Refactor s3select to support parquet. (#7023)

Also handle pretty formatted JSON documents.

pkg/s3select/progress.go

@@ -0,0 +1,90 @@
+/*
+ * 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"
+	"fmt"
+	"io"
+	"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
+}
+
+func (pr *progressReader) Read(p []byte) (n int, err error) {
+	return pr.processedReader.Read(p)
+}
+
+func (pr *progressReader) Close() error {
+	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
+}