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minio/pkg/fs/fs-object.go

401 lines
12 KiB

/*
* Minio Cloud 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 fs
import (
"bytes"
"io"
"os"
"path/filepath"
"strings"
"crypto/md5"
"encoding/base64"
"encoding/hex"
"runtime"
"github.com/minio/minio/pkg/atomic"
"github.com/minio/minio/pkg/crypto/sha256"
"github.com/minio/minio/pkg/disk"
"github.com/minio/minio/pkg/ioutils"
"github.com/minio/minio/pkg/mimedb"
"github.com/minio/minio/pkg/probe"
"github.com/minio/minio/pkg/s3/signature4"
)
/// Object Operations
// GetObject - GET object
func (fs Filesystem) GetObject(w io.Writer, bucket, object string, start, length int64) (int64, *probe.Error) {
// Critical region requiring read lock.
fs.rwLock.RLock()
defer fs.rwLock.RUnlock()
// Input validation.
if !IsValidBucketName(bucket) {
return 0, probe.NewError(BucketNameInvalid{Bucket: bucket})
}
if !IsValidObjectName(object) {
return 0, probe.NewError(ObjectNameInvalid{Bucket: bucket, Object: object})
}
// normalize buckets.
bucket = fs.denormalizeBucket(bucket)
bucketPath := filepath.Join(fs.path, bucket)
if _, e := os.Stat(bucketPath); e != nil {
if os.IsNotExist(e) {
return 0, probe.NewError(BucketNotFound{Bucket: bucket})
}
return 0, probe.NewError(e)
}
objectPath := filepath.Join(bucketPath, object)
filestat, err := os.Stat(objectPath)
switch err := err.(type) {
case nil:
if filestat.IsDir() {
return 0, probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
default:
if os.IsNotExist(err) {
return 0, probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
return 0, probe.NewError(err)
}
file, err := os.Open(objectPath)
if err != nil {
return 0, probe.NewError(err)
}
defer file.Close()
_, err = file.Seek(start, os.SEEK_SET)
if err != nil {
return 0, probe.NewError(err)
}
var count int64
if length > 0 {
count, err = io.CopyN(w, file, length)
if err != nil {
return count, probe.NewError(err)
}
} else {
count, err = io.Copy(w, file)
if err != nil {
return count, probe.NewError(err)
}
}
return count, nil
}
// GetObjectMetadata - get object metadata.
func (fs Filesystem) GetObjectMetadata(bucket, object string) (ObjectMetadata, *probe.Error) {
// Input validation.
if !IsValidBucketName(bucket) {
return ObjectMetadata{}, probe.NewError(BucketNameInvalid{Bucket: bucket})
}
if !IsValidObjectName(object) {
return ObjectMetadata{}, probe.NewError(ObjectNameInvalid{Bucket: bucket, Object: bucket})
}
// Normalize buckets.
bucket = fs.denormalizeBucket(bucket)
bucketPath := filepath.Join(fs.path, bucket)
if _, e := os.Stat(bucketPath); e != nil {
if os.IsNotExist(e) {
return ObjectMetadata{}, probe.NewError(BucketNotFound{Bucket: bucket})
}
return ObjectMetadata{}, probe.NewError(e)
}
metadata, err := getMetadata(fs.path, bucket, object)
if err != nil {
return ObjectMetadata{}, err.Trace(bucket, object)
}
if metadata.Mode.IsDir() {
return ObjectMetadata{}, probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
return metadata, nil
}
// getMetadata - get object metadata.
func getMetadata(rootPath, bucket, object string) (ObjectMetadata, *probe.Error) {
// 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().
var objectPath string
// For windows use its special os.PathSeparator == "\\"
if runtime.GOOS == "windows" {
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objectPath = rootPath + string(os.PathSeparator) + bucket + string(os.PathSeparator) + object
} else {
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objectPath = rootPath + string(os.PathSeparator) + bucket + string(os.PathSeparator) + object
}
stat, err := os.Stat(objectPath)
if err != nil {
if os.IsNotExist(err) {
return ObjectMetadata{}, probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
return ObjectMetadata{}, probe.NewError(err)
}
contentType := "application/octet-stream"
if runtime.GOOS == "windows" {
object = filepath.ToSlash(object)
}
if objectExt := filepath.Ext(object); objectExt != "" {
content, ok := mimedb.DB[strings.ToLower(strings.TrimPrefix(objectExt, "."))]
if ok {
contentType = content.ContentType
}
}
metadata := ObjectMetadata{
Bucket: bucket,
Object: object,
LastModified: stat.ModTime(),
Size: stat.Size(),
ContentType: contentType,
Mode: stat.Mode(),
}
return metadata, nil
}
// isMD5SumEqual - returns error if md5sum mismatches, success its `nil`
func isMD5SumEqual(expectedMD5Sum, actualMD5Sum string) bool {
// Verify the md5sum.
if expectedMD5Sum != "" && actualMD5Sum != "" {
// Decode md5sum to bytes from their hexadecimal
// representations.
expectedMD5SumBytes, err := hex.DecodeString(expectedMD5Sum)
if err != nil {
return false
}
actualMD5SumBytes, err := hex.DecodeString(actualMD5Sum)
if err != nil {
return false
}
// Verify md5sum bytes are equal after successful decoding.
if !bytes.Equal(expectedMD5SumBytes, actualMD5SumBytes) {
return false
}
return true
}
return false
}
// CreateObject - create an object.
func (fs Filesystem) CreateObject(bucket, object, expectedMD5Sum string, size int64, data io.Reader, sig *signature4.Sign) (ObjectMetadata, *probe.Error) {
di, e := disk.GetInfo(fs.path)
if e != nil {
return ObjectMetadata{}, probe.NewError(e)
}
// Remove 5% from total space for cumulative disk space used for
// journalling, inodes etc.
availableDiskSpace := (float64(di.Free) / (float64(di.Total) - (0.05 * float64(di.Total)))) * 100
if int64(availableDiskSpace) <= fs.minFreeDisk {
return ObjectMetadata{}, probe.NewError(RootPathFull{Path: fs.path})
}
// Check bucket name valid.
if !IsValidBucketName(bucket) {
return ObjectMetadata{}, probe.NewError(BucketNameInvalid{Bucket: bucket})
}
bucket = fs.denormalizeBucket(bucket)
bucketPath := filepath.Join(fs.path, bucket)
if _, e = os.Stat(bucketPath); e != nil {
if os.IsNotExist(e) {
return ObjectMetadata{}, probe.NewError(BucketNotFound{Bucket: bucket})
}
return ObjectMetadata{}, probe.NewError(e)
}
// Verify object path legal.
if !IsValidObjectName(object) {
return ObjectMetadata{}, probe.NewError(ObjectNameInvalid{Bucket: bucket, Object: object})
}
// Get object path.
objectPath := filepath.Join(bucketPath, object)
if expectedMD5Sum != "" {
var expectedMD5SumBytes []byte
expectedMD5SumBytes, e = base64.StdEncoding.DecodeString(expectedMD5Sum)
if e != nil {
// Pro-actively close the connection.
return ObjectMetadata{}, probe.NewError(InvalidDigest{MD5: expectedMD5Sum})
}
expectedMD5Sum = hex.EncodeToString(expectedMD5SumBytes)
}
// Write object.
file, e := atomic.FileCreateWithPrefix(objectPath, expectedMD5Sum+"$tmpobject")
if e != nil {
switch e := e.(type) {
case *os.PathError:
if e.Op == "mkdir" {
if strings.Contains(e.Error(), "not a directory") {
return ObjectMetadata{}, probe.NewError(ObjectExistsAsPrefix{Bucket: bucket, Prefix: object})
}
}
return ObjectMetadata{}, probe.NewError(e)
default:
return ObjectMetadata{}, probe.NewError(e)
}
}
// Instantiate checksum hashers and create a multiwriter.
md5Hasher := md5.New()
sha256Hasher := sha256.New()
objectWriter := io.MultiWriter(file, md5Hasher, sha256Hasher)
if size > 0 {
if _, e = io.CopyN(objectWriter, data, size); e != nil {
file.CloseAndPurge()
return ObjectMetadata{}, probe.NewError(e)
}
} else {
if _, e = io.Copy(objectWriter, data); e != nil {
file.CloseAndPurge()
return ObjectMetadata{}, probe.NewError(e)
}
}
md5Sum := hex.EncodeToString(md5Hasher.Sum(nil))
// Verify if the written object is equal to what is expected, only
// if it is requested as such.
if expectedMD5Sum != "" {
if !isMD5SumEqual(expectedMD5Sum, md5Sum) {
file.CloseAndPurge()
return ObjectMetadata{}, probe.NewError(BadDigest{MD5: expectedMD5Sum, Bucket: bucket, Object: object})
}
}
sha256Sum := hex.EncodeToString(sha256Hasher.Sum(nil))
if sig != nil {
ok, err := sig.DoesSignatureMatch(sha256Sum)
if err != nil {
file.CloseAndPurge()
return ObjectMetadata{}, err.Trace()
}
if !ok {
file.CloseAndPurge()
return ObjectMetadata{}, probe.NewError(SignDoesNotMatch{})
}
}
file.Close()
// Set stat again to get the latest metadata.
st, e := os.Stat(objectPath)
if e != nil {
return ObjectMetadata{}, probe.NewError(e)
}
contentType := "application/octet-stream"
if objectExt := filepath.Ext(objectPath); objectExt != "" {
content, ok := mimedb.DB[strings.ToLower(strings.TrimPrefix(objectExt, "."))]
if ok {
contentType = content.ContentType
}
}
newObject := ObjectMetadata{
Bucket: bucket,
Object: object,
LastModified: st.ModTime(),
Size: st.Size(),
ContentType: contentType,
MD5: md5Sum,
}
return newObject, nil
}
// deleteObjectPath - delete object path if its empty.
func deleteObjectPath(basePath, deletePath, bucket, object string) *probe.Error {
if basePath == deletePath {
return nil
}
// Verify if the path exists.
pathSt, e := os.Stat(deletePath)
if e != nil {
if os.IsNotExist(e) {
return probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
return probe.NewError(e)
}
if pathSt.IsDir() {
// Verify if directory is empty.
empty, e := ioutils.IsDirEmpty(deletePath)
if e != nil {
return probe.NewError(e)
}
if !empty {
return nil
}
}
// Attempt to remove path.
if e := os.Remove(deletePath); e != nil {
return probe.NewError(e)
}
// Recursively go down the next path and delete again.
if err := deleteObjectPath(basePath, filepath.Dir(deletePath), bucket, object); err != nil {
return err.Trace(basePath, deletePath, bucket, object)
}
return nil
}
// DeleteObject - delete object.
func (fs Filesystem) DeleteObject(bucket, object string) *probe.Error {
// Check bucket name valid
if !IsValidBucketName(bucket) {
return probe.NewError(BucketNameInvalid{Bucket: bucket})
}
bucket = fs.denormalizeBucket(bucket)
bucketPath := filepath.Join(fs.path, bucket)
// Check bucket exists
if _, e := os.Stat(bucketPath); e != nil {
if os.IsNotExist(e) {
return probe.NewError(BucketNotFound{Bucket: bucket})
}
return probe.NewError(e)
}
// Verify object path legal
if !IsValidObjectName(object) {
return probe.NewError(ObjectNameInvalid{Bucket: bucket, Object: object})
}
// 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().
var objectPath string
if runtime.GOOS == "windows" {
9 years ago
objectPath = fs.path + string(os.PathSeparator) + bucket + string(os.PathSeparator) + object
} else {
9 years ago
objectPath = fs.path + string(os.PathSeparator) + bucket + string(os.PathSeparator) + object
}
// Delete object path if its empty.
err := deleteObjectPath(bucketPath, objectPath, bucket, object)
if err != nil {
if os.IsNotExist(err.ToGoError()) {
return probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
return err.Trace(bucketPath, objectPath, bucket, object)
}
return nil
}