minio/cmd/fs-v1-metadata.go
Harshavardhana 4747adfcb4 fs: Enable returning ETag along with ListObjects() (#4042)
This is to comply with S3 behavior, we previously removed
reading `fs.json` for optimization reasons but we have a
reason to believe that providing ETag and using gjson
provides needed benefit of not having to deal with
unmarshalling overhead of golang stdlib.

Fixes #4028
2017-04-04 09:14:03 -07:00

309 lines
7.4 KiB
Go

/*
* Minio Cloud Storage, (C) 2016, 2017, 2017 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 cmd
import (
"encoding/json"
"io"
"io/ioutil"
"os"
pathutil "path"
"sort"
"strings"
"github.com/minio/minio/pkg/lock"
"github.com/minio/minio/pkg/mimedb"
"github.com/tidwall/gjson"
)
const (
fsMetaJSONFile = "fs.json"
fsFormatJSONFile = "format.json"
)
// A fsMetaV1 represents a metadata header mapping keys to sets of values.
type fsMetaV1 struct {
Version string `json:"version"`
Format string `json:"format"`
Minio struct {
Release string `json:"release"`
} `json:"minio"`
// Metadata map for current object `fs.json`.
Meta map[string]string `json:"meta,omitempty"`
Parts []objectPartInfo `json:"parts,omitempty"`
}
// Converts metadata to object info.
func (m fsMetaV1) ToObjectInfo(bucket, object string, fi os.FileInfo) ObjectInfo {
if len(m.Meta) == 0 {
m.Meta = make(map[string]string)
}
// Guess content-type from the extension if possible.
if m.Meta["content-type"] == "" {
if objectExt := pathutil.Ext(object); objectExt != "" {
if content, ok := mimedb.DB[strings.ToLower(strings.TrimPrefix(objectExt, "."))]; ok {
m.Meta["content-type"] = content.ContentType
}
}
}
objInfo := ObjectInfo{
Bucket: bucket,
Name: object,
}
// We set file info only if its valid.
objInfo.ModTime = timeSentinel
if fi != nil {
objInfo.ModTime = fi.ModTime()
objInfo.Size = fi.Size()
objInfo.IsDir = fi.IsDir()
}
objInfo.MD5Sum = m.Meta["md5Sum"]
objInfo.ContentType = m.Meta["content-type"]
objInfo.ContentEncoding = m.Meta["content-encoding"]
// md5Sum has already been extracted into objInfo.MD5Sum. We
// need to remove it from m.Meta to avoid it from appearing as
// part of response headers. e.g, X-Minio-* or X-Amz-*.
delete(m.Meta, "md5Sum")
// Save all the other userdefined API.
objInfo.UserDefined = m.Meta
// Success..
return objInfo
}
// ObjectPartIndex - returns the index of matching object part number.
func (m fsMetaV1) ObjectPartIndex(partNumber int) (partIndex int) {
for i, part := range m.Parts {
if partNumber == part.Number {
partIndex = i
return partIndex
}
}
return -1
}
// AddObjectPart - add a new object part in order.
func (m *fsMetaV1) AddObjectPart(partNumber int, partName string, partETag string, partSize int64) {
partInfo := objectPartInfo{
Number: partNumber,
Name: partName,
ETag: partETag,
Size: partSize,
}
// Update part info if it already exists.
for i, part := range m.Parts {
if partNumber == part.Number {
m.Parts[i] = partInfo
return
}
}
// Proceed to include new part info.
m.Parts = append(m.Parts, partInfo)
// Parts in fsMeta should be in sorted order by part number.
sort.Sort(byObjectPartNumber(m.Parts))
}
func (m *fsMetaV1) WriteTo(lk *lock.LockedFile) (n int64, err error) {
var metadataBytes []byte
metadataBytes, err = json.Marshal(m)
if err != nil {
return 0, traceError(err)
}
if err = lk.Truncate(0); err != nil {
return 0, traceError(err)
}
if _, err = lk.Write(metadataBytes); err != nil {
return 0, traceError(err)
}
// Success.
return int64(len(metadataBytes)), nil
}
func parseFSVersion(fsMetaBuf []byte) string {
return gjson.GetBytes(fsMetaBuf, "version").String()
}
func parseFSFormat(fsMetaBuf []byte) string {
return gjson.GetBytes(fsMetaBuf, "format").String()
}
func parseFSRelease(fsMetaBuf []byte) string {
return gjson.GetBytes(fsMetaBuf, "minio.release").String()
}
func parseFSMetaMap(fsMetaBuf []byte) map[string]string {
// Get xlMetaV1.Meta map.
metaMapResult := gjson.GetBytes(fsMetaBuf, "meta").Map()
metaMap := make(map[string]string)
for key, valResult := range metaMapResult {
metaMap[key] = valResult.String()
}
return metaMap
}
func parseFSParts(fsMetaBuf []byte) []objectPartInfo {
// Parse the FS Parts.
partsResult := gjson.GetBytes(fsMetaBuf, "parts").Array()
partInfo := make([]objectPartInfo, len(partsResult))
for i, p := range partsResult {
info := objectPartInfo{}
info.Number = int(p.Get("number").Int())
info.Name = p.Get("name").String()
info.ETag = p.Get("etag").String()
info.Size = p.Get("size").Int()
partInfo[i] = info
}
return partInfo
}
func (m *fsMetaV1) ReadFrom(lk *lock.LockedFile) (n int64, err error) {
var fsMetaBuf []byte
fi, err := lk.Stat()
if err != nil {
return 0, traceError(err)
}
fsMetaBuf, err = ioutil.ReadAll(io.NewSectionReader(lk, 0, fi.Size()))
if err != nil {
return 0, traceError(err)
}
if len(fsMetaBuf) == 0 {
return 0, traceError(io.EOF)
}
// obtain version.
m.Version = parseFSVersion(fsMetaBuf)
// obtain format.
m.Format = parseFSFormat(fsMetaBuf)
// obtain metadata.
m.Meta = parseFSMetaMap(fsMetaBuf)
// obtain parts info list.
m.Parts = parseFSParts(fsMetaBuf)
// obtain minio release date.
m.Minio.Release = parseFSRelease(fsMetaBuf)
// Success.
return int64(len(fsMetaBuf)), nil
}
// FS metadata constants.
const (
// FS backend meta version.
fsMetaVersion = "1.0.0"
// FS backend meta format.
fsMetaFormat = "fs"
// Add more constants here.
)
// newFSMetaV1 - initializes new fsMetaV1.
func newFSMetaV1() (fsMeta fsMetaV1) {
fsMeta = fsMetaV1{}
fsMeta.Version = fsMetaVersion
fsMeta.Format = fsMetaFormat
fsMeta.Minio.Release = ReleaseTag
return fsMeta
}
// newFSFormatV1 - initializes new formatConfigV1 with FS format info.
func newFSFormatV1() (format *formatConfigV1) {
return &formatConfigV1{
Version: "1",
Format: "fs",
FS: &fsFormat{
Version: "1",
},
}
}
// loads format.json from minioMetaBucket if it exists.
func loadFormatFS(fsPath string) (*formatConfigV1, error) {
rlk, err := lock.RLockedOpenFile(pathJoin(fsPath, minioMetaBucket, fsFormatJSONFile))
if err != nil {
if os.IsNotExist(err) {
return nil, errUnformattedDisk
}
return nil, err
}
defer rlk.Close()
formatBytes, err := ioutil.ReadAll(rlk)
if err != nil {
return nil, err
}
format := &formatConfigV1{}
if err = json.Unmarshal(formatBytes, format); err != nil {
return nil, err
}
return format, nil
}
// writes FS format (format.json) into minioMetaBucket.
func saveFormatFS(formatPath string, fsFormat *formatConfigV1) error {
metadataBytes, err := json.Marshal(fsFormat)
if err != nil {
return err
}
// fsFormatJSONFile - format.json file stored in minioMetaBucket(.minio.sys) directory.
lk, err := lock.LockedOpenFile(preparePath(formatPath), os.O_CREATE|os.O_WRONLY, 0600)
if err != nil {
return err
}
defer lk.Close()
_, err = lk.Write(metadataBytes)
// Success.
return err
}
// Return if the part info in uploadedParts and completeParts are same.
func isPartsSame(uploadedParts []objectPartInfo, completeParts []completePart) bool {
if len(uploadedParts) != len(completeParts) {
return false
}
for i := range completeParts {
if uploadedParts[i].Number != completeParts[i].PartNumber ||
uploadedParts[i].ETag != completeParts[i].ETag {
return false
}
}
return true
}