[#1085] shard: rename Evacuate to Dump

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

pkg/local_object_storage/shard/dump.go

@@ -0,0 +1,130 @@
+package shard
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+	"os"
+
+	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/blobstor"
+	"github.com/nspcc-dev/neofs-node/pkg/local_object_storage/writecache"
+)
+
+var dumpMagic = []byte("NEOF")
+
+// DumpPrm groups the parameters of Dump operation.
+type DumpPrm struct {
+	path         string
+	stream       io.Writer
+	ignoreErrors bool
+}
+
+// WithPath is an Dump option to set the destination path.
+func (p *DumpPrm) WithPath(path string) *DumpPrm {
+	p.path = path
+	return p
+}
+
+// WithStream is an Dump option to set the destination stream.
+// It takes priority over `path` option.
+func (p *DumpPrm) WithStream(r io.Writer) *DumpPrm {
+	p.stream = r
+	return p
+}
+
+// WithIgnoreErrors is an Dump option to allow ignore all errors during iteration.
+// This includes invalid blobovniczas as well as corrupted objects.
+func (p *DumpPrm) WithIgnoreErrors(ignore bool) *DumpPrm {
+	p.ignoreErrors = ignore
+	return p
+}
+
+// DumpRes groups the result fields of Dump operation.
+type DumpRes struct {
+	count int
+}
+
+// Count return amount of object written.
+func (r *DumpRes) Count() int {
+	return r.count
+}
+
+var ErrMustBeReadOnly = errors.New("shard must be in read-only mode")
+
+// Dump dumps all objects from the shard to a file or stream.
+//
+// Returns any error encountered.
+func (s *Shard) Dump(prm *DumpPrm) (*DumpRes, error) {
+	s.m.RLock()
+	defer s.m.RUnlock()
+
+	if s.info.Mode != ModeReadOnly {
+		return nil, ErrMustBeReadOnly
+	}
+
+	w := prm.stream
+	if w == nil {
+		f, err := os.OpenFile(prm.path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0640)
+		if err != nil {
+			return nil, err
+		}
+		defer f.Close()
+
+		w = f
+	}
+
+	_, err := w.Write(dumpMagic)
+	if err != nil {
+		return nil, err
+	}
+
+	var count int
+
+	if s.hasWriteCache() {
+		err := s.writeCache.Iterate(new(writecache.IterationPrm).WithHandler(func(data []byte) error {
+			var size [4]byte
+			binary.LittleEndian.PutUint32(size[:], uint32(len(data)))
+			if _, err := w.Write(size[:]); err != nil {
+				return err
+			}
+
+			if _, err := w.Write(data); err != nil {
+				return err
+			}
+
+			count++
+			return nil
+		}).WithIgnoreErrors(prm.ignoreErrors))
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	var pi blobstor.IteratePrm
+
+	if prm.ignoreErrors {
+		pi.IgnoreErrors()
+	}
+	pi.SetIterationHandler(func(elem blobstor.IterationElement) error {
+		data := elem.ObjectData()
+
+		var size [4]byte
+		binary.LittleEndian.PutUint32(size[:], uint32(len(data)))
+		if _, err := w.Write(size[:]); err != nil {
+			return err
+		}
+
+		if _, err := w.Write(data); err != nil {
+			return err
+		}
+
+		count++
+		return nil
+	})
+
+	if _, err := s.blobStor.Iterate(pi); err != nil {
+		return nil, err
+	}
+
+	return &DumpRes{count: count}, nil
+}