Renaming functions in Votetally and cache to better represent their p…

…urpose

VoteTallyCache has been refactored to simplify some logic.

consensus/clique/src/main/java/tech/pegasys/pantheon/consensus/clique/CliqueHelpers.java

@@ -38,9 +38,9 @@ public static boolean addressIsAllowedToProduceNextBlock(
       final ProtocolContext<CliqueContext> protocolContext,
       final BlockHeader parent) {
     final VoteTally validatorProvider =
-        protocolContext.getConsensusState().getVoteTallyCache().getVoteTallyAtBlock(parent);
+        protocolContext.getConsensusState().getVoteTallyCache().getVoteTallyAfterBlock(parent);
 
-    if (!validatorProvider.getCurrentValidators().contains(candidate)) {
+    if (!validatorProvider.getValidators().contains(candidate)) {
       return false;
     }
 
@@ -72,7 +72,7 @@ public static boolean addressIsAllowedToProduceNextBlock(
   }
 
   private static int minimumBlocksSincePreviousSigning(final ValidatorProvider validatorProvider) {
-    final int validatorCount = validatorProvider.getCurrentValidators().size();
+    final int validatorCount = validatorProvider.getValidators().size();
     // The number of contiguous blocks in which a signer may only sign 1 (as taken from clique spec)
     final int signerLimit = (validatorCount / 2) + 1;
     return signerLimit - 1;

consensus/clique/src/main/java/tech/pegasys/pantheon/consensus/clique/VoteTallyCache.java

@@ -50,7 +50,18 @@ public VoteTallyCache(
     this.epochManager = epochManager;
   }
 
-  public VoteTally getVoteTallyAtBlock(final BlockHeader header) {
+  /**
+   * Determines the VoteTally for a given block header, by back-tracing the blockchain to a
+   * previously cached value or epoch block. Then appyling votes in each intermediate header such
+   * that representative state can be provided. This function assumes the vote cast in {@code
+   * header} is applied, thus the voteTally returned contains the group of validators who are
+   * permitted to partake in the next block's creation.
+   *
+   * @param header the header of the block after which the VoteTally is to be returned
+   * @return The Vote Tally (and therefore validators) following the application of all votes upto
+   *     and including the requested header.
+   */
+  public VoteTally getVoteTallyAfterBlock(final BlockHeader header) {
     try {
       return voteTallyCache.get(header.getHash(), () -> populateCacheUptoAndIncluding(header));
     } catch (final ExecutionException ex) {
@@ -64,7 +75,8 @@ private VoteTally populateCacheUptoAndIncluding(final BlockHeader start) {
     VoteTally voteTally = null;
 
     while (true) { // Will run into an epoch block (and thus a VoteTally) to break loop.
-      voteTally = findMostRecentAvailableVoteTally(header, intermediateBlocks);
+      intermediateBlocks.push(header);
+      voteTally = getValidatorsAfter(header);
       if (voteTally != null) {
         break;
       }
@@ -80,24 +92,22 @@ private VoteTally populateCacheUptoAndIncluding(final BlockHeader start) {
     return constructMissingCacheEntries(intermediateBlocks, voteTally);
   }
 
-  private VoteTally findMostRecentAvailableVoteTally(
-      final BlockHeader header, final Deque<BlockHeader> intermediateBlockHeaders) {
-    intermediateBlockHeaders.push(header);
-    VoteTally voteTally = voteTallyCache.getIfPresent(header.getParentHash());
-    if ((voteTally == null) && (epochManager.isEpochBlock(header.getNumber()))) {
-      final CliqueExtraData extraData = CliqueExtraData.decode(header.getExtraData());
-      voteTally = new VoteTally(extraData.getValidators());
+  private VoteTally getValidatorsAfter(final BlockHeader header) {
+    if (epochManager.isEpochBlock(header.getNumber())) {
+      final CliqueBlockInterface blockInterface = new CliqueBlockInterface();
+      return new VoteTally(blockInterface.validatorsInBlock(header));
     }
 
-    return voteTally;
+    return voteTallyCache.getIfPresent(header.getParentHash());
   }
 
   private VoteTally constructMissingCacheEntries(
       final Deque<BlockHeader> headers, final VoteTally tally) {
+    final VoteTally mutableVoteTally = tally.copy();
     while (!headers.isEmpty()) {
       final BlockHeader h = headers.pop();
-      voteTallyUpdater.updateForBlock(h, tally);
-      voteTallyCache.put(h.getHash(), tally.copy());
+      voteTallyUpdater.updateForBlock(h, mutableVoteTally);
+      voteTallyCache.put(h.getHash(), mutableVoteTally.copy());
     }
     return tally;
   }

consensus/clique/src/main/java/tech/pegasys/pantheon/consensus/clique/blockcreation/CliqueBlockCreator.java

@@ -85,7 +85,8 @@ protected BlockHeader createFinalBlockHeader(final SealableBlockHeader sealableB
             .blockHashFunction(blockHashFunction);
 
     final CliqueContext cliqueContext = protocolContext.getConsensusState();
-    final VoteTally voteTally = cliqueContext.getVoteTallyCache().getVoteTallyAtBlock(parentHeader);
+    final VoteTally voteTally =
+        cliqueContext.getVoteTallyCache().getVoteTallyAfterBlock(parentHeader);
 
     final Optional<ValidatorVote> vote =
         cliqueContext

consensus/clique/src/main/java/tech/pegasys/pantheon/consensus/clique/blockcreation/CliqueBlockScheduler.java

@@ -60,11 +60,11 @@ private int calculateTurnBasedDelay(final BlockHeader parentHeader) {
     if (nextProposer.equals(localNodeAddress)) {
       return 0;
     }
-    return calculatorOutOfTurnDelay(voteTallyCache.getVoteTallyAtBlock(parentHeader));
+    return calculatorOutOfTurnDelay(voteTallyCache.getVoteTallyAfterBlock(parentHeader));
   }
 
   private int calculatorOutOfTurnDelay(final ValidatorProvider validators) {
-    final int countSigners = validators.getCurrentValidators().size();
+    final int countSigners = validators.getValidators().size();
     final double multiplier = (countSigners / 2d) + 1;
     final int maxDelay = (int) (multiplier * OUT_OF_TURN_DELAY_MULTIPLIER_MILLIS);
     return r.nextInt(maxDelay) + 1;

consensus/clique/src/main/java/tech/pegasys/pantheon/consensus/clique/blockcreation/CliqueMinerExecutor.java

@@ -101,8 +101,11 @@ public BytesValue calculateExtraData(final BlockHeader parentHeader) {
     // Building ON TOP of canonical head, if the next block is epoch, include validators.
     if (epochManager.isEpochBlock(parentHeader.getNumber() + 1)) {
       final VoteTally voteTally =
-          protocolContext.getConsensusState().getVoteTallyCache().getVoteTallyAtBlock(parentHeader);
-      validators.addAll(voteTally.getCurrentValidators());
+          protocolContext
+              .getConsensusState()
+              .getVoteTallyCache()
+              .getVoteTallyAfterBlock(parentHeader);
+      validators.addAll(voteTally.getValidators());
     }
 
     final CliqueExtraData extraData = new CliqueExtraData(vanityDataToInsert, null, validators);

consensus/clique/src/main/java/tech/pegasys/pantheon/consensus/clique/blockcreation/CliqueProposerSelector.java

@@ -45,8 +45,8 @@ public CliqueProposerSelector(final VoteTallyCache voteTallyCache) {
    */
   public Address selectProposerForNextBlock(final BlockHeader parentHeader) {
 
-    final VoteTally parentVoteTally = voteTallyCache.getVoteTallyAtBlock(parentHeader);
-    final List<Address> validatorSet = new ArrayList<>(parentVoteTally.getCurrentValidators());
+    final VoteTally parentVoteTally = voteTallyCache.getVoteTallyAfterBlock(parentHeader);
+    final List<Address> validatorSet = new ArrayList<>(parentVoteTally.getValidators());
 
     final long nextBlockNumber = parentHeader.getNumber() + 1L;
     final int indexIntoValidators = (int) (nextBlockNumber % validatorSet.size());

consensus/clique/src/main/java/tech/pegasys/pantheon/consensus/clique/headervalidationrules/CliqueExtraDataValidationRule.java

@@ -59,9 +59,9 @@ public boolean validate(
       final ProtocolContext<CliqueContext> protocolContext) {
     try {
       final VoteTally validatorProvider =
-          protocolContext.getConsensusState().getVoteTallyCache().getVoteTallyAtBlock(parent);
+          protocolContext.getConsensusState().getVoteTallyCache().getVoteTallyAfterBlock(parent);
 
-      final Collection<Address> storedValidators = validatorProvider.getCurrentValidators();
+      final Collection<Address> storedValidators = validatorProvider.getValidators();
       return extraDataIsValid(storedValidators, header);
 
     } catch (final RLPException ex) {

consensus/clique/src/main/java/tech/pegasys/pantheon/consensus/clique/jsonrpc/methods/CliqueGetSigners.java

@@ -53,7 +53,7 @@ public String getName() {
   public JsonRpcResponse response(final JsonRpcRequest request) {
     final Optional<BlockHeader> blockHeader = determineBlockHeader(request);
     return blockHeader
-        .map(bh -> voteTallyCache.getVoteTallyAtBlock(bh).getCurrentValidators())
+        .map(bh -> voteTallyCache.getVoteTallyAfterBlock(bh).getValidators())
         .map(addresses -> addresses.stream().map(Objects::toString).collect(Collectors.toList()))
         .<JsonRpcResponse>map(addresses -> new JsonRpcSuccessResponse(request.getId(), addresses))
         .orElse(new JsonRpcErrorResponse(request.getId(), JsonRpcError.INTERNAL_ERROR));

consensus/clique/src/main/java/tech/pegasys/pantheon/consensus/clique/jsonrpc/methods/CliqueGetSignersAtHash.java

@@ -53,7 +53,7 @@ public String getName() {
   public JsonRpcResponse response(final JsonRpcRequest request) {
     final Optional<BlockHeader> blockHeader = determineBlockHeader(request);
     return blockHeader
-        .map(bh -> voteTallyCache.getVoteTallyAtBlock(bh).getCurrentValidators())
+        .map(bh -> voteTallyCache.getVoteTallyAfterBlock(bh).getValidators())
         .map(addresses -> addresses.stream().map(Objects::toString).collect(Collectors.toList()))
         .<JsonRpcResponse>map(addresses -> new JsonRpcSuccessResponse(request.getId(), addresses))
         .orElse(new JsonRpcErrorResponse(request.getId(), JsonRpcError.INTERNAL_ERROR));

consensus/clique/src/test/java/tech/pegasys/pantheon/consensus/clique/CliqueDifficultyCalculatorTest.java

@@ -51,7 +51,7 @@ public void setup() {
     validatorList.add(AddressHelpers.calculateAddressWithRespectTo(localAddr, 1));
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     final VoteProposer voteProposer = new VoteProposer();
 
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);

consensus/clique/src/test/java/tech/pegasys/pantheon/consensus/clique/NodeCanProduceNextBlockTest.java

@@ -73,7 +73,7 @@ public void networkWithOneValidatorIsAllowedToCreateConsecutiveBlocks() {
     blockChain = createInMemoryBlockchain(genesisBlock);
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     final VoteProposer voteProposer = new VoteProposer();
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);
     cliqueProtocolContext = new ProtocolContext<>(blockChain, null, cliqueContext);
@@ -98,7 +98,7 @@ public void networkWithTwoValidatorsIsAllowedToProduceBlockIfNotPreviousBlockPro
     blockChain = createInMemoryBlockchain(genesisBlock);
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     final VoteProposer voteProposer = new VoteProposer();
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);
     cliqueProtocolContext = new ProtocolContext<>(blockChain, null, cliqueContext);
@@ -132,7 +132,7 @@ public void networkWithTwoValidatorsIsNotAllowedToProduceBlockIfIsPreviousBlockP
     blockChain = createInMemoryBlockchain(genesisBlock);
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     final VoteProposer voteProposer = new VoteProposer();
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);
     cliqueProtocolContext = new ProtocolContext<>(blockChain, null, cliqueContext);
@@ -162,7 +162,7 @@ public void withThreeValidatorsMustHaveOneBlockBetweenSignings() {
     blockChain = createInMemoryBlockchain(genesisBlock);
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     final VoteProposer voteProposer = new VoteProposer();
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);
     cliqueProtocolContext = new ProtocolContext<>(blockChain, null, cliqueContext);
@@ -207,7 +207,7 @@ public void signerIsValidIfInsufficientBlocksExistInHistory() {
     blockChain = createInMemoryBlockchain(genesisBlock);
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     final VoteProposer voteProposer = new VoteProposer();
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);
     cliqueProtocolContext = new ProtocolContext<>(blockChain, null, cliqueContext);
@@ -236,7 +236,7 @@ public void exceptionIsThrownIfOnAnOrphanedChain() {
     blockChain = createInMemoryBlockchain(genesisBlock);
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     final VoteProposer voteProposer = new VoteProposer();
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);
     cliqueProtocolContext = new ProtocolContext<>(blockChain, null, cliqueContext);
@@ -260,7 +260,7 @@ public void nonValidatorIsNotAllowedToCreateABlock() {
     blockChain = createInMemoryBlockchain(genesisBlock);
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     final VoteProposer voteProposer = new VoteProposer();
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);
     cliqueProtocolContext = new ProtocolContext<>(blockChain, null, cliqueContext);

consensus/clique/src/test/java/tech/pegasys/pantheon/consensus/clique/VoteTallyCacheTest.java

@@ -87,7 +87,7 @@ public void parentBlockVoteTallysAreCachedWhenChildVoteTallyRequested() {
     // The votetallyUpdater should be invoked for the requested block, and all parents including
     // the epoch (genesis) block.
     final ArgumentCaptor<BlockHeader> varArgs = ArgumentCaptor.forClass(BlockHeader.class);
-    cache.getVoteTallyAtBlock(block_2.getHeader());
+    cache.getVoteTallyAfterBlock(block_2.getHeader());
     verify(tallyUpdater, times(3)).updateForBlock(varArgs.capture(), any());
     assertThat(varArgs.getAllValues())
         .isEqualTo(
@@ -97,10 +97,10 @@ public void parentBlockVoteTallysAreCachedWhenChildVoteTallyRequested() {
 
     // Requesting the vote tally to the parent block should not invoke the voteTallyUpdater as the
     // vote tally was cached from previous operation.
-    cache.getVoteTallyAtBlock(block_1.getHeader());
+    cache.getVoteTallyAfterBlock(block_1.getHeader());
     verifyZeroInteractions(tallyUpdater);
 
-    cache.getVoteTallyAtBlock(block_2.getHeader());
+    cache.getVoteTallyAfterBlock(block_2.getHeader());
     verifyZeroInteractions(tallyUpdater);
   }
 
@@ -113,7 +113,7 @@ public void exceptionThrownIfNoParentBlockExists() {
     final Block orphanBlock = createEmptyBlock(4, Hash.ZERO);
 
     assertThatExceptionOfType(UncheckedExecutionException.class)
-        .isThrownBy(() -> cache.getVoteTallyAtBlock(orphanBlock.getHeader()))
+        .isThrownBy(() -> cache.getVoteTallyAfterBlock(orphanBlock.getHeader()))
         .withMessageContaining(
             "Supplied block was on a orphaned chain, unable to generate " + "VoteTally.");
   }
@@ -125,14 +125,14 @@ public void walkBackStopsWhenACachedVoteTallyIsFound() {
         new VoteTallyCache(blockChain, tallyUpdater, new EpochManager(30_000));
 
     // Load the Cache up to block_2
-    cache.getVoteTallyAtBlock(block_2.getHeader());
+    cache.getVoteTallyAfterBlock(block_2.getHeader());
 
     reset(tallyUpdater);
 
     // Append new blocks to the chain, and ensure the walkback only goes as far as block_2.
     final Block block_3 = createEmptyBlock(4, block_2.getHeader().getHash());
     // Load the Cache up to block_2
-    cache.getVoteTallyAtBlock(block_3.getHeader());
+    cache.getVoteTallyAfterBlock(block_3.getHeader());
 
     // The votetallyUpdater should be invoked for the requested block, and all parents including
     // the epoch (genesis) block.

consensus/clique/src/test/java/tech/pegasys/pantheon/consensus/clique/blockcreation/CliqueBlockCreatorTest.java

@@ -75,7 +75,7 @@ public void setup() {
     validatorList.add(otherAddress);
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     voteProposer = new VoteProposer();
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);
 

consensus/clique/src/test/java/tech/pegasys/pantheon/consensus/clique/blockcreation/CliqueBlockSchedulerTest.java

@@ -51,7 +51,7 @@ public void setup() {
     validatorList.add(AddressHelpers.calculateAddressWithRespectTo(localAddr, 1));
 
     voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
 
     blockHeaderBuilder = new BlockHeaderTestFixture();
   }

consensus/clique/src/test/java/tech/pegasys/pantheon/consensus/clique/blockcreation/CliqueMinerExecutorTest.java

@@ -66,7 +66,7 @@ public void setup() {
     validatorList.add(AddressHelpers.calculateAddressWithRespectTo(localAddress, 3));
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     final VoteProposer voteProposer = new VoteProposer();
 
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);

consensus/clique/src/test/java/tech/pegasys/pantheon/consensus/clique/blockcreation/CliqueProposerSelectorTest.java

@@ -43,7 +43,7 @@ public class CliqueProposerSelectorTest {
   @Before
   public void setup() {
     voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(voteTally);
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(voteTally);
   }
 
   @Test

consensus/clique/src/test/java/tech/pegasys/pantheon/consensus/clique/headervalidationrules/CliqueDifficultyValidationRuleTest.java

@@ -56,7 +56,7 @@ public void setup() {
     validatorList.add(AddressHelpers.calculateAddressWithRespectTo(localAddress, 1));
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
     final VoteProposer voteProposer = new VoteProposer();
 
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, voteProposer, null);

consensus/clique/src/test/java/tech/pegasys/pantheon/consensus/clique/headervalidationrules/CliqueExtraDataValidationRuleTest.java

@@ -54,7 +54,7 @@ public void setup() {
     validatorList.add(AddressHelpers.calculateAddressWithRespectTo(localAddr, 1));
 
     final VoteTallyCache voteTallyCache = mock(VoteTallyCache.class);
-    when(voteTallyCache.getVoteTallyAtBlock(any())).thenReturn(new VoteTally(validatorList));
+    when(voteTallyCache.getVoteTallyAfterBlock(any())).thenReturn(new VoteTally(validatorList));
 
     final CliqueContext cliqueContext = new CliqueContext(voteTallyCache, null, null);
     cliqueProtocolContext = new ProtocolContext<>(null, null, cliqueContext);

consensus/clique/src/test/java/tech/pegasys/pantheon/consensus/clique/jsonrpc/methods/CliqueGetSignersAtHashTest.java

@@ -109,8 +109,8 @@ public void returnsValidatorsForBlockHash() {
     when(blockchainQueries.blockByHash(Hash.fromHexString(BLOCK_HASH)))
         .thenReturn(Optional.of(blockWithMetadata));
     when(blockWithMetadata.getHeader()).thenReturn(blockHeader);
-    when(voteTallyCache.getVoteTallyAtBlock(blockHeader)).thenReturn(voteTally);
-    when(voteTally.getCurrentValidators()).thenReturn(validators);
+    when(voteTallyCache.getVoteTallyAfterBlock(blockHeader)).thenReturn(voteTally);
+    when(voteTally.getValidators()).thenReturn(validators);
 
     final JsonRpcSuccessResponse response = (JsonRpcSuccessResponse) method.response(request);
     assertEquals(validatorsAsStrings, response.getResult());