Bump libcompose and its dependencies

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

@@ -0,0 +1,127 @@
+package storage
+
+import (
+	"encoding/json"
+	"errors"
+	"io"
+	"path/filepath"
+	"unicode/utf8"
+)
+
+// ErrDuplicatePath occurs when a tar archive has more than one entry for the
+// same file path
+var ErrDuplicatePath = errors.New("duplicates of file paths not supported")
+
+// Packer describes the methods to pack Entries to a storage destination
+type Packer interface {
+	// AddEntry packs the Entry and returns its position
+	AddEntry(e Entry) (int, error)
+}
+
+// Unpacker describes the methods to read Entries from a source
+type Unpacker interface {
+	// Next returns the next Entry being unpacked, or error, until io.EOF
+	Next() (*Entry, error)
+}
+
+/* TODO(vbatts) figure out a good model for this
+type PackUnpacker interface {
+	Packer
+	Unpacker
+}
+*/
+
+type jsonUnpacker struct {
+	seen seenNames
+	dec  *json.Decoder
+}
+
+func (jup *jsonUnpacker) Next() (*Entry, error) {
+	var e Entry
+	err := jup.dec.Decode(&e)
+	if err != nil {
+		return nil, err
+	}
+
+	// check for dup name
+	if e.Type == FileType {
+		cName := filepath.Clean(e.GetName())
+		if _, ok := jup.seen[cName]; ok {
+			return nil, ErrDuplicatePath
+		}
+		jup.seen[cName] = struct{}{}
+	}
+
+	return &e, err
+}
+
+// NewJSONUnpacker provides an Unpacker that reads Entries (SegmentType and
+// FileType) as a json document.
+//
+// Each Entry read are expected to be delimited by new line.
+func NewJSONUnpacker(r io.Reader) Unpacker {
+	return &jsonUnpacker{
+		dec:  json.NewDecoder(r),
+		seen: seenNames{},
+	}
+}
+
+type jsonPacker struct {
+	w    io.Writer
+	e    *json.Encoder
+	pos  int
+	seen seenNames
+}
+
+type seenNames map[string]struct{}
+
+func (jp *jsonPacker) AddEntry(e Entry) (int, error) {
+	// if Name is not valid utf8, switch it to raw first.
+	if e.Name != "" {
+		if !utf8.ValidString(e.Name) {
+			e.NameRaw = []byte(e.Name)
+			e.Name = ""
+		}
+	}
+
+	// check early for dup name
+	if e.Type == FileType {
+		cName := filepath.Clean(e.GetName())
+		if _, ok := jp.seen[cName]; ok {
+			return -1, ErrDuplicatePath
+		}
+		jp.seen[cName] = struct{}{}
+	}
+
+	e.Position = jp.pos
+	err := jp.e.Encode(e)
+	if err != nil {
+		return -1, err
+	}
+
+	// made it this far, increment now
+	jp.pos++
+	return e.Position, nil
+}
+
+// NewJSONPacker provides a Packer that writes each Entry (SegmentType and
+// FileType) as a json document.
+//
+// The Entries are delimited by new line.
+func NewJSONPacker(w io.Writer) Packer {
+	return &jsonPacker{
+		w:    w,
+		e:    json.NewEncoder(w),
+		seen: seenNames{},
+	}
+}
+
+/*
+TODO(vbatts) perhaps have a more compact packer/unpacker, maybe using msgapck
+(https://github.com/ugorji/go)
+
+
+Even though, since our jsonUnpacker and jsonPacker just take
+io.Reader/io.Writer, then we can get away with passing them a
+gzip.Reader/gzip.Writer
+*/