Implement percentiles array size limit for eth_feeHistory (#8748)

* implement percentiles array size limit for eth_feeHistory

Signed-off-by: garyschulte <[email protected]>

Author: garyschulte

CHANGELOG.md

@@ -8,6 +8,7 @@
 #### Fusaka Devnet
 - EIP-7825 - Transaction gas limit cap [#8700](https://github.com/hyperledger/besu/pull/8700)
 - EIP-7823 - Modexp upper bounds [#8632](https://github.com/hyperledger/besu/pull/8632)
+- implement rewardPercentile cap in eth_feeHistory [#8748](https://github.com/hyperledger/besu/pull/8748)
 
 ### Bug fixes
 

ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/EthFeeHistory.java

@@ -67,6 +67,7 @@ public class EthFeeHistory implements JsonRpcMethod {
   private final ApiConfiguration apiConfiguration;
   private final Cache<RewardCacheKey, List<Wei>> cache;
   private static final int MAXIMUM_CACHE_SIZE = 100_000;
+  private static final int MAXIMUM_QUERY_PERCENTILES = 100;
 
   record RewardCacheKey(Hash blockHash, List<Double> rewardPercentiles) {}
 
@@ -139,8 +140,9 @@ public JsonRpcResponse response(final JsonRpcRequestContext request) {
     final List<Double> gasUsedRatios = getGasUsedRatios(blockHeaderRange);
     final List<Double> blobGasUsedRatios = getBlobGasUsedRatios(blockHeaderRange);
     final Optional<List<List<Wei>>> maybeRewards =
-        maybeRewardPercentiles.map(
-            percentiles -> getRewards(percentiles, blockHeaderRange, nextBaseFee));
+        maybeRewardPercentiles
+            .filter(list -> list.size() <= MAXIMUM_QUERY_PERCENTILES)
+            .map(percentiles -> getRewards(percentiles, blockHeaderRange, nextBaseFee));
     return new JsonRpcSuccessResponse(
         requestId,
         createFeeHistoryResult(

ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/methods/EthFeeHistoryTest.java

@@ -61,6 +61,8 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
 import java.util.stream.Stream;
 
 import org.apache.tuweni.bytes.Bytes;
@@ -368,6 +370,48 @@ public void allZeroPercentilesForZeroBlock() {
     assertThat(result.getReward()).isEqualTo(List.of(List.of("0x0")));
   }
 
+  @Test
+  public void assertMaximumPercentilesArraySize() {
+    final ProtocolSpec londonSpec = mock(ProtocolSpec.class);
+    when(londonSpec.getFeeMarket()).thenReturn(FeeMarket.london(5));
+    final BlockDataGenerator.BlockOptions blockOptions = BlockDataGenerator.BlockOptions.create();
+    blockOptions.hasTransactions(false);
+    blockOptions.setParentHash(blockchain.getChainHeadHash());
+    blockOptions.setBlockNumber(11);
+    final Block emptyBlock = gen.block(blockOptions);
+    blockchain.appendBlock(emptyBlock, gen.receipts(emptyBlock));
+    when(protocolSchedule.getForNextBlockHeader(
+            eq(blockchain.getChainHeadHeader()),
+            eq(blockchain.getChainHeadHeader().getTimestamp())))
+        .thenReturn(londonSpec);
+
+    double[] biglist = new double[500];
+    Arrays.fill(biglist, 1d);
+    List<Double> oversizeRewardPercentiles =
+        Arrays.stream(biglist).boxed().collect(Collectors.toList());
+
+    List<Double> maxRewardPercentiles =
+        IntStream.rangeClosed(1, 100)
+            .mapToDouble(i -> i / 100d)
+            .boxed()
+            .collect(Collectors.toList());
+
+    // assert we return no percentiles for array sizes > 100
+    final FeeHistory.FeeHistoryResult result =
+        (FeeHistory.FeeHistoryResult)
+            ((JsonRpcSuccessResponse) feeHistoryRequest("0x1", "latest", oversizeRewardPercentiles))
+                .getResult();
+    assertThat(result.getReward()).isNull();
+
+    // assert we will return percentiles for array sizes <= 100
+    final FeeHistory.FeeHistoryResult resultOk =
+        (FeeHistory.FeeHistoryResult)
+            ((JsonRpcSuccessResponse) feeHistoryRequest("0x1", "latest", maxRewardPercentiles))
+                .getResult();
+    assertThat(resultOk.getReward()).isNotNull();
+    assertThat(resultOk.getReward().get(0).size()).isEqualTo(100);
+  }
+
   private void assertFeeMetadataSize(final Object feeObject, final int blockCount) {
     assertThat(((ImmutableFeeHistoryResult) feeObject).getBaseFeePerGas().size())
         .isEqualTo(blockCount + 1);