mirror of
https://github.com/vbatts/merkle.git
synced 2024-11-13 18:48:37 +00:00
progress on a streaming interface
This commit is contained in:
parent
949cec0dce
commit
fd362c6aa5
3 changed files with 74 additions and 18 deletions
22
node.go
22
node.go
|
@ -1,23 +1,22 @@
|
|||
package merkle
|
||||
|
||||
import (
|
||||
"crypto"
|
||||
_ "crypto/sha1" // to satisfy our DefaultHash
|
||||
"crypto/sha1"
|
||||
"fmt"
|
||||
"hash"
|
||||
)
|
||||
|
||||
var (
|
||||
// DefaultHash is for checksum of blocks and nodes
|
||||
DefaultHash = crypto.SHA1
|
||||
// DefaultHashMaker is for checksum of blocks and nodes
|
||||
DefaultHashMaker = func() hash.Hash { return sha1.New() }
|
||||
)
|
||||
|
||||
// HashMaker produces a new has for use in making checksums
|
||||
type HashMaker func() hash.Hash
|
||||
|
||||
// NewNode returns a new Node with the DefaultHash for checksums
|
||||
// NewNode returns a new Node with the DefaultHashMaker for checksums
|
||||
func NewNode() *Node {
|
||||
return NewNodeHash(DefaultHash.New)
|
||||
return NewNodeHash(DefaultHashMaker)
|
||||
}
|
||||
|
||||
// NewNodeHash returns a new Node using the provided crypto.Hash for checksums
|
||||
|
@ -25,13 +24,22 @@ func NewNodeHash(h HashMaker) *Node {
|
|||
return &Node{hash: h}
|
||||
}
|
||||
|
||||
// NewNodeHashBlock returns a new Node using the provided crypto.Hash, and calculates the block's checksum
|
||||
func NewNodeHashBlock(h HashMaker, b []byte) *Node {
|
||||
n := &Node{hash: h}
|
||||
h1 := n.hash()
|
||||
h1.Write(b)
|
||||
n.checksum = h1.Sum(nil)
|
||||
return n
|
||||
}
|
||||
|
||||
// Node is a fundamental part of the tree.
|
||||
type Node struct {
|
||||
hash HashMaker
|
||||
checksum []byte
|
||||
Parent, Left, Right *Node
|
||||
|
||||
pos int // XXX maybe keep their order when it is a direct block's hash
|
||||
//pos int // XXX maybe keep their order when it is a direct block's hash
|
||||
}
|
||||
|
||||
// IsLeaf indicates this node is for specific block (and has no children)
|
||||
|
|
|
@ -9,7 +9,7 @@ import (
|
|||
func TestNodeSums(t *testing.T) {
|
||||
var (
|
||||
nodes []*Node
|
||||
h = DefaultHash.New()
|
||||
h = DefaultHashMaker()
|
||||
words = `Who were expelled from the academy for crazy & publishing obscene odes on the windows of the skull`
|
||||
expectedChecksum = "819fe8fed7a46900bd0613344c5ba2be336c74db"
|
||||
)
|
||||
|
@ -19,7 +19,7 @@ func TestNodeSums(t *testing.T) {
|
|||
t.Errorf("on word %q, encountered %s", word, err)
|
||||
}
|
||||
sum := h.Sum(nil)
|
||||
nodes = append(nodes, &Node{checksum: sum, hash: DefaultHash.New})
|
||||
nodes = append(nodes, &Node{checksum: sum, hash: DefaultHashMaker})
|
||||
}
|
||||
|
||||
newNodes := nodes
|
||||
|
|
66
stream.go
66
stream.go
|
@ -1,14 +1,18 @@
|
|||
package merkle
|
||||
|
||||
import "hash"
|
||||
import (
|
||||
"hash"
|
||||
"log"
|
||||
)
|
||||
|
||||
// NewHash provides a hash.Hash to generate a merkle.Tree checksum, given a
|
||||
// HashMaker for the checksums of the blocks written and the blockSize of each
|
||||
// block per node in the tree.
|
||||
func NewHash(hm HashMaker, merkleBlockSize int) hash.Hash {
|
||||
func NewHash(hm HashMaker, merkleBlockLength int) hash.Hash {
|
||||
mh := new(merkleHash)
|
||||
mh.blockSize = merkleBlockSize
|
||||
mh.blockSize = merkleBlockLength
|
||||
mh.hm = hm
|
||||
mh.tree = &Tree{Nodes: []*Node{}, BlockLength: merkleBlockLength}
|
||||
return mh
|
||||
}
|
||||
|
||||
|
@ -18,9 +22,11 @@ func NewHash(hm HashMaker, merkleBlockSize int) hash.Hash {
|
|||
|
||||
// TODO satisfy the hash.Hash interface
|
||||
type merkleHash struct {
|
||||
blockSize int
|
||||
tree Tree
|
||||
hm HashMaker
|
||||
blockSize int
|
||||
tree *Tree
|
||||
hm HashMaker
|
||||
lastBlock []byte // as needed, for Sum()
|
||||
partialLastBlock bool
|
||||
}
|
||||
|
||||
// XXX this will be tricky, as the last block can be less than the BlockSize.
|
||||
|
@ -32,15 +38,57 @@ type merkleHash struct {
|
|||
//
|
||||
// if that last block was complete, then no worries. start the next node.
|
||||
func (mh *merkleHash) Sum(b []byte) []byte {
|
||||
return nil
|
||||
// TODO check if len(mh.lastBlock) < blockSize
|
||||
sum, err := mh.tree.Root().Checksum()
|
||||
if err != nil {
|
||||
log.Println(err)
|
||||
}
|
||||
return sum
|
||||
}
|
||||
|
||||
func (mh *merkleHash) Write(b []byte) (int, error) {
|
||||
return 0, nil
|
||||
// basically we need to:
|
||||
// * chunk these writes into blockSize
|
||||
// * create Node of the sum
|
||||
// * add the Node to the tree
|
||||
// * stash remainder in the mh.lastBlock
|
||||
|
||||
var (
|
||||
curBlock = make([]byte, mh.blockSize)
|
||||
numBytes int = 0
|
||||
numWritten int
|
||||
)
|
||||
if mh.lastBlock != nil && len(mh.lastBlock) > 0 {
|
||||
numBytes = copy(curBlock, mh.lastBlock)
|
||||
// not adding to numWritten, since these blocks were accounted for in a
|
||||
// prior Write()
|
||||
}
|
||||
|
||||
if numBytes > 0 {
|
||||
copy(curBlock, b[:(mh.blockSize-numBytes)])
|
||||
numWritten += (mh.blockSize - numBytes)
|
||||
// TODO Node for curBlock
|
||||
n := NewNodeHashBlock(mh.hm, curBlock)
|
||||
_ = n
|
||||
}
|
||||
|
||||
numBytes = len(b) - numBytes
|
||||
for i := 0; i < numBytes/mh.blockSize; i++ {
|
||||
// TODO Node for curBlock
|
||||
}
|
||||
|
||||
// TODO stash (numBytes % mh.blockSize) in mh.lastBlock
|
||||
|
||||
// TODO if len(mh.lastBlock) < blockSize, then set that before returning
|
||||
return numWritten, nil
|
||||
}
|
||||
|
||||
func (mh *merkleHash) Reset() {
|
||||
mh.Tree = Tree{}
|
||||
mh.tree = &Tree{}
|
||||
mh.lastBlock = nil
|
||||
}
|
||||
|
||||
// likely not the best to pass this through and not use our own node block
|
||||
// size, but let's revisit this.
|
||||
func (mh *merkleHash) BlockSize() int { return mh.hm().BlockSize() }
|
||||
func (mh *merkleHash) Size() int { return mh.hm().Size() }
|
||||
|
|
Loading…
Reference in a new issue