Initial checkin from CRI-O repo

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

vendor/github.com/vbatts/tar-split/tar/storage/getter.go

@@ -0,0 +1,104 @@
+package storage
+
+import (
+	"bytes"
+	"errors"
+	"hash/crc64"
+	"io"
+	"os"
+	"path/filepath"
+)
+
+// FileGetter is the interface for getting a stream of a file payload,
+// addressed by name/filename. Presumably, the names will be scoped to relative
+// file paths.
+type FileGetter interface {
+	// Get returns a stream for the provided file path
+	Get(filename string) (output io.ReadCloser, err error)
+}
+
+// FilePutter is the interface for storing a stream of a file payload,
+// addressed by name/filename.
+type FilePutter interface {
+	// Put returns the size of the stream received, and the crc64 checksum for
+	// the provided stream
+	Put(filename string, input io.Reader) (size int64, checksum []byte, err error)
+}
+
+// FileGetPutter is the interface that groups both Getting and Putting file
+// payloads.
+type FileGetPutter interface {
+	FileGetter
+	FilePutter
+}
+
+// NewPathFileGetter returns a FileGetter that is for files relative to path
+// relpath.
+func NewPathFileGetter(relpath string) FileGetter {
+	return &pathFileGetter{root: relpath}
+}
+
+type pathFileGetter struct {
+	root string
+}
+
+func (pfg pathFileGetter) Get(filename string) (io.ReadCloser, error) {
+	return os.Open(filepath.Join(pfg.root, filename))
+}
+
+type bufferFileGetPutter struct {
+	files map[string][]byte
+}
+
+func (bfgp bufferFileGetPutter) Get(name string) (io.ReadCloser, error) {
+	if _, ok := bfgp.files[name]; !ok {
+		return nil, errors.New("no such file")
+	}
+	b := bytes.NewBuffer(bfgp.files[name])
+	return &readCloserWrapper{b}, nil
+}
+
+func (bfgp *bufferFileGetPutter) Put(name string, r io.Reader) (int64, []byte, error) {
+	crc := crc64.New(CRCTable)
+	buf := bytes.NewBuffer(nil)
+	cw := io.MultiWriter(crc, buf)
+	i, err := io.Copy(cw, r)
+	if err != nil {
+		return 0, nil, err
+	}
+	bfgp.files[name] = buf.Bytes()
+	return i, crc.Sum(nil), nil
+}
+
+type readCloserWrapper struct {
+	io.Reader
+}
+
+func (w *readCloserWrapper) Close() error { return nil }
+
+// NewBufferFileGetPutter is a simple in-memory FileGetPutter
+//
+// Implication is this is memory intensive...
+// Probably best for testing or light weight cases.
+func NewBufferFileGetPutter() FileGetPutter {
+	return &bufferFileGetPutter{
+		files: map[string][]byte{},
+	}
+}
+
+// NewDiscardFilePutter is a bit bucket FilePutter
+func NewDiscardFilePutter() FilePutter {
+	return &bitBucketFilePutter{}
+}
+
+type bitBucketFilePutter struct {
+}
+
+func (bbfp *bitBucketFilePutter) Put(name string, r io.Reader) (int64, []byte, error) {
+	c := crc64.New(CRCTable)
+	i, err := io.Copy(c, r)
+	return i, c.Sum(nil), err
+}
+
+// CRCTable is the default table used for crc64 sum calculations
+var CRCTable = crc64.MakeTable(crc64.ISO)