minio/cmd/storage-interface.go
Harshavardhana d46386246f
api: Introduce metadata update APIs to update only metadata (#11962)
Current implementation heavily relies on readAllFileInfo
but with the advent of xl.meta inlined with data, we cannot
easily avoid reading data when we are only interested is
updating metadata, this leads to invariably write
amplification during metadata updates, repeatedly reading
data when we are only interested in updating metadata.

This PR ensures that we implement a metadata only update
API at storage layer, that handles updates to metadata alone
for any given version - given the version is valid and
present.

This helps reduce the chattiness for following calls..

- PutObjectTags
- DeleteObjectTags
- PutObjectLegalHold
- PutObjectRetention
- ReplicateObject (updates metadata on replication status)
2021-04-04 13:32:31 -07:00

128 lines
4.7 KiB
Go

/*
* 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 cmd
import (
"context"
"io"
)
// StorageAPI interface.
type StorageAPI interface {
// Stringified version of disk.
String() string
// Storage operations.
IsOnline() bool // Returns true if disk is online.
IsLocal() bool
Hostname() string // Returns host name if remote host.
Endpoint() Endpoint // Returns endpoint.
Close() error
GetDiskID() (string, error)
SetDiskID(id string)
Healing() *healingTracker // Returns nil if disk is not healing.
DiskInfo(ctx context.Context) (info DiskInfo, err error)
NSScanner(ctx context.Context, cache dataUsageCache) (dataUsageCache, error)
// Volume operations.
MakeVol(ctx context.Context, volume string) (err error)
MakeVolBulk(ctx context.Context, volumes ...string) (err error)
ListVols(ctx context.Context) (vols []VolInfo, err error)
StatVol(ctx context.Context, volume string) (vol VolInfo, err error)
DeleteVol(ctx context.Context, volume string, forceDelete bool) (err error)
// WalkDir will walk a directory on disk and return a metacache stream on wr.
WalkDir(ctx context.Context, opts WalkDirOptions, wr io.Writer) error
// Metadata operations
DeleteVersion(ctx context.Context, volume, path string, fi FileInfo, forceDelMarker bool) error
DeleteVersions(ctx context.Context, volume string, versions []FileInfo) []error
WriteMetadata(ctx context.Context, volume, path string, fi FileInfo) error
UpdateMetadata(ctx context.Context, volume, path string, fi FileInfo) error
ReadVersion(ctx context.Context, volume, path, versionID string, readData bool) (FileInfo, error)
RenameData(ctx context.Context, srcVolume, srcPath, dataDir, dstVolume, dstPath string) error
// File operations.
ListDir(ctx context.Context, volume, dirPath string, count int) ([]string, error)
ReadFile(ctx context.Context, volume string, path string, offset int64, buf []byte, verifier *BitrotVerifier) (n int64, err error)
AppendFile(ctx context.Context, volume string, path string, buf []byte) (err error)
CreateFile(ctx context.Context, volume, path string, size int64, reader io.Reader) error
ReadFileStream(ctx context.Context, volume, path string, offset, length int64) (io.ReadCloser, error)
RenameFile(ctx context.Context, srcVolume, srcPath, dstVolume, dstPath string) error
CheckParts(ctx context.Context, volume string, path string, fi FileInfo) error
CheckFile(ctx context.Context, volume string, path string) (err error)
Delete(ctx context.Context, volume string, path string, recursive bool) (err error)
VerifyFile(ctx context.Context, volume, path string, fi FileInfo) error
// Write all data, syncs the data to disk.
// Should be used for smaller payloads.
WriteAll(ctx context.Context, volume string, path string, b []byte) (err error)
// Read all.
ReadAll(ctx context.Context, volume string, path string) (buf []byte, err error)
GetDiskLoc() (poolIdx, setIdx, diskIdx int) // Retrieve location indexes.
SetDiskLoc(poolIdx, setIdx, diskIdx int) // Set location indexes.
}
// storageReader is an io.Reader view of a disk
type storageReader struct {
storage StorageAPI
volume, path string
offset int64
}
func (r *storageReader) Read(p []byte) (n int, err error) {
nn, err := r.storage.ReadFile(context.TODO(), r.volume, r.path, r.offset, p, nil)
r.offset += nn
n = int(nn)
if err == io.ErrUnexpectedEOF && nn > 0 {
err = io.EOF
}
return
}
// storageWriter is a io.Writer view of a disk.
type storageWriter struct {
storage StorageAPI
volume, path string
}
func (w *storageWriter) Write(p []byte) (n int, err error) {
err = w.storage.AppendFile(context.TODO(), w.volume, w.path, p)
if err == nil {
n = len(p)
}
return
}
// StorageWriter returns a new io.Writer which appends data to the file
// at the given disk, volume and path.
func StorageWriter(storage StorageAPI, volume, path string) io.Writer {
return &storageWriter{storage, volume, path}
}
// StorageReader returns a new io.Reader which reads data to the file
// at the given disk, volume, path and offset.
func StorageReader(storage StorageAPI, volume, path string, offset int64) io.Reader {
return &storageReader{storage, volume, path, offset}
}