You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
113 lines
3.1 KiB
113 lines
3.1 KiB
![]()
8 years ago
|
/*
|
||
|
* 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 (
|
||
|
"math/rand"
|
||
|
"path"
|
||
|
"sync"
|
||
|
"time"
|
||
|
)
|
||
|
|
||
|
// getRandomDisk - gives a random disk at any point in time from the
|
||
|
// available pool of disks.
|
||
|
func (xl xlObjects) getRandomDisk() (disk StorageAPI) {
|
||
|
rand.Seed(time.Now().UTC().UnixNano()) // Seed with current time.
|
||
|
randIndex := rand.Intn(len(xl.storageDisks) - 1)
|
||
|
disk = xl.storageDisks[randIndex] // Pick a random disk.
|
||
|
return disk
|
||
|
}
|
||
|
|
||
|
// This function does the following check, suppose
|
||
|
// object is "a/b/c/d", stat makes sure that objects ""a/b/c""
|
||
|
// "a/b" and "a" do not exist.
|
||
|
func (xl xlObjects) parentDirIsObject(bucket, parent string) bool {
|
||
|
var isParentDirObject func(string) bool
|
||
|
isParentDirObject = func(p string) bool {
|
||
|
if p == "." {
|
||
|
return false
|
||
|
}
|
||
|
if xl.isObject(bucket, p) {
|
||
|
// If there is already a file at prefix "p" return error.
|
||
|
return true
|
||
|
}
|
||
|
// Check if there is a file as one of the parent paths.
|
||
|
return isParentDirObject(path.Dir(p))
|
||
|
}
|
||
|
return isParentDirObject(parent)
|
||
|
}
|
||
|
|
||
|
func (xl xlObjects) isObject(bucket, prefix string) bool {
|
||
|
// Create errs and volInfo slices of storageDisks size.
|
||
|
var errs = make([]error, len(xl.storageDisks))
|
||
|
|
||
|
// Allocate a new waitgroup.
|
||
|
var wg = &sync.WaitGroup{}
|
||
|
for index, disk := range xl.storageDisks {
|
||
|
wg.Add(1)
|
||
|
// Stat file on all the disks in a routine.
|
||
|
go func(index int, disk StorageAPI) {
|
||
|
defer wg.Done()
|
||
|
_, err := disk.StatFile(bucket, path.Join(prefix, xlMetaJSONFile))
|
||
|
if err != nil {
|
||
|
errs[index] = err
|
||
|
return
|
||
|
}
|
||
|
errs[index] = nil
|
||
|
}(index, disk)
|
||
|
}
|
||
|
|
||
|
// Wait for all the Stat operations to finish.
|
||
|
wg.Wait()
|
||
|
|
||
|
var errFileNotFoundCount int
|
||
|
for _, err := range errs {
|
||
|
if err != nil {
|
||
|
if err == errFileNotFound {
|
||
|
errFileNotFoundCount++
|
||
|
// If we have errors with file not found greater than allowed read
|
||
|
// quorum we return err as errFileNotFound.
|
||
|
if errFileNotFoundCount > len(xl.storageDisks)-xl.readQuorum {
|
||
|
return false
|
||
|
}
|
||
|
continue
|
||
|
}
|
||
|
errorIf(err, "Unable to access file "+path.Join(bucket, prefix))
|
||
|
return false
|
||
|
}
|
||
|
}
|
||
|
return true
|
||
|
}
|
||
|
|
||
|
// statPart - stat a part file.
|
||
|
func (xl xlObjects) statPart(bucket, objectPart string) (fileInfo FileInfo, err error) {
|
||
|
// Count for errors encountered.
|
||
|
var xlJSONErrCount = 0
|
||
|
|
||
|
// Return the first success entry based on the selected random disk.
|
||
|
for xlJSONErrCount < len(xl.storageDisks) {
|
||
|
// Choose a random disk on each attempt.
|
||
|
disk := xl.getRandomDisk()
|
||
|
fileInfo, err = disk.StatFile(bucket, objectPart)
|
||
|
if err == nil {
|
||
|
return fileInfo, nil
|
||
|
}
|
||
|
xlJSONErrCount++ // Update error count.
|
||
|
}
|
||
|
return FileInfo{}, err
|
||
|
}
|