Switch to using blake3 hashes and skipping empty blocks

go.mod

@@ -8,8 +8,8 @@ require (
 	github.com/onsi/ginkgo/v2 v2.14.0
 	github.com/onsi/gomega v1.30.0
 	github.com/spf13/pflag v1.0.5
+	github.com/zeebo/blake3 v0.2.4
 	go.uber.org/zap v1.27.0
-	golang.org/x/crypto v0.21.0
 	sigs.k8s.io/controller-runtime v0.17.3
 )
 
@@ -21,6 +21,7 @@ require (
 	github.com/google/gofuzz v1.2.0 // indirect
 	github.com/google/pprof v0.0.0-20210720184732-4bb14d4b1be1 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/klauspost/cpuid/v2 v2.0.12 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	go.uber.org/multierr v1.11.0 // indirect

go.sum

@@ -30,6 +30,8 @@ github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnr
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/klauspost/cpuid/v2 v2.0.12 h1:p9dKCg8i4gmOxtv35DvrYoWqYzQrvEVdjQ762Y0OqZE=
+github.com/klauspost/cpuid/v2 v2.0.12/go.mod h1:g2LTdtYhdyuGPqyWyv7qRAmj1WBqxuObKfj5c0PQa7c=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
@@ -50,6 +52,12 @@ github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcU
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
+github.com/zeebo/assert v1.1.0 h1:hU1L1vLTHsnO8x8c9KAR5GmM5QscxHg5RNU5z5qbUWY=
+github.com/zeebo/assert v1.1.0/go.mod h1:Pq9JiuJQpG8JLJdtkwrJESF0Foym2/D9XMU5ciN/wJ0=
+github.com/zeebo/blake3 v0.2.4 h1:KYQPkhpRtcqh0ssGYcKLG1JYvddkEA8QwCM/yBqhaZI=
+github.com/zeebo/blake3 v0.2.4/go.mod h1:7eeQ6d2iXWRGF6npfaxl2CU+xy2Fjo2gxeyZGCRUjcE=
+github.com/zeebo/pcg v1.0.1 h1:lyqfGeWiv4ahac6ttHs+I5hwtH/+1mrhlCtVNQM2kHo=
+github.com/zeebo/pcg v1.0.1/go.mod h1:09F0S9iiKrwn9rlI5yjLkmrug154/YRW6KnnXVDM/l4=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=
 go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=
@@ -59,8 +67,6 @@ go.uber.org/zap v1.27.0/go.mod h1:GB2qFLM7cTU87MWRP2mPIjqfIDnGu+VIO4V/SdhGo2E=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/crypto v0.21.0 h1:X31++rzVUdKhX5sWmSOFZxx8UW/ldWx55cbf08iNAMA=
-golang.org/x/crypto v0.21.0/go.mod h1:0BP7YvVV9gBbVKyeTG0Gyn+gZm94bibOW5BjDEYAOMs=
 golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=

pkg/blockrsync/client.go

@@ -1,6 +1,7 @@
 package blockrsync
 
 import (
+	"bytes"
 	"encoding/binary"
 	"fmt"
 	"io"
@@ -42,19 +43,26 @@ func (b *BlockrsyncClient) ConnectToTarget() error {
 	}
 	b.log.Info("Opened file", "file", b.sourceFile)
 	defer f.Close()
-
+	b.log.V(3).Info("Connecting to target", "address", b.connectionProvider.TargetAddress())
+	conn, err := b.connectionProvider.Connect()
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+	b.log.Info("Connected to target, reading file to hash")
 	size, err := b.hasher.HashFile(b.sourceFile)
 	if err != nil {
 		return err
 	}
 	b.sourceSize = size
 	b.log.V(5).Info("Hashed file", "filename", b.sourceFile, "size", size)
-	conn, err := b.connectionProvider.Connect()
-	if err != nil {
+	reader := snappy.NewReader(conn)
+	if match, err := b.hasher.CompareHashHash(conn); err != nil {
 		return err
+	} else if match {
+		b.log.Info("No differences found, exiting")
+		return nil
 	}
-	defer conn.Close()
-	reader := snappy.NewReader(conn)
 	var diff []int64
 	if blockSize, sourceHashes, err := b.hasher.DeserializeHashes(reader); err != nil {
 		return err
@@ -141,12 +149,7 @@ func (b *BlockrsyncClient) writeBlocksToServer(writer io.Writer, offsets []int64
 }
 
 func isEmptyBlock(buf []byte) bool {
-	for _, b := range buf {
-		if b != 0 {
-			return false
-		}
-	}
-	return true
+	return bytes.Equal(buf, emptyBlock)
 }
 
 func int64SortFunc(i, j int64) int {
@@ -160,6 +163,7 @@ func int64SortFunc(i, j int64) int {
 
 type ConnectionProvider interface {
 	Connect() (io.ReadWriteCloser, error)
+	TargetAddress() string
 }
 
 type NetworkConnectionProvider struct {
@@ -177,9 +181,13 @@ func (n *NetworkConnectionProvider) Connect() (io.ReadWriteCloser, error) {
 			if retryCount > 30 {
 				return nil, fmt.Errorf("unable to connect to target after %d retries", retryCount)
 			}
-			time.Sleep(time.Second)
+			time.Sleep(time.Second * 10)
 			retryCount++
 		}
 	}
 	return conn, nil
 }
+
+func (n *NetworkConnectionProvider) TargetAddress() string {
+	return n.targetAddress
+}

pkg/blockrsync/hasher.go

@@ -15,12 +15,18 @@ import (
 	"time"
 
 	"github.com/go-logr/logr"
-	"golang.org/x/crypto/blake2b"
+	"github.com/zeebo/blake3"
 )
 
 const (
 	DefaultBlockSize   = int64(64 * 1024)
 	defaultConcurrency = 25
+	blake3HashLength   = 32
+)
+
+var (
+	emptyBlock []byte
+	zeroHash   []byte
 )
 
 type Hasher interface {
@@ -30,6 +36,7 @@ type Hasher interface {
 	SerializeHashes(io.Writer) error
 	DeserializeHashes(io.Reader) (int64, map[int64][]byte, error)
 	BlockSize() int64
+	CompareHashHash(io.ReadWriter) (bool, error)
 }
 
 type OffsetHash struct {
@@ -44,9 +51,13 @@ type FileHasher struct {
 	blockSize int64
 	fileSize  int64
 	log       logr.Logger
+	// Hash of hashes
+	hashHash []byte
 }
 
 func NewFileHasher(blockSize int64, log logr.Logger) Hasher {
+	emptyBlock = make([]byte, blockSize)
+	zeroHash = computeZeroHash()
 	return &FileHasher{
 		blockSize: blockSize,
 		queue:     make(chan int64, defaultConcurrency),
@@ -56,10 +67,17 @@ func NewFileHasher(blockSize int64, log logr.Logger) Hasher {
 	}
 }
 
+func computeZeroHash() []byte {
+	h := blake3.New()
+	h.Write(emptyBlock)
+	return h.Sum(nil)
+}
+
 func (f *FileHasher) HashFile(fileName string) (int64, error) {
 	f.log.V(3).Info("Hashing file", "file", fileName)
 	t := time.Now()
 	defer func() {
+		f.hashHash = f.calculateHashHash()
 		f.log.V(3).Info("Hashing took", "milliseconds", time.Since(t).Milliseconds())
 	}()
 	done := make(chan struct{})
@@ -79,10 +97,7 @@ func (f *FileHasher) HashFile(fileName string) (int64, error) {
 
 	for i := 0; i < count; i++ {
 		wg.Add(1)
-		h, err := blake2b.New512(nil)
-		if err != nil {
-			return 0, err
-		}
+		h := blake3.New()
 		go func(h hash.Hash) {
 			defer wg.Done()
 			osFile, err := os.Open(fileName)
@@ -110,6 +125,14 @@ func (f *FileHasher) HashFile(fileName string) (int64, error) {
 	}
 }
 
+func (f *FileHasher) calculateHashHash() []byte {
+	h := blake3.New()
+	for _, v := range f.hashes {
+		h.Write(v)
+	}
+	return h.Sum(nil)
+}
+
 func (f *FileHasher) getFileSize(fileName string) (int64, error) {
 	file, err := os.Open(fileName)
 	if err != nil {
@@ -153,17 +176,23 @@ func (f *FileHasher) calculateHash(offset int64, rs io.ReadSeeker, h hash.Hash)
 		f.log.V(5).Info("Failed to read")
 		return err
 	}
-	n, err = h.Write(buf[:n])
-	if err != nil {
-		f.log.V(5).Info("Failed to write to hash")
-		return err
-	}
-	if n != len(buf) {
-		f.log.V(5).Info("Finished reading file")
+	var hash []byte
+	if bytes.Equal(buf, emptyBlock) {
+		hash = zeroHash
+	} else {
+		n, err = h.Write(buf[:n])
+		if err != nil {
+			f.log.V(5).Info("Failed to write to hash")
+			return err
+		}
+		if n != len(buf) {
+			f.log.V(5).Info("Finished reading file")
+		}
+		hash = h.Sum(nil)
 	}
 	offsetHash := OffsetHash{
 		Offset: offset,
-		Hash:   h.Sum(nil),
+		Hash:   hash,
 	}
 	f.res <- offsetHash
 	return nil
@@ -210,6 +239,7 @@ func (f *FileHasher) SerializeHashes(w io.Writer) error {
 	if err := binary.Write(w, binary.LittleEndian, int64(f.blockSize)); err != nil {
 		return err
 	}
+
 	length := len(f.hashes)
 	f.log.V(5).Info("Number of blocks", "size", length)
 	if err := binary.Write(w, binary.LittleEndian, int64(length)); err != nil {
@@ -225,8 +255,8 @@ func (f *FileHasher) SerializeHashes(w io.Writer) error {
 		if err := binary.Write(w, binary.LittleEndian, k); err != nil {
 			return err
 		}
-		if len(f.hashes[k]) != 64 {
-			return errors.New("invalid hash length")
+		if len(f.hashes[k]) != blake3HashLength {
+			return fmt.Errorf("invalid hash length %d", len(f.hashes[k]))
 		}
 		if n, err := w.Write(f.hashes[k]); err != nil {
 			return err
@@ -248,6 +278,7 @@ func (f *FileHasher) DeserializeHashes(r io.Reader) (int64, map[int64][]byte, er
 	if err := binary.Read(r, binary.LittleEndian, &blockSize); err != nil {
 		return 0, nil, err
 	}
+	f.log.V(5).Info("Block size", "size", blockSize)
 	var length int64
 	if err := binary.Read(r, binary.LittleEndian, &length); err != nil {
 		return 0, nil, err
@@ -263,7 +294,7 @@ func (f *FileHasher) DeserializeHashes(r io.Reader) (int64, map[int64][]byte, er
 		if offset < 0 || offset > length*blockSize {
 			return 0, nil, fmt.Errorf("invalid offset %d", offset)
 		}
-		hash := make([]byte, 64)
+		hash := make([]byte, blake3HashLength)
 		if n, err := io.ReadFull(r, hash); err != nil {
 			return 0, nil, err
 		} else {
@@ -275,6 +306,22 @@ func (f *FileHasher) DeserializeHashes(r io.Reader) (int64, map[int64][]byte, er
 	return blockSize, hashes, nil
 }
 
+func (f *FileHasher) CompareHashHash(rw io.ReadWriter) (bool, error) {
+	f.log.V(5).Info("Comparing hash of hashes", "hash", base64.StdEncoding.EncodeToString(f.hashHash))
+	if n, err := rw.Write(f.hashHash); err != nil {
+		return false, err
+	} else {
+		f.log.V(5).Info("Wrote hash of hashes", "bytes", n)
+	}
+	hashHash := make([]byte, blake3HashLength)
+	if n, err := io.ReadFull(rw, hashHash); err != nil {
+		return false, err
+	} else {
+		f.log.V(5).Info("Read hash of hashes", "bytes", n, "hash", base64.StdEncoding.EncodeToString(hashHash))
+	}
+	return bytes.Equal(hashHash, f.hashHash), nil
+}
+
 func (f *FileHasher) BlockSize() int64 {
 	return f.blockSize
 }

pkg/blockrsync/hasher_test.go

@@ -64,7 +64,7 @@ var _ = Describe("hasher tests", func() {
 		Expect(err).ToNot(HaveOccurred())
 		hashes := hasher.GetHashes()
 		// 16 for the blocksize and length, 72 for each hash
-		Expect(b.Len()).To(Equal(72*len(hashes) + 16))
+		Expect(b.Len()).To(Equal(40*len(hashes) + 16))
 		r := io.Reader(&b)
 		blockSize, h, err := hasher.DeserializeHashes(r)
 		Expect(err).ToNot(HaveOccurred())

pkg/blockrsync/server.go

@@ -67,6 +67,12 @@ func (b *BlockrsyncServer) StartServer() error {
 	defer conn.Close()
 	writer := snappy.NewBufferedWriter(conn)
 	<-readyChan
+	if match, err := b.hasher.CompareHashHash(conn); err != nil {
+		return err
+	} else if match {
+		b.log.Info("No differences found, exiting")
+		return nil
+	}
 
 	if err := b.writeHashes(writer); err != nil {
 		return err
@@ -99,6 +105,7 @@ func (b *BlockrsyncServer) writeBlocksToFile(f *os.File, reader io.Reader) error
 		_, err = handleReadError(err, nocallback)
 		return err
 	}
+	b.targetFileSize = max(b.targetFileSize, sourceSize)
 	if err := b.truncateFileIfNeeded(f, sourceSize, b.targetFileSize); err != nil {
 		_, err = handleReadError(err, nocallback)
 		return err
@@ -131,16 +138,15 @@ func (b *BlockrsyncServer) truncateFileIfNeeded(f *os.File, sourceSize, targetSi
 	if err != nil {
 		return err
 	}
-	if targetSize > sourceSize {
-		b.log.V(5).Info("Source size", "size", sourceSize)
-		if info.Mode()&(os.ModeDevice|os.ModeCharDevice) == 0 {
-			// Not a block device, truncate the file if it is larger than the source file
-			// Truncate the target file if it is larger than the source file
-			b.log.V(5).Info("Source is smaller than target, truncating file")
-			if err := f.Truncate(sourceSize); err != nil {
-				return err
-			}
-		} else {
+	b.log.V(5).Info("Source size", "size", sourceSize)
+	if info.Mode()&(os.ModeDevice|os.ModeCharDevice) == 0 {
+		// Not a block device, set the file size to the received size
+		b.log.V(3).Info("Setting target file size", "size", targetSize)
+		if err := f.Truncate(sourceSize); err != nil {
+			return err
+		}
+	} else {
+		if targetSize > sourceSize {
 			// empty out existing blocks
 			PunchHole(f, sourceSize, targetSize-sourceSize)
 		}