Rename of structs and methods (#6230)

Rename of ErasureStorage to Erasure (and rename of related variables and methods)

cmd/erasure-encode.go

@@ -0,0 +1,109 @@
+/*
+ * Minio Cloud Storage, (C) 2016 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 cmd
+
+import (
+	"context"
+	"io"
+
+	"sync"
+
+	"github.com/minio/minio/cmd/logger"
+)
+
+// Writes in parallel to bitrotWriters
+type parallelWriter struct {
+	writers     []*bitrotWriter
+	writeQuorum int
+	errs        []error
+}
+
+// Append appends data to bitrotWriters in parallel.
+func (p *parallelWriter) Append(ctx context.Context, blocks [][]byte) error {
+	var wg sync.WaitGroup
+
+	for i := range p.writers {
+		if p.writers[i] == nil {
+			p.errs[i] = errDiskNotFound
+			continue
+		}
+
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			p.errs[i] = p.writers[i].Append(blocks[i])
+			if p.errs[i] != nil {
+				p.writers[i] = nil
+			}
+		}(i)
+	}
+	wg.Wait()
+
+	// If nilCount >= p.writeQuorum, we return nil. This is because HealFile() uses
+	// CreateFile with p.writeQuorum=1 to accommodate healing of single disk.
+	// i.e if we do no return here in such a case, reduceWriteQuorumErrs() would
+	// return a quorum error to HealFile().
+	nilCount := 0
+	for _, err := range p.errs {
+		if err == nil {
+			nilCount++
+		}
+	}
+	if nilCount >= p.writeQuorum {
+		return nil
+	}
+	return reduceWriteQuorumErrs(ctx, p.errs, objectOpIgnoredErrs, p.writeQuorum)
+}
+
+// Encode reads from the reader, erasure-encodes the data and writes to the writers.
+func (e *Erasure) Encode(ctx context.Context, src io.Reader, writers []*bitrotWriter, buf []byte, quorum int) (total int64, err error) {
+	writer := &parallelWriter{
+		writers:     writers,
+		writeQuorum: quorum,
+		errs:        make([]error, len(writers)),
+	}
+
+	for {
+		var blocks [][]byte
+		n, err := io.ReadFull(src, buf)
+		if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
+			logger.LogIf(ctx, err)
+			return 0, err
+		}
+		eof := err == io.EOF || err == io.ErrUnexpectedEOF
+		if n == 0 && total != 0 {
+			// Reached EOF, nothing more to be done.
+			break
+		}
+		// We take care of the situation where if n == 0 and total == 0 by creating empty data and parity files.
+		blocks, err = e.EncodeData(ctx, buf[:n])
+		if err != nil {
+			logger.LogIf(ctx, err)
+			return 0, err
+		}
+
+		if err = writer.Append(ctx, blocks); err != nil {
+			logger.LogIf(ctx, err)
+			return 0, err
+		}
+		total += int64(n)
+		if eof {
+			break
+		}
+	}
+	return total, nil
+}