utils/tarsum* -> pkg/tarsum

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)

tarsum/tarsum.go

@@ -0,0 +1,183 @@
+package tarsum
+
+import (
+	"bytes"
+	"compress/gzip"
+	"crypto/sha256"
+	"encoding/hex"
+	"hash"
+	"io"
+	"sort"
+	"strconv"
+	"strings"
+
+	"github.com/docker/docker/utils"
+	"github.com/docker/docker/vendor/src/code.google.com/p/go/src/pkg/archive/tar"
+)
+
+type TarSum struct {
+	io.Reader
+	tarR               *tar.Reader
+	tarW               *tar.Writer
+	gz                 writeCloseFlusher
+	bufTar             *bytes.Buffer
+	bufGz              *bytes.Buffer
+	h                  hash.Hash
+	sums               map[string]string
+	currentFile        string
+	finished           bool
+	first              bool
+	DisableCompression bool
+}
+
+type writeCloseFlusher interface {
+	io.WriteCloser
+	Flush() error
+}
+
+type nopCloseFlusher struct {
+	io.Writer
+}
+
+func (n *nopCloseFlusher) Close() error {
+	return nil
+}
+
+func (n *nopCloseFlusher) Flush() error {
+	return nil
+}
+
+func (ts *TarSum) encodeHeader(h *tar.Header) error {
+	for _, elem := range [][2]string{
+		{"name", h.Name},
+		{"mode", strconv.Itoa(int(h.Mode))},
+		{"uid", strconv.Itoa(h.Uid)},
+		{"gid", strconv.Itoa(h.Gid)},
+		{"size", strconv.Itoa(int(h.Size))},
+		{"mtime", strconv.Itoa(int(h.ModTime.UTC().Unix()))},
+		{"typeflag", string([]byte{h.Typeflag})},
+		{"linkname", h.Linkname},
+		{"uname", h.Uname},
+		{"gname", h.Gname},
+		{"devmajor", strconv.Itoa(int(h.Devmajor))},
+		{"devminor", strconv.Itoa(int(h.Devminor))},
+		// {"atime", strconv.Itoa(int(h.AccessTime.UTC().Unix()))},
+		// {"ctime", strconv.Itoa(int(h.ChangeTime.UTC().Unix()))},
+	} {
+		if _, err := ts.h.Write([]byte(elem[0] + elem[1])); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (ts *TarSum) Read(buf []byte) (int, error) {
+	if ts.gz == nil {
+		ts.bufTar = bytes.NewBuffer([]byte{})
+		ts.bufGz = bytes.NewBuffer([]byte{})
+		ts.tarR = tar.NewReader(ts.Reader)
+		ts.tarW = tar.NewWriter(ts.bufTar)
+		if !ts.DisableCompression {
+			ts.gz = gzip.NewWriter(ts.bufGz)
+		} else {
+			ts.gz = &nopCloseFlusher{Writer: ts.bufGz}
+		}
+		ts.h = sha256.New()
+		ts.h.Reset()
+		ts.first = true
+		ts.sums = make(map[string]string)
+	}
+
+	if ts.finished {
+		return ts.bufGz.Read(buf)
+	}
+	buf2 := make([]byte, len(buf), cap(buf))
+
+	n, err := ts.tarR.Read(buf2)
+	if err != nil {
+		if err == io.EOF {
+			if _, err := ts.h.Write(buf2[:n]); err != nil {
+				return 0, err
+			}
+			if !ts.first {
+				ts.sums[ts.currentFile] = hex.EncodeToString(ts.h.Sum(nil))
+				ts.h.Reset()
+			} else {
+				ts.first = false
+			}
+
+			currentHeader, err := ts.tarR.Next()
+			if err != nil {
+				if err == io.EOF {
+					if err := ts.gz.Close(); err != nil {
+						return 0, err
+					}
+					ts.finished = true
+					return n, nil
+				}
+				return n, err
+			}
+			ts.currentFile = strings.TrimSuffix(strings.TrimPrefix(currentHeader.Name, "./"), "/")
+			if err := ts.encodeHeader(currentHeader); err != nil {
+				return 0, err
+			}
+			if err := ts.tarW.WriteHeader(currentHeader); err != nil {
+				return 0, err
+			}
+			if _, err := ts.tarW.Write(buf2[:n]); err != nil {
+				return 0, err
+			}
+			ts.tarW.Flush()
+			if _, err := io.Copy(ts.gz, ts.bufTar); err != nil {
+				return 0, err
+			}
+			ts.gz.Flush()
+
+			return ts.bufGz.Read(buf)
+		}
+		return n, err
+	}
+
+	// Filling the hash buffer
+	if _, err = ts.h.Write(buf2[:n]); err != nil {
+		return 0, err
+	}
+
+	// Filling the tar writter
+	if _, err = ts.tarW.Write(buf2[:n]); err != nil {
+		return 0, err
+	}
+	ts.tarW.Flush()
+
+	// Filling the gz writter
+	if _, err = io.Copy(ts.gz, ts.bufTar); err != nil {
+		return 0, err
+	}
+	ts.gz.Flush()
+
+	return ts.bufGz.Read(buf)
+}
+
+func (ts *TarSum) Sum(extra []byte) string {
+	var sums []string
+
+	for _, sum := range ts.sums {
+		sums = append(sums, sum)
+	}
+	sort.Strings(sums)
+	h := sha256.New()
+	if extra != nil {
+		h.Write(extra)
+	}
+	for _, sum := range sums {
+		utils.Debugf("-->%s<--", sum)
+		h.Write([]byte(sum))
+	}
+	checksum := "tarsum+sha256:" + hex.EncodeToString(h.Sum(nil))
+	utils.Debugf("checksum processed: %s", checksum)
+	return checksum
+}
+
+func (ts *TarSum) GetSums() map[string]string {
+	return ts.sums
+}