trie: cache collapsed tries node, not rlp blobs (#16876)

The current trie memory database/cache that we do pruning on stores
trie nodes as binary rlp encoded blobs, and also stores the node
relationships/references for GC purposes. However, most of the trie
nodes (everything apart from a value node) is in essence just a
collection of references.

This PR switches out the RLP encoded trie blobs with the
collapsed-but-not-serialized trie nodes. This permits most of the
references to be recovered from within the node data structure,
avoiding the need to track them a second time (expensive memory wise).

3 files changed, 5 insertions, 5 deletions

diff --git a/core/blockchain.go b/core/blockchain.go
index 34832252a..0b50e3f37 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -672,7 +672,7 @@ func (bc *BlockChain) Stop() {
 			}
 		}
 		for !bc.triegc.Empty() {
-			triedb.Dereference(bc.triegc.PopItem().(common.Hash), common.Hash{})
+			triedb.Dereference(bc.triegc.PopItem().(common.Hash))
 		}
 		if size, _ := triedb.Size(); size != 0 {
 			log.Error("Dangling trie nodes after full cleanup")
@@ -947,7 +947,7 @@ func (bc *BlockChain) WriteBlockWithState(block *types.Block, receipts []*types.
 					bc.triegc.Push(root, number)
 					break
 				}
-				triedb.Dereference(root.(common.Hash), common.Hash{})
+				triedb.Dereference(root.(common.Hash))
 			}
 		}
 	}
diff --git a/core/blockchain_test.go b/core/blockchain_test.go
index f409bb7b0..687209bfa 100644
--- a/core/blockchain_test.go
+++ b/core/blockchain_test.go
@@ -1313,8 +1313,8 @@ func TestTrieForkGC(t *testing.T) {
 	}
 	// Dereference all the recent tries and ensure no past trie is left in
 	for i := 0; i < triesInMemory; i++ {
-		chain.stateCache.TrieDB().Dereference(blocks[len(blocks)-1-i].Root(), common.Hash{})
-		chain.stateCache.TrieDB().Dereference(forks[len(blocks)-1-i].Root(), common.Hash{})
+		chain.stateCache.TrieDB().Dereference(blocks[len(blocks)-1-i].Root())
+		chain.stateCache.TrieDB().Dereference(forks[len(blocks)-1-i].Root())
 	}
 	if len(chain.stateCache.TrieDB().Nodes()) > 0 {
 		t.Fatalf("stale tries still alive after garbase collection")
diff --git a/core/state/statedb.go b/core/state/statedb.go
index ffea761d9..92d394ae3 100644
--- a/core/state/statedb.go
+++ b/core/state/statedb.go
@@ -596,7 +596,7 @@ func (s *StateDB) Commit(deleteEmptyObjects bool) (root common.Hash, err error)
 		case isDirty:
 			// Write any contract code associated with the state object
 			if stateObject.code != nil && stateObject.dirtyCode {
-				s.db.TrieDB().Insert(common.BytesToHash(stateObject.CodeHash()), stateObject.code)
+				s.db.TrieDB().InsertBlob(common.BytesToHash(stateObject.CodeHash()), stateObject.code)
 				stateObject.dirtyCode = false
 			}
 			// Write any storage changes in the state object to its storage trie.