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minio/pkg/storage/donut/bucket.go

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16 KiB

/*
* 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 (
"bytes"
"fmt"
"hash"
"io"
"path/filepath"
"strconv"
"strings"
"sync"
"time"
"crypto/md5"
"encoding/hex"
"encoding/json"
"github.com/minio/minio/pkg/iodine"
"github.com/minio/minio/pkg/utils/split"
)
// internal struct carrying bucket specific information
type bucket struct {
name string
acl string
time time.Time
donutName string
nodes map[string]Node
lock *sync.RWMutex
}
// 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.nodes = nodes
b.lock = new(sync.RWMutex)
return b, bucketMetadata, nil
}
// ListObjects - list all objects
func (b bucket) ListObjects() (map[string]object, error) {
b.lock.RLock()
defer b.lock.RUnlock()
nodeSlice := 0
objects := make(map[string]object)
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)
files, err := disk.ListDir(bucketPath)
if err != nil {
return nil, iodine.New(err, nil)
}
for _, file := range files {
newObject, err := newObject(file.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: newObject.name}, nil)
}
objects[objectName] = newObject
}
}
nodeSlice = nodeSlice + 1
}
return objects, nil
}
// ReadObject - open an object to read
func (b bucket) ReadObject(objectName string) (reader io.ReadCloser, size int64, err error) {
b.lock.RLock()
defer b.lock.RUnlock()
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) {
b.lock.Lock()
defer b.lock.Unlock()
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 {
if strings.TrimSpace(expectedMD5Sum) != "" && strings.TrimSpace(actualMD5Sum) != "" {
expectedMD5SumBytes, err := hex.DecodeString(expectedMD5Sum)
if err != nil {
return iodine.New(err, nil)
}
actualMD5SumBytes, err := hex.DecodeString(actualMD5Sum)
if err != nil {
return iodine.New(err, nil)
}
if !bytes.Equal(expectedMD5SumBytes, actualMD5SumBytes) {
return iodine.New(BadDigest{}, nil)
}
return nil
}
return iodine.New(InvalidArgument{}, nil)
}
// writeObjectMetadata - write additional object metadata
func (b bucket) writeObjectMetadata(objectName string, objectMetadata map[string]string) error {
if len(objectMetadata) == 0 {
return iodine.New(InvalidArgument{}, nil)
}
objectMetadataWriters, err := b.getDiskWriters(objectName, objectMetadataConfig)
if err != nil {
return iodine.New(err, nil)
}
for _, objectMetadataWriter := range objectMetadataWriters {
defer objectMetadataWriter.Close()
}
for _, objectMetadataWriter := range objectMetadataWriters {
jenc := json.NewEncoder(objectMetadataWriter)
if err := jenc.Encode(objectMetadata); err != nil {
return iodine.New(err, nil)
}
}
return nil
}
// writeDonutObjectMetadata - write donut related object metadata
func (b bucket) writeDonutObjectMetadata(objectName string, objectMetadata map[string]string) error {
if len(objectMetadata) == 0 {
return iodine.New(InvalidArgument{}, nil)
}
objectMetadataWriters, err := b.getDiskWriters(objectName, donutObjectMetadataConfig)
if err != nil {
return iodine.New(err, nil)
}
for _, objectMetadataWriter := range objectMetadataWriters {
defer objectMetadataWriter.Close()
}
for _, objectMetadataWriter := range objectMetadataWriters {
jenc := json.NewEncoder(objectMetadataWriter)
if err := jenc.Encode(objectMetadata); err != nil {
return iodine.New(err, nil)
}
}
return nil
}
// TODO - This a temporary normalization of objectNames, need to find a better way
//
// normalizedObjectName - all objectNames with "/" get normalized to a simple objectName
//
// example:
// user provided value - "this/is/my/deep/directory/structure"
// donut normalized value - "this-is-my-deep-directory-structure"
//
func (b bucket) normalizeObjectName(objectName string) string {
// replace every '/' with '-'
return strings.Replace(objectName, "/", "-", -1)
}
// getDataAndParity - calculate k, m (data and parity) values from number of disks
func (b bucket) getDataAndParity(totalWriters int) (k uint8, m uint8, err error) {
if totalWriters <= 1 {
return 0, 0, iodine.New(InvalidArgument{}, nil)
}
quotient := totalWriters / 2 // not using float or abs to let integer round off to lower value
// quotient cannot be bigger than (255 / 2) = 127
if quotient > 127 {
return 0, 0, iodine.New(ParityOverflow{}, nil)
}
remainder := totalWriters % 2 // will be 1 for odd and 0 for even numbers
k = uint8(quotient + remainder)
m = uint8(quotient)
return k, m, nil
}
// 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")
if err != nil {
return 0, 0, iodine.New(err, nil)
}
chunkCount := 0
totalLength := 0
for chunk := range chunks {
if chunk.Err == nil {
totalLength = totalLength + len(chunk.Data)
encodedBlocks, _ := encoder.Encode(chunk.Data)
summer.Write(chunk.Data)
for blockIndex, block := range encodedBlocks {
_, err := io.Copy(writers[blockIndex], bytes.NewBuffer(block))
if err != nil {
return 0, 0, iodine.New(err, nil)
}
}
}
chunkCount = chunkCount + 1
}
return chunkCount, totalLength, nil
}
// readEncodedData -
func (b bucket) readEncodedData(objectName string, writer *io.PipeWriter, donutObjectMetadata map[string]string) {
expectedMd5sum, err := hex.DecodeString(donutObjectMetadata["sys.md5"])
if err != nil {
writer.CloseWithError(iodine.New(err, nil))
return
}
readers, err := b.getDiskReaders(objectName, "data")
if err != nil {
writer.CloseWithError(iodine.New(err, nil))
return
}
hasher := md5.New()
mwriter := io.MultiWriter(writer, hasher)
switch len(readers) == 1 {
case false:
totalChunks, totalLeft, blockSize, k, m, err := b.donutMetadata2Values(donutObjectMetadata)
if err != nil {
writer.CloseWithError(iodine.New(err, nil))
return
}
technique, ok := donutObjectMetadata["sys.erasureTechnique"]
if !ok {
writer.CloseWithError(iodine.New(MissingErasureTechnique{}, nil))
return
}
encoder, err := newEncoder(uint8(k), uint8(m), technique)
if err != nil {
writer.CloseWithError(iodine.New(err, nil))
return
}
for i := 0; i < totalChunks; i++ {
decodedData, err := b.decodeEncodedData(totalLeft, blockSize, readers, encoder, writer)
if err != nil {
writer.CloseWithError(iodine.New(err, nil))
return
}
_, err = io.Copy(mwriter, bytes.NewBuffer(decodedData))
if err != nil {
writer.CloseWithError(iodine.New(err, nil))
return
}
totalLeft = totalLeft - int64(blockSize)
}
case true:
_, err := io.Copy(writer, readers[0])
if err != nil {
writer.CloseWithError(iodine.New(err, nil))
return
}
}
// check if decodedData md5sum matches
if !bytes.Equal(expectedMd5sum, hasher.Sum(nil)) {
writer.CloseWithError(iodine.New(ChecksumMismatch{}, nil))
return
}
writer.Close()
return
}
// decodeEncodedData -
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
} else {
curBlockSize = totalLeft // cast is safe, blockSize in if protects
}
curChunkSize, err := encoder.GetEncodedBlockLen(int(curBlockSize))
if err != nil {
return nil, iodine.New(err, nil)
}
encodedBytes := make([][]byte, len(readers))
for i, reader := range readers {
var bytesBuffer bytes.Buffer
_, err := io.CopyN(&bytesBuffer, reader, int64(curChunkSize))
if err != nil {
return nil, iodine.New(err, nil)
}
encodedBytes[i] = bytesBuffer.Bytes()
}
decodedData, err := encoder.Decode(encodedBytes, int(curBlockSize))
if err != nil {
return nil, iodine.New(err, nil)
}
return decodedData, nil
}
// donutMetadata2Values -
func (b bucket) donutMetadata2Values(donutObjectMetadata map[string]string) (totalChunks int, totalLeft, blockSize int64, k, m uint64, err error) {
totalChunks, err = strconv.Atoi(donutObjectMetadata["sys.chunkCount"])
if err != nil {
return 0, 0, 0, 0, 0, iodine.New(err, nil)
}
totalLeft, err = strconv.ParseInt(donutObjectMetadata["sys.size"], 10, 64)
if err != nil {
return 0, 0, 0, 0, 0, iodine.New(err, nil)
}
blockSize, err = strconv.ParseInt(donutObjectMetadata["sys.blockSize"], 10, 64)
if err != nil {
return 0, 0, 0, 0, 0, iodine.New(err, nil)
}
k, err = strconv.ParseUint(donutObjectMetadata["sys.erasureK"], 10, 8)
if err != nil {
return 0, 0, 0, 0, 0, iodine.New(err, nil)
}
m, err = strconv.ParseUint(donutObjectMetadata["sys.erasureM"], 10, 8)
if err != nil {
return 0, 0, 0, 0, 0, iodine.New(err, nil)
}
return totalChunks, totalLeft, blockSize, k, m, nil
}
// getDiskReaders -
func (b bucket) getDiskReaders(objectName, objectMeta string) ([]io.ReadCloser, error) {
var readers []io.ReadCloser
nodeSlice := 0
for _, node := range b.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 {
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[order] = objectSlice
}
nodeSlice = nodeSlice + 1
}
return readers, nil
}
// getDiskWriters -
func (b bucket) getDiskWriters(objectName, objectMeta string) ([]io.WriteCloser, error) {
var writers []io.WriteCloser
nodeSlice := 0
for _, node := range b.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 {
bucketSlice := fmt.Sprintf("%s$%d$%d", b.name, nodeSlice, order)
objectPath := filepath.Join(b.donutName, bucketSlice, objectName, objectMeta)
objectSlice, err := disk.CreateFile(objectPath)
if err != nil {
return nil, iodine.New(err, nil)
}
writers[order] = objectSlice
}
nodeSlice = nodeSlice + 1
}
return writers, nil
}