OP#792 initial commit after fork

cmd/bitrot-whole.go

@@ -0,0 +1,91 @@
+// 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 cmd
+
+import (
+	"context"
+	"hash"
+	"io"
+)
+
+// Implementation to calculate bitrot for the whole file.
+type wholeBitrotWriter struct {
+	disk      StorageAPI
+	volume    string
+	filePath  string
+	shardSize int64 // This is the shard size of the erasure logic
+	hash.Hash       // For bitrot hash
+}
+
+func (b *wholeBitrotWriter) Write(p []byte) (int, error) {
+	err := b.disk.AppendFile(context.TODO(), b.volume, b.filePath, p)
+	if err != nil {
+		return 0, err
+	}
+	_, err = b.Hash.Write(p)
+	if err != nil {
+		return 0, err
+	}
+	return len(p), nil
+}
+
+func (b *wholeBitrotWriter) Close() error {
+	return nil
+}
+
+// Returns whole-file bitrot writer.
+func newWholeBitrotWriter(disk StorageAPI, volume, filePath string, algo BitrotAlgorithm, shardSize int64) io.WriteCloser {
+	return &wholeBitrotWriter{disk, volume, filePath, shardSize, algo.New()}
+}
+
+// Implementation to verify bitrot for the whole file.
+type wholeBitrotReader struct {
+	disk       StorageAPI
+	volume     string
+	filePath   string
+	verifier   *BitrotVerifier // Holds the bit-rot info
+	tillOffset int64           // Affects the length of data requested in disk.ReadFile depending on Read()'s offset
+	buf        []byte          // Holds bit-rot verified data
+}
+
+func (b *wholeBitrotReader) ReadAt(buf []byte, offset int64) (n int, err error) {
+	if b.buf == nil {
+		b.buf = make([]byte, b.tillOffset-offset)
+		if _, err := b.disk.ReadFile(context.TODO(), b.volume, b.filePath, offset, b.buf, b.verifier); err != nil {
+			return 0, err
+		}
+	}
+	if len(b.buf) < len(buf) {
+		return 0, errLessData
+	}
+	n = copy(buf, b.buf)
+	b.buf = b.buf[n:]
+	return n, nil
+}
+
+// Returns whole-file bitrot reader.
+func newWholeBitrotReader(disk StorageAPI, volume, filePath string, algo BitrotAlgorithm, tillOffset int64, sum []byte) *wholeBitrotReader {
+	return &wholeBitrotReader{
+		disk:       disk,
+		volume:     volume,
+		filePath:   filePath,
+		verifier:   &BitrotVerifier{algo, sum},
+		tillOffset: tillOffset,
+		buf:        nil,
+	}
+}