Implement eip 3529 (#2238)

Signed-off-by: Karim TAAM <karim.t2am@gmail.com>

CHANGELOG.md

@@ -7,6 +7,7 @@
 * Added support for the upcoming BAIKAL ephemeral testnet and removed the configuration for the deprecated YOLOv3 ephemeral testnet. [\#2237](https://github.com/hyperledger/besu/pull/2237)
 * Added support for the London Network Upgrade, although the block number must be set manually with `--override-genesis-config=londonBlock=<blocknumber>`. This is because the block numbers haven't been determined yet. The next release will include the number in the genesis file so it will support London with no intervention. [\#2237](https://github.com/hyperledger/besu/pull/2237)
 * Implemented [EIP-3541](https://eips.ethereum.org/EIPS/eip-3541): Reject new contracts starting with the 0xEF byte [\#2243](https://github.com/hyperledger/besu/pull/2243)
+* Implemented [EIP-3529](https://eips.ethereum.org/EIPS/eip-3529): Reduction in refunds [\#2238](https://github.com/hyperledger/besu/pull/2238)
 
 
 ### Bug Fixes

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/BerlinGasCalculator.java

@@ -45,18 +45,18 @@ public class BerlinGasCalculator extends IstanbulGasCalculator {
   private static final Gas COLD_ACCOUNT_ACCESS_COST = Gas.of(2600);
   private static final Gas WARM_STORAGE_READ_COST = Gas.of(100);
   private static final Gas ACCESS_LIST_ADDRESS_COST = Gas.of(2400);
-  private static final Gas ACCESS_LIST_STORAGE_COST = Gas.of(1900);
+  protected static final Gas ACCESS_LIST_STORAGE_COST = Gas.of(1900);
 
   // redefinitions for EIP-2929
   private static final Gas SLOAD_GAS = WARM_STORAGE_READ_COST;
-  private static final Gas SSTORE_RESET_GAS = Gas.of(5000L).minus(COLD_SLOAD_COST);
+  protected static final Gas SSTORE_RESET_GAS = Gas.of(5000L).minus(COLD_SLOAD_COST);
 
   // unchanged from Istanbul
   private static final Gas SSTORE_SET_GAS = Gas.of(20_000);
   private static final Gas SSTORE_CLEARS_SCHEDULE = Gas.of(15_000);
 
-  private static final Gas SSTORE_SET_GAS_LESS_SLOAD_GAS = SSTORE_SET_GAS.minus(SLOAD_GAS);
+  protected static final Gas SSTORE_SET_GAS_LESS_SLOAD_GAS = SSTORE_SET_GAS.minus(SLOAD_GAS);
-  private static final Gas SSTORE_RESET_GAS_LESS_SLOAD_GAS = SSTORE_RESET_GAS.minus(SLOAD_GAS);
+  protected static final Gas SSTORE_RESET_GAS_LESS_SLOAD_GAS = SSTORE_RESET_GAS.minus(SLOAD_GAS);
   private static final Gas NEGATIVE_SSTORE_CLEARS_SCHEDULE = Gas.ZERO.minus(SSTORE_CLEARS_SCHEDULE);
 
   // unchanged from Frontier

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/LondonGasCalculator.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package org.hyperledger.besu.ethereum.mainnet;
+
+import org.hyperledger.besu.ethereum.core.Account;
+import org.hyperledger.besu.ethereum.core.Gas;
+
+import org.apache.tuweni.units.bigints.UInt256;
+
+public class LondonGasCalculator extends BerlinGasCalculator {
+
+  // redefinitions for EIP-3529
+  private static final Gas SSTORE_CLEARS_SCHEDULE = SSTORE_RESET_GAS.plus(ACCESS_LIST_STORAGE_COST);
+
+  private static final Gas NEGATIVE_SSTORE_CLEARS_SCHEDULE = Gas.ZERO.minus(SSTORE_CLEARS_SCHEDULE);
+
+  // redefinitions for EIP-3529
+  private static final int NEW_MAX_REFUND_QUOTIENT = 5;
+
+  protected LondonGasCalculator() {}
+
+  // Redefined refund amount from EIP-3529
+  @Override
+  public Gas getSelfDestructRefundAmount() {
+    return Gas.ZERO;
+  }
+
+  // defined in Berlin, but re-implemented with new constants
+  @Override
+  // As per https://eips.ethereum.org/EIPS/eip-3529
+  public Gas calculateStorageRefundAmount(
+      final Account account, final UInt256 key, final UInt256 newValue) {
+    final UInt256 currentValue = account.getStorageValue(key);
+    if (currentValue.equals(newValue)) {
+      return Gas.ZERO;
+    } else {
+      final UInt256 originalValue = account.getOriginalStorageValue(key);
+      if (originalValue.equals(currentValue)) {
+        if (originalValue.isZero()) {
+          return Gas.ZERO;
+        } else if (newValue.isZero()) {
+          return SSTORE_CLEARS_SCHEDULE;
+        } else {
+          return Gas.ZERO;
+        }
+      } else {
+        Gas refund = Gas.ZERO;
+        if (!originalValue.isZero()) {
+          if (currentValue.isZero()) {
+            refund = NEGATIVE_SSTORE_CLEARS_SCHEDULE;
+          } else if (newValue.isZero()) {
+            refund = SSTORE_CLEARS_SCHEDULE;
+          }
+        }
+
+        if (originalValue.equals(newValue)) {
+          refund =
+              refund.plus(
+                  originalValue.isZero()
+                      ? SSTORE_SET_GAS_LESS_SLOAD_GAS
+                      : SSTORE_RESET_GAS_LESS_SLOAD_GAS);
+        }
+        return refund;
+      }
+    }
+  }
+
+  @Override
+  public long getMaxRefundQuotient() {
+    return NEW_MAX_REFUND_QUOTIENT;
+  };
+}

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/MainnetProtocolSpecs.java

@@ -533,6 +533,7 @@ public abstract class MainnetProtocolSpecs {
             configStackSizeLimit,
             enableRevertReason,
             quorumCompatibilityMode)
+        .gasCalculator(LondonGasCalculator::new)
         .transactionValidatorBuilder(
             gasCalculator ->
                 new MainnetTransactionValidator(

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/MainnetTransactionProcessor.java

@@ -466,11 +466,13 @@ public class MainnetTransactionProcessor {
     }
   }
 
-  protected static Gas refunded(
+  protected Gas refunded(
       final Transaction transaction, final Gas gasRemaining, final Gas gasRefund) {
     // Integer truncation takes care of the the floor calculation needed after the divide.
     final Gas maxRefundAllowance =
-        Gas.of(transaction.getGasLimit()).minus(gasRemaining).dividedBy(2);
+        Gas.of(transaction.getGasLimit())
+            .minus(gasRemaining)
+            .dividedBy(gasCalculator.getMaxRefundQuotient());
     final Gas refundAllowance = maxRefundAllowance.min(gasRefund);
     return gasRemaining.plus(refundAllowance);
   }

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/privacy/PrivateTransactionProcessor.java

@@ -235,11 +235,12 @@ public class PrivateTransactionProcessor {
   }
 
   @SuppressWarnings("unused")
-  private static Gas refunded(
+  private Gas refunded(final Transaction transaction, final Gas gasRemaining, final Gas gasRefund) {
-      final Transaction transaction, final Gas gasRemaining, final Gas gasRefund) {
     // Integer truncation takes care of the the floor calculation needed after the divide.
     final Gas maxRefundAllowance =
-        Gas.of(transaction.getGasLimit()).minus(gasRemaining).dividedBy(2);
+        Gas.of(transaction.getGasLimit())
+            .minus(gasRemaining)
+            .dividedBy(gasCalculator.getMaxRefundQuotient());
     final Gas refundAllowance = maxRefundAllowance.min(gasRefund);
     return gasRemaining.plus(refundAllowance);
   }

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/vm/GasCalculator.java

@@ -434,4 +434,8 @@ public interface GasCalculator {
   default Gas modExpGasCost(final Bytes input) {
     return Gas.ZERO;
   }
+
+  default long getMaxRefundQuotient() {
+    return 2;
+  };
 }

ethereum/core/src/test/java/org/hyperledger/besu/ethereum/vm/operations/LondonSStoreOperationGasCostTest.java

@@ -0,0 +1,106 @@
+/*
+ * Copyright 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.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package org.hyperledger.besu.ethereum.vm.operations;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.hyperledger.besu.config.StubGenesisConfigOptions;
+import org.hyperledger.besu.config.experimental.ExperimentalEIPs;
+import org.hyperledger.besu.ethereum.core.Account;
+import org.hyperledger.besu.ethereum.core.Gas;
+import org.hyperledger.besu.ethereum.core.TestCodeExecutor;
+import org.hyperledger.besu.ethereum.mainnet.MainnetProtocolSchedule;
+import org.hyperledger.besu.ethereum.mainnet.ProtocolSchedule;
+import org.hyperledger.besu.ethereum.vm.MessageFrame;
+import org.hyperledger.besu.ethereum.vm.MessageFrame.State;
+
+import org.apache.tuweni.units.bigints.UInt256;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class LondonSStoreOperationGasCostTest {
+
+  private static ProtocolSchedule protocolSchedule;
+
+  @Parameters(name = "Code: {0}, Original: {1}")
+  public static Object[][] scenarios() {
+    // Tests specified in EIP-3539.
+    return new Object[][] {
+      {"0x60006000556000600055", 0, 212, 0},
+      {"0x60006000556001600055", 0, 20112, 0},
+      {"0x60016000556000600055", 0, 20112, 19900},
+      {"0x60016000556002600055", 0, 20112, 0},
+      {"0x60016000556001600055", 0, 20112, 0},
+      {"0x60006000556000600055", 1, 3012, 4800},
+      {"0x60006000556001600055", 1, 3012, 2800},
+      {"0x60006000556002600055", 1, 3012, 0},
+      {"0x60026000556000600055", 1, 3012, 4800},
+      {"0x60026000556003600055", 1, 3012, 0},
+      {"0x60026000556001600055", 1, 3012, 2800},
+      {"0x60026000556002600055", 1, 3012, 0},
+      {"0x60016000556000600055", 1, 3012, 4800},
+      {"0x60016000556002600055", 1, 3012, 0},
+      {"0x60016000556001600055", 1, 212, 0},
+      {"0x600160005560006000556001600055", 0, 40118, 19900},
+      {"0x600060005560016000556000600055", 1, 5918, 7600},
+    };
+  }
+
+  private TestCodeExecutor codeExecutor;
+
+  @Parameter public String code;
+
+  @Parameter(value = 1)
+  public int originalValue;
+
+  @Parameter(value = 2)
+  public int expectedGasUsed;
+
+  @Parameter(value = 3)
+  public int expectedGasRefund;
+
+  @Before
+  public void setUp() {
+    ExperimentalEIPs.eip1559Enabled = true;
+    protocolSchedule =
+        MainnetProtocolSchedule.fromConfig(new StubGenesisConfigOptions().londonBlock(0));
+    codeExecutor = new TestCodeExecutor(protocolSchedule);
+  }
+
+  @Test
+  public void shouldCalculateGasAccordingToEip3529() {
+    final long gasLimit = 1_000_000;
+    final MessageFrame frame =
+        codeExecutor.executeCode(
+            code,
+            Account.DEFAULT_VERSION,
+            gasLimit,
+            account -> account.setStorageValue(UInt256.ZERO, UInt256.valueOf(originalValue)));
+    assertThat(frame.getState()).isEqualTo(State.COMPLETED_SUCCESS);
+    assertThat(frame.getRemainingGas()).isEqualTo(Gas.of(gasLimit - (expectedGasUsed + 2100)));
+    assertThat(frame.getGasRefund()).isEqualTo(Gas.of(expectedGasRefund));
+  }
+
+  @After
+  public void reset() {
+    ExperimentalEIPs.eip1559Enabled = ExperimentalEIPs.EIP1559_ENABLED_DEFAULT_VALUE;
+  }
+}