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path: root/trie/secure_trie.go
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Diffstat (limited to 'trie/secure_trie.go')
-rw-r--r--trie/secure_trie.go33
1 files changed, 23 insertions, 10 deletions
diff --git a/trie/secure_trie.go b/trie/secure_trie.go
index efe875bc8..2a8b57214 100644
--- a/trie/secure_trie.go
+++ b/trie/secure_trie.go
@@ -24,6 +24,8 @@ import (
var secureKeyPrefix = []byte("secure-key-")
+const secureKeyLength = 11 + 32 // Length of the above prefix + 32byte hash
+
// SecureTrie wraps a trie with key hashing. In a secure trie, all
// access operations hash the key using keccak256. This prevents
// calling code from creating long chains of nodes that
@@ -35,10 +37,11 @@ var secureKeyPrefix = []byte("secure-key-")
//
// SecureTrie is not safe for concurrent use.
type SecureTrie struct {
- trie Trie
- hashKeyBuf []byte
- secKeyBuf [200]byte
- secKeyCache map[string][]byte
+ trie Trie
+ hashKeyBuf [secureKeyLength]byte
+ secKeyBuf [200]byte
+ secKeyCache map[string][]byte
+ secKeyCacheOwner *SecureTrie // Pointer to self, replace the key cache on mismatch
}
// NewSecure creates a trie with an existing root node from db.
@@ -56,8 +59,7 @@ func NewSecure(root common.Hash, db Database) (*SecureTrie, error) {
return nil, err
}
return &SecureTrie{
- trie: *trie,
- secKeyCache: make(map[string][]byte),
+ trie: *trie,
}, nil
}
@@ -104,7 +106,7 @@ func (t *SecureTrie) TryUpdate(key, value []byte) error {
if err != nil {
return err
}
- t.secKeyCache[string(hk)] = common.CopyBytes(key)
+ t.getSecKeyCache()[string(hk)] = common.CopyBytes(key)
return nil
}
@@ -119,14 +121,14 @@ func (t *SecureTrie) Delete(key []byte) {
// If a node was not found in the database, a MissingNodeError is returned.
func (t *SecureTrie) TryDelete(key []byte) error {
hk := t.hashKey(key)
- delete(t.secKeyCache, string(hk))
+ delete(t.getSecKeyCache(), string(hk))
return t.trie.TryDelete(hk)
}
// GetKey returns the sha3 preimage of a hashed key that was
// previously used to store a value.
func (t *SecureTrie) GetKey(shaKey []byte) []byte {
- if key, ok := t.secKeyCache[string(shaKey)]; ok {
+ if key, ok := t.getSecKeyCache()[string(shaKey)]; ok {
return key
}
key, _ := t.trie.db.Get(t.secKey(shaKey))
@@ -165,7 +167,7 @@ func (t *SecureTrie) NodeIterator() *NodeIterator {
// the trie's database. Calling code must ensure that the changes made to db are
// written back to the trie's attached database before using the trie.
func (t *SecureTrie) CommitTo(db DatabaseWriter) (root common.Hash, err error) {
- if len(t.secKeyCache) > 0 {
+ if len(t.getSecKeyCache()) > 0 {
for hk, key := range t.secKeyCache {
if err := db.Put(t.secKey([]byte(hk)), key); err != nil {
return common.Hash{}, err
@@ -196,3 +198,14 @@ func (t *SecureTrie) hashKey(key []byte) []byte {
returnHasherToPool(h)
return buf
}
+
+// getSecKeyCache returns the current secure key cache, creating a new one if
+// ownership changed (i.e. the current secure trie is a copy of another owning
+// the actual cache).
+func (t *SecureTrie) getSecKeyCache() map[string][]byte {
+ if t != t.secKeyCacheOwner {
+ t.secKeyCacheOwner = t
+ t.secKeyCache = make(map[string][]byte)
+ }
+ return t.secKeyCache
+}