minio/pkg/fs/fs-object.go
Harshavardhana 9dca46e156 signature: Use a layered approach for signature verification.
Signature calculation has now moved out from being a package to
top-level as a layered mechanism.

In case of payload calculation with body, go-routines are initiated
to simultaneously write and calculate shasum. Errors are sent
over the writer so that the lower layer removes the temporary files
properly.
2016-03-26 15:21:05 -07:00

384 lines
11 KiB
Go

/*
* 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"
"crypto/md5"
"io"
"os"
"path/filepath"
"strings"
"encoding/hex"
"runtime"
"github.com/minio/minio/pkg/atomic"
"github.com/minio/minio/pkg/disk"
"github.com/minio/minio/pkg/mimedb"
"github.com/minio/minio/pkg/probe"
)
/// 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)
objectPath := filepath.Join(fs.path, bucket, object)
file, e := os.Open(objectPath)
if e != nil {
// If the object doesn't exist, the bucket might not exist either. Stat for
// the bucket and give a better error message if that is true.
if os.IsNotExist(e) {
_, e = os.Stat(filepath.Join(fs.path, bucket))
if os.IsNotExist(e) {
return 0, probe.NewError(BucketNotFound{Bucket: bucket})
}
return 0, probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
return 0, probe.NewError(e)
}
defer file.Close()
_, e = file.Seek(start, os.SEEK_SET)
if e != nil {
// When the "handle is invalid", the file might be a directory on Windows.
if runtime.GOOS == "windows" && strings.Contains(e.Error(), "handle is invalid") {
return 0, probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
return 0, probe.NewError(e)
}
var count int64
// Copy over the whole file if the length is non-positive.
if length > 0 {
count, e = io.CopyN(w, file, length)
} else {
count, e = io.Copy(w, file)
}
if e != nil {
// This call will fail if the object is a directory. Stat the file to see if
// this is true, if so, return an ObjectNotFound error.
stat, e := os.Stat(objectPath)
if e == nil && stat.IsDir() {
return count, probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
return count, probe.NewError(e)
}
return count, nil
}
// GetObjectInfo - get object info.
func (fs Filesystem) GetObjectInfo(bucket, object string) (ObjectInfo, *probe.Error) {
// Input validation.
if !IsValidBucketName(bucket) {
return ObjectInfo{}, probe.NewError(BucketNameInvalid{Bucket: bucket})
}
if !IsValidObjectName(object) {
return ObjectInfo{}, 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 ObjectInfo{}, probe.NewError(BucketNotFound{Bucket: bucket})
}
return ObjectInfo{}, probe.NewError(e)
}
info, err := getObjectInfo(fs.path, bucket, object)
if err != nil {
if os.IsNotExist(err.ToGoError()) {
return ObjectInfo{}, probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
return ObjectInfo{}, err.Trace(bucket, object)
}
if info.IsDir {
return ObjectInfo{}, probe.NewError(ObjectNotFound{Bucket: bucket, Object: object})
}
return info, nil
}
// getObjectInfo - get object stat info.
func getObjectInfo(rootPath, bucket, object string) (ObjectInfo, *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" {
objectPath = rootPath + string(os.PathSeparator) + bucket + string(os.PathSeparator) + object
} else {
objectPath = rootPath + string(os.PathSeparator) + bucket + string(os.PathSeparator) + object
}
stat, e := os.Stat(objectPath)
if e != nil {
return ObjectInfo{}, probe.NewError(e)
}
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 := ObjectInfo{
Bucket: bucket,
Name: object,
ModifiedTime: stat.ModTime(),
Size: stat.Size(),
ContentType: contentType,
IsDir: stat.Mode().IsDir(),
}
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 string, object string, size int64, data io.Reader, md5Bytes []byte) (ObjectInfo, *probe.Error) {
di, e := disk.GetInfo(fs.path)
if e != nil {
return ObjectInfo{}, 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 ObjectInfo{}, probe.NewError(RootPathFull{Path: fs.path})
}
// Check bucket name valid.
if !IsValidBucketName(bucket) {
return ObjectInfo{}, 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 ObjectInfo{}, probe.NewError(BucketNotFound{Bucket: bucket})
}
return ObjectInfo{}, probe.NewError(e)
}
// Verify object path legal.
if !IsValidObjectName(object) {
return ObjectInfo{}, probe.NewError(ObjectNameInvalid{Bucket: bucket, Object: object})
}
// Get object path.
objectPath := filepath.Join(bucketPath, object)
// md5Hex representation.
var md5Hex string
if len(md5Bytes) != 0 {
md5Hex = hex.EncodeToString(md5Bytes)
}
// Write object.
file, e := atomic.FileCreateWithPrefix(objectPath, md5Hex+"$tmpobject")
if e != nil {
switch e := e.(type) {
case *os.PathError:
if e.Op == "mkdir" {
if strings.Contains(e.Error(), "not a directory") {
return ObjectInfo{}, probe.NewError(ObjectExistsAsPrefix{Bucket: bucket, Prefix: object})
}
}
return ObjectInfo{}, probe.NewError(e)
default:
return ObjectInfo{}, probe.NewError(e)
}
}
defer file.Close()
// Initialize md5 writer.
md5Writer := md5.New()
// Instantiate a new multi writer.
multiWriter := io.MultiWriter(md5Writer, file)
// Instantiate checksum hashers and create a multiwriter.
if size > 0 {
if _, e = io.CopyN(multiWriter, data, size); e != nil {
file.CloseAndPurge()
return ObjectInfo{}, probe.NewError(e)
}
} else {
if _, e = io.Copy(multiWriter, data); e != nil {
file.CloseAndPurge()
return ObjectInfo{}, probe.NewError(e)
}
}
newMD5Hex := hex.EncodeToString(md5Writer.Sum(nil))
if len(md5Bytes) != 0 {
if newMD5Hex != md5Hex {
return ObjectInfo{}, probe.NewError(BadDigest{md5Hex, newMD5Hex})
}
}
// Set stat again to get the latest metadata.
st, e := os.Stat(file.Name())
if e != nil {
return ObjectInfo{}, 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 := ObjectInfo{
Bucket: bucket,
Name: object,
ModifiedTime: st.ModTime(),
Size: st.Size(),
MD5Sum: newMD5Hex,
ContentType: contentType,
}
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 := 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" {
objectPath = fs.path + string(os.PathSeparator) + bucket + string(os.PathSeparator) + object
} else {
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
}