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minio/pkg/s3select/progress.go

109 lines
2.5 KiB

/*
* MinIO Cloud Storage, (C) 2019 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 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 {
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
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
return pr.rc.Close()
}
func (pr *progressReader) Stats() (bytesScanned, bytesProcessed int64) {
return pr.scannedReader.BytesRead(), pr.processedReader.BytesRead()
}
func newProgressReader(rc io.ReadCloser, compType CompressionType) (*progressReader, error) {
scannedReader := newCountUpReader(rc)
var r io.Reader
var err error
switch compType {
case noneType:
r = scannedReader
case gzipType:
if r, err = gzip.NewReader(scannedReader); err != nil {
return nil, errTruncatedInput(err)
}
case bzip2Type:
r = bzip2.NewReader(scannedReader)
default:
return nil, errInvalidCompressionFormat(fmt.Errorf("unknown compression type '%v'", compType))
}
return &progressReader{
rc: rc,
scannedReader: scannedReader,
processedReader: newCountUpReader(r),
}, nil
}