minio/pkg/storage/drivers/fs/fs_object.go

296 lines
8.2 KiB
Go

/*
* Mini 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 filesystem
import (
"bytes"
"io"
"os"
"path/filepath"
"strings"
"crypto/md5"
"encoding/base64"
"encoding/hex"
"encoding/json"
"errors"
"github.com/minio/minio/pkg/iodine"
"github.com/minio/minio/pkg/storage/drivers"
)
/// Object Operations
// GetPartialObject - GET object from range
func (fs *fsDriver) GetPartialObject(w io.Writer, bucket, object string, start, length int64) (int64, error) {
// validate bucket
if drivers.IsValidBucket(bucket) == false {
return 0, iodine.New(drivers.BucketNameInvalid{Bucket: bucket}, nil)
}
// validate object
if drivers.IsValidObjectName(object) == false {
return 0, iodine.New(drivers.ObjectNameInvalid{Bucket: bucket, Object: object}, nil)
}
objectPath := filepath.Join(fs.root, bucket, object)
filestat, err := os.Stat(objectPath)
switch err := err.(type) {
case nil:
{
if filestat.IsDir() {
return 0, iodine.New(drivers.ObjectNotFound{Bucket: bucket, Object: object}, nil)
}
}
default:
{
if os.IsNotExist(err) {
return 0, iodine.New(drivers.ObjectNotFound{Bucket: bucket, Object: object}, nil)
}
return 0, iodine.New(err, nil)
}
}
file, err := os.Open(objectPath)
if err != nil {
return 0, iodine.New(err, nil)
}
defer file.Close()
_, err = file.Seek(start, os.SEEK_SET)
if err != nil {
return 0, iodine.New(err, nil)
}
count, err := io.CopyN(w, file, length)
if err != nil {
return count, iodine.New(err, nil)
}
return count, nil
}
// GetObject - GET object from key
func (fs *fsDriver) GetObject(w io.Writer, bucket string, object string) (int64, error) {
// validate bucket
if drivers.IsValidBucket(bucket) == false {
return 0, iodine.New(drivers.BucketNameInvalid{Bucket: bucket}, nil)
}
// validate object
if drivers.IsValidObjectName(object) == false {
return 0, iodine.New(drivers.ObjectNameInvalid{Bucket: bucket, Object: object}, nil)
}
objectPath := filepath.Join(fs.root, bucket, object)
filestat, err := os.Stat(objectPath)
switch err := err.(type) {
case nil:
{
if filestat.IsDir() {
return 0, iodine.New(drivers.ObjectNotFound{Bucket: bucket, Object: object}, nil)
}
}
default:
{
if os.IsNotExist(err) {
return 0, iodine.New(drivers.ObjectNotFound{Bucket: bucket, Object: object}, nil)
}
return 0, iodine.New(err, nil)
}
}
file, err := os.Open(objectPath)
defer file.Close()
if err != nil {
return 0, drivers.EmbedError(bucket, object, err)
}
count, err := io.Copy(w, file)
if err != nil {
return count, iodine.New(err, nil)
}
return count, nil
}
// GetObjectMetadata - HEAD object
func (fs *fsDriver) GetObjectMetadata(bucket, object string) (drivers.ObjectMetadata, error) {
if drivers.IsValidBucket(bucket) == false {
return drivers.ObjectMetadata{}, iodine.New(drivers.BucketNameInvalid{Bucket: bucket}, nil)
}
if drivers.IsValidObjectName(object) == false {
return drivers.ObjectMetadata{}, iodine.New(drivers.ObjectNameInvalid{Bucket: bucket, Object: bucket}, nil)
}
// Do not use filepath.Join() since filepath.Join strips off any object names with '/', use them as is
// in a static manner so that we can send a proper 'ObjectNotFound' reply back upon os.Stat()
objectPath := fs.root + "/" + bucket + "/" + object
stat, err := os.Stat(objectPath)
if os.IsNotExist(err) {
return drivers.ObjectMetadata{}, iodine.New(drivers.ObjectNotFound{Bucket: bucket, Object: object}, nil)
}
_, err = os.Stat(objectPath + "$metadata")
if os.IsNotExist(err) {
return drivers.ObjectMetadata{}, iodine.New(drivers.ObjectNotFound{Bucket: bucket, Object: object}, nil)
}
file, err := os.Open(objectPath + "$metadata")
defer file.Close()
if err != nil {
return drivers.ObjectMetadata{}, iodine.New(err, nil)
}
var deserializedMetadata Metadata
decoder := json.NewDecoder(file)
err = decoder.Decode(&deserializedMetadata)
if err != nil {
return drivers.ObjectMetadata{}, iodine.New(err, nil)
}
contentType := "application/octet-stream"
if deserializedMetadata.ContentType != "" {
contentType = deserializedMetadata.ContentType
}
contentType = strings.TrimSpace(contentType)
etag := bucket + "#" + filepath.Base(object)
if len(deserializedMetadata.Md5sum) != 0 {
etag = hex.EncodeToString(deserializedMetadata.Md5sum)
}
metadata := drivers.ObjectMetadata{
Bucket: bucket,
Key: object,
Created: stat.ModTime(),
Size: stat.Size(),
Md5: etag,
ContentType: contentType,
}
return metadata, nil
}
// isMD5SumEqual - returns error if md5sum mismatches, success its `nil`
func 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(errors.New("bad digest, md5sum mismatch"), nil)
}
return nil
}
return iodine.New(errors.New("invalid argument"), nil)
}
// CreateObject - PUT object
func (fs *fsDriver) CreateObject(bucket, key, contentType, expectedMD5Sum string, size int64, data io.Reader) (string, error) {
fs.lock.Lock()
defer fs.lock.Unlock()
// check bucket name valid
if drivers.IsValidBucket(bucket) == false {
return "", iodine.New(drivers.BucketNameInvalid{Bucket: bucket}, nil)
}
// check bucket exists
if _, err := os.Stat(filepath.Join(fs.root, bucket)); os.IsNotExist(err) {
return "", iodine.New(drivers.BucketNotFound{Bucket: bucket}, nil)
}
// verify object path legal
if drivers.IsValidObjectName(key) == false {
return "", iodine.New(drivers.ObjectNameInvalid{Bucket: bucket, Object: key}, nil)
}
// verify content type
if contentType == "" {
contentType = "application/octet-stream"
}
contentType = strings.TrimSpace(contentType)
// get object path
objectPath := filepath.Join(fs.root, bucket, key)
objectDir := filepath.Dir(objectPath)
if _, err := os.Stat(objectDir); os.IsNotExist(err) {
err = os.MkdirAll(objectDir, 0700)
if err != nil {
return "", iodine.New(err, nil)
}
}
// check if object exists
if _, err := os.Stat(objectPath); !os.IsNotExist(err) {
return "", iodine.New(drivers.ObjectExists{
Bucket: bucket,
Object: key,
}, nil)
}
if strings.TrimSpace(expectedMD5Sum) != "" {
expectedMD5SumBytes, err := base64.StdEncoding.DecodeString(strings.TrimSpace(expectedMD5Sum))
if err != nil {
// pro-actively close the connection
return "", iodine.New(drivers.InvalidDigest{Md5: expectedMD5Sum}, nil)
}
expectedMD5Sum = hex.EncodeToString(expectedMD5SumBytes)
}
// write object
file, err := os.OpenFile(objectPath, os.O_WRONLY|os.O_CREATE, 0600)
if err != nil {
return "", iodine.New(err, nil)
}
defer file.Close()
h := md5.New()
mw := io.MultiWriter(file, h)
_, err = io.CopyN(mw, data, size)
if err != nil {
return "", iodine.New(err, nil)
}
file, err = os.OpenFile(objectPath+"$metadata", os.O_WRONLY|os.O_CREATE, 0600)
if err != nil {
return "", iodine.New(err, nil)
}
defer file.Close()
metadata := &Metadata{
ContentType: contentType,
Md5sum: h.Sum(nil),
}
// serialize metadata to json
encoder := json.NewEncoder(file)
err = encoder.Encode(metadata)
md5Sum := hex.EncodeToString(metadata.Md5sum)
// Verify if the written object is equal to what is expected, only if it is requested as such
if strings.TrimSpace(expectedMD5Sum) != "" {
if err := isMD5SumEqual(strings.TrimSpace(expectedMD5Sum), md5Sum); err != nil {
return "", iodine.New(drivers.BadDigest{Md5: expectedMD5Sum, Bucket: bucket, Key: key}, nil)
}
}
return md5Sum, nil
}