storj.io/minio@v0.0.0-20230509071714-0cbc90f649b1/pkg/s3select/progress.go (about)

     1  /*
     2   * MinIO Cloud Storage, (C) 2019 MinIO, Inc.
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  package s3select
    18  
    19  import (
    20  	"compress/bzip2"
    21  	"errors"
    22  	"fmt"
    23  	"io"
    24  	"sync"
    25  	"sync/atomic"
    26  
    27  	gzip "github.com/klauspost/pgzip"
    28  )
    29  
    30  type countUpReader struct {
    31  	reader    io.Reader
    32  	bytesRead int64
    33  }
    34  
    35  func (r *countUpReader) Read(p []byte) (n int, err error) {
    36  	n, err = r.reader.Read(p)
    37  	atomic.AddInt64(&r.bytesRead, int64(n))
    38  	return n, err
    39  }
    40  
    41  func (r *countUpReader) BytesRead() int64 {
    42  	if r == nil {
    43  		return 0
    44  	}
    45  	return atomic.LoadInt64(&r.bytesRead)
    46  }
    47  
    48  func newCountUpReader(reader io.Reader) *countUpReader {
    49  	return &countUpReader{
    50  		reader: reader,
    51  	}
    52  }
    53  
    54  type progressReader struct {
    55  	rc              io.ReadCloser
    56  	scannedReader   *countUpReader
    57  	processedReader *countUpReader
    58  
    59  	closedMu sync.Mutex
    60  	gzr      *gzip.Reader
    61  	closed   bool
    62  }
    63  
    64  func (pr *progressReader) Read(p []byte) (n int, err error) {
    65  	// This ensures that Close will block until Read has completed.
    66  	// This allows another goroutine to close the reader.
    67  	pr.closedMu.Lock()
    68  	defer pr.closedMu.Unlock()
    69  	if pr.closed {
    70  		return 0, errors.New("progressReader: read after Close")
    71  	}
    72  	return pr.processedReader.Read(p)
    73  }
    74  
    75  func (pr *progressReader) Close() error {
    76  	pr.closedMu.Lock()
    77  	defer pr.closedMu.Unlock()
    78  	if pr.closed {
    79  		return nil
    80  	}
    81  	pr.closed = true
    82  	if pr.gzr != nil {
    83  		pr.gzr.Close()
    84  	}
    85  	return pr.rc.Close()
    86  }
    87  
    88  func (pr *progressReader) Stats() (bytesScanned, bytesProcessed int64) {
    89  	if pr == nil {
    90  		return 0, 0
    91  	}
    92  	return pr.scannedReader.BytesRead(), pr.processedReader.BytesRead()
    93  }
    94  
    95  func newProgressReader(rc io.ReadCloser, compType CompressionType) (*progressReader, error) {
    96  	if rc == nil {
    97  		return nil, errors.New("newProgressReader: nil reader provided")
    98  	}
    99  	scannedReader := newCountUpReader(rc)
   100  	pr := progressReader{
   101  		rc:            rc,
   102  		scannedReader: scannedReader,
   103  	}
   104  	var err error
   105  	var r io.Reader
   106  
   107  	switch compType {
   108  	case noneType:
   109  		r = scannedReader
   110  	case gzipType:
   111  		pr.gzr, err = gzip.NewReader(scannedReader)
   112  		if err != nil {
   113  			if errors.Is(err, gzip.ErrHeader) || errors.Is(err, gzip.ErrChecksum) {
   114  				return nil, errInvalidGZIPCompressionFormat(err)
   115  			}
   116  			return nil, errTruncatedInput(err)
   117  		}
   118  		r = pr.gzr
   119  	case bzip2Type:
   120  		r = bzip2.NewReader(scannedReader)
   121  	default:
   122  		return nil, errInvalidCompressionFormat(fmt.Errorf("unknown compression type '%v'", compType))
   123  	}
   124  	pr.processedReader = newCountUpReader(r)
   125  
   126  	return &pr, nil
   127  }