Single threaded world state persistence

ethereum/eth/src/main/java/tech/pegasys/pantheon/ethereum/eth/sync/worldstate/AccountTrieNodeDataRequest.java

@@ -12,8 +12,6 @@
  */
 package tech.pegasys.pantheon.ethereum.eth.sync.worldstate;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 import tech.pegasys.pantheon.ethereum.core.Hash;
 import tech.pegasys.pantheon.ethereum.rlp.RLP;
 import tech.pegasys.pantheon.ethereum.trie.MerklePatriciaTrie;
@@ -33,8 +31,7 @@ class AccountTrieNodeDataRequest extends TrieNodeDataRequest {
   }
 
   @Override
-  public void persist(final Updater updater) {
-    checkNotNull(getData(), "Must set data before node can be persisted.");
+  protected void doPersist(final Updater updater) {
     updater.putAccountStateTrieNode(getHash(), getData());
   }
 

ethereum/eth/src/main/java/tech/pegasys/pantheon/ethereum/eth/sync/worldstate/CodeNodeDataRequest.java

@@ -12,8 +12,6 @@
  */
 package tech.pegasys.pantheon.ethereum.eth.sync.worldstate;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 import tech.pegasys.pantheon.ethereum.core.Hash;
 import tech.pegasys.pantheon.ethereum.worldstate.WorldStateStorage;
 import tech.pegasys.pantheon.ethereum.worldstate.WorldStateStorage.Updater;
@@ -29,8 +27,7 @@ class CodeNodeDataRequest extends NodeDataRequest {
   }
 
   @Override
-  public void persist(final Updater updater) {
-    checkNotNull(getData(), "Must set data before node can be persisted.");
+  protected void doPersist(final Updater updater) {
     updater.putCode(getHash(), getData());
   }
 

ethereum/eth/src/main/java/tech/pegasys/pantheon/ethereum/eth/sync/worldstate/NodeDataRequest.java

@@ -12,6 +12,8 @@
  */
 package tech.pegasys.pantheon.ethereum.eth.sync.worldstate;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 import tech.pegasys.pantheon.ethereum.core.Hash;
 import tech.pegasys.pantheon.ethereum.rlp.RLP;
 import tech.pegasys.pantheon.ethereum.rlp.RLPInput;
@@ -28,6 +30,7 @@ public abstract class NodeDataRequest {
   private final RequestType requestType;
   private final Hash hash;
   private BytesValue data;
+  private boolean requiresPersisting = true;
   private final AtomicInteger failedRequestCount = new AtomicInteger(0);
 
   protected NodeDataRequest(final RequestType requestType, final Hash hash) {
@@ -52,14 +55,14 @@ public static BytesValue serialize(final NodeDataRequest request) {
   }
 
   public static NodeDataRequest deserialize(final BytesValue encoded) {
-    RLPInput in = RLP.input(encoded);
+    final RLPInput in = RLP.input(encoded);
     in.enterList();
-    RequestType requestType = RequestType.fromValue(in.readByte());
-    Hash hash = Hash.wrap(in.readBytes32());
-    int failureCount = in.readIntScalar();
+    final RequestType requestType = RequestType.fromValue(in.readByte());
+    final Hash hash = Hash.wrap(in.readBytes32());
+    final int failureCount = in.readIntScalar();
     in.leaveList();
 
-    NodeDataRequest deserialized;
+    final NodeDataRequest deserialized;
     switch (requestType) {
       case ACCOUNT_TRIE_NODE:
         deserialized = createAccountDataRequest(hash);
@@ -105,6 +108,11 @@ public NodeDataRequest setData(final BytesValue data) {
     return this;
   }
 
+  public NodeDataRequest setRequiresPersisting(final boolean requiresPersisting) {
+    this.requiresPersisting = requiresPersisting;
+    return this;
+  }
+
   public int trackFailure() {
     return failedRequestCount.incrementAndGet();
   }
@@ -113,7 +121,14 @@ private void setFailureCount(final int failures) {
     failedRequestCount.set(failures);
   }
 
-  public abstract void persist(final WorldStateStorage.Updater updater);
+  public final void persist(final WorldStateStorage.Updater updater) {
+    if (requiresPersisting) {
+      checkNotNull(getData(), "Must set data before node can be persisted.");
+      doPersist(updater);
+    }
+  }
+
+  protected abstract void doPersist(final WorldStateStorage.Updater updater);
 
   public abstract Stream<NodeDataRequest> getChildRequests();
 

ethereum/eth/src/main/java/tech/pegasys/pantheon/ethereum/eth/sync/worldstate/StorageTrieNodeDataRequest.java

@@ -12,8 +12,6 @@
  */
 package tech.pegasys.pantheon.ethereum.eth.sync.worldstate;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
 import tech.pegasys.pantheon.ethereum.core.Hash;
 import tech.pegasys.pantheon.ethereum.worldstate.WorldStateStorage;
 import tech.pegasys.pantheon.ethereum.worldstate.WorldStateStorage.Updater;
@@ -30,8 +28,7 @@ class StorageTrieNodeDataRequest extends TrieNodeDataRequest {
   }
 
   @Override
-  public void persist(final Updater updater) {
-    checkNotNull(getData(), "Must set data before node can be persisted.");
+  protected void doPersist(final Updater updater) {
     updater.putAccountStorageTrieNode(getHash(), getData());
   }
 

ethereum/eth/src/main/java/tech/pegasys/pantheon/ethereum/eth/sync/worldstate/TrieNodeDataRequest.java

@@ -13,6 +13,7 @@
 package tech.pegasys.pantheon.ethereum.eth.sync.worldstate;
 
 import tech.pegasys.pantheon.ethereum.core.Hash;
+import tech.pegasys.pantheon.ethereum.trie.MerklePatriciaTrie;
 import tech.pegasys.pantheon.ethereum.trie.Node;
 import tech.pegasys.pantheon.ethereum.trie.TrieNodeDecoder;
 import tech.pegasys.pantheon.util.bytes.BytesValue;
@@ -58,7 +59,11 @@ private Stream<NodeDataRequest> getRequestsFromLoadedTrieNode(final Node<BytesVa
   private Stream<NodeDataRequest> getRequestsFromChildTrieNode(final Node<BytesValue> trieNode) {
     if (trieNode.isReferencedByHash()) {
       // If child nodes are reference by hash, we need to download them
-      NodeDataRequest req = createChildNodeDataRequest(Hash.wrap(trieNode.getHash()));
+      final Hash hash = Hash.wrap(trieNode.getHash());
+      if (MerklePatriciaTrie.EMPTY_TRIE_NODE_HASH.equals(hash) || BytesValue.EMPTY.equals(hash)) {
+        return Stream.empty();
+      }
+      final NodeDataRequest req = createChildNodeDataRequest(hash);
       return Stream.of(req);
     }
     // Otherwise if the child's value has been inlined we can go ahead and process it