pr feedback: use bufio.Reader, Read vs io.ReadFull, renaming

Signed-off-by: Maksim An <[email protected]>

cmd/dmverity-vhd/main.go

@@ -213,9 +213,9 @@ var rootHashVHDCommand = cli.Command{
  return errors.Wrapf(err, "failed to uncompress layer %s", diffID.String())
  }
 
- hash, err := tar2ext4.ConvertAndRootDigest(rc)
+ hash, err := tar2ext4.ConvertAndComputeRootDigest(rc)
  if err != nil {
- return errors.Wrapf(err, "failed to compute root hash")
+ return errors.Wrap(err, "failed to compute root hash")
  }
  fmt.Fprintf(os.Stdout, "Layer %d\nroot hash: %x\n", layerNumber, hash)
  }

ext4/dmverity/dmverity.go

@@ -17,8 +17,8 @@ import (
 
 const (
  blockSize = compactext4.BlockSize
- // bufioSize is a default buffer size to use with bufio.Reader
- bufioSize = 1024 * 1024 // 1MB
+ // MerkleTreeBufioSize is a default buffer size to use with bufio.Reader
+ MerkleTreeBufioSize = 1024 * 1024 // 1MB
  // RecommendedVHDSizeGB is the recommended size in GB for VHDs, which is not a hard limit.
  RecommendedVHDSizeGB = 128 * 1024 * 1024 * 1024
 )
@@ -73,16 +73,16 @@ type VerityInfo struct {
  Version uint32
 }
 
-// MerkleTreeWithReader constructs dm-verity hash-tree for a given io.Reader with a fixed salt (0-byte) and algorithm (sha256).
-func MerkleTreeWithReader(r io.Reader) ([]byte, error) {
+// MerkleTree constructs dm-verity hash-tree for a given bufio.Reader with a fixed salt (0-byte) and algorithm (sha256).
+func MerkleTree(br *bufio.Reader) ([]byte, error) {
  layers := make([][]byte, 0)
- currentLevel := bufio.NewReaderSize(r, bufioSize)
+ var currentLevel io.Reader = br
 
  for {
  nextLevel := bytes.NewBuffer(make([]byte, 0))
  for {
  block := make([]byte, blockSize)
- if _, err := currentLevel.Read(block); err != nil {
+ if _, err := io.ReadFull(currentLevel, block); err != nil {
  if err == io.EOF {
  break
  }
@@ -96,7 +96,7 @@ func MerkleTreeWithReader(r io.Reader) ([]byte, error) {
  nextLevel.Write(padding)
 
  layers = append(layers, nextLevel.Bytes())
- currentLevel = bufio.NewReaderSize(nextLevel, bufioSize)
+ currentLevel = bufio.NewReaderSize(nextLevel, MerkleTreeBufioSize)
 
  // This means that only root hash remains and our job is done
  if nextLevel.Len() == blockSize {
@@ -114,11 +114,6 @@ func MerkleTreeWithReader(r io.Reader) ([]byte, error) {
  return tree.Bytes(), nil
 }
 
-// MerkleTree constructs dm-verity hash-tree for a given byte array with a fixed salt (0-byte) and algorithm (sha256).
-func MerkleTree(data []byte) ([]byte, error) {
- return MerkleTreeWithReader(bytes.NewBuffer(data))
-}
-
 // RootHash computes root hash of dm-verity hash-tree
 func RootHash(tree []byte) []byte {
  return hash2(salt, tree[:blockSize])

ext4/tar2ext4/tar2ext4.go

@@ -189,7 +189,7 @@ func Convert(r io.Reader, w io.ReadWriteSeeker, options ...Option) error {
  return err
  }
 
- merkleTree, err := dmverity.MerkleTreeWithReader(w)
+ merkleTree, err := dmverity.MerkleTree(bufio.NewReaderSize(w, dmverity.MerkleTreeBufioSize))
  if err != nil {
  return errors.Wrap(err, "failed to build merkle tree")
  }
@@ -264,10 +264,10 @@ func ReadExt4SuperBlock(vhdPath string) (*format.SuperBlock, error) {
  return &sb, nil
 }
 
-// ConvertAndRootDigest writes a compact ext4 file system image that contains the files in the
+// ConvertAndComputeRootDigest writes a compact ext4 file system image that contains the files in the
 // input tar stream, computes and returns its cryptographic digest. Convert is called with minimal
 // options: ConvertWhiteout and MaximumDiskSize set to dmverity.RecommendedVHDSizeGB.
-func ConvertAndRootDigest(r io.Reader) (string, error) {
+func ConvertAndComputeRootDigest(r io.Reader) (string, error) {
  out, err := ioutil.TempFile("", "")
  if err != nil {
  return "", fmt.Errorf("failed to create temporary file: %s", err)
@@ -289,7 +289,7 @@ func ConvertAndRootDigest(r io.Reader) (string, error) {
  return "", fmt.Errorf("failed to seek start on temp file when creating merkle tree: %s", err)
  }
 
- tree, err := dmverity.MerkleTreeWithReader(r)
+ tree, err := dmverity.MerkleTree(bufio.NewReaderSize(out, dmverity.MerkleTreeBufioSize))
  if err != nil {
  return "", fmt.Errorf("failed to create merkle tree: %s", err)
  }

internal/tools/securitypolicy/main.go

@@ -167,7 +167,7 @@ func createPolicyFromConfig(config Config) (securitypolicy.SecurityPolicy, error
  return p, err
  }
 
- hashString, err := tar2ext4.ConvertAndRootDigest(r)
+ hashString, err := tar2ext4.ConvertAndComputeRootDigest(r)
  if err != nil {
  return p, err
  }