minio/pkg/s3select/progress.go

129 lines
3.1 KiB
Go

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package s3select
import (
"compress/bzip2"
"errors"
"fmt"
"io"
"sync"
"sync/atomic"
gzip "github.com/klauspost/pgzip"
)
type countUpReader struct {
reader io.Reader
bytesRead int64
}
func (r *countUpReader) Read(p []byte) (n int, err error) {
n, err = r.reader.Read(p)
atomic.AddInt64(&r.bytesRead, int64(n))
return n, err
}
func (r *countUpReader) BytesRead() int64 {
if r == nil {
return 0
}
return atomic.LoadInt64(&r.bytesRead)
}
func newCountUpReader(reader io.Reader) *countUpReader {
return &countUpReader{
reader: reader,
}
}
type progressReader struct {
rc io.ReadCloser
scannedReader *countUpReader
processedReader *countUpReader
closedMu sync.Mutex
gzr *gzip.Reader
closed bool
}
func (pr *progressReader) Read(p []byte) (n int, err error) {
// This ensures that Close will block until Read has completed.
// This allows another goroutine to close the reader.
pr.closedMu.Lock()
defer pr.closedMu.Unlock()
if pr.closed {
return 0, errors.New("progressReader: read after Close")
}
return pr.processedReader.Read(p)
}
func (pr *progressReader) Close() error {
pr.closedMu.Lock()
defer pr.closedMu.Unlock()
if pr.closed {
return nil
}
pr.closed = true
if pr.gzr != nil {
pr.gzr.Close()
}
return pr.rc.Close()
}
func (pr *progressReader) Stats() (bytesScanned, bytesProcessed int64) {
if pr == nil {
return 0, 0
}
return pr.scannedReader.BytesRead(), pr.processedReader.BytesRead()
}
func newProgressReader(rc io.ReadCloser, compType CompressionType) (*progressReader, error) {
if rc == nil {
return nil, errors.New("newProgressReader: nil reader provided")
}
scannedReader := newCountUpReader(rc)
pr := progressReader{
rc: rc,
scannedReader: scannedReader,
}
var err error
var r io.Reader
switch compType {
case noneType:
r = scannedReader
case gzipType:
pr.gzr, err = gzip.NewReader(scannedReader)
if err != nil {
if errors.Is(err, gzip.ErrHeader) || errors.Is(err, gzip.ErrChecksum) {
return nil, errInvalidGZIPCompressionFormat(err)
}
return nil, errTruncatedInput(err)
}
r = pr.gzr
case bzip2Type:
r = bzip2.NewReader(scannedReader)
default:
return nil, errInvalidCompressionFormat(fmt.Errorf("unknown compression type '%v'", compType))
}
pr.processedReader = newCountUpReader(r)
return &pr, nil
}