XL: Rename, cleanup and add more comments. (#1769)

- xl-v1-bucket.go - removes a whole bunch of code.
- {xl-v1,fs-v1}-metadata.go - add a lot of comments and rename functions
   appropriately.
This commit is contained in:
Harshavardhana
2016-05-26 03:15:01 -07:00
committed by Harshavardhana
parent 553fdb9211
commit b2293c2bf4
19 changed files with 207 additions and 290 deletions

View File

@@ -64,234 +64,102 @@ func (xl xlObjects) MakeBucket(bucket string) error {
if volumeExistsErrCnt == len(xl.storageDisks) {
return toObjectErr(errVolumeExists, bucket)
} else if createVolErr > len(xl.storageDisks)-xl.writeQuorum {
// Return errWriteQuorum if errors were more than
// allowed write quorum.
// Return errWriteQuorum if errors were more than allowed write quorum.
return toObjectErr(errWriteQuorum, bucket)
}
return nil
}
// getAllBucketInfo - list bucket info from all disks.
// Returns error slice indicating the failed volume stat operations.
func (xl xlObjects) getAllBucketInfo(bucketName string) ([]BucketInfo, []error) {
// Create errs and volInfo slices of storageDisks size.
var errs = make([]error, len(xl.storageDisks))
var volsInfo = make([]VolInfo, len(xl.storageDisks))
// getBucketInfo - returns the BucketInfo from one of the disks picked
// at random.
func (xl xlObjects) getBucketInfo(bucketName string) (bucketInfo BucketInfo, err error) {
// Count for errors encountered.
var bucketErrCount = 0
// Allocate a new waitgroup.
var wg = &sync.WaitGroup{}
for index, disk := range xl.storageDisks {
wg.Add(1)
// Stat volume on all the disks in a routine.
go func(index int, disk StorageAPI) {
defer wg.Done()
volInfo, err := disk.StatVol(bucketName)
if err != nil {
errs[index] = err
return
}
volsInfo[index] = volInfo
errs[index] = nil
}(index, disk)
}
// Wait for all the Stat operations to finish.
wg.Wait()
// Return the concocted values.
var bucketsInfo = make([]BucketInfo, len(xl.storageDisks))
for _, volInfo := range volsInfo {
if IsValidBucketName(volInfo.Name) {
bucketsInfo = append(bucketsInfo, BucketInfo{
// Return the first successful lookup from a random list of disks.
for bucketErrCount < len(xl.storageDisks) {
disk := xl.getRandomDisk() // Choose a random disk on each attempt.
var volInfo VolInfo
volInfo, err = disk.StatVol(bucketName)
if err == nil {
bucketInfo = BucketInfo{
Name: volInfo.Name,
Created: volInfo.Created,
})
}
}
return bucketsInfo, errs
}
// listAllBucketInfo - list all stat volume info from all disks.
// Returns
// - stat volume info for all online disks.
// - boolean to indicate if healing is necessary.
// - error if any.
func (xl xlObjects) listAllBucketInfo(bucketName string) ([]BucketInfo, bool, error) {
bucketsInfo, errs := xl.getAllBucketInfo(bucketName)
notFoundCount := 0
for _, err := range errs {
if err == errVolumeNotFound {
notFoundCount++
// If we have errors with file not found greater than allowed read
// quorum we return err as errFileNotFound.
if notFoundCount > len(xl.storageDisks)-xl.readQuorum {
return nil, false, errVolumeNotFound
}
return bucketInfo, nil
}
bucketErrCount++ // Update error count.
}
// Calculate online disk count.
onlineDiskCount := 0
for index := range errs {
if errs[index] == nil {
onlineDiskCount++
}
}
var heal bool
// If online disks count is lesser than configured disks, most
// probably we need to heal the file, additionally verify if the
// count is lesser than readQuorum, if not we throw an error.
if onlineDiskCount < len(xl.storageDisks) {
// Online disks lesser than total storage disks, needs to be
// healed. unless we do not have readQuorum.
heal = true
// Verify if online disks count are lesser than readQuorum
// threshold, return an error if yes.
if onlineDiskCount < xl.readQuorum {
return nil, false, errReadQuorum
}
}
// Return success.
return bucketsInfo, heal, nil
return BucketInfo{}, err
}
// Checks whether bucket exists.
func (xl xlObjects) isBucketExist(bucketName string) bool {
func (xl xlObjects) isBucketExist(bucket string) bool {
nsMutex.RLock(bucket, "")
defer nsMutex.RUnlock(bucket, "")
// Check whether bucket exists.
_, _, err := xl.listAllBucketInfo(bucketName)
_, err := xl.getBucketInfo(bucket)
if err != nil {
if err == errVolumeNotFound {
return false
}
errorIf(err, "Stat failed on bucket "+bucketName+".")
errorIf(err, "Stat failed on bucket "+bucket+".")
return false
}
return true
}
// GetBucketInfo - get bucket info.
// GetBucketInfo - returns BucketInfo for a bucket.
func (xl xlObjects) GetBucketInfo(bucket string) (BucketInfo, error) {
// Verify if bucket is valid.
if !IsValidBucketName(bucket) {
return BucketInfo{}, BucketNameInvalid{Bucket: bucket}
}
nsMutex.RLock(bucket, "")
defer nsMutex.RUnlock(bucket, "")
// List and figured out if we need healing.
bucketsInfo, heal, err := xl.listAllBucketInfo(bucket)
bucketInfo, err := xl.getBucketInfo(bucket)
if err != nil {
return BucketInfo{}, toObjectErr(err, bucket)
}
return bucketInfo, nil
}
// Heal for missing entries.
if heal {
go func() {
// Create bucket if missing on disks.
for index, bktInfo := range bucketsInfo {
if bktInfo.Name != "" {
// listBuckets - returns list of all buckets from a disk picked at random.
func (xl xlObjects) listBuckets() (bucketsInfo []BucketInfo, err error) {
// Count for errors encountered.
var listBucketsErrCount = 0
// Return the first successful lookup from a random list of disks.
for listBucketsErrCount < len(xl.storageDisks) {
disk := xl.getRandomDisk() // Choose a random disk on each attempt.
var volsInfo []VolInfo
volsInfo, err = disk.ListVols()
if err == nil {
// NOTE: The assumption here is that volumes across all disks in
// readQuorum have consistent view i.e they all have same number
// of buckets. This is essentially not verified since healing
// should take care of this.
var bucketsInfo []BucketInfo
for _, volInfo := range volsInfo {
// StorageAPI can send volume names which are incompatible
// with buckets, handle it and skip them.
if !IsValidBucketName(volInfo.Name) {
continue
}
// Bucketinfo name would be an empty string, create it.
xl.storageDisks[index].MakeVol(bucket)
bucketsInfo = append(bucketsInfo, BucketInfo{
Name: volInfo.Name,
Created: volInfo.Created,
})
}
}()
}
// From all bucketsInfo, calculate the actual usage values.
var total, free int64
var bucketInfo BucketInfo
for _, bucketInfo = range bucketsInfo {
if bucketInfo.Name == "" {
continue
return bucketsInfo, nil
}
free += bucketInfo.Free
total += bucketInfo.Total
listBucketsErrCount++ // Update error count.
}
// Update the aggregated values.
bucketInfo.Free = free
bucketInfo.Total = total
return BucketInfo{
Name: bucket,
Created: bucketInfo.Created,
Total: bucketInfo.Total,
Free: bucketInfo.Free,
}, nil
return nil, err
}
func (xl xlObjects) listBuckets() ([]BucketInfo, error) {
// Initialize sync waitgroup.
var wg = &sync.WaitGroup{}
// Success vols map carries successful results of ListVols from each disks.
var successVols = make([][]VolInfo, len(xl.storageDisks))
for index, disk := range xl.storageDisks {
wg.Add(1) // Add each go-routine to wait for.
go func(index int, disk StorageAPI) {
// Indicate wait group as finished.
defer wg.Done()
// Initiate listing.
volsInfo, _ := disk.ListVols()
successVols[index] = volsInfo
}(index, disk)
}
// Wait for all the list volumes running in parallel to finish.
wg.Wait()
// From success vols map calculate aggregated usage values.
var volsInfo []VolInfo
var total, free int64
for _, volsInfo = range successVols {
var volInfo VolInfo
for _, volInfo = range volsInfo {
if volInfo.Name == "" {
continue
}
if !IsValidBucketName(volInfo.Name) {
continue
}
break
}
free += volInfo.Free
total += volInfo.Total
}
// Save the updated usage values back into the vols.
for index, volInfo := range volsInfo {
volInfo.Free = free
volInfo.Total = total
volsInfo[index] = volInfo
}
// NOTE: The assumption here is that volumes across all disks in
// readQuorum have consistent view i.e they all have same number
// of buckets. This is essentially not verified since healing
// should take care of this.
var bucketsInfo []BucketInfo
for _, volInfo := range volsInfo {
// StorageAPI can send volume names which are incompatible
// with buckets, handle it and skip them.
if !IsValidBucketName(volInfo.Name) {
continue
}
bucketsInfo = append(bucketsInfo, BucketInfo{
Name: volInfo.Name,
Created: volInfo.Created,
Total: volInfo.Total,
Free: volInfo.Free,
})
}
return bucketsInfo, nil
}
// ListBuckets - list buckets.
// ListBuckets - lists all the buckets, sorted by its name.
func (xl xlObjects) ListBuckets() ([]BucketInfo, error) {
bucketInfos, err := xl.listBuckets()
if err != nil {
@@ -302,7 +170,7 @@ func (xl xlObjects) ListBuckets() ([]BucketInfo, error) {
return bucketInfos, nil
}
// DeleteBucket - delete a bucket.
// DeleteBucket - deletes a bucket.
func (xl xlObjects) DeleteBucket(bucket string) error {
// Verify if bucket is valid.
if !IsValidBucketName(bucket) {