introduce ramTrie

claimtrie/claimtrie.go

@@ -46,7 +46,7 @@ type ClaimTrie struct {
 	nodeManager node.Manager
 
 	// Prefix tree (trie) that manages merkle hash of each node.
-	merkleTrie *merkletrie.MerkleTrie
+	merkleTrie merkletrie.MerkleTrie
 
 	// Current block height, which is increased by one when AppendBlock() is called.
 	height int32
@@ -99,6 +99,11 @@ func New(cfg config.Config) (*ClaimTrie, error) {
 	trie := merkletrie.New(nodeManager, trieRepo)
 	cleanups = append(cleanups, trie.Close)
 
+		persistentTrie := merkletrie.NewPersistentTrie(nodeManager, trieRepo)
+		cleanups = append(cleanups, persistentTrie.Close)
+		trie = persistentTrie
+	}
+
 	// Restore the last height.
 	previousHeight, err := blockRepo.Load()
 	if err != nil {
@@ -110,12 +115,11 @@ func New(cfg config.Config) (*ClaimTrie, error) {
 		if err != nil {
 			return nil, fmt.Errorf("get hash: %w", err)
 		}
-		trie.SetRoot(hash)
-
 		_, err = nodeManager.IncrementHeightTo(previousHeight)
 		if err != nil {
 			return nil, fmt.Errorf("node manager init: %w", err)
 		}
+		trie.SetRoot(hash, nil) // keep this after IncrementHeightTo
 	}
 
 	ct := &ClaimTrie{
@@ -275,7 +279,7 @@ func (ct *ClaimTrie) AppendBlock() error {
 	ct.blockRepo.Set(ct.height, h)
 
 	if hitFork {
-		ct.merkleTrie.SetRoot(h) // for clearing the memory entirely
+		ct.merkleTrie.SetRoot(h, names) // for clearing the memory entirely
 		runtime.GC()
 	}
 
@@ -337,12 +341,21 @@ func (ct *ClaimTrie) ResetHeight(height int32) error {
 		return err
 	}
 
+	passedHashFork := ct.height >= param.AllClaimsInMerkleForkHeight && height < param.AllClaimsInMerkleForkHeight
 	ct.height = height
 	hash, err := ct.blockRepo.Get(height)
 	if err != nil {
 		return err
 	}
-	ct.merkleTrie.SetRoot(hash)
+
+	if passedHashFork {
+		names = nil // force them to reconsider all names
+	}
+	ct.merkleTrie.SetRoot(hash, names)
+
+	if !ct.MerkleHash().IsEqual(hash) {
+		return fmt.Errorf("unable to restore the hash at height %d", height)
+	}
 	return nil
 }
 

claimtrie/claimtrie_test.go

@@ -231,3 +231,39 @@ func verifyBestIndex(t *testing.T, ct *ClaimTrie, name string, idx uint32, claim
 		r.Equal(idx, n.BestClaim.OutPoint.Index)
 	}
 }
+
+func TestRebuild(t *testing.T) {
+	r := require.New(t)
+	setup(t)
+	ct, err := New(true)
+	r.NoError(err)
+	r.NotNil(ct)
+	defer func() {
+		err := ct.Close()
+		r.NoError(err)
+	}()
+
+	hash := chainhash.HashH([]byte{1, 2, 3})
+
+	o1 := wire.OutPoint{Hash: hash, Index: 1}
+	err = ct.AddClaim([]byte("test1"), o1, node.NewClaimID(o1), 1, nil)
+	r.NoError(err)
+
+	o2 := wire.OutPoint{Hash: hash, Index: 2}
+	err = ct.AddClaim([]byte("test2"), o2, node.NewClaimID(o2), 2, nil)
+	r.NoError(err)
+
+	err = ct.AppendBlock()
+	r.NoError(err)
+
+	m := ct.MerkleHash()
+	r.NotNil(m)
+	r.NotEqual(*merkletrie.EmptyTrieHash, *m)
+
+	ct.merkleTrie = merkletrie.NewRamTrie(ct.nodeManager)
+	ct.merkleTrie.SetRoot(m, nil)
+
+	m2 := ct.MerkleHash()
+	r.NotNil(m2)
+	r.Equal(*m, *m2)
+}

claimtrie/cmd/cmd/block.go

@@ -135,9 +135,9 @@ var blockNameCmd = &cobra.Command{
 			return fmt.Errorf("can't open merkle trie repo: %w", err)
 		}
 
-		trie := merkletrie.New(nil, trieRepo)
+		trie := merkletrie.NewPersistentTrie(nil, trieRepo)
 		defer trie.Close()
-		trie.SetRoot(hash)
+		trie.SetRoot(hash, nil)
 		if len(args) > 1 {
 			trie.Dump(args[1], param.AllClaimsInMerkleForkHeight >= int32(height))
 		} else {

claimtrie/merkletrie/collapsedtrie.go

@@ -1,21 +1,21 @@
 package merkletrie
 
 import (
-	"github.com/lbryio/chain/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
 )
 
 type KeyType []byte
 
-type PrefixTrieNode struct { // implements sort.Interface
+type collapsedVertex struct { // implements sort.Interface
-	children  []*PrefixTrieNode
+	children   []*collapsedVertex
 	key        KeyType
-	hash      *chainhash.Hash
+	merkleHash *chainhash.Hash
-	hasClaims bool
+	claimHash  *chainhash.Hash
 }
 
 // insertAt inserts v into s at index i and returns the new slice.
 // https://stackoverflow.com/questions/42746972/golang-insert-to-a-sorted-slice
-func insertAt(data []*PrefixTrieNode, i int, v *PrefixTrieNode) []*PrefixTrieNode {
+func insertAt(data []*collapsedVertex, i int, v *collapsedVertex) []*collapsedVertex {
 	if i == len(data) {
 		// Insert at end is the easy case.
 		return append(data, v)
@@ -30,7 +30,7 @@ func insertAt(data []*PrefixTrieNode, i int, v *PrefixTrieNode) []*PrefixTrieNod
 	return data
 }
 
-func (ptn *PrefixTrieNode) Insert(value *PrefixTrieNode) *PrefixTrieNode {
+func (ptn *collapsedVertex) Insert(value *collapsedVertex) *collapsedVertex {
 	// keep it sorted (and sort.Sort is too slow)
 	index := sortSearch(ptn.children, value.key[0])
 	ptn.children = insertAt(ptn.children, index, value)
@@ -40,7 +40,7 @@ func (ptn *PrefixTrieNode) Insert(value *PrefixTrieNode) *PrefixTrieNode {
 
 // this sort.Search is stolen shamelessly from search.go,
 // and modified for performance to not need a closure
-func sortSearch(nodes []*PrefixTrieNode, b byte) int {
+func sortSearch(nodes []*collapsedVertex, b byte) int {
 	i, j := 0, len(nodes)
 	for i < j {
 		h := int(uint(i+j) >> 1) // avoid overflow when computing h
@@ -55,9 +55,9 @@ func sortSearch(nodes []*PrefixTrieNode, b byte) int {
 	return i
 }
 
-func (ptn *PrefixTrieNode) FindNearest(start KeyType) (int, *PrefixTrieNode) {
+func (ptn *collapsedVertex) findNearest(key KeyType) (int, *collapsedVertex) {
 	// none of the children overlap on the first char or we would have a parent node with that char
-	index := sortSearch(ptn.children, start[0])
+	index := sortSearch(ptn.children, key[0])
 	hits := ptn.children[index:]
 	if len(hits) > 0 {
 		return index, hits[0]
@@ -65,26 +65,17 @@ func (ptn *PrefixTrieNode) FindNearest(start KeyType) (int, *PrefixTrieNode) {
 	return -1, nil
 }
 
-type PrefixTrie interface {
+type collapsedTrie struct {
-	InsertOrFind(value KeyType) (bool, *PrefixTrieNode)
+	Root  *collapsedVertex
-	Find(value KeyType) *PrefixTrieNode
-	FindPath(value KeyType) ([]int, []*PrefixTrieNode)
-	IterateFrom(start KeyType, handler func(value *PrefixTrieNode) bool)
-	Erase(value KeyType) bool
-	NodeCount() int
-}
-
-type prefixTrie struct {
-	root  *PrefixTrieNode
 	Nodes int
 }
 
-func NewPrefixTrie() PrefixTrie {
+func NewCollapsedTrie() *collapsedTrie {
-	// we never delete the root node
+	// we never delete the Root node
-	return &prefixTrie{root: &PrefixTrieNode{key: make(KeyType, 0)}, Nodes: 1}
+	return &collapsedTrie{Root: &collapsedVertex{key: make(KeyType, 0)}, Nodes: 1}
 }
 
-func (pt *prefixTrie) NodeCount() int {
+func (pt *collapsedTrie) NodeCount() int {
 	return pt.Nodes
 }
 
@@ -101,10 +92,11 @@ func matchLength(a, b KeyType) int {
 	return minLen
 }
 
-func (pt *prefixTrie) insert(value KeyType, node *PrefixTrieNode) (bool, *PrefixTrieNode) {
+func (pt *collapsedTrie) insert(value KeyType, node *collapsedVertex) (bool, *collapsedVertex) {
-	index, child := node.FindNearest(value)
+	index, child := node.findNearest(value)
 	match := 0
 	if index >= 0 { // if we found a child
+		child.merkleHash = nil
 		match = matchLength(value, child.key)
 		if len(value) == match && len(child.key) == match {
 			return false, child
@@ -112,12 +104,12 @@ func (pt *prefixTrie) insert(value KeyType, node *PrefixTrieNode) (bool, *Prefix
 	}
 	if match <= 0 {
 		pt.Nodes++
-		return true, node.Insert(&PrefixTrieNode{key: value})
+		return true, node.Insert(&collapsedVertex{key: value})
 	}
 	if match < len(child.key) {
-		grandChild := PrefixTrieNode{key: child.key[match:], children: child.children,
+		grandChild := collapsedVertex{key: child.key[match:], children: child.children,
-			hasClaims: child.hasClaims, hash: child.hash}
+			claimHash: child.claimHash, merkleHash: child.merkleHash}
-		newChild := PrefixTrieNode{key: child.key[0:match], children: []*PrefixTrieNode{&grandChild}}
+		newChild := collapsedVertex{key: child.key[0:match], children: []*collapsedVertex{&grandChild}}
 		child = &newChild
 		node.children[index] = child
 		pt.Nodes++
@@ -128,15 +120,21 @@ func (pt *prefixTrie) insert(value KeyType, node *PrefixTrieNode) (bool, *Prefix
 	return pt.insert(value[match:], child)
 }
 
-func (pt *prefixTrie) InsertOrFind(value KeyType) (bool, *PrefixTrieNode) {
+func (pt *collapsedTrie) InsertOrFind(value KeyType) (bool, *collapsedVertex) {
+	pt.Root.merkleHash = nil
 	if len(value) <= 0 {
-		return false, pt.root
+		return false, pt.Root
 	}
-	return pt.insert(value, pt.root)
+
+	// we store the name so we need to make our own copy of it
+	// this avoids errors where this function is called via the DB iterator
+	v2 := make([]byte, len(value))
+	copy(v2, value)
+	return pt.insert(v2, pt.Root)
 }
 
-func find(value KeyType, node *PrefixTrieNode, pathIndexes *[]int, path *[]*PrefixTrieNode) *PrefixTrieNode {
+func find(value KeyType, node *collapsedVertex, pathIndexes *[]int, path *[]*collapsedVertex) *collapsedVertex {
-	index, child := node.FindNearest(value)
+	index, child := node.findNearest(value)
 	if index < 0 {
 		return nil
 	}
@@ -162,34 +160,36 @@ func find(value KeyType, node *PrefixTrieNode, pathIndexes *[]int, path *[]*Pref
 	return find(value[match:], child, pathIndexes, path)
 }
 
-func (pt *prefixTrie) Find(value KeyType) *PrefixTrieNode {
+func (pt *collapsedTrie) Find(value KeyType) *collapsedVertex {
 	if len(value) <= 0 {
-		return pt.root
+		return pt.Root
 	}
-	return find(value, pt.root, nil, nil)
+	return find(value, pt.Root, nil, nil)
 }
 
-func (pt *prefixTrie) FindPath(value KeyType) ([]int, []*PrefixTrieNode) {
+func (pt *collapsedTrie) FindPath(value KeyType) ([]int, []*collapsedVertex) {
 	pathIndexes := []int{-1}
-	path := []*PrefixTrieNode{pt.root}
+	path := []*collapsedVertex{pt.Root}
-	result := find(value, pt.root, &pathIndexes, &path)
+	if len(value) > 0 {
-	if result == nil {
+		result := find(value, pt.Root, &pathIndexes, &path)
+		if result == nil { // not sure I want this line
 			return nil, nil
-	} // not sure I want this line
+		}
+	}
 	return pathIndexes, path
 }
 
 // IterateFrom can be used to find a value and run a function on that value.
 // If the handler returns true it continues to iterate through the children of value.
-func (pt *prefixTrie) IterateFrom(start KeyType, handler func(value *PrefixTrieNode) bool) {
+func (pt *collapsedTrie) IterateFrom(start KeyType, handler func(value *collapsedVertex) bool) {
-	node := find(start, pt.root, nil, nil)
+	node := find(start, pt.Root, nil, nil)
 	if node == nil {
 		return
 	}
 	iterateFrom(node, handler)
 }
 
-func iterateFrom(node *PrefixTrieNode, handler func(value *PrefixTrieNode) bool) {
+func iterateFrom(node *collapsedVertex, handler func(value *collapsedVertex) bool) {
 	for handler(node) {
 		for _, child := range node.children {
 			iterateFrom(child, handler)
@@ -197,19 +197,25 @@ func iterateFrom(node *PrefixTrieNode, handler func(value *PrefixTrieNode) bool)
 	}
 }
 
-func (pt *prefixTrie) Erase(value KeyType) bool {
+func (pt *collapsedTrie) Erase(value KeyType) bool {
 	indexes, path := pt.FindPath(value)
 	if path == nil || len(path) <= 1 {
+		if len(path) == 1 {
+			path[0].merkleHash = nil
+			path[0].claimHash = nil
+		}
 		return false
 	}
 	nodes := pt.Nodes
-	for i := len(path) - 1; i > 0; i-- {
+	i := len(path) - 1
+	path[i].claimHash = nil // this is the thing we are erasing; the rest is book-keeping
+	for ; i > 0; i-- {
 		childCount := len(path[i].children)
-		noClaimData := !path[i].hasClaims
+		noClaimData := path[i].claimHash == nil
+		path[i].merkleHash = nil
 		if childCount == 1 && noClaimData {
 			path[i].key = append(path[i].key, path[i].children[0].key...)
-			path[i].hash = nil
+			path[i].claimHash = path[i].children[0].claimHash
-			path[i].hasClaims = path[i].children[0].hasClaims
 			path[i].children = path[i].children[0].children
 			pt.Nodes--
 			continue
@@ -222,5 +228,8 @@ func (pt *prefixTrie) Erase(value KeyType) bool {
 		}
 		break
 	}
+	for ; i >= 0; i-- {
+		path[i].merkleHash = nil
+	}
 	return nodes > pt.Nodes
 }

claimtrie/merkletrie/collapsedtrie_test.go

@@ -9,10 +9,10 @@ import (
 )
 
 func b(value string) []byte      { return []byte(value) }
-func eq(x []byte, y string) bool { return bytes.Compare(x, b(y)) == 0 }
+func eq(x []byte, y string) bool { return bytes.Equal(x, b(y)) }
 
 func TestInsertAndErase(t *testing.T) {
-	trie := NewPrefixTrie()
+	trie := NewCollapsedTrie()
 	assert.True(t, trie.NodeCount() == 1)
 	inserted, node := trie.InsertOrFind(b("abc"))
 	assert.True(t, inserted)
@@ -45,8 +45,28 @@ func TestInsertAndErase(t *testing.T) {
 	assert.Equal(t, 1, trie.NodeCount())
 }
 
-func TestPrefixTrie(t *testing.T) {
+func TestNilNameHandling(t *testing.T) {
-	inserts := 1000000
+	trie := NewCollapsedTrie()
+	inserted, n := trie.InsertOrFind([]byte("test"))
+	assert.True(t, inserted)
+	n.claimHash = EmptyTrieHash
+	inserted, n = trie.InsertOrFind(nil)
+	assert.False(t, inserted)
+	n.claimHash = EmptyTrieHash
+	n.merkleHash = EmptyTrieHash
+	inserted, n = trie.InsertOrFind(nil)
+	assert.False(t, inserted)
+	assert.NotNil(t, n.claimHash)
+	assert.Nil(t, n.merkleHash)
+	nodeRemoved := trie.Erase(nil)
+	assert.False(t, nodeRemoved)
+	inserted, n = trie.InsertOrFind(nil)
+	assert.False(t, inserted)
+	assert.Nil(t, n.claimHash)
+}
+
+func TestCollapsedTriePerformance(t *testing.T) {
+	inserts := 10000 // increase this to 1M for more interesting results
 	data := make([][]byte, inserts)
 	rand.Seed(42)
 	for i := 0; i < inserts; i++ {
@@ -58,21 +78,21 @@ func TestPrefixTrie(t *testing.T) {
 		}
 	}
 
-	trie := NewPrefixTrie()
+	trie := NewCollapsedTrie()
 	// doing my own timing because I couldn't get the B.Run method to work:
 	start := time.Now()
 	for i := 0; i < inserts; i++ {
 		_, node := trie.InsertOrFind(data[i])
 		assert.NotNil(t, node, "Failure at %d of %d", i, inserts)
 	}
-	t.Logf("Insertion in %f sec.", time.Now().Sub(start).Seconds())
+	t.Logf("Insertion in %f sec.", time.Since(start).Seconds())
 
 	start = time.Now()
 	for i := 0; i < inserts; i++ {
 		node := trie.Find(data[i])
 		assert.True(t, bytes.HasSuffix(data[i], node.key), "Failure on %d of %d", i, inserts)
 	}
-	t.Logf("Lookup in %f sec. on %d nodes.", time.Now().Sub(start).Seconds(), trie.NodeCount())
+	t.Logf("Lookup in %f sec. on %d nodes.", time.Since(start).Seconds(), trie.NodeCount())
 
 	start = time.Now()
 	for i := 0; i < inserts; i++ {
@@ -81,12 +101,12 @@ func TestPrefixTrie(t *testing.T) {
 		assert.True(t, len(path) > 1)
 		assert.True(t, bytes.HasSuffix(data[i], path[len(path)-1].key))
 	}
-	t.Logf("Parents in %f sec.", time.Now().Sub(start).Seconds())
+	t.Logf("Parents in %f sec.", time.Since(start).Seconds())
 
 	start = time.Now()
 	for i := 0; i < inserts; i++ {
 		trie.Erase(data[i])
 	}
-	t.Logf("Deletion in %f sec.", time.Now().Sub(start).Seconds())
+	t.Logf("Deletion in %f sec.", time.Since(start).Seconds())
 	assert.Equal(t, 1, trie.NodeCount())
 }

claimtrie/merkletrie/merkletrie.go

@@ -7,25 +7,27 @@ import (
 	"sync"
 
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/claimtrie/node"
+
 	"github.com/cockroachdb/pebble"
 )
 
 var (
-	// EmptyTrieHash represents the Merkle Hash of an empty MerkleTrie.
+	// EmptyTrieHash represents the Merkle Hash of an empty PersistentTrie.
 	// "0000000000000000000000000000000000000000000000000000000000000001"
 	EmptyTrieHash  = &chainhash.Hash{1}
 	NoChildrenHash = &chainhash.Hash{2}
 	NoClaimsHash   = &chainhash.Hash{3}
 )
 
-// ValueStore enables MerkleTrie to query node values from different implementations.
+// ValueStore enables PersistentTrie to query node values from different implementations.
 type ValueStore interface {
-	ClaimHashes(name []byte) []*chainhash.Hash
 	Hash(name []byte) *chainhash.Hash
+	IterateNames(predicate func(name []byte) bool)
 }
 
-// MerkleTrie implements a 256-way prefix tree.
+// PersistentTrie implements a 256-way prefix tree.
-type MerkleTrie struct {
+type PersistentTrie struct {
 	store ValueStore
 	repo  Repo
 
@@ -33,10 +35,10 @@ type MerkleTrie struct {
 	bufs *sync.Pool
 }
 
-// New returns a MerkleTrie.
+// NewPersistentTrie returns a PersistentTrie.
-func New(store ValueStore, repo Repo) *MerkleTrie {
+func NewPersistentTrie(store ValueStore, repo Repo) *PersistentTrie {
 
-	tr := &MerkleTrie{
+	tr := &PersistentTrie{
 		store: store,
 		repo:  repo,
 		bufs: &sync.Pool{
@@ -50,14 +52,14 @@ func New(store ValueStore, repo Repo) *MerkleTrie {
 	return tr
 }
 
-// SetRoot drops all resolved nodes in the MerkleTrie, and set the root with specified hash.
+// SetRoot drops all resolved nodes in the PersistentTrie, and set the Root with specified hash.
-func (t *MerkleTrie) SetRoot(h *chainhash.Hash) {
+func (t *PersistentTrie) SetRoot(h *chainhash.Hash, names [][]byte) {
 	t.root = newVertex(h)
 }
 
 // Update updates the nodes along the path to the key.
 // Each node is resolved or created with their Hash cleared.
-func (t *MerkleTrie) Update(name []byte, restoreChildren bool) {
+func (t *PersistentTrie) Update(name []byte, restoreChildren bool) {
 
 	n := t.root
 	for i, ch := range name {
@@ -80,7 +82,7 @@ func (t *MerkleTrie) Update(name []byte, restoreChildren bool) {
 }
 
 // resolveChildLinks updates the links on n
-func (t *MerkleTrie) resolveChildLinks(n *vertex, key []byte) {
+func (t *PersistentTrie) resolveChildLinks(n *vertex, key []byte) {
 
 	if n.merkleHash == nil {
 		return
@@ -108,9 +110,9 @@ func (t *MerkleTrie) resolveChildLinks(n *vertex, key []byte) {
 	}
 }
 
-// MerkleHash returns the Merkle Hash of the MerkleTrie.
+// MerkleHash returns the Merkle Hash of the PersistentTrie.
 // All nodes must have been resolved before calling this function.
-func (t *MerkleTrie) MerkleHash() *chainhash.Hash {
+func (t *PersistentTrie) MerkleHash() *chainhash.Hash {
 	buf := make([]byte, 0, 256)
 	if h := t.merkle(buf, t.root); h == nil {
 		return EmptyTrieHash
@@ -120,7 +122,7 @@ func (t *MerkleTrie) MerkleHash() *chainhash.Hash {
 
 // merkle recursively resolves the hashes of the node.
 // All nodes must have been resolved before calling this function.
-func (t *MerkleTrie) merkle(prefix []byte, v *vertex) *chainhash.Hash {
+func (t *PersistentTrie) merkle(prefix []byte, v *vertex) *chainhash.Hash {
 	if v.merkleHash != nil {
 		return v.merkleHash
 	}
@@ -178,7 +180,7 @@ func keysInOrder(v *vertex) []byte {
 	return keys
 }
 
-func (t *MerkleTrie) MerkleHashAllClaims() *chainhash.Hash {
+func (t *PersistentTrie) MerkleHashAllClaims() *chainhash.Hash {
 	buf := make([]byte, 0, 256)
 	if h := t.merkleAllClaims(buf, t.root); h == nil {
 		return EmptyTrieHash
@@ -186,7 +188,7 @@ func (t *MerkleTrie) MerkleHashAllClaims() *chainhash.Hash {
 	return t.root.merkleHash
 }
 
-func (t *MerkleTrie) merkleAllClaims(prefix []byte, v *vertex) *chainhash.Hash {
+func (t *PersistentTrie) merkleAllClaims(prefix []byte, v *vertex) *chainhash.Hash {
 	if v.merkleHash != nil {
 		return v.merkleHash
 	}
@@ -213,32 +215,25 @@ func (t *MerkleTrie) merkleAllClaims(prefix []byte, v *vertex) *chainhash.Hash {
 		}
 	}
 
-	var claimsHash *chainhash.Hash
 	if v.hasValue {
-		claimsHash = v.claimsHash
+		if v.claimsHash == nil {
-		if claimsHash == nil {
+			v.claimsHash = t.store.Hash(prefix)
-			claimHashes := t.store.ClaimHashes(prefix)
+			v.hasValue = v.claimsHash != nil
-			if len(claimHashes) > 0 {
-				claimsHash = computeMerkleRoot(claimHashes)
-				v.claimsHash = claimsHash
-			} else {
-				v.hasValue = false
-			}
 		}
 	}
 
-	if len(childHashes) > 1 || claimsHash != nil { // yeah, about that 1 there -- old code used the condensed trie
+	if len(childHashes) > 1 || v.claimsHash != nil { // yeah, about that 1 there -- old code used the condensed trie
 		left := NoChildrenHash
 		if len(childHashes) > 0 {
-			left = computeMerkleRoot(childHashes)
+			left = node.ComputeMerkleRoot(childHashes)
 		}
 		right := NoClaimsHash
-		if claimsHash != nil {
+		if v.claimsHash != nil {
-			b.Write(claimsHash[:]) // for Has Value, nolint : errchk
+			b.Write(v.claimsHash[:]) // for Has Value, nolint : errchk
-			right = claimsHash
+			right = v.claimsHash
 		}
 
-		h := hashMerkleBranches(left, right)
+		h := node.HashMerkleBranches(left, right)
 		v.merkleHash = h
 		t.repo.Set(append(prefix, h[:]...), b.Bytes())
 	} else if len(childHashes) == 1 {
@@ -249,11 +244,11 @@ func (t *MerkleTrie) merkleAllClaims(prefix []byte, v *vertex) *chainhash.Hash {
 	return v.merkleHash
 }
 
-func (t *MerkleTrie) Close() error {
+func (t *PersistentTrie) Close() error {
 	return t.repo.Close()
 }
 
-func (t *MerkleTrie) Dump(s string, allClaims bool) {
+func (t *PersistentTrie) Dump(s string, allClaims bool) {
 	v := t.root
 
 	for i := 0; i < len(s); i++ {

claimtrie/merkletrie/merkletrie_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/claimtrie/node"
 
 	"github.com/stretchr/testify/require"
 )
@@ -15,10 +16,10 @@ func TestName(t *testing.T) {
 	target, _ := chainhash.NewHashFromStr("e9ffb584c62449f157c8be88257bd1eebb2d8ef824f5c86b43c4f8fd9e800d6a")
 
 	data := []*chainhash.Hash{EmptyTrieHash}
-	root := computeMerkleRoot(data)
+	root := node.ComputeMerkleRoot(data)
 	r.True(EmptyTrieHash.IsEqual(root))
 
 	data = append(data, NoChildrenHash, NoClaimsHash)
-	root = computeMerkleRoot(data)
+	root = node.ComputeMerkleRoot(data)
 	r.True(target.IsEqual(root))
 }

claimtrie/merkletrie/ramtrie.go

@@ -0,0 +1,139 @@
+package merkletrie
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/claimtrie/node"
+	"sync"
+)
+
+type MerkleTrie interface {
+	SetRoot(h *chainhash.Hash, names [][]byte)
+	Update(name []byte, restoreChildren bool)
+	MerkleHash() *chainhash.Hash
+	MerkleHashAllClaims() *chainhash.Hash
+}
+
+type RamTrie struct {
+	collapsedTrie
+	store ValueStore
+	bufs  *sync.Pool
+}
+
+func NewRamTrie(s ValueStore) *RamTrie {
+	return &RamTrie{
+		store: s,
+		bufs: &sync.Pool{
+			New: func() interface{} {
+				return new(bytes.Buffer)
+			},
+		},
+		collapsedTrie: collapsedTrie{Root: &collapsedVertex{}},
+	}
+}
+
+func (rt *RamTrie) SetRoot(h *chainhash.Hash, names [][]byte) {
+	if rt.Root.merkleHash.IsEqual(h) {
+		return
+	}
+
+	// if names is nil then we need to query all names
+	if names == nil {
+		fmt.Printf("Building the entire claim trie in RAM...\n")
+		// TODO: should technically clear the old trie first
+		rt.store.IterateNames(func(name []byte) bool {
+			rt.Update(name, false)
+			return true
+		})
+	} else {
+		for _, name := range names {
+			rt.Update(name, false)
+		}
+	}
+}
+
+func (rt *RamTrie) Update(name []byte, _ bool) {
+	h := rt.store.Hash(name)
+	if h == nil {
+		rt.Erase(name)
+	} else {
+		_, n := rt.InsertOrFind(name)
+		n.claimHash = h
+	}
+}
+
+func (rt *RamTrie) MerkleHash() *chainhash.Hash {
+	if h := rt.merkleHash(rt.Root); h == nil {
+		return EmptyTrieHash
+	}
+	return rt.Root.merkleHash
+}
+
+func (rt *RamTrie) merkleHash(v *collapsedVertex) *chainhash.Hash {
+	if v.merkleHash != nil {
+		return v.merkleHash
+	}
+
+	b := rt.bufs.Get().(*bytes.Buffer)
+	defer rt.bufs.Put(b)
+	b.Reset()
+
+	for _, ch := range v.children {
+		h := rt.merkleHash(ch)              // h is a pointer; don't destroy its data
+		b.WriteByte(ch.key[0])              // nolint : errchk
+		b.Write(rt.completeHash(h, ch.key)) // nolint : errchk
+	}
+
+	if v.claimHash != nil {
+		b.Write(v.claimHash[:])
+	}
+
+	if b.Len() > 0 {
+		h := chainhash.DoubleHashH(b.Bytes())
+		v.merkleHash = &h
+	}
+
+	return v.merkleHash
+}
+
+func (rt *RamTrie) completeHash(h *chainhash.Hash, childKey KeyType) []byte {
+	var data [chainhash.HashSize + 1]byte
+	copy(data[1:], h[:])
+	for i := len(childKey) - 1; i > 0; i-- {
+		data[0] = childKey[i]
+		copy(data[1:], chainhash.DoubleHashB(data[:]))
+	}
+	return data[1:]
+}
+
+func (rt *RamTrie) MerkleHashAllClaims() *chainhash.Hash {
+	return rt.merkleHashAllClaims(rt.Root)
+}
+
+func (rt *RamTrie) merkleHashAllClaims(v *collapsedVertex) *chainhash.Hash {
+	if v.merkleHash != nil {
+		return v.merkleHash
+	}
+
+	childHashes := make([]*chainhash.Hash, 0, len(v.children))
+	for _, ch := range v.children {
+		h := rt.merkleHashAllClaims(ch)
+		childHashes = append(childHashes, h)
+	}
+
+	claimHash := NoClaimsHash
+	if v.claimHash != nil {
+		claimHash = v.claimHash
+	} else if len(childHashes) == 0 {
+		return v.merkleHash
+	}
+
+	childHash := NoChildrenHash
+	if len(childHashes) > 0 {
+		childHash = node.ComputeMerkleRoot(childHashes)
+	}
+
+	v.merkleHash = node.HashMerkleBranches(childHash, claimHash)
+	return v.merkleHash
+}

claimtrie/merkletrie/repo.go

@@ -4,7 +4,7 @@ import (
 	"io"
 )
 
-// Repo defines APIs for MerkleTrie to access persistence layer.
+// Repo defines APIs for PersistentTrie to access persistence layer.
 type Repo interface {
 	Get(key []byte) ([]byte, io.Closer, error)
 	Set(key, value []byte) error

claimtrie/node/hashfunc.go

@@ -1,8 +1,8 @@
-package merkletrie
+package node
 
 import "github.com/btcsuite/btcd/chaincfg/chainhash"
 
-func hashMerkleBranches(left *chainhash.Hash, right *chainhash.Hash) *chainhash.Hash {
+func HashMerkleBranches(left *chainhash.Hash, right *chainhash.Hash) *chainhash.Hash {
 	// Concatenate the left and right nodes.
 	var hash [chainhash.HashSize * 2]byte
 	copy(hash[:chainhash.HashSize], left[:])
@@ -12,7 +12,7 @@ func hashMerkleBranches(left *chainhash.Hash, right *chainhash.Hash) *chainhash.
 	return &newHash
 }
 
-func computeMerkleRoot(hashes []*chainhash.Hash) *chainhash.Hash {
+func ComputeMerkleRoot(hashes []*chainhash.Hash) *chainhash.Hash {
 	if len(hashes) <= 0 {
 		return nil
 	}
@@ -21,7 +21,7 @@ func computeMerkleRoot(hashes []*chainhash.Hash) *chainhash.Hash {
 			hashes = append(hashes, hashes[len(hashes)-1])
 		}
 		for i := 0; i < len(hashes); i += 2 { // TODO: parallelize this loop (or use a lib that does it)
-			hashes[i>>1] = hashMerkleBranches(hashes[i], hashes[i+1])
+			hashes[i>>1] = HashMerkleBranches(hashes[i], hashes[i+1])
 		}
 		hashes = hashes[:len(hashes)>>1]
 	}

claimtrie/node/manager.go

@@ -21,7 +21,6 @@ type Manager interface {
 	Node(name []byte) (*Node, error)
 	NextUpdateHeightOfNode(name []byte) ([]byte, int32)
 	IterateNames(predicate func(name []byte) bool)
-	ClaimHashes(name []byte) []*chainhash.Hash
 	Hash(name []byte) *chainhash.Hash
 }
 
@@ -295,7 +294,7 @@ func (nm *BaseManager) IterateNames(predicate func(name []byte) bool) {
 	nm.repo.IterateAll(predicate)
 }
 
-func (nm *BaseManager) ClaimHashes(name []byte) []*chainhash.Hash {
+func (nm *BaseManager) claimHashes(name []byte) *chainhash.Hash {
 
 	n, err := nm.Node(name)
 	if err != nil || n == nil {
@@ -308,11 +307,18 @@ func (nm *BaseManager) ClaimHashes(name []byte) []*chainhash.Hash {
 			claimHashes = append(claimHashes, calculateNodeHash(c.OutPoint, n.TakenOverAt))
 		}
 	}
-	return claimHashes
+	if len(claimHashes) > 0 {
+		return ComputeMerkleRoot(claimHashes)
+	}
+	return nil
 }
 
 func (nm *BaseManager) Hash(name []byte) *chainhash.Hash {
 
+	if nm.height >= param.AllClaimsInMerkleForkHeight {
+		return nm.claimHashes(name)
+	}
+
 	n, err := nm.Node(name)
 	if err != nil {
 		return nil