[PAN-1247] Implement eth_submitHashrate JSON RPC API

ethereum/blockcreation/src/main/java/tech/pegasys/pantheon/ethereum/blockcreation/EthHashBlockCreator.java

@@ -103,6 +103,10 @@ public boolean submitWork(final EthHashSolution solution) {
     return nonceSolver.submitSolution(solution);
   }
 
+  public boolean submitHashesPerSecond(final String remoteMinerId, final long hashrate) {
+    return nonceSolver.submitHashesPerSecond(remoteMinerId, hashrate);
+  }
+
   @Override
   public void cancel() {
     super.cancel();

ethereum/blockcreation/src/main/java/tech/pegasys/pantheon/ethereum/blockcreation/EthHashBlockMiner.java

@@ -52,4 +52,8 @@ public Optional<Long> getHashesPerSecond() {
   public boolean submitWork(final EthHashSolution solution) {
     return blockCreator.submitWork(solution);
   }
+
+  public boolean submitHashesPerSecond(final String remoteMinerId, final long hashrate) {
+    return blockCreator.submitHashesPerSecond(remoteMinerId, hashrate);
+  }
 }

ethereum/blockcreation/src/main/java/tech/pegasys/pantheon/ethereum/blockcreation/EthHashMiningCoordinator.java

@@ -73,6 +73,15 @@ public boolean submitWork(final EthHashSolution solution) {
     }
   }
 
+  @Override
+  public boolean submitHashesPerSecond(final String remoteMinerId, final long hashrate) {
+    synchronized (this) {
+      return currentRunningMiner
+          .map(miner -> miner.submitHashesPerSecond(remoteMinerId, hashrate))
+          .orElse(false);
+    }
+  }
+
   @Override
   protected void haltCurrentMiningOperation() {
     currentRunningMiner.ifPresent(

ethereum/blockcreation/src/main/java/tech/pegasys/pantheon/ethereum/blockcreation/MiningCoordinator.java

@@ -47,6 +47,11 @@ default Optional<Long> hashesPerSecond() {
         "Current consensus mechanism prevents querying of hashrate.");
   }
 
+  default boolean submitHashesPerSecond(final String remoteMinerId, final long hashrate) {
+    throw new UnsupportedOperationException(
+        "Current consensus mechanism prevents submitting hashrate.");
+  }
+
   default Optional<EthHashSolverInputs> getWorkDefinition() {
     throw new UnsupportedOperationException(
         "Current consensus mechanism prevents querying work definition.");

ethereum/core/src/main/java/tech/pegasys/pantheon/ethereum/mainnet/EthHashSolver.java

@@ -18,10 +18,13 @@
 import tech.pegasys.pantheon.util.uint.UInt256;
 
 import java.util.Arrays;
+import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
 
 import com.google.common.base.Stopwatch;
 
@@ -72,6 +75,7 @@ public EthHashSolution getSolution() throws InterruptedException, ExecutionExcep
   private final Iterable<Long> nonceGenerator;
   private final EthHasher ethHasher;
   private volatile long hashesPerSecond = NO_MINING_CONDUCTED;
+  private final Map<String, Long> hashPerSecondOfRemoteMiners = new ConcurrentHashMap<>();
 
   private volatile Optional<EthHashSolverJob> currentJob = Optional.empty();
 
@@ -129,10 +133,16 @@ public Optional<EthHashSolverInputs> getWorkDefinition() {
   }
 
   public Optional<Long> hashesPerSecond() {
-    if (hashesPerSecond == NO_MINING_CONDUCTED) {
+    if (hashesPerSecond == NO_MINING_CONDUCTED && hashPerSecondOfRemoteMiners.isEmpty()) {
       return Optional.empty();
     }
-    return Optional.of(hashesPerSecond);
+
+    AtomicLong totalHashrate = new AtomicLong(hashesPerSecond);
+    // add remote miners hashes per second if present
+    totalHashrate.addAndGet(
+        hashPerSecondOfRemoteMiners.values().stream().mapToLong(Long::longValue).sum());
+
+    return Optional.of(totalHashrate.longValue());
   }
 
   public boolean submitSolution(final EthHashSolution solution) {
@@ -156,4 +166,9 @@ public boolean submitSolution(final EthHashSolution solution) {
     }
     return false;
   }
+
+  public boolean submitHashesPerSecond(final String remoteMinerId, final long hashesPerSecond) {
+    hashPerSecondOfRemoteMiners.put(remoteMinerId, hashesPerSecond);
+    return true;
+  }
 }

ethereum/jsonrpc/src/main/java/tech/pegasys/pantheon/ethereum/jsonrpc/RpcMethod.java

@@ -69,6 +69,7 @@ public enum RpcMethod {
   ETH_GET_UNCLE_COUNT_BY_BLOCK_NUMBER("eth_getUncleCountByBlockNumber"),
   ETH_GET_WORK("eth_getWork"),
   ETH_HASHRATE("eth_hashrate"),
+  ETH_SUBMIT_HASHRATE("eth_submitHashrate"),
   ETH_MINING("eth_mining"),
   ETH_NEW_BLOCK_FILTER("eth_newBlockFilter"),
   ETH_NEW_FILTER("eth_newFilter"),

ethereum/jsonrpc/src/main/java/tech/pegasys/pantheon/ethereum/jsonrpc/internal/methods/EthSubmitHashrate.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2018 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.jsonrpc.internal.methods;
+
+import tech.pegasys.pantheon.ethereum.blockcreation.MiningCoordinator;
+import tech.pegasys.pantheon.ethereum.jsonrpc.RpcMethod;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.JsonRpcRequest;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.parameters.JsonRpcParameter;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcError;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcErrorResponse;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcResponse;
+import tech.pegasys.pantheon.ethereum.jsonrpc.internal.response.JsonRpcSuccessResponse;
+
+public class EthSubmitHashrate implements JsonRpcMethod {
+
+  private final MiningCoordinator miningCoordinator;
+  private final JsonRpcParameter parameters;
+
+  public EthSubmitHashrate(
+      final MiningCoordinator miningCoordinator, final JsonRpcParameter parameters) {
+    this.miningCoordinator = miningCoordinator;
+    this.parameters = parameters;
+  }
+
+  @Override
+  public String getName() {
+    return RpcMethod.ETH_SUBMIT_HASHRATE.getMethodName();
+  }
+
+  @Override
+  public JsonRpcResponse response(final JsonRpcRequest req) {
+    try {
+
+      if (req.getParamLength() != 2) {
+        return new JsonRpcErrorResponse(req.getId(), JsonRpcError.INVALID_PARAMS);
+      }
+
+      final long hashrate = parameters.required(req.getParams(), 0, long.class);
+      final String remoteMinerId = parameters.required(req.getParams(), 1, String.class);
+
+      return new JsonRpcSuccessResponse(
+          req.getId(), miningCoordinator.submitHashesPerSecond(remoteMinerId, hashrate));
+    } catch (final UnsupportedOperationException ex) {
+      return new JsonRpcErrorResponse(req.getId(), JsonRpcError.INVALID_REQUEST);
+    }
+  }
+}