Golang blob.RefFromHash函數代碼示例

func blobDetails(contents io.ReadSeeker) (bref blob.Ref, size uint32, err error) {
	s1 := sha1.New()
	if _, err = contents.Seek(0, 0); err != nil {
		return
	}
	defer func() {
		if _, seekErr := contents.Seek(0, 0); seekErr != nil {
			if err == nil {
				err = seekErr
			} else {
				err = fmt.Errorf("%s, cannot seek back: %v", err, seekErr)
			}
		}
	}()
	sz, err := io.CopyN(s1, contents, constants.MaxBlobSize+1)
	if err == nil || err == io.EOF {
		bref, err = blob.RefFromHash(s1), nil
	} else {
		err = fmt.Errorf("error reading contents: %v", err)
		return
	}
	if sz > constants.MaxBlobSize {
		err = fmt.Errorf("blob size cannot be bigger than %d", constants.MaxBlobSize)
	}
	size = uint32(sz)
	return
}

func (pt *packTest) testOpenWholeRef(t *testing.T, wholeRef blob.Ref, wantSize int64) {
	rc, gotSize, err := pt.sto.OpenWholeRef(wholeRef, 0)
	if err != nil {
		t.Errorf("OpenWholeRef = %v", err)
		return
	}
	defer rc.Close()
	if gotSize != wantSize {
		t.Errorf("OpenWholeRef size = %v; want %v", gotSize, wantSize)
		return
	}
	h := blob.NewHash()
	n, err := io.Copy(h, rc)
	if err != nil {
		t.Errorf("OpenWholeRef read error: %v", err)
		return
	}
	if n != wantSize {
		t.Errorf("OpenWholeRef read %v bytes; want %v", n, wantSize)
		return
	}
	gotRef := blob.RefFromHash(h)
	if gotRef != wholeRef {
		t.Errorf("OpenWholeRef read contents = %v; want %v", gotRef, wholeRef)
	}
}

// This is the simple 1MB chunk version. The rolling checksum version is below.
func writeFileMapOld(bs blobserver.StatReceiver, file *Builder, r io.Reader) (blob.Ref, error) {
	parts, size := []BytesPart{}, int64(0)

	var buf bytes.Buffer
	for {
		buf.Reset()
		n, err := io.Copy(&buf, io.LimitReader(r, maxBlobSize))
		if err != nil {
			return blob.Ref{}, err
		}
		if n == 0 {
			break
		}

		hash := blob.NewHash()
		io.Copy(hash, bytes.NewReader(buf.Bytes()))
		br := blob.RefFromHash(hash)
		hasBlob, err := serverHasBlob(bs, br)
		if err != nil {
			return blob.Ref{}, err
		}
		if !hasBlob {
			sb, err := bs.ReceiveBlob(br, &buf)
			if err != nil {
				return blob.Ref{}, err
			}
			if want := (blob.SizedRef{br, uint32(n)}); sb != want {
				return blob.Ref{}, fmt.Errorf("schema/filewriter: wrote %s, expect", sb, want)
			}
		}

		size += n
		parts = append(parts, BytesPart{
			BlobRef: br,
			Size:    uint64(n),
			Offset:  0, // into BlobRef to read from (not of dest)
		})
	}

	err := file.PopulateParts(size, parts)
	if err != nil {
		return blob.Ref{}, err
	}

	json := file.Blob().JSON()
	if err != nil {
		return blob.Ref{}, err
	}
	br := blob.SHA1FromString(json)
	sb, err := bs.ReceiveBlob(br, strings.NewReader(json))
	if err != nil {
		return blob.Ref{}, err
	}
	if expect := (blob.SizedRef{br, uint32(len(json))}); expect != sb {
		return blob.Ref{}, fmt.Errorf("schema/filewriter: wrote %s bytes, got %s ack'd", expect, sb)
	}

	return br, nil
}

func (pk *packer) pack() error {
	if err := pk.scanChunks(); err != nil {
		return err
	}

	// TODO: decide as a fuction of schemaRefs and dataRefs
	// already in s.large whether it makes sense to still compact
	// this from a savings standpoint. For now we just always do.
	// Maybe we'd have knobs in the future. Ideally not.

	// Don't pack a file if we already have its wholeref stored
	// otherwise (perhaps under a different filename). But that
	// means we have to compute its wholeref first. We assume the
	// blob source will cache these lookups so it's not too
	// expensive to do two passes over the input.
	h := blob.NewHash()
	var err error
	pk.wholeSize, err = io.Copy(h, pk.fr)
	if err != nil {
		return err
	}
	pk.wholeRef = blob.RefFromHash(h)
	wholeKey := wholeMetaPrefix + pk.wholeRef.String()
	_, err = pk.s.meta.Get(wholeKey)
	if err == nil {
		// Nil error means there was some knowledge of this wholeref.
		return fmt.Errorf("already have wholeref %v packed; not packing again", pk.wholeRef)
	} else if err != sorted.ErrNotFound {
		return err
	}

	pk.chunksRemain = pk.dataRefs
	var trunc blob.Ref
MakingZips:
	for len(pk.chunksRemain) > 0 {
		if err := pk.writeAZip(trunc); err != nil {
			if needTrunc, ok := err.(needsTruncatedAfterError); ok {
				trunc = needTrunc.Ref
				if fn := testHookSawTruncate; fn != nil {
					fn(trunc)
				}
				continue MakingZips
			}
			return err
		}
		trunc = blob.Ref{}
	}

	// Record the final wholeMetaPrefix record:
	err = pk.s.meta.Set(wholeKey, fmt.Sprintf("%d %d", pk.wholeSize, len(pk.zips)))
	if err != nil {
		return fmt.Errorf("Error setting %s: %v", wholeKey, err)
	}

	return nil
}

func blobDetails(contents io.ReadSeeker) (bref blob.Ref, size int64, err error) {
	s1 := sha1.New()
	contents.Seek(0, 0)
	size, err = io.Copy(s1, contents)
	if err == nil {
		bref = blob.RefFromHash(s1)
	}
	contents.Seek(0, 0)
	return
}

func (d *defaultStatHasher) Hash(fileName string) (blob.Ref, error) {
	s1 := sha1.New()
	file, err := os.Open(fileName)
	if err != nil {
		return blob.Ref{}, err
	}
	defer file.Close()
	_, err = io.Copy(s1, file)
	if err != nil {
		return blob.Ref{}, err
	}
	return blob.RefFromHash(s1), nil
}

func testSizedBlob(t *testing.T, r io.Reader, b1 blob.Ref, size int64) {
	h := b1.Hash()
	n, err := io.Copy(h, r)
	if err != nil {
		t.Fatalf("error reading from %s: %v", r, err)
	}
	if n != size {
		t.Fatalf("read %d bytes from %s, metadata said %d!", n, r, size)
	}
	b2 := blob.RefFromHash(h)
	if b2 != b1 {
		t.Fatalf("content mismatch (awaited %s, got %s)", b1, b2)
	}
}

func (h *DeployHandler) storeInstanceConf(conf *InstanceConf) (blob.Ref, error) {
	contents, err := json.Marshal(conf)
	if err != nil {
		return blob.Ref{}, fmt.Errorf("could not json encode instance config: %v", err)
	}
	hash := blob.NewHash()
	_, err = io.Copy(hash, bytes.NewReader(contents))
	if err != nil {
		return blob.Ref{}, fmt.Errorf("could not hash blob contents: %v", err)
	}
	br := blob.RefFromHash(hash)
	if _, err := blobserver.Receive(h.instConf, br, bytes.NewReader(contents)); err != nil {
		return blob.Ref{}, fmt.Errorf("could not store instance config blob: %v", err)
	}
	return br, nil
}

// Blob builds the Blob. The builder continues to be usable after a call to Build.
func (bb *Builder) Blob() *Blob {
	json, err := mapJSON(bb.m)
	if err != nil {
		panic(err)
	}
	ss, err := parseSuperset(strings.NewReader(json))
	if err != nil {
		panic(err)
	}
	h := blob.NewHash()
	h.Write([]byte(json))
	return &Blob{
		str: json,
		ss:  ss,
		br:  blob.RefFromHash(h),
	}
}

func TestPackLarge(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping in short mode")
	}
	const fileSize = 17 << 20 // more than 16 MB, so more than one zip
	const fileName = "foo.dat"
	fileContents := randBytes(fileSize)

	hash := blob.NewHash()
	hash.Write(fileContents)
	wholeRef := blob.RefFromHash(hash)

	pt := testPack(t,
		func(sto blobserver.Storage) error {
			_, err := schema.WriteFileFromReader(sto, fileName, bytes.NewReader(fileContents))
			return err
		},
		wantNumLargeBlobs(2),
		wantNumSmallBlobs(0),
	)

	// Verify we wrote the correct "w:*" meta rows.
	got := map[string]string{}
	want := map[string]string{
		"w:" + wholeRef.String():        "17825792 2",
		"w:" + wholeRef.String() + ":0": "sha1-9b4a3d114c059988075c87293c86ee7cbc6f4af5 37 0 16709479",
		"w:" + wholeRef.String() + ":1": "sha1-fe6326ac6b389ffe302623e4a501bfc8c6272e8e 37 16709479 1116313",
	}
	if err := sorted.Foreach(pt.sto.meta, func(key, value string) error {
		if strings.HasPrefix(key, "b:") {
			return nil
		}
		got[key] = value
		return nil
	}); err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(got, want) {
		t.Errorf("'w:*' meta rows = %v; want %v", got, want)
	}

	// And verify we can read it back out.
	pt.testOpenWholeRef(t, wholeRef, fileSize)
}

func stdinBlobHandle() (uh *client.UploadHandle, err error) {
	var buf bytes.Buffer
	size, err := io.Copy(&buf, cmdmain.Stdin)
	if err != nil {
		return
	}
	// TODO(bradfitz,mpl): limit this buffer size?
	file := buf.Bytes()
	h := blob.NewHash()
	size, err = io.Copy(h, bytes.NewReader(file))
	if err != nil {
		return
	}
	return &client.UploadHandle{
		BlobRef:  blob.RefFromHash(h),
		Size:     size,
		Contents: io.LimitReader(bytes.NewReader(file), size),
	}, nil
}

func TestPackNormal(t *testing.T) {
	const fileSize = 5 << 20
	const fileName = "foo.dat"
	fileContents := randBytes(fileSize)

	hash := blob.NewHash()
	hash.Write(fileContents)
	wholeRef := blob.RefFromHash(hash)

	pt := testPack(t,
		func(sto blobserver.Storage) error {
			_, err := schema.WriteFileFromReader(sto, fileName, bytes.NewReader(fileContents))
			return err
		},
		wantNumLargeBlobs(1),
		wantNumSmallBlobs(0),
	)
	// And verify we can read it back out.
	pt.testOpenWholeRef(t, wholeRef, fileSize)
}

func stdinBlobHandle() (uh *client.UploadHandle, err error) {
	var buf bytes.Buffer
	size, err := io.CopyN(&buf, cmdmain.Stdin, constants.MaxBlobSize+1)
	if err != nil {
		return
	}
	if size > constants.MaxBlobSize {
		err = fmt.Errorf("blob size cannot be bigger than %d", constants.MaxBlobSize)
	}
	file := buf.Bytes()
	h := blob.NewHash()
	size, err = io.Copy(h, bytes.NewReader(file))
	if err != nil {
		return
	}
	return &client.UploadHandle{
		BlobRef:  blob.RefFromHash(h),
		Size:     uint32(size),
		Contents: io.LimitReader(bytes.NewReader(file), size),
	}, nil
}

func TestReindex(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping in short mode")
	}

	type file struct {
		size     int64
		name     string
		contents []byte
	}
	files := []file{
		{17 << 20, "foo.dat", randBytesSrc(17<<20, 42)},
		{10 << 20, "bar.dat", randBytesSrc(10<<20, 43)},
		{5 << 20, "baz.dat", randBytesSrc(5<<20, 44)},
	}

	pt := testPack(t,
		func(sto blobserver.Storage) error {
			for _, f := range files {
				if _, err := schema.WriteFileFromReader(sto, f.name, bytes.NewReader(f.contents)); err != nil {
					return err
				}
			}
			return nil
		},
		wantNumLargeBlobs(4),
		wantNumSmallBlobs(0),
	)

	// backup the meta that is supposed to be lost/erased.
	// pt.sto.reindex allocates a new pt.sto.meta, so meta != pt.sto.meta after it is called.
	meta := pt.sto.meta

	// and build new meta index
	if err := pt.sto.reindex(context.TODO(), func() (sorted.KeyValue, error) {
		return sorted.NewMemoryKeyValue(), nil
	}); err != nil {
		t.Fatal(err)
	}

	// check that new meta is identical to "lost" one
	newRows := 0
	if err := sorted.Foreach(pt.sto.meta, func(key, newValue string) error {
		oldValue, err := meta.Get(key)
		if err != nil {
			t.Fatalf("Could not get value for %v in old meta: %v", key, err)
		}
		if oldValue != newValue {
			t.Fatalf("Reindexing error: for key %v, got %v, want %v", key, newValue, oldValue)
		}
		newRows++
		return nil
	}); err != nil {
		t.Fatal(err)
	}

	// make sure they have the same number of entries too, to be sure that the reindexing
	// did not miss entries that the old meta had.
	oldRows := countSortedRows(t, meta)
	if oldRows != newRows {
		t.Fatalf("index number of entries mismatch: got %d entries in new index, wanted %d (as in index before reindexing)", newRows, oldRows)
	}

	// And verify we can read one of the files back out.
	hash := blob.NewHash()
	hash.Write(files[0].contents)
	pt.testOpenWholeRef(t, blob.RefFromHash(hash), files[0].size)
}

// b: the parsed file schema blob
// mm: keys to populate
func (ix *Index) populateFile(fetcher blob.Fetcher, b *schema.Blob, mm *mutationMap) (err error) {
	var times []time.Time // all creation or mod times seen; may be zero
	times = append(times, b.ModTime())

	blobRef := b.BlobRef()
	fr, err := b.NewFileReader(fetcher)
	if err != nil {
		return err
	}
	defer fr.Close()
	mime, reader := magic.MIMETypeFromReader(fr)

	sha1 := sha1.New()
	var copyDest io.Writer = sha1
	var imageBuf *keepFirstN // or nil
	if strings.HasPrefix(mime, "image/") {
		// Emperically derived 1MiB assuming CR2 images require more than any
		// other filetype we support:
		//   https://gist.github.com/wathiede/7982372
		imageBuf = &keepFirstN{N: 1 << 20}
		copyDest = io.MultiWriter(copyDest, imageBuf)
	}
	size, err := io.Copy(copyDest, reader)
	if err != nil {
		return err
	}
	wholeRef := blob.RefFromHash(sha1)

	if imageBuf != nil {
		if conf, err := images.DecodeConfig(bytes.NewReader(imageBuf.Bytes)); err == nil {
			mm.Set(keyImageSize.Key(blobRef), keyImageSize.Val(fmt.Sprint(conf.Width), fmt.Sprint(conf.Height)))
		}
		if ft, err := schema.FileTime(bytes.NewReader(imageBuf.Bytes)); err == nil {
			log.Printf("filename %q exif = %v, %v", b.FileName(), ft, err)
			times = append(times, ft)
		} else {
			log.Printf("filename %q exif = %v, %v", b.FileName(), ft, err)
		}

		indexEXIF(wholeRef, imageBuf.Bytes, mm)
	}

	var sortTimes []time.Time
	for _, t := range times {
		if !t.IsZero() {
			sortTimes = append(sortTimes, t)
		}
	}
	sort.Sort(types.ByTime(sortTimes))
	var time3339s string
	switch {
	case len(sortTimes) == 1:
		time3339s = types.Time3339(sortTimes[0]).String()
	case len(sortTimes) >= 2:
		oldest, newest := sortTimes[0], sortTimes[len(sortTimes)-1]
		time3339s = types.Time3339(oldest).String() + "," + types.Time3339(newest).String()
	}

	mm.Set(keyWholeToFileRef.Key(wholeRef, blobRef), "1")
	mm.Set(keyFileInfo.Key(blobRef), keyFileInfo.Val(size, b.FileName(), mime))
	mm.Set(keyFileTimes.Key(blobRef), keyFileTimes.Val(time3339s))

	if strings.HasPrefix(mime, "audio/") {
		indexMusic(io.NewSectionReader(fr, 0, fr.Size()), wholeRef, mm)
	}

	return nil
}