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minio/object-common.go

193 lines
5.2 KiB

/*
* Minio Cloud Storage, (C) 2016 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 main
import (
"crypto/md5"
"encoding/hex"
"io"
"path"
"sort"
)
/// Common object layer functions.
// makeBucket - create a bucket, is a common function for both object layers.
func makeBucket(storage StorageAPI, bucket string) error {
// Verify if bucket is valid.
if !IsValidBucketName(bucket) {
return BucketNameInvalid{Bucket: bucket}
}
if err := storage.MakeVol(bucket); err != nil {
return toObjectErr(err, bucket)
}
// This happens for the first time, but keep this here since this
// is the only place where it can be made expensive optimizing all
// other calls.
// Create minio meta volume, if it doesn't exist yet.
if err := storage.MakeVol(minioMetaBucket); err != nil {
if err != errVolumeExists {
return toObjectErr(err, minioMetaBucket)
}
}
return nil
}
// getBucketInfo - fetch bucket info, is a common function for both object layers.
func getBucketInfo(storage StorageAPI, bucket string) (BucketInfo, error) {
// Verify if bucket is valid.
if !IsValidBucketName(bucket) {
return BucketInfo{}, BucketNameInvalid{Bucket: bucket}
}
vi, err := storage.StatVol(bucket)
if err != nil {
return BucketInfo{}, toObjectErr(err, bucket)
}
return BucketInfo{
Name: bucket,
Created: vi.Created,
Total: vi.Total,
Free: vi.Free,
}, nil
}
// listBuckets - list all buckets, is a common function for both object layers.
func listBuckets(storage StorageAPI) ([]BucketInfo, error) {
var bucketInfos []BucketInfo
vols, err := storage.ListVols()
if err != nil {
return nil, toObjectErr(err)
}
for _, vol := range vols {
// StorageAPI can send volume names which are incompatible
// with buckets, handle it and skip them.
if !IsValidBucketName(vol.Name) {
continue
}
bucketInfos = append(bucketInfos, BucketInfo{
Name: vol.Name,
Created: vol.Created,
Total: vol.Total,
Free: vol.Free,
})
}
sort.Sort(byBucketName(bucketInfos))
return bucketInfos, nil
}
// deleteBucket - deletes a bucket, is a common function for both the layers.
func deleteBucket(storage StorageAPI, bucket string) error {
// Verify if bucket is valid.
if !IsValidBucketName(bucket) {
return BucketNameInvalid{Bucket: bucket}
}
if err := storage.DeleteVol(bucket); err != nil {
return toObjectErr(err)
}
return nil
}
// putObjectCommon - create an object, is a common function for both object layers.
func putObjectCommon(storage StorageAPI, bucket string, object string, size int64, data io.Reader, metadata map[string]string) (string, error) {
// Verify if bucket is valid.
if !IsValidBucketName(bucket) {
return "", BucketNameInvalid{Bucket: bucket}
}
if !IsValidObjectName(object) {
return "", ObjectNameInvalid{
Bucket: bucket,
Object: object,
}
}
// Check whether the bucket exists.
if isExist, err := isBucketExist(storage, bucket); err != nil {
return "", err
} else if !isExist {
return "", BucketNotFound{Bucket: bucket}
}
tempObj := path.Join(tmpMetaPrefix, bucket, object)
fileWriter, err := storage.CreateFile(minioMetaBucket, tempObj)
if err != nil {
return "", toObjectErr(err, bucket, object)
}
// Initialize md5 writer.
md5Writer := md5.New()
// Instantiate a new multi writer.
multiWriter := io.MultiWriter(md5Writer, fileWriter)
// Instantiate checksum hashers and create a multiwriter.
if size > 0 {
if _, err = io.CopyN(multiWriter, data, size); err != nil {
if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
return "", clErr
}
return "", toObjectErr(err, bucket, object)
}
} else {
if _, err = io.Copy(multiWriter, data); err != nil {
if clErr := safeCloseAndRemove(fileWriter); clErr != nil {
return "", clErr
}
return "", toObjectErr(err, bucket, object)
}
}
newMD5Hex := hex.EncodeToString(md5Writer.Sum(nil))
// md5Hex representation.
var md5Hex string
if len(metadata) != 0 {
md5Hex = metadata["md5Sum"]
}
if md5Hex != "" {
if newMD5Hex != md5Hex {
if err = safeCloseAndRemove(fileWriter); err != nil {
return "", err
}
return "", BadDigest{md5Hex, newMD5Hex}
}
}
err = fileWriter.Close()
if err != nil {
return "", err
}
err = storage.RenameFile(minioMetaBucket, tempObj, bucket, object)
if err != nil {
if derr := storage.DeleteFile(minioMetaBucket, tempObj); derr != nil {
return "", derr
}
return "", toObjectErr(err, bucket, object)
}
// Return md5sum, successfully wrote object.
return newMD5Hex, nil
}
// checks whether bucket exists.
func isBucketExist(storage StorageAPI, bucketName string) (bool, error) {
// Check whether bucket exists.
if _, e := storage.StatVol(bucketName); e != nil {
if e == errVolumeNotFound {
return false, nil
}
return false, e
}
return true, nil
}