Add serialization functionality to NodeDataRequest (#724)

Signed-off-by: Adrian Sutton <adrian.sutton@consensys.net>

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

@@ -27,7 +27,7 @@ import java.util.List;
 class AccountTrieNodeDataRequest extends TrieNodeDataRequest {
 
   AccountTrieNodeDataRequest(final Hash hash) {
-    super(Kind.ACCOUNT_TRIE_NODE, hash);
+    super(RequestType.ACCOUNT_TRIE_NODE, hash);
   }
 
   @Override

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

@@ -22,7 +22,7 @@ import java.util.stream.Stream;
 class CodeNodeDataRequest extends NodeDataRequest {
 
   CodeNodeDataRequest(final Hash hash) {
-    super(Kind.CODE, hash);
+    super(RequestType.CODE, hash);
   }
 
   @Override

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

@@ -13,24 +13,22 @@
 package tech.pegasys.pantheon.ethereum.eth.sync.worldstate;
 
 import tech.pegasys.pantheon.ethereum.core.Hash;
+import tech.pegasys.pantheon.ethereum.rlp.RLP;
+import tech.pegasys.pantheon.ethereum.rlp.RLPInput;
+import tech.pegasys.pantheon.ethereum.rlp.RLPOutput;
 import tech.pegasys.pantheon.ethereum.worldstate.WorldStateStorage;
 import tech.pegasys.pantheon.util.bytes.BytesValue;
 
 import java.util.stream.Stream;
 
-abstract class NodeDataRequest {
-  public enum Kind {
-    ACCOUNT_TRIE_NODE,
-    STORAGE_TRIE_NODE,
-    CODE
-  }
+public abstract class NodeDataRequest {
 
-  private final Kind kind;
+  private final RequestType requestType;
   private final Hash hash;
   private BytesValue data;
 
-  protected NodeDataRequest(final Kind kind, final Hash hash) {
-    this.kind = kind;
+  protected NodeDataRequest(final RequestType requestType, final Hash hash) {
+    this.requestType = requestType;
     this.hash = hash;
   }
 
@@ -46,8 +44,40 @@ abstract class NodeDataRequest {
     return new CodeNodeDataRequest(hash);
   }
 
-  public Kind getKind() {
-    return kind;
+  public static BytesValue serialize(final NodeDataRequest request) {
+    return RLP.encode(request::writeTo);
+  }
+
+  public static NodeDataRequest deserialize(final BytesValue encoded) {
+    RLPInput in = RLP.input(encoded);
+    in.enterList();
+    RequestType requestType = RequestType.fromValue(in.readByte());
+    Hash hash = Hash.wrap(in.readBytes32());
+    in.leaveList();
+
+    switch (requestType) {
+      case ACCOUNT_TRIE_NODE:
+        return createAccountDataRequest(hash);
+      case STORAGE_TRIE_NODE:
+        return createStorageDataRequest(hash);
+      case CODE:
+        return createCodeRequest(hash);
+      default:
+        throw new IllegalArgumentException(
+            "Unable to deserialize provided data into a valid "
+                + NodeDataRequest.class.getSimpleName());
+    }
+  }
+
+  private void writeTo(final RLPOutput out) {
+    out.startList();
+    out.writeByte(requestType.getValue());
+    out.writeBytesValue(hash);
+    out.endList();
+  }
+
+  public RequestType getRequestType() {
+    return requestType;
   }
 
   public Hash getHash() {

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

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.ethereum.eth.sync.worldstate;
+
+public enum RequestType {
+  ACCOUNT_TRIE_NODE((byte) 1),
+  STORAGE_TRIE_NODE((byte) 2),
+  CODE((byte) 3);
+
+  private final byte value;
+
+  RequestType(final byte value) {
+    this.value = value;
+  }
+
+  public byte getValue() {
+    return value;
+  }
+
+  public static RequestType fromValue(final byte value) {
+    switch (value) {
+      case (byte) 1:
+        return ACCOUNT_TRIE_NODE;
+      case (byte) 2:
+        return STORAGE_TRIE_NODE;
+      case (byte) 3:
+        return CODE;
+      default:
+        throw new IllegalArgumentException("Invalid value supplied");
+    }
+  }
+}

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

@@ -24,7 +24,7 @@ import java.util.List;
 class StorageTrieNodeDataRequest extends TrieNodeDataRequest {
 
   StorageTrieNodeDataRequest(final Hash hash) {
-    super(Kind.STORAGE_TRIE_NODE, hash);
+    super(RequestType.STORAGE_TRIE_NODE, hash);
   }
 
   @Override

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

@@ -24,7 +24,7 @@ abstract class TrieNodeDataRequest extends NodeDataRequest {
 
   private static final TrieNodeDecoder nodeDecoder = TrieNodeDecoder.create();
 
-  TrieNodeDataRequest(final Kind kind, final Hash hash) {
+  TrieNodeDataRequest(final RequestType kind, final Hash hash) {
     super(kind, hash);
   }
 

ethereum/eth/src/test/java/tech/pegasys/pantheon/ethereum/eth/sync/worldstate/NodeDataRequestTest.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.ethereum.eth.sync.worldstate;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import tech.pegasys.pantheon.ethereum.core.BlockDataGenerator;
+
+import org.junit.Test;
+
+public class NodeDataRequestTest {
+
+  @Test
+  public void serializesAccountTrieNodeRequests() {
+    BlockDataGenerator gen = new BlockDataGenerator(0);
+    AccountTrieNodeDataRequest request = NodeDataRequest.createAccountDataRequest(gen.hash());
+    NodeDataRequest sedeRequest = serializeThenDeserialize(request);
+    assertRequestsEquals(sedeRequest, request);
+    assertThat(sedeRequest).isInstanceOf(AccountTrieNodeDataRequest.class);
+  }
+
+  @Test
+  public void serializesStorageTrieNodeRequests() {
+    BlockDataGenerator gen = new BlockDataGenerator(0);
+    StorageTrieNodeDataRequest request = NodeDataRequest.createStorageDataRequest(gen.hash());
+    NodeDataRequest sedeRequest = serializeThenDeserialize(request);
+    assertRequestsEquals(sedeRequest, request);
+    assertThat(sedeRequest).isInstanceOf(StorageTrieNodeDataRequest.class);
+  }
+
+  @Test
+  public void serializesCodeRequests() {
+    BlockDataGenerator gen = new BlockDataGenerator(0);
+    CodeNodeDataRequest request = NodeDataRequest.createCodeRequest(gen.hash());
+    NodeDataRequest sedeRequest = serializeThenDeserialize(request);
+    assertRequestsEquals(sedeRequest, request);
+    assertThat(sedeRequest).isInstanceOf(CodeNodeDataRequest.class);
+  }
+
+  private NodeDataRequest serializeThenDeserialize(final NodeDataRequest request) {
+    return NodeDataRequest.deserialize(NodeDataRequest.serialize(request));
+  }
+
+  private void assertRequestsEquals(final NodeDataRequest actual, final NodeDataRequest expected) {
+    assertThat(actual.getRequestType()).isEqualTo(expected.getRequestType());
+    assertThat(actual.getHash()).isEqualTo(expected.getHash());
+    assertThat(actual.getData()).isEqualTo(expected.getData());
+  }
+}