.
 //
-func ValidateParams(k, m uint8, technique Technique) (*ErasureParams, error) {
+func ValidateParams(k, m uint8, technique Technique) (*Params, error) {
 	if k < 1 {
 		return nil, errors.New("k cannot be zero")
 	}
@@ -89,7 +89,7 @@ func ValidateParams(k, m uint8, technique Technique) (*ErasureParams, error) {
 		return nil, errors.New("Technique can be either vandermonde or cauchy")
 	}
 
-	return &ErasureParams{
+	return &Params{
 		K:         k,
 		M:         m,
 		Technique: technique,
@@ -97,7 +97,7 @@ func ValidateParams(k, m uint8, technique Technique) (*ErasureParams, error) {
 }
 
 // NewErasure creates an encoder object with a given set of parameters.
-func NewErasure(ep *ErasureParams) *Erasure {
+func NewErasure(ep *Params) *Erasure {
 	var k = C.int(ep.K)
 	var m = C.int(ep.M)
 

pkg/storage/donut/bucket.go

@@ -18,21 +18,212 @@ package donut
 
 import (
 	"bytes"
-	"crypto/md5"
-	"encoding/hex"
-	"encoding/json"
 	"fmt"
 	"hash"
 	"io"
 	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
+
+	"crypto/md5"
+	"encoding/hex"
+	"encoding/json"
 
 	"github.com/minio/minio/pkg/iodine"
 	"github.com/minio/minio/pkg/utils/split"
 )
 
-/// This file contains all the internal functions used by Bucket interface
+// internal struct carrying bucket specific information
+type bucket struct {
+	name      string
+	acl       string
+	time      time.Time
+	donutName string
+	nodes     map[string]Node
+	objects   map[string]object
+}
+
+// newBucket - instantiate a new bucket
+func newBucket(bucketName, aclType, donutName string, nodes map[string]Node) (bucket, map[string]string, error) {
+	errParams := map[string]string{
+		"bucketName": bucketName,
+		"donutName":  donutName,
+		"aclType":    aclType,
+	}
+	if strings.TrimSpace(bucketName) == "" || strings.TrimSpace(donutName) == "" {
+		return bucket{}, nil, iodine.New(InvalidArgument{}, errParams)
+	}
+	bucketMetadata := make(map[string]string)
+	bucketMetadata["acl"] = aclType
+	t := time.Now().UTC()
+	bucketMetadata["created"] = t.Format(time.RFC3339Nano)
+	b := bucket{}
+	b.name = bucketName
+	b.acl = aclType
+	b.time = t
+	b.donutName = donutName
+	b.objects = make(map[string]object)
+	b.nodes = nodes
+	return b, bucketMetadata, nil
+}
+
+// ListObjects - list all objects
+func (b bucket) ListObjects() (map[string]object, error) {
+	nodeSlice := 0
+	for _, node := range b.nodes {
+		disks, err := node.ListDisks()
+		if err != nil {
+			return nil, iodine.New(err, nil)
+		}
+		for order, disk := range disks {
+			bucketSlice := fmt.Sprintf("%s$%d$%d", b.name, nodeSlice, order)
+			bucketPath := filepath.Join(b.donutName, bucketSlice)
+			objects, err := disk.ListDir(bucketPath)
+			if err != nil {
+				return nil, iodine.New(err, nil)
+			}
+			for _, object := range objects {
+				newObject, err := newObject(object.Name(), filepath.Join(disk.GetPath(), bucketPath))
+				if err != nil {
+					return nil, iodine.New(err, nil)
+				}
+				newObjectMetadata, err := newObject.GetObjectMetadata()
+				if err != nil {
+					return nil, iodine.New(err, nil)
+				}
+				objectName, ok := newObjectMetadata["object"]
+				if !ok {
+					return nil, iodine.New(ObjectCorrupted{Object: object.Name()}, nil)
+				}
+				b.objects[objectName] = newObject
+			}
+		}
+		nodeSlice = nodeSlice + 1
+	}
+	return b.objects, nil
+}
+
+// ReadObject - open an object to read
+func (b bucket) ReadObject(objectName string) (reader io.ReadCloser, size int64, err error) {
+	reader, writer := io.Pipe()
+	// get list of objects
+	objects, err := b.ListObjects()
+	if err != nil {
+		return nil, 0, iodine.New(err, nil)
+	}
+	// check if object exists
+	object, ok := objects[objectName]
+	if !ok {
+		return nil, 0, iodine.New(ObjectNotFound{Object: objectName}, nil)
+	}
+	// verify if objectMetadata is readable, before we serve the request
+	objectMetadata, err := object.GetObjectMetadata()
+	if err != nil {
+		return nil, 0, iodine.New(err, nil)
+	}
+	if objectName == "" || writer == nil || len(objectMetadata) == 0 {
+		return nil, 0, iodine.New(InvalidArgument{}, nil)
+	}
+	size, err = strconv.ParseInt(objectMetadata["size"], 10, 64)
+	if err != nil {
+		return nil, 0, iodine.New(err, nil)
+	}
+	// verify if donutObjectMetadata is readable, before we server the request
+	donutObjectMetadata, err := object.GetDonutObjectMetadata()
+	if err != nil {
+		return nil, 0, iodine.New(err, nil)
+	}
+	// read and reply back to GetObject() request in a go-routine
+	go b.readEncodedData(b.normalizeObjectName(objectName), writer, donutObjectMetadata)
+	return reader, size, nil
+}
+
+// WriteObject - write a new object into bucket
+func (b bucket) WriteObject(objectName string, objectData io.Reader, expectedMD5Sum string, metadata map[string]string) (string, error) {
+	if objectName == "" || objectData == nil {
+		return "", iodine.New(InvalidArgument{}, nil)
+	}
+	writers, err := b.getDiskWriters(b.normalizeObjectName(objectName), "data")
+	if err != nil {
+		return "", iodine.New(err, nil)
+	}
+	summer := md5.New()
+	objectMetadata := make(map[string]string)
+	donutObjectMetadata := make(map[string]string)
+	objectMetadata["version"] = objectMetadataVersion
+	donutObjectMetadata["version"] = donutObjectMetadataVersion
+	size := metadata["contentLength"]
+	sizeInt, err := strconv.ParseInt(size, 10, 64)
+	if err != nil {
+		return "", iodine.New(err, nil)
+	}
+
+	// if total writers are only '1' do not compute erasure
+	switch len(writers) == 1 {
+	case true:
+		mw := io.MultiWriter(writers[0], summer)
+		totalLength, err := io.CopyN(mw, objectData, sizeInt)
+		if err != nil {
+			return "", iodine.New(err, nil)
+		}
+		donutObjectMetadata["sys.size"] = strconv.FormatInt(totalLength, 10)
+		objectMetadata["size"] = strconv.FormatInt(totalLength, 10)
+	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)
+		}
+		// encoded data with k, m and write
+		chunkCount, totalLength, err := b.writeEncodedData(k, m, writers, objectData, summer)
+		if err != nil {
+			return "", iodine.New(err, nil)
+		}
+		/// donutMetadata section
+		donutObjectMetadata["sys.blockSize"] = strconv.Itoa(10 * 1024 * 1024)
+		donutObjectMetadata["sys.chunkCount"] = strconv.Itoa(chunkCount)
+		donutObjectMetadata["sys.erasureK"] = strconv.FormatUint(uint64(k), 10)
+		donutObjectMetadata["sys.erasureM"] = strconv.FormatUint(uint64(m), 10)
+		donutObjectMetadata["sys.erasureTechnique"] = "Cauchy"
+		donutObjectMetadata["sys.size"] = strconv.Itoa(totalLength)
+		// keep size inside objectMetadata as well for Object API requests
+		objectMetadata["size"] = strconv.Itoa(totalLength)
+	}
+	objectMetadata["bucket"] = b.name
+	objectMetadata["object"] = objectName
+	// store all user provided metadata
+	for k, v := range metadata {
+		objectMetadata[k] = v
+	}
+	dataMd5sum := summer.Sum(nil)
+	objectMetadata["created"] = time.Now().UTC().Format(time.RFC3339Nano)
+
+	// keeping md5sum for the object in two different places
+	// one for object storage and another is for internal use
+	objectMetadata["md5"] = hex.EncodeToString(dataMd5sum)
+	donutObjectMetadata["sys.md5"] = hex.EncodeToString(dataMd5sum)
+
+	// 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), objectMetadata["md5"]); err != nil {
+			return "", iodine.New(err, nil)
+		}
+	}
+	// write donut specific metadata
+	if err := b.writeDonutObjectMetadata(b.normalizeObjectName(objectName), donutObjectMetadata); err != nil {
+		return "", iodine.New(err, nil)
+	}
+	// write object specific metadata
+	if err := b.writeObjectMetadata(b.normalizeObjectName(objectName), objectMetadata); err != nil {
+		return "", iodine.New(err, nil)
+	}
+	// close all writers, when control flow reaches here
+	for _, writer := range writers {
+		writer.Close()
+	}
+	return objectMetadata["md5"], nil
+}
 
 // isMD5SumEqual - returns error if md5sum mismatches, other its `nil`
 func (b bucket) isMD5SumEqual(expectedMD5Sum, actualMD5Sum string) error {
@@ -127,7 +318,7 @@ func (b bucket) getDataAndParity(totalWriters int) (k uint8, m uint8, err error)
 // writeEncodedData -
 func (b bucket) writeEncodedData(k, m uint8, writers []io.WriteCloser, objectData io.Reader, summer hash.Hash) (int, int, error) {
 	chunks := split.Stream(objectData, 10*1024*1024)
-	encoder, err := NewEncoder(k, m, "Cauchy")
+	encoder, err := newEncoder(k, m, "Cauchy")
 	if err != nil {
 		return 0, 0, iodine.New(err, nil)
 	}
@@ -176,7 +367,7 @@ func (b bucket) readEncodedData(objectName string, writer *io.PipeWriter, donutO
 			writer.CloseWithError(iodine.New(MissingErasureTechnique{}, nil))
 			return
 		}
-		encoder, err := NewEncoder(uint8(k), uint8(m), technique)
+		encoder, err := newEncoder(uint8(k), uint8(m), technique)
 		if err != nil {
 			writer.CloseWithError(iodine.New(err, nil))
 			return
@@ -211,7 +402,7 @@ func (b bucket) readEncodedData(objectName string, writer *io.PipeWriter, donutO
 }
 
 // decodeEncodedData -
-func (b bucket) decodeEncodedData(totalLeft, blockSize int64, readers []io.ReadCloser, encoder Encoder, writer *io.PipeWriter) ([]byte, error) {
+func (b bucket) decodeEncodedData(totalLeft, blockSize int64, readers []io.ReadCloser, encoder encoder, writer *io.PipeWriter) ([]byte, error) {
 	var curBlockSize int64
 	if blockSize < totalLeft {
 		curBlockSize = blockSize
@@ -273,14 +464,14 @@ func (b bucket) getDiskReaders(objectName, objectMeta string) ([]io.ReadCloser,
 			return nil, iodine.New(err, nil)
 		}
 		readers = make([]io.ReadCloser, len(disks))
-		for _, disk := range disks {
+		for order, disk := range disks {
-			bucketSlice := fmt.Sprintf("%s$%d$%d", b.name, nodeSlice, disk.GetOrder())
+			bucketSlice := fmt.Sprintf("%s$%d$%d", b.name, nodeSlice, order)
 			objectPath := filepath.Join(b.donutName, bucketSlice, objectName, objectMeta)
 			objectSlice, err := disk.OpenFile(objectPath)
 			if err != nil {
 				return nil, iodine.New(err, nil)
 			}
-			readers[disk.GetOrder()] = objectSlice
+			readers[order] = objectSlice
 		}
 		nodeSlice = nodeSlice + 1
 	}
@@ -297,14 +488,14 @@ func (b bucket) getDiskWriters(objectName, objectMeta string) ([]io.WriteCloser,
 			return nil, iodine.New(err, nil)
 		}
 		writers = make([]io.WriteCloser, len(disks))
-		for _, disk := range disks {
+		for order, disk := range disks {
-			bucketSlice := fmt.Sprintf("%s$%d$%d", b.name, nodeSlice, disk.GetOrder())
+			bucketSlice := fmt.Sprintf("%s$%d$%d", b.name, nodeSlice, order)
 			objectPath := filepath.Join(b.donutName, bucketSlice, objectName, objectMeta)
-			objectSlice, err := disk.MakeFile(objectPath)
+			objectSlice, err := disk.CreateFile(objectPath)
 			if err != nil {
 				return nil, iodine.New(err, nil)
 			}
-			writers[disk.GetOrder()] = objectSlice
+			writers[order] = objectSlice
 		}
 		nodeSlice = nodeSlice + 1
 	}

pkg/storage/donut/disk/disk.go

@@ -0,0 +1,175 @@
+/*
+ * Minimalist Object Storage, (C) 2015 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or impliedisk.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package disk
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+
+	"github.com/minio/minio/pkg/iodine"
+)
+
+// Disk container for disk parameters
+type Disk struct {
+	path   string
+	fsInfo map[string]string
+}
+
+// New - instantiate new disk
+func New(diskPath string) (Disk, error) {
+	if diskPath == "" {
+		return Disk{}, iodine.New(InvalidArgument{}, nil)
+	}
+	s := syscall.Statfs_t{}
+	err := syscall.Statfs(diskPath, &s)
+	if err != nil {
+		return Disk{}, iodine.New(err, nil)
+	}
+	st, err := os.Stat(diskPath)
+	if err != nil {
+		return Disk{}, iodine.New(err, nil)
+	}
+	if !st.IsDir() {
+		return Disk{}, iodine.New(syscall.ENOTDIR, nil)
+	}
+	disk := Disk{
+		path:   diskPath,
+		fsInfo: make(map[string]string),
+	}
+	if fsType := getFSType(s.Type); fsType != "UNKNOWN" {
+		disk.fsInfo["FSType"] = fsType
+		disk.fsInfo["MountPoint"] = disk.path
+		return disk, nil
+	}
+	return Disk{}, iodine.New(UnsupportedFilesystem{Type: strconv.FormatInt(s.Type, 10)},
+		map[string]string{"Type": strconv.FormatInt(s.Type, 10)})
+}
+
+// GetPath - get root disk path
+func (disk Disk) GetPath() string {
+	return disk.path
+}
+
+// GetFSInfo - get disk filesystem and its usage information
+func (disk Disk) GetFSInfo() map[string]string {
+	s := syscall.Statfs_t{}
+	err := syscall.Statfs(disk.path, &s)
+	if err != nil {
+		return nil
+	}
+	disk.fsInfo["Total"] = formatBytes(s.Bsize * int64(s.Blocks))
+	disk.fsInfo["Free"] = formatBytes(s.Bsize * int64(s.Bfree))
+	disk.fsInfo["TotalB"] = strconv.FormatInt(s.Bsize*int64(s.Blocks), 10)
+	disk.fsInfo["FreeB"] = strconv.FormatInt(s.Bsize*int64(s.Bfree), 10)
+	return disk.fsInfo
+}
+
+// MakeDir - make a directory inside disk root path
+func (disk Disk) MakeDir(dirname string) error {
+	return os.MkdirAll(filepath.Join(disk.path, dirname), 0700)
+}
+
+// ListDir - list a directory inside disk root path, get only directories
+func (disk Disk) ListDir(dirname string) ([]os.FileInfo, error) {
+	dir, err := os.Open(filepath.Join(disk.path, dirname))
+	if err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	contents, err := dir.Readdir(-1)
+	if err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	var directories []os.FileInfo
+	for _, content := range contents {
+		// Include only directories, ignore everything else
+		if content.IsDir() {
+			directories = append(directories, content)
+		}
+	}
+	return directories, nil
+}
+
+// ListFiles - list a directory inside disk root path, get only files
+func (disk Disk) ListFiles(dirname string) ([]os.FileInfo, error) {
+	dir, err := os.Open(filepath.Join(disk.path, dirname))
+	if err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	contents, err := dir.Readdir(-1)
+	if err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	var files []os.FileInfo
+	for _, content := range contents {
+		// Include only regular files, ignore everything else
+		if content.Mode().IsRegular() {
+			files = append(files, content)
+		}
+	}
+	return files, nil
+}
+
+// CreateFile - create a file inside disk root path
+func (disk Disk) CreateFile(filename string) (*os.File, error) {
+	if filename == "" {
+		return nil, iodine.New(InvalidArgument{}, nil)
+	}
+	filePath := filepath.Join(disk.path, filename)
+	// Create directories if they don't exist
+	if err := os.MkdirAll(filepath.Dir(filePath), 0700); err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	dataFile, err := os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE, 0600)
+	if err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	return dataFile, nil
+}
+
+// OpenFile - read a file inside disk root path
+func (disk Disk) OpenFile(filename string) (*os.File, error) {
+	if filename == "" {
+		return nil, iodine.New(InvalidArgument{}, nil)
+	}
+	dataFile, err := os.Open(filepath.Join(disk.path, filename))
+	if err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	return dataFile, nil
+}
+
+// formatBytes - Convert bytes to human readable string. Like a 2 MB, 64.2 KB, 52 B
+func formatBytes(i int64) (result string) {
+	switch {
+	case i > (1024 * 1024 * 1024 * 1024):
+		result = fmt.Sprintf("%.02f TB", float64(i)/1024/1024/1024/1024)
+	case i > (1024 * 1024 * 1024):
+		result = fmt.Sprintf("%.02f GB", float64(i)/1024/1024/1024)
+	case i > (1024 * 1024):
+		result = fmt.Sprintf("%.02f MB", float64(i)/1024/1024)
+	case i > 1024:
+		result = fmt.Sprintf("%.02f KB", float64(i)/1024)
+	default:
+		result = fmt.Sprintf("%d B", i)
+	}
+	result = strings.Trim(result, " ")
+	return
+}

pkg/storage/donut/disk/disk_darwin.go

@@ -14,33 +14,9 @@
  * limitations under the License.
  */
 
-package donut
+package disk
 
-import (
+import "strconv"
-	"fmt"
-	"strconv"
-	"strings"
-)
-
-/// This file contains all the internal functions used inside Disk interface
-
-// formatBytes - Convert bytes to human readable string. Like a 2 MB, 64.2 KB, 52 B
-func (d disk) formatBytes(i uint64) (result string) {
-	switch {
-	case i > (1024 * 1024 * 1024 * 1024):
-		result = fmt.Sprintf("%.02f TB", float64(i)/1024/1024/1024/1024)
-	case i > (1024 * 1024 * 1024):
-		result = fmt.Sprintf("%.02f GB", float64(i)/1024/1024/1024)
-	case i > (1024 * 1024):
-		result = fmt.Sprintf("%.02f MB", float64(i)/1024/1024)
-	case i > 1024:
-		result = fmt.Sprintf("%.02f KB", float64(i)/1024)
-	default:
-		result = fmt.Sprintf("%d B", i)
-	}
-	result = strings.Trim(result, " ")
-	return
-}
 
 // fsType2StrinMap - list of filesystems supported by donut
 var fsType2StringMap = map[string]string{
@@ -48,7 +24,7 @@ var fsType2StringMap = map[string]string{
 }
 
 // getFSType - get filesystem type
-func (d disk) getFSType(fsType uint32) string {
+func getFSType(fsType uint32) string {
 	fsTypeHex := strconv.FormatUint(uint64(fsType), 16)
 	fsTypeString, ok := fsType2StringMap[fsTypeHex]
 	if ok == false {

pkg/storage/donut/disk/disk_linux.go

@@ -14,35 +14,11 @@
  * limitations under the License.
  */
 
-package donut
+package disk
 
-import (
+import "strconv"
-	"fmt"
-	"strconv"
-	"strings"
-)
 
-/// This file contains all the internal functions used inside Disk interface
+// fsType2StringMap - list of filesystems supported by donut on linux
-
-// formatBytes - Convert bytes to human readable string. Like a 2 MB, 64.2 KB, 52 B
-func (d disk) formatBytes(i int64) (result string) {
-	switch {
-	case i > (1024 * 1024 * 1024 * 1024):
-		result = fmt.Sprintf("%.02f TB", float64(i)/1024/1024/1024/1024)
-	case i > (1024 * 1024 * 1024):
-		result = fmt.Sprintf("%.02f GB", float64(i)/1024/1024/1024)
-	case i > (1024 * 1024):
-		result = fmt.Sprintf("%.02f MB", float64(i)/1024/1024)
-	case i > 1024:
-		result = fmt.Sprintf("%.02f KB", float64(i)/1024)
-	default:
-		result = fmt.Sprintf("%d B", i)
-	}
-	result = strings.Trim(result, " ")
-	return
-}
-
-// fsType2StrinMap - list of filesystems supported by donut
 var fsType2StringMap = map[string]string{
 	"1021994":  "TMPFS",
 	"137d":     "EXT",
@@ -58,7 +34,7 @@ var fsType2StringMap = map[string]string{
 }
 
 // getFSType - get filesystem type
-func (d disk) getFSType(fsType int64) string {
+func getFSType(fsType int64) string {
 	fsTypeHex := strconv.FormatInt(fsType, 16)
 	fsTypeString, ok := fsType2StringMap[fsTypeHex]
 	if ok == false {

pkg/storage/donut/disk/errors.go

@@ -0,0 +1,17 @@
+package disk
+
+// InvalidArgument invalid argument
+type InvalidArgument struct{}
+
+func (e InvalidArgument) Error() string {
+	return "Invalid argument"
+}
+
+// UnsupportedFilesystem unsupported filesystem type
+type UnsupportedFilesystem struct {
+	Type string
+}
+
+func (e UnsupportedFilesystem) Error() string {
+	return "Unsupported filesystem: " + e.Type
+}

pkg/storage/donut/donut.go

@@ -16,12 +16,15 @@
 
 package donut
 
-import "github.com/minio/minio/pkg/iodine"
+import (
+	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/storage/donut/disk"
+)
 
 // donut struct internal data
 type donut struct {
 	name    string
-	buckets map[string]Bucket
+	buckets map[string]bucket
 	nodes   map[string]Node
 }
 
@@ -47,16 +50,17 @@ func (d donut) attachDonutNode(hostname string, disks []string) error {
 	if err != nil {
 		return iodine.New(err, nil)
 	}
-	for i, disk := range disks {
+	donutName := d.name
+	for i, d := range disks {
 		// Order is necessary for maps, keep order number separately
-		newDisk, err := NewDisk(disk, i)
+		newDisk, err := disk.New(d)
 		if err != nil {
 			return iodine.New(err, nil)
 		}
-		if err := newDisk.MakeDir(d.name); err != nil {
+		if err := newDisk.MakeDir(donutName); err != nil {
 			return iodine.New(err, nil)
 		}
-		if err := node.AttachDisk(newDisk); err != nil {
+		if err := node.AttachDisk(newDisk, i); err != nil {
 			return iodine.New(err, nil)
 		}
 	}
@@ -72,7 +76,7 @@ func NewDonut(donutName string, nodeDiskMap map[string][]string) (Donut, error)
 		return nil, iodine.New(InvalidArgument{}, nil)
 	}
 	nodes := make(map[string]Node)
-	buckets := make(map[string]Bucket)
+	buckets := make(map[string]bucket)
 	d := donut{
 		name:    donutName,
 		nodes:   nodes,

pkg/storage/donut/donut_bucket.go

@@ -1,223 +0,0 @@
-/*
- * Minimalist Object Storage, (C) 2015 Minio, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package donut
-
-import (
-	"fmt"
-	"io"
-	"os"
-	"path/filepath"
-	"strconv"
-	"strings"
-	"time"
-
-	"crypto/md5"
-	"encoding/hex"
-
-	"github.com/minio/minio/pkg/iodine"
-)
-
-// internal struct carrying bucket specific information
-type bucket struct {
-	name      string
-	acl       string
-	time      time.Time
-	donutName string
-	nodes     map[string]Node
-	objects   map[string]Object
-}
-
-// NewBucket - instantiate a new bucket
-func NewBucket(bucketName, aclType, donutName string, nodes map[string]Node) (Bucket, map[string]string, error) {
-	errParams := map[string]string{
-		"bucketName": bucketName,
-		"donutName":  donutName,
-		"aclType":    aclType,
-	}
-	if strings.TrimSpace(bucketName) == "" || strings.TrimSpace(donutName) == "" {
-		return nil, nil, iodine.New(InvalidArgument{}, errParams)
-	}
-	bucketMetadata := make(map[string]string)
-	bucketMetadata["acl"] = aclType
-	t := time.Now().UTC()
-	bucketMetadata["created"] = t.Format(time.RFC3339Nano)
-	b := bucket{}
-	b.name = bucketName
-	b.acl = aclType
-	b.time = t
-	b.donutName = donutName
-	b.objects = make(map[string]Object)
-	b.nodes = nodes
-	return b, bucketMetadata, nil
-}
-
-// ListObjects - list all objects
-func (b bucket) ListObjects() (map[string]Object, error) {
-	nodeSlice := 0
-	for _, node := range b.nodes {
-		disks, err := node.ListDisks()
-		if err != nil {
-			return nil, iodine.New(err, nil)
-		}
-		for _, disk := range disks {
-			bucketSlice := fmt.Sprintf("%s$%d$%d", b.name, nodeSlice, disk.GetOrder())
-			bucketPath := filepath.Join(b.donutName, bucketSlice)
-			objects, err := disk.ListDir(bucketPath)
-			if err != nil {
-				return nil, iodine.New(err, nil)
-			}
-			for _, object := range objects {
-				newObject, err := NewObject(object.Name(), filepath.Join(disk.GetPath(), bucketPath))
-				if err != nil {
-					return nil, iodine.New(err, nil)
-				}
-				newObjectMetadata, err := newObject.GetObjectMetadata()
-				if err != nil {
-					return nil, iodine.New(err, nil)
-				}
-				objectName, ok := newObjectMetadata["object"]
-				if !ok {
-					return nil, iodine.New(ObjectCorrupted{Object: object.Name()}, nil)
-				}
-				b.objects[objectName] = newObject
-			}
-		}
-		nodeSlice = nodeSlice + 1
-	}
-	return b.objects, nil
-}
-
-// GetObject - get object
-func (b bucket) GetObject(objectName string) (reader io.ReadCloser, size int64, err error) {
-	reader, writer := io.Pipe()
-	// get list of objects
-	objects, err := b.ListObjects()
-	if err != nil {
-		return nil, 0, iodine.New(err, nil)
-	}
-	// check if object exists
-	object, ok := objects[objectName]
-	if !ok {
-		return nil, 0, iodine.New(os.ErrNotExist, nil)
-	}
-	// verify if objectMetadata is readable, before we serve the request
-	objectMetadata, err := object.GetObjectMetadata()
-	if err != nil {
-		return nil, 0, iodine.New(err, nil)
-	}
-	if objectName == "" || writer == nil || len(objectMetadata) == 0 {
-		return nil, 0, iodine.New(InvalidArgument{}, nil)
-	}
-	size, err = strconv.ParseInt(objectMetadata["size"], 10, 64)
-	if err != nil {
-		return nil, 0, iodine.New(err, nil)
-	}
-	// verify if donutObjectMetadata is readable, before we server the request
-	donutObjectMetadata, err := object.GetDonutObjectMetadata()
-	if err != nil {
-		return nil, 0, iodine.New(err, nil)
-	}
-	// read and reply back to GetObject() request in a go-routine
-	go b.readEncodedData(b.normalizeObjectName(objectName), writer, donutObjectMetadata)
-	return reader, size, nil
-}
-
-// PutObject - put a new object
-func (b bucket) PutObject(objectName string, objectData io.Reader, expectedMD5Sum string, metadata map[string]string) (string, error) {
-	if objectName == "" || objectData == nil {
-		return "", iodine.New(InvalidArgument{}, nil)
-	}
-	writers, err := b.getDiskWriters(b.normalizeObjectName(objectName), "data")
-	if err != nil {
-		return "", iodine.New(err, nil)
-	}
-	summer := md5.New()
-	objectMetadata := make(map[string]string)
-	donutObjectMetadata := make(map[string]string)
-	objectMetadata["version"] = objectMetadataVersion
-	donutObjectMetadata["version"] = donutObjectMetadataVersion
-	size := metadata["contentLength"]
-	sizeInt, err := strconv.ParseInt(size, 10, 64)
-	if err != nil {
-		return "", iodine.New(err, nil)
-	}
-
-	// if total writers are only '1' do not compute erasure
-	switch len(writers) == 1 {
-	case true:
-		mw := io.MultiWriter(writers[0], summer)
-		totalLength, err := io.CopyN(mw, objectData, sizeInt)
-		if err != nil {
-			return "", iodine.New(err, nil)
-		}
-		donutObjectMetadata["sys.size"] = strconv.FormatInt(totalLength, 10)
-		objectMetadata["size"] = strconv.FormatInt(totalLength, 10)
-	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)
-		}
-		// encoded data with k, m and write
-		chunkCount, totalLength, err := b.writeEncodedData(k, m, writers, objectData, summer)
-		if err != nil {
-			return "", iodine.New(err, nil)
-		}
-		/// donutMetadata section
-		donutObjectMetadata["sys.blockSize"] = strconv.Itoa(10 * 1024 * 1024)
-		donutObjectMetadata["sys.chunkCount"] = strconv.Itoa(chunkCount)
-		donutObjectMetadata["sys.erasureK"] = strconv.FormatUint(uint64(k), 10)
-		donutObjectMetadata["sys.erasureM"] = strconv.FormatUint(uint64(m), 10)
-		donutObjectMetadata["sys.erasureTechnique"] = "Cauchy"
-		donutObjectMetadata["sys.size"] = strconv.Itoa(totalLength)
-		// keep size inside objectMetadata as well for Object API requests
-		objectMetadata["size"] = strconv.Itoa(totalLength)
-	}
-	objectMetadata["bucket"] = b.name
-	objectMetadata["object"] = objectName
-	// store all user provided metadata
-	for k, v := range metadata {
-		objectMetadata[k] = v
-	}
-	dataMd5sum := summer.Sum(nil)
-	objectMetadata["created"] = time.Now().UTC().Format(time.RFC3339Nano)
-
-	// keeping md5sum for the object in two different places
-	// one for object storage and another is for internal use
-	objectMetadata["md5"] = hex.EncodeToString(dataMd5sum)
-	donutObjectMetadata["sys.md5"] = hex.EncodeToString(dataMd5sum)
-
-	// 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), objectMetadata["md5"]); err != nil {
-			return "", iodine.New(err, nil)
-		}
-	}
-	// write donut specific metadata
-	if err := b.writeDonutObjectMetadata(b.normalizeObjectName(objectName), donutObjectMetadata); err != nil {
-		return "", iodine.New(err, nil)
-	}
-	// write object specific metadata
-	if err := b.writeObjectMetadata(b.normalizeObjectName(objectName), objectMetadata); err != nil {
-		return "", iodine.New(err, nil)
-	}
-	// close all writers, when control flow reaches here
-	for _, writer := range writers {
-		writer.Close()
-	}
-	return objectMetadata["md5"], nil
-}

pkg/storage/donut/donut_disk_darwin.go

@@ -1,155 +0,0 @@
-/*
- * Minimalist Object Storage, (C) 2015 Minio, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package donut
-
-import (
-	"os"
-	"path/filepath"
-	"strconv"
-	"syscall"
-
-	"io/ioutil"
-
-	"github.com/minio/minio/pkg/iodine"
-)
-
-// internal disk struct
-type disk struct {
-	root       string
-	order      int
-	filesystem map[string]string
-}
-
-// NewDisk - instantiate new disk
-func NewDisk(diskPath string, diskOrder int) (Disk, error) {
-	if diskPath == "" || diskOrder < 0 {
-		return nil, iodine.New(InvalidArgument{}, nil)
-	}
-	s := syscall.Statfs_t{}
-	err := syscall.Statfs(diskPath, &s)
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	st, err := os.Stat(diskPath)
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	if !st.IsDir() {
-		return nil, iodine.New(syscall.ENOTDIR, nil)
-	}
-	d := disk{
-		root:       diskPath,
-		order:      diskOrder,
-		filesystem: make(map[string]string),
-	}
-	if fsType := d.getFSType(s.Type); fsType != "UNKNOWN" {
-		d.filesystem["FSType"] = fsType
-		d.filesystem["MountPoint"] = d.root
-		return d, nil
-	}
-	return nil, iodine.New(UnsupportedFilesystem{
-		Type: strconv.FormatInt(s.Type, 10),
-	}, map[string]string{"Type": strconv.FormatInt(s.Type, 10)})
-}
-
-// GetPath - get root disk path
-func (d disk) GetPath() string {
-	return d.root
-}
-
-// GetOrder - get order of disk present in graph
-func (d disk) GetOrder() int {
-	return d.order
-}
-
-// GetFSInfo - get disk filesystem and its usage information
-func (d disk) GetFSInfo() map[string]string {
-	s := syscall.Statfs_t{}
-	err := syscall.Statfs(d.root, &s)
-	if err != nil {
-		return nil
-	}
-	d.filesystem["Total"] = d.formatBytes(uint64(s.Bsize) * s.Blocks)
-	d.filesystem["Free"] = d.formatBytes(uint64(s.Bsize) * s.Bfree)
-	return d.filesystem
-}
-
-// MakeDir - make a directory inside disk root path
-func (d disk) MakeDir(dirname string) error {
-	return os.MkdirAll(filepath.Join(d.root, dirname), 0700)
-}
-
-// ListDir - list a directory inside disk root path, get only directories
-func (d disk) ListDir(dirname string) ([]os.FileInfo, error) {
-	contents, err := ioutil.ReadDir(filepath.Join(d.root, dirname))
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	var directories []os.FileInfo
-	for _, content := range contents {
-		// Include only directories, ignore everything else
-		if content.IsDir() {
-			directories = append(directories, content)
-		}
-	}
-	return directories, nil
-}
-
-// ListFiles - list a directory inside disk root path, get only files
-func (d disk) ListFiles(dirname string) ([]os.FileInfo, error) {
-	contents, err := ioutil.ReadDir(filepath.Join(d.root, dirname))
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	var files []os.FileInfo
-	for _, content := range contents {
-		// Include only regular files, ignore everything else
-		if content.Mode().IsRegular() {
-			files = append(files, content)
-		}
-	}
-	return files, nil
-}
-
-// MakeFile - create a file inside disk root path
-func (d disk) MakeFile(filename string) (*os.File, error) {
-	if filename == "" {
-		return nil, iodine.New(InvalidArgument{}, nil)
-	}
-	filePath := filepath.Join(d.root, filename)
-	// Create directories if they don't exist
-	if err := os.MkdirAll(filepath.Dir(filePath), 0700); err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	dataFile, err := os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE, 0600)
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	return dataFile, nil
-}
-
-// OpenFile - read a file inside disk root path
-func (d disk) OpenFile(filename string) (*os.File, error) {
-	if filename == "" {
-		return nil, iodine.New(InvalidArgument{}, nil)
-	}
-	dataFile, err := os.Open(filepath.Join(d.root, filename))
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	return dataFile, nil
-}

pkg/storage/donut/donut_disk_linux.go

@@ -1,155 +0,0 @@
-/*
- * Minimalist Object Storage, (C) 2015 Minio, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package donut
-
-import (
-	"os"
-	"path/filepath"
-	"strconv"
-	"syscall"
-
-	"io/ioutil"
-
-	"github.com/minio/minio/pkg/iodine"
-)
-
-// internal disk struct
-type disk struct {
-	root       string
-	order      int
-	filesystem map[string]string
-}
-
-// NewDisk - instantiate new disk
-func NewDisk(diskPath string, diskOrder int) (Disk, error) {
-	if diskPath == "" || diskOrder < 0 {
-		return nil, iodine.New(InvalidArgument{}, nil)
-	}
-	s := syscall.Statfs_t{}
-	err := syscall.Statfs(diskPath, &s)
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	st, err := os.Stat(diskPath)
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	if !st.IsDir() {
-		return nil, iodine.New(syscall.ENOTDIR, nil)
-	}
-	d := disk{
-		root:       diskPath,
-		order:      diskOrder,
-		filesystem: make(map[string]string),
-	}
-	if fsType := d.getFSType(s.Type); fsType != "UNKNOWN" {
-		d.filesystem["FSType"] = fsType
-		d.filesystem["MountPoint"] = d.root
-		return d, nil
-	}
-	return nil, iodine.New(UnsupportedFilesystem{
-		Type: strconv.FormatInt(s.Type, 10),
-	}, map[string]string{"Type": strconv.FormatInt(s.Type, 10)})
-}
-
-// GetPath - get root disk path
-func (d disk) GetPath() string {
-	return d.root
-}
-
-// GetOrder - get order of disk present in graph
-func (d disk) GetOrder() int {
-	return d.order
-}
-
-// GetFSInfo - get disk filesystem and its usage information
-func (d disk) GetFSInfo() map[string]string {
-	s := syscall.Statfs_t{}
-	err := syscall.Statfs(d.root, &s)
-	if err != nil {
-		return nil
-	}
-	d.filesystem["Total"] = d.formatBytes(s.Bsize * int64(s.Blocks))
-	d.filesystem["Free"] = d.formatBytes(s.Bsize * int64(s.Bfree))
-	return d.filesystem
-}
-
-// MakeDir - make a directory inside disk root path
-func (d disk) MakeDir(dirname string) error {
-	return os.MkdirAll(filepath.Join(d.root, dirname), 0700)
-}
-
-// ListDir - list a directory inside disk root path, get only directories
-func (d disk) ListDir(dirname string) ([]os.FileInfo, error) {
-	contents, err := ioutil.ReadDir(filepath.Join(d.root, dirname))
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	var directories []os.FileInfo
-	for _, content := range contents {
-		// Include only directories, ignore everything else
-		if content.IsDir() {
-			directories = append(directories, content)
-		}
-	}
-	return directories, nil
-}
-
-// ListFiles - list a directory inside disk root path, get only files
-func (d disk) ListFiles(dirname string) ([]os.FileInfo, error) {
-	contents, err := ioutil.ReadDir(filepath.Join(d.root, dirname))
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	var files []os.FileInfo
-	for _, content := range contents {
-		// Include only regular files, ignore everything else
-		if content.Mode().IsRegular() {
-			files = append(files, content)
-		}
-	}
-	return files, nil
-}
-
-// MakeFile - create a file inside disk root path
-func (d disk) MakeFile(filename string) (*os.File, error) {
-	if filename == "" {
-		return nil, iodine.New(InvalidArgument{}, nil)
-	}
-	filePath := filepath.Join(d.root, filename)
-	// Create directories if they don't exist
-	if err := os.MkdirAll(filepath.Dir(filePath), 0700); err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	dataFile, err := os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE, 0600)
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	return dataFile, nil
-}
-
-// OpenFile - read a file inside disk root path
-func (d disk) OpenFile(filename string) (*os.File, error) {
-	if filename == "" {
-		return nil, iodine.New(InvalidArgument{}, nil)
-	}
-	dataFile, err := os.Open(filepath.Join(d.root, filename))
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	return dataFile, nil
-}

pkg/storage/donut/donut_internal_interfaces.go

@@ -1,69 +0,0 @@
-/*
- * Minimalist Object Storage, (C) 2015 Minio, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package donut
-
-import (
-	"io"
-	"os"
-)
-
-// Encoder interface
-type Encoder interface {
-	GetEncodedBlockLen(dataLength int) (int, error)
-	Encode(data []byte) (encodedData [][]byte, err error)
-	Decode(encodedData [][]byte, dataLength int) (data []byte, err error)
-}
-
-// Bucket interface
-type Bucket interface {
-	ListObjects() (map[string]Object, error)
-
-	GetObject(object string) (io.ReadCloser, int64, error)
-	PutObject(object string, contents io.Reader, expectedMD5Sum string, metadata map[string]string) (string, error)
-}
-
-// Object interface
-type Object interface {
-	GetObjectMetadata() (map[string]string, error)
-	GetDonutObjectMetadata() (map[string]string, error)
-}
-
-// Node interface
-type Node interface {
-	ListDisks() (map[string]Disk, error)
-	AttachDisk(disk Disk) error
-	DetachDisk(disk Disk) error
-
-	GetNodeName() string
-	SaveConfig() error
-	LoadConfig() error
-}
-
-// Disk interface
-type Disk interface {
-	MakeDir(dirname string) error
-
-	ListDir(dirname string) ([]os.FileInfo, error)
-	ListFiles(dirname string) ([]os.FileInfo, error)
-
-	MakeFile(path string) (*os.File, error)
-	OpenFile(path string) (*os.File, error)
-
-	GetPath() string
-	GetOrder() int
-	GetFSInfo() map[string]string
-}

pkg/storage/donut/encoder.go

@@ -42,8 +42,8 @@ func getErasureTechnique(technique string) (encoding.Technique, error) {
 	}
 }
 
-// NewEncoder - instantiate a new encoder
+// newEncoder - instantiate a new encoder
-func NewEncoder(k, m uint8, technique string) (Encoder, error) {
+func newEncoder(k, m uint8, technique string) (encoder, error) {
 	errParams := map[string]string{
 		"k":         strconv.FormatUint(uint64(k), 10),
 		"m":         strconv.FormatUint(uint64(m), 10),
@@ -52,11 +52,11 @@ func NewEncoder(k, m uint8, technique string) (Encoder, error) {
 	e := encoder{}
 	t, err := getErasureTechnique(technique)
 	if err != nil {
-		return nil, iodine.New(err, errParams)
+		return encoder{}, iodine.New(err, errParams)
 	}
 	params, err := encoding.ValidateParams(k, m, t)
 	if err != nil {
-		return nil, iodine.New(err, errParams)
+		return encoder{}, iodine.New(err, errParams)
 	}
 	e.encoder = encoding.NewErasure(params)
 	e.k = k

pkg/storage/donut/interfaces.go

@@ -16,7 +16,11 @@
 
 package donut
 
-import "io"
+import (
+	"io"
+
+	"github.com/minio/minio/pkg/storage/donut/disk"
+)
 
 // Collection of Donut specification interfaces
 
@@ -28,16 +32,16 @@ type Donut interface {
 
 // ObjectStorage is a donut object storage interface
 type ObjectStorage interface {
-	// Storage service Operations
+	// Storage service operations
 	GetBucketMetadata(bucket string) (map[string]string, error)
 	SetBucketMetadata(bucket string, metadata map[string]string) error
 	ListBuckets() (map[string]map[string]string, error)
 	MakeBucket(bucket, acl string) error
 
-	// Bucket Operations
+	// Bucket operations
-	ListObjects(bucket, prefix, marker, delim string, maxKeys int) (result []string, prefixes []string, isTruncated bool, err error)
+	ListObjects(bucket, prefix, marker, delim string, maxKeys int) (objects []string, prefixes []string, isTruncated bool, err error)
 
-	// Object Operations
+	// Object operations
 	GetObject(bucket, object string) (io.ReadCloser, int64, error)
 	GetObjectMetadata(bucket, object string) (map[string]string, error)
 	PutObject(bucket, object, expectedMD5Sum string, reader io.ReadCloser, metadata map[string]string) (string, error)
@@ -55,3 +59,14 @@ type Management interface {
 	SaveConfig() error
 	LoadConfig() error
 }
+
+// Node interface for node management
+type Node interface {
+	ListDisks() (map[int]disk.Disk, error)
+	AttachDisk(disk disk.Disk, diskOrder int) error
+	DetachDisk(diskOrder int) error
+
+	GetNodeName() string
+	SaveConfig() error
+	LoadConfig() error
+}

pkg/storage/donut/management.go

@@ -21,8 +21,8 @@ func (d donut) Info() (nodeDiskMap map[string][]string, err error) {
 			return nil, iodine.New(err, nil)
 		}
 		diskList := make([]string, len(disks))
-		for diskName, disk := range disks {
+		for diskOrder, disk := range disks {
-			diskList[disk.GetOrder()] = diskName
+			diskList[diskOrder] = disk.GetPath()
 		}
 		nodeDiskMap[nodeName] = diskList
 	}
@@ -52,14 +52,14 @@ func (d donut) SaveConfig() error {
 		if err != nil {
 			return iodine.New(err, nil)
 		}
-		for _, disk := range disks {
+		for order, disk := range disks {
 			donutConfigPath := filepath.Join(d.name, donutConfig)
-			donutConfigWriter, err := disk.MakeFile(donutConfigPath)
+			donutConfigWriter, err := disk.CreateFile(donutConfigPath)
 			defer donutConfigWriter.Close()
 			if err != nil {
 				return iodine.New(err, nil)
 			}
-			nodeDiskMap[hostname][disk.GetOrder()] = disk.GetPath()
+			nodeDiskMap[hostname][order] = disk.GetPath()
 			jenc := json.NewEncoder(donutConfigWriter)
 			if err := jenc.Encode(nodeDiskMap); err != nil {
 				return iodine.New(err, nil)

pkg/storage/donut/node.go

@@ -16,12 +16,15 @@
 
 package donut
 
-import "github.com/minio/minio/pkg/iodine"
+import (
+	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/storage/donut/disk"
+)
 
 // node struct internal
 type node struct {
 	hostname string
-	disks    map[string]Disk
+	disks    map[int]disk.Disk
 }
 
 // NewNode - instantiates a new node
@@ -29,7 +32,7 @@ func NewNode(hostname string) (Node, error) {
 	if hostname == "" {
 		return nil, iodine.New(InvalidArgument{}, nil)
 	}
-	disks := make(map[string]Disk)
+	disks := make(map[int]disk.Disk)
 	n := node{
 		hostname: hostname,
 		disks:    disks,
@@ -43,22 +46,22 @@ func (n node) GetNodeName() string {
 }
 
 // ListDisks - return number of disks
-func (n node) ListDisks() (map[string]Disk, error) {
+func (n node) ListDisks() (map[int]disk.Disk, error) {
 	return n.disks, nil
 }
 
 // AttachDisk - attach a disk
-func (n node) AttachDisk(disk Disk) error {
+func (n node) AttachDisk(disk disk.Disk, diskOrder int) error {
-	if disk == nil {
+	if diskOrder < 0 {
 		return iodine.New(InvalidArgument{}, nil)
 	}
-	n.disks[disk.GetPath()] = disk
+	n.disks[diskOrder] = disk
 	return nil
 }
 
 // DetachDisk - detach a disk
-func (n node) DetachDisk(disk Disk) error {
+func (n node) DetachDisk(diskOrder int) error {
-	delete(n.disks, disk.GetPath())
+	delete(n.disks, diskOrder)
 	return nil
 }
 

pkg/storage/donut/object.go

@@ -32,10 +32,10 @@ type object struct {
 	donutObjectMetadata map[string]string
 }
 
-// NewObject - instantiate a new object
+// newObject - instantiate a new object
-func NewObject(objectName, p string) (Object, error) {
+func newObject(objectName, p string) (object, error) {
 	if objectName == "" {
-		return nil, iodine.New(InvalidArgument{}, nil)
+		return object{}, iodine.New(InvalidArgument{}, nil)
 	}
 	o := object{}
 	o.name = objectName
@@ -47,7 +47,7 @@ func (o object) GetObjectMetadata() (map[string]string, error) {
 	objectMetadata := make(map[string]string)
 	objectMetadataBytes, err := ioutil.ReadFile(filepath.Join(o.objectPath, objectMetadataConfig))
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, iodine.New(ObjectNotFound{Object: o.name}, nil)
 	}
 	if err := json.Unmarshal(objectMetadataBytes, &objectMetadata); err != nil {
 		return nil, iodine.New(err, nil)
@@ -60,7 +60,7 @@ func (o object) GetDonutObjectMetadata() (map[string]string, error) {
 	donutObjectMetadata := make(map[string]string)
 	donutObjectMetadataBytes, err := ioutil.ReadFile(filepath.Join(o.objectPath, donutObjectMetadataConfig))
 	if err != nil {
-		return nil, iodine.New(err, nil)
+		return nil, iodine.New(ObjectNotFound{Object: o.name}, nil)
 	}
 	if err := json.Unmarshal(donutObjectMetadataBytes, &donutObjectMetadata); err != nil {
 		return nil, iodine.New(err, nil)

pkg/storage/donut/objectstorage.go

@@ -17,7 +17,11 @@
 package donut
 
 import (
+	"encoding/json"
+	"fmt"
 	"io"
+	"os"
+	"path/filepath"
 	"sort"
 	"strconv"
 	"strings"
@@ -185,7 +189,7 @@ func (d donut) PutObject(bucket, object, expectedMD5Sum string, reader io.ReadCl
 			return "", iodine.New(ObjectExists{Object: object}, nil)
 		}
 	}
-	md5sum, err := d.buckets[bucket].PutObject(object, reader, expectedMD5Sum, metadata)
+	md5sum, err := d.buckets[bucket].WriteObject(object, reader, expectedMD5Sum, metadata)
 	if err != nil {
 		return "", iodine.New(err, errParams)
 	}
@@ -211,16 +215,7 @@ func (d donut) GetObject(bucket, object string) (reader io.ReadCloser, size int6
 	if _, ok := d.buckets[bucket]; !ok {
 		return nil, 0, iodine.New(BucketNotFound{Bucket: bucket}, errParams)
 	}
-	objectList, err := d.buckets[bucket].ListObjects()
+	return d.buckets[bucket].ReadObject(object)
-	if err != nil {
-		return nil, 0, iodine.New(err, nil)
-	}
-	for objectName := range objectList {
-		if objectName == object {
-			return d.buckets[bucket].GetObject(object)
-		}
-	}
-	return nil, 0, iodine.New(ObjectNotFound{Object: object}, nil)
 }
 
 // GetObjectMetadata - get object metadata
@@ -246,3 +241,157 @@ func (d donut) GetObjectMetadata(bucket, object string) (map[string]string, erro
 	}
 	return donutObject.GetObjectMetadata()
 }
+
+// getDiskWriters -
+func (d donut) getBucketMetadataWriters() ([]io.WriteCloser, error) {
+	var writers []io.WriteCloser
+	for _, node := range d.nodes {
+		disks, err := node.ListDisks()
+		if err != nil {
+			return nil, iodine.New(err, nil)
+		}
+		writers = make([]io.WriteCloser, len(disks))
+		for order, disk := range disks {
+			bucketMetaDataWriter, err := disk.CreateFile(filepath.Join(d.name, bucketMetadataConfig))
+			if err != nil {
+				return nil, iodine.New(err, nil)
+			}
+			writers[order] = bucketMetaDataWriter
+		}
+	}
+	return writers, nil
+}
+
+func (d donut) getBucketMetadataReaders() ([]io.ReadCloser, error) {
+	var readers []io.ReadCloser
+	for _, node := range d.nodes {
+		disks, err := node.ListDisks()
+		if err != nil {
+			return nil, iodine.New(err, nil)
+		}
+		readers = make([]io.ReadCloser, len(disks))
+		for order, disk := range disks {
+			bucketMetaDataReader, err := disk.OpenFile(filepath.Join(d.name, bucketMetadataConfig))
+			if err != nil {
+				return nil, iodine.New(err, nil)
+			}
+			readers[order] = bucketMetaDataReader
+		}
+	}
+	return readers, nil
+}
+
+//
+func (d donut) setDonutBucketMetadata(metadata map[string]map[string]string) error {
+	writers, err := d.getBucketMetadataWriters()
+	if err != nil {
+		return iodine.New(err, nil)
+	}
+	for _, writer := range writers {
+		defer writer.Close()
+	}
+	for _, writer := range writers {
+		jenc := json.NewEncoder(writer)
+		if err := jenc.Encode(metadata); err != nil {
+			return iodine.New(err, nil)
+		}
+	}
+	return nil
+}
+
+func (d donut) getDonutBucketMetadata() (map[string]map[string]string, error) {
+	metadata := make(map[string]map[string]string)
+	readers, err := d.getBucketMetadataReaders()
+	if err != nil {
+		return nil, iodine.New(err, nil)
+	}
+	for _, reader := range readers {
+		defer reader.Close()
+	}
+	for _, reader := range readers {
+		jenc := json.NewDecoder(reader)
+		if err := jenc.Decode(&metadata); err != nil {
+			return nil, iodine.New(err, nil)
+		}
+	}
+	return metadata, nil
+}
+
+func (d donut) makeDonutBucket(bucketName, acl string) error {
+	err := d.getDonutBuckets()
+	if err != nil {
+		return iodine.New(err, nil)
+	}
+	if _, ok := d.buckets[bucketName]; ok {
+		return iodine.New(BucketExists{Bucket: bucketName}, nil)
+	}
+	bucket, bucketMetadata, err := newBucket(bucketName, acl, d.name, d.nodes)
+	if err != nil {
+		return iodine.New(err, nil)
+	}
+	nodeNumber := 0
+	d.buckets[bucketName] = bucket
+	for _, node := range d.nodes {
+		disks, err := node.ListDisks()
+		if err != nil {
+			return iodine.New(err, nil)
+		}
+		for order, disk := range disks {
+			bucketSlice := fmt.Sprintf("%s$%d$%d", bucketName, nodeNumber, order)
+			err := disk.MakeDir(filepath.Join(d.name, bucketSlice))
+			if err != nil {
+				return iodine.New(err, nil)
+			}
+		}
+		nodeNumber = nodeNumber + 1
+	}
+	metadata, err := d.getDonutBucketMetadata()
+	if err != nil {
+		err = iodine.ToError(err)
+		if os.IsNotExist(err) {
+			metadata := make(map[string]map[string]string)
+			metadata[bucketName] = bucketMetadata
+			err = d.setDonutBucketMetadata(metadata)
+			if err != nil {
+				return iodine.New(err, nil)
+			}
+			return nil
+		}
+		return iodine.New(err, nil)
+	}
+	metadata[bucketName] = bucketMetadata
+	err = d.setDonutBucketMetadata(metadata)
+	if err != nil {
+		return iodine.New(err, nil)
+	}
+	return nil
+}
+
+func (d donut) getDonutBuckets() error {
+	for _, node := range d.nodes {
+		disks, err := node.ListDisks()
+		if err != nil {
+			return iodine.New(err, nil)
+		}
+		for _, disk := range disks {
+			dirs, err := disk.ListDir(d.name)
+			if err != nil {
+				return iodine.New(err, nil)
+			}
+			for _, dir := range dirs {
+				splitDir := strings.Split(dir.Name(), "$")
+				if len(splitDir) < 3 {
+					return iodine.New(CorruptedBackend{Backend: dir.Name()}, nil)
+				}
+				bucketName := splitDir[0]
+				// we dont need this NewBucket once we cache from makeDonutBucket()
+				bucket, _, err := newBucket(bucketName, "private", d.name, d.nodes)
+				if err != nil {
+					return iodine.New(err, nil)
+				}
+				d.buckets[bucketName] = bucket
+			}
+		}
+	}
+	return nil
+}

pkg/storage/donut/objectstorage_internal.go

@@ -1,184 +0,0 @@
-/*
- * Minimalist Object Storage, (C) 2015 Minio, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package donut
-
-import (
-	"encoding/json"
-	"fmt"
-	"io"
-	"os"
-	"path/filepath"
-	"strings"
-
-	"github.com/minio/minio/pkg/iodine"
-)
-
-/// This file contains all the internal functions used by Object interface
-
-// getDiskWriters -
-func (d donut) getBucketMetadataWriters() ([]io.WriteCloser, error) {
-	var writers []io.WriteCloser
-	for _, node := range d.nodes {
-		disks, err := node.ListDisks()
-		if err != nil {
-			return nil, iodine.New(err, nil)
-		}
-		writers = make([]io.WriteCloser, len(disks))
-		for _, disk := range disks {
-			bucketMetaDataWriter, err := disk.MakeFile(filepath.Join(d.name, bucketMetadataConfig))
-			if err != nil {
-				return nil, iodine.New(err, nil)
-			}
-			writers[disk.GetOrder()] = bucketMetaDataWriter
-		}
-	}
-	return writers, nil
-}
-
-func (d donut) getBucketMetadataReaders() ([]io.ReadCloser, error) {
-	var readers []io.ReadCloser
-	for _, node := range d.nodes {
-		disks, err := node.ListDisks()
-		if err != nil {
-			return nil, iodine.New(err, nil)
-		}
-		readers = make([]io.ReadCloser, len(disks))
-		for _, disk := range disks {
-			bucketMetaDataReader, err := disk.OpenFile(filepath.Join(d.name, bucketMetadataConfig))
-			if err != nil {
-				return nil, iodine.New(err, nil)
-			}
-			readers[disk.GetOrder()] = bucketMetaDataReader
-		}
-	}
-	return readers, nil
-}
-
-//
-func (d donut) setDonutBucketMetadata(metadata map[string]map[string]string) error {
-	writers, err := d.getBucketMetadataWriters()
-	if err != nil {
-		return iodine.New(err, nil)
-	}
-	for _, writer := range writers {
-		defer writer.Close()
-	}
-	for _, writer := range writers {
-		jenc := json.NewEncoder(writer)
-		if err := jenc.Encode(metadata); err != nil {
-			return iodine.New(err, nil)
-		}
-	}
-	return nil
-}
-
-func (d donut) getDonutBucketMetadata() (map[string]map[string]string, error) {
-	metadata := make(map[string]map[string]string)
-	readers, err := d.getBucketMetadataReaders()
-	if err != nil {
-		return nil, iodine.New(err, nil)
-	}
-	for _, reader := range readers {
-		defer reader.Close()
-	}
-	for _, reader := range readers {
-		jenc := json.NewDecoder(reader)
-		if err := jenc.Decode(&metadata); err != nil {
-			return nil, iodine.New(err, nil)
-		}
-	}
-	return metadata, nil
-}
-
-func (d donut) makeDonutBucket(bucketName, acl string) error {
-	err := d.getDonutBuckets()
-	if err != nil {
-		return iodine.New(err, nil)
-	}
-	if _, ok := d.buckets[bucketName]; ok {
-		return iodine.New(BucketExists{Bucket: bucketName}, nil)
-	}
-	bucket, bucketMetadata, err := NewBucket(bucketName, acl, d.name, d.nodes)
-	if err != nil {
-		return iodine.New(err, nil)
-	}
-	nodeNumber := 0
-	d.buckets[bucketName] = bucket
-	for _, node := range d.nodes {
-		disks, err := node.ListDisks()
-		if err != nil {
-			return iodine.New(err, nil)
-		}
-		for _, disk := range disks {
-			bucketSlice := fmt.Sprintf("%s$%d$%d", bucketName, nodeNumber, disk.GetOrder())
-			err := disk.MakeDir(filepath.Join(d.name, bucketSlice))
-			if err != nil {
-				return iodine.New(err, nil)
-			}
-		}
-		nodeNumber = nodeNumber + 1
-	}
-	metadata, err := d.getDonutBucketMetadata()
-	if err != nil {
-		err = iodine.ToError(err)
-		if os.IsNotExist(err) {
-			metadata := make(map[string]map[string]string)
-			metadata[bucketName] = bucketMetadata
-			err = d.setDonutBucketMetadata(metadata)
-			if err != nil {
-				return iodine.New(err, nil)
-			}
-			return nil
-		}
-		return iodine.New(err, nil)
-	}
-	metadata[bucketName] = bucketMetadata
-	err = d.setDonutBucketMetadata(metadata)
-	if err != nil {
-		return iodine.New(err, nil)
-	}
-	return nil
-}
-
-func (d donut) getDonutBuckets() error {
-	for _, node := range d.nodes {
-		disks, err := node.ListDisks()
-		if err != nil {
-			return iodine.New(err, nil)
-		}
-		for _, disk := range disks {
-			dirs, err := disk.ListDir(d.name)
-			if err != nil {
-				return iodine.New(err, nil)
-			}
-			for _, dir := range dirs {
-				splitDir := strings.Split(dir.Name(), "$")
-				if len(splitDir) < 3 {
-					return iodine.New(CorruptedBackend{Backend: dir.Name()}, nil)
-				}
-				bucketName := splitDir[0]
-				// we dont need this NewBucket once we cache from makeDonutBucket()
-				bucket, _, err := NewBucket(bucketName, "private", d.name, d.nodes)
-				if err != nil {
-					return iodine.New(err, nil)
-				}
-				d.buckets[bucketName] = bucket
-			}
-		}
-	}
-	return nil
-}

pkg/storage/donut/rebalance.go

@@ -22,12 +22,13 @@ import (
 	"strings"
 
 	"github.com/minio/minio/pkg/iodine"
+	"github.com/minio/minio/pkg/storage/donut/disk"
 )
 
 // Rebalance -
 func (d donut) Rebalance() error {
 	var totalOffSetLength int
-	var newDisks []Disk
+	var newDisks []disk.Disk
 	var existingDirs []os.FileInfo
 	for _, node := range d.nodes {
 		disks, err := node.ListDisks()