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-rw-r--r--trie/iterator.go141
-rw-r--r--trie/iterator_test.go32
-rw-r--r--trie/sync_test.go95
3 files changed, 260 insertions, 8 deletions
diff --git a/trie/iterator.go b/trie/iterator.go
index 5f205e081..ceef52ec8 100644
--- a/trie/iterator.go
+++ b/trie/iterator.go
@@ -18,22 +18,27 @@ package trie
import (
"bytes"
+ "fmt"
+ "github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
)
+// Iterator is a key-value trie iterator to traverse the data contents.
type Iterator struct {
trie *Trie
- Key []byte
- Value []byte
+ Key []byte // Current data key on which the iterator is positioned on
+ Value []byte // Current data value on which the iterator is positioned on
}
+// NewIterator creates a new key-value iterator.
func NewIterator(trie *Trie) *Iterator {
return &Iterator{trie: trie, Key: nil}
}
+// Next moves the iterator forward with one key-value entry.
func (self *Iterator) Next() bool {
isIterStart := false
if self.Key == nil {
@@ -142,6 +147,138 @@ func (self *Iterator) key(node interface{}) []byte {
}
return self.key(rn)
}
+ return nil
+}
+
+// nodeIteratorState represents the iteration state at one particular node of the
+// trie, which can be resumed at a later invocation.
+type nodeIteratorState struct {
+ hash common.Hash // Hash of the node being iterated (nil if not standalone)
+ node node // Trie node being iterated
+ parent common.Hash // Hash of the first full ancestor node (nil if current is the root)
+ child int // Child to be processed next
+}
+
+// NodeIterator is an iterator to traverse the trie post-order.
+type NodeIterator struct {
+ trie *Trie // Trie being iterated
+ stack []*nodeIteratorState // Hierarchy of trie nodes persisting the iteration state
+
+ Hash common.Hash // Hash of the current node being iterated (nil if not standalone)
+ Node node // Current node being iterated (internal representation)
+ Parent common.Hash // Hash of the first full ancestor node (nil if current is the root)
+ Leaf bool // Flag whether the current node is a value (data) node
+ LeafBlob []byte // Data blob contained within a leaf (otherwise nil)
+
+ Error error // Failure set in case of an internal error in the iterator
+}
+
+// NewNodeIterator creates an post-order trie iterator.
+func NewNodeIterator(trie *Trie) *NodeIterator {
+ if bytes.Compare(trie.Root(), emptyRoot.Bytes()) == 0 {
+ return new(NodeIterator)
+ }
+ return &NodeIterator{trie: trie}
+}
+
+// Next moves the iterator to the next node, returning whether there are any
+// further nodes. In case of an internal error this method returns false and
+// sets the Error field to the encountered failure.
+func (it *NodeIterator) Next() bool {
+ // If the iterator failed previously, don't do anything
+ if it.Error != nil {
+ return false
+ }
+ // Otherwise step forward with the iterator and report any errors
+ if err := it.step(); err != nil {
+ it.Error = err
+ return false
+ }
+ return it.retrieve()
+}
+
+// step moves the iterator to the next node of the trie.
+func (it *NodeIterator) step() error {
+ // Abort if we reached the end of the iteration
+ if it.trie == nil {
+ return nil
+ }
+ // Initialize the iterator if we've just started, or pop off the old node otherwise
+ if len(it.stack) == 0 {
+ it.stack = append(it.stack, &nodeIteratorState{node: it.trie.root, child: -1})
+ if it.stack[0].node == nil {
+ return fmt.Errorf("root node missing: %x", it.trie.Root())
+ }
+ } else {
+ it.stack = it.stack[:len(it.stack)-1]
+ if len(it.stack) == 0 {
+ it.trie = nil
+ return nil
+ }
+ }
+ // Continue iteration to the next child
+ for {
+ parent := it.stack[len(it.stack)-1]
+ ancestor := parent.hash
+ if (ancestor == common.Hash{}) {
+ ancestor = parent.parent
+ }
+ if node, ok := parent.node.(fullNode); ok {
+ // Full node, traverse all children, then the node itself
+ if parent.child >= len(node) {
+ break
+ }
+ for parent.child++; parent.child < len(node); parent.child++ {
+ if current := node[parent.child]; current != nil {
+ it.stack = append(it.stack, &nodeIteratorState{node: current, parent: ancestor, child: -1})
+ break
+ }
+ }
+ } else if node, ok := parent.node.(shortNode); ok {
+ // Short node, traverse the pointer singleton child, then the node itself
+ if parent.child >= 0 {
+ break
+ }
+ parent.child++
+ it.stack = append(it.stack, &nodeIteratorState{node: node.Val, parent: ancestor, child: -1})
+ } else if hash, ok := parent.node.(hashNode); ok {
+ // Hash node, resolve the hash child from the database, then the node itself
+ if parent.child >= 0 {
+ break
+ }
+ parent.child++
+ node, err := it.trie.resolveHash(hash, nil, nil)
+ if err != nil {
+ return err
+ }
+ it.stack = append(it.stack, &nodeIteratorState{hash: common.BytesToHash(hash), node: node, parent: ancestor, child: -1})
+ } else {
+ break
+ }
+ }
return nil
}
+
+// retrieve pulls and caches the current trie node the iterator is traversing.
+// In case of a value node, the additional leaf blob is also populated with the
+// data contents for external interpretation.
+//
+// The method returns whether there are any more data left for inspection.
+func (it *NodeIterator) retrieve() bool {
+ // Clear out any previously set values
+ it.Hash, it.Node, it.Parent, it.Leaf, it.LeafBlob = common.Hash{}, nil, common.Hash{}, false, nil
+
+ // If the iteration's done, return no available data
+ if it.trie == nil {
+ return false
+ }
+ // Otherwise retrieve the current node and resolve leaf accessors
+ state := it.stack[len(it.stack)-1]
+
+ it.Hash, it.Node, it.Parent = state.hash, state.node, state.parent
+ if value, ok := it.Node.(valueNode); ok {
+ it.Leaf, it.LeafBlob = true, []byte(value)
+ }
+ return true
+}
diff --git a/trie/iterator_test.go b/trie/iterator_test.go
index fdc60b412..dc8276116 100644
--- a/trie/iterator_test.go
+++ b/trie/iterator_test.go
@@ -16,7 +16,12 @@
package trie
-import "testing"
+import (
+ "testing"
+
+ "github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/ethdb"
+)
func TestIterator(t *testing.T) {
trie := newEmpty()
@@ -47,3 +52,28 @@ func TestIterator(t *testing.T) {
}
}
}
+
+// Tests that the node iterator indeed walks over the entire database contents.
+func TestNodeIteratorCoverage(t *testing.T) {
+ // Create some arbitrary test trie to iterate
+ db, trie, _ := makeTestTrie()
+
+ // Gather all the node hashes found by the iterator
+ hashes := make(map[common.Hash]struct{})
+ for it := NewNodeIterator(trie); it.Next(); {
+ if it.Hash != (common.Hash{}) {
+ hashes[it.Hash] = struct{}{}
+ }
+ }
+ // Cross check the hashes and the database itself
+ for hash, _ := range hashes {
+ if _, err := db.Get(hash.Bytes()); err != nil {
+ t.Errorf("failed to retrieve reported node %x: %v", hash, err)
+ }
+ }
+ for _, key := range db.(*ethdb.MemDatabase).Keys() {
+ if _, ok := hashes[common.BytesToHash(key)]; !ok {
+ t.Errorf("state entry not reported %x", key)
+ }
+ }
+}
diff --git a/trie/sync_test.go b/trie/sync_test.go
index 9c036a3a9..a81f7650e 100644
--- a/trie/sync_test.go
+++ b/trie/sync_test.go
@@ -33,6 +33,7 @@ func makeTestTrie() (ethdb.Database, *Trie, map[string][]byte) {
// Fill it with some arbitrary data
content := make(map[string][]byte)
for i := byte(0); i < 255; i++ {
+ // Map the same data under multiple keys
key, val := common.LeftPadBytes([]byte{1, i}, 32), []byte{i}
content[string(key)] = val
trie.Update(key, val)
@@ -40,9 +41,19 @@ func makeTestTrie() (ethdb.Database, *Trie, map[string][]byte) {
key, val = common.LeftPadBytes([]byte{2, i}, 32), []byte{i}
content[string(key)] = val
trie.Update(key, val)
+
+ // Add some other data to inflate th trie
+ for j := byte(3); j < 13; j++ {
+ key, val = common.LeftPadBytes([]byte{j, i}, 32), []byte{j, i}
+ content[string(key)] = val
+ trie.Update(key, val)
+ }
}
trie.Commit()
+ // Remove any potentially cached data from the test trie creation
+ globalCache.Clear()
+
// Return the generated trie
return db, trie, content
}
@@ -50,10 +61,17 @@ func makeTestTrie() (ethdb.Database, *Trie, map[string][]byte) {
// checkTrieContents cross references a reconstructed trie with an expected data
// content map.
func checkTrieContents(t *testing.T, db Database, root []byte, content map[string][]byte) {
+ // Remove any potentially cached data from the trie synchronisation
+ globalCache.Clear()
+
+ // Check root availability and trie contents
trie, err := New(common.BytesToHash(root), db)
if err != nil {
t.Fatalf("failed to create trie at %x: %v", root, err)
}
+ if err := checkTrieConsistency(db, common.BytesToHash(root)); err != nil {
+ t.Fatalf("inconsistent trie at %x: %v", root, err)
+ }
for key, val := range content {
if have := trie.Get([]byte(key)); bytes.Compare(have, val) != 0 {
t.Errorf("entry %x: content mismatch: have %x, want %x", key, have, val)
@@ -61,6 +79,22 @@ func checkTrieContents(t *testing.T, db Database, root []byte, content map[strin
}
}
+// checkTrieConsistency checks that all nodes in a trie are indeed present.
+func checkTrieConsistency(db Database, root common.Hash) error {
+ // Remove any potentially cached data from the test trie creation or previous checks
+ globalCache.Clear()
+
+ // Create and iterate a trie rooted in a subnode
+ trie, err := New(root, db)
+ if err != nil {
+ return nil // // Consider a non existent state consistent
+ }
+ it := NewNodeIterator(trie)
+ for it.Next() {
+ }
+ return it.Error
+}
+
// Tests that an empty trie is not scheduled for syncing.
func TestEmptyTrieSync(t *testing.T) {
emptyA, _ := New(common.Hash{}, nil)
@@ -102,7 +136,7 @@ func testIterativeTrieSync(t *testing.T, batch int) {
}
queue = append(queue[:0], sched.Missing(batch)...)
}
- // Cross check that the two tries re in sync
+ // Cross check that the two tries are in sync
checkTrieContents(t, dstDb, srcTrie.Root(), srcData)
}
@@ -132,7 +166,7 @@ func TestIterativeDelayedTrieSync(t *testing.T) {
}
queue = append(queue[len(results):], sched.Missing(10000)...)
}
- // Cross check that the two tries re in sync
+ // Cross check that the two tries are in sync
checkTrieContents(t, dstDb, srcTrie.Root(), srcData)
}
@@ -173,7 +207,7 @@ func testIterativeRandomTrieSync(t *testing.T, batch int) {
queue[hash] = struct{}{}
}
}
- // Cross check that the two tries re in sync
+ // Cross check that the two tries are in sync
checkTrieContents(t, dstDb, srcTrie.Root(), srcData)
}
@@ -216,7 +250,7 @@ func TestIterativeRandomDelayedTrieSync(t *testing.T) {
queue[hash] = struct{}{}
}
}
- // Cross check that the two tries re in sync
+ // Cross check that the two tries are in sync
checkTrieContents(t, dstDb, srcTrie.Root(), srcData)
}
@@ -252,6 +286,57 @@ func TestDuplicateAvoidanceTrieSync(t *testing.T) {
}
queue = append(queue[:0], sched.Missing(0)...)
}
- // Cross check that the two tries re in sync
+ // Cross check that the two tries are in sync
checkTrieContents(t, dstDb, srcTrie.Root(), srcData)
}
+
+// Tests that at any point in time during a sync, only complete sub-tries are in
+// the database.
+func TestIncompleteTrieSync(t *testing.T) {
+ // Create a random trie to copy
+ srcDb, srcTrie, _ := makeTestTrie()
+
+ // Create a destination trie and sync with the scheduler
+ dstDb, _ := ethdb.NewMemDatabase()
+ sched := NewTrieSync(common.BytesToHash(srcTrie.Root()), dstDb, nil)
+
+ added := []common.Hash{}
+ queue := append([]common.Hash{}, sched.Missing(1)...)
+ for len(queue) > 0 {
+ // Fetch a batch of trie nodes
+ results := make([]SyncResult, len(queue))
+ for i, hash := range queue {
+ data, err := srcDb.Get(hash.Bytes())
+ if err != nil {
+ t.Fatalf("failed to retrieve node data for %x: %v", hash, err)
+ }
+ results[i] = SyncResult{hash, data}
+ }
+ // Process each of the trie nodes
+ if index, err := sched.Process(results); err != nil {
+ t.Fatalf("failed to process result #%d: %v", index, err)
+ }
+ for _, result := range results {
+ added = append(added, result.Hash)
+ }
+ // Check that all known sub-tries in the synced trie is complete
+ for _, root := range added {
+ if err := checkTrieConsistency(dstDb, root); err != nil {
+ t.Fatalf("trie inconsistent: %v", err)
+ }
+ }
+ // Fetch the next batch to retrieve
+ queue = append(queue[:0], sched.Missing(1)...)
+ }
+ // Sanity check that removing any node from the database is detected
+ for _, node := range added[1:] {
+ key := node.Bytes()
+ value, _ := dstDb.Get(key)
+
+ dstDb.Delete(key)
+ if err := checkTrieConsistency(dstDb, added[0]); err == nil {
+ t.Fatalf("trie inconsistency not caught, missing: %x", key)
+ }
+ dstDb.Put(key, value)
+ }
+}
generated by cgit (git 2.34.1) at 2024-10-11 20:26:20 +0800