Add metrics to DefaultBlockchain to get TPS and Mgas/s (#7105)

* Add gasUsedCounter and numberOfTransactionsCounter counters to DefaultBlockchain

Signed-off-by: Ameziane H <ameziane.hamlat@consensys.net>

* Make the attributes final

Signed-off-by: Ameziane H <ameziane.hamlat@consensys.net>

* Spotless

Signed-off-by: Ameziane H <ameziane.hamlat@consensys.net>

* Add a changelog entry

Signed-off-by: Ameziane H <ameziane.hamlat@consensys.net>

---------

Signed-off-by: Ameziane H <ameziane.hamlat@consensys.net>
Co-authored-by: Sally MacFarlane <macfarla.github@gmail.com>

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Breaking Changes
 
 ### Additions and Improvements
+- Add two counters to DefaultBlockchain in order to be able to calculate TPS and Mgas/s [#7105](https://github.com/hyperledger/besu/pull/7105)
 
 ### Bug fixes
 - Make `eth_gasPrice` aware of the base fee market [#7102](https://github.com/hyperledger/besu/pull/7102)

ethereum/core/src/main/java/org/hyperledger/besu/ethereum/chain/DefaultBlockchain.java

@@ -33,6 +33,7 @@ import org.hyperledger.besu.ethereum.core.TransactionReceipt;
 import org.hyperledger.besu.metrics.BesuMetricCategory;
 import org.hyperledger.besu.metrics.prometheus.PrometheusMetricsSystem;
 import org.hyperledger.besu.plugin.services.MetricsSystem;
+import org.hyperledger.besu.plugin.services.metrics.Counter;
 import org.hyperledger.besu.util.InvalidConfigurationException;
 import org.hyperledger.besu.util.Subscribers;
 
@@ -83,6 +84,9 @@ public class DefaultBlockchain implements MutableBlockchain {
   private final Optional<Cache<Hash, List<TransactionReceipt>>> transactionReceiptsCache;
   private final Optional<Cache<Hash, Difficulty>> totalDifficultyCache;
 
+  private final Counter gasUsedCounter;
+  private final Counter numberOfTransactionsCounter;
+
   private DefaultBlockchain(
       final Optional<Block> genesisBlock,
       final BlockchainStorage blockchainStorage,
@@ -117,6 +121,7 @@ public class DefaultBlockchain implements MutableBlockchain {
         "blockchain_height",
         "The current height of the canonical chain",
         this::getChainHeadBlockNumber);
+
     metricsSystem.createGauge(
         BesuMetricCategory.BLOCKCHAIN,
         "difficulty_total",
@@ -135,6 +140,10 @@ public class DefaultBlockchain implements MutableBlockchain {
         "Gas used by the current chain head block",
         () -> getChainHeadHeader().getGasUsed());
 
+    gasUsedCounter =
+        metricsSystem.createCounter(
+            BesuMetricCategory.BLOCKCHAIN, "chain_head_gas_used_counter", "Counter for Gas used");
+
     metricsSystem.createLongGauge(
         BesuMetricCategory.BLOCKCHAIN,
         "chain_head_gas_limit",
@@ -147,6 +156,12 @@ public class DefaultBlockchain implements MutableBlockchain {
         "Number of transactions in the current chain head block",
         () -> chainHeadTransactionCount);
 
+    numberOfTransactionsCounter =
+        metricsSystem.createCounter(
+            BesuMetricCategory.BLOCKCHAIN,
+            "chain_head_transaction_count_counter",
+            "Counter for the number of transactions");
+
     metricsSystem.createIntegerGauge(
         BesuMetricCategory.BLOCKCHAIN,
         "chain_head_ommer_count",
@@ -524,6 +539,10 @@ public class DefaultBlockchain implements MutableBlockchain {
     updater.setChainHead(newBlockHash);
     indexTransactionForBlock(
         updater, newBlockHash, blockWithReceipts.getBlock().getBody().getTransactions());
+    gasUsedCounter.inc(blockWithReceipts.getHeader().getGasUsed());
+    numberOfTransactionsCounter.inc(
+        blockWithReceipts.getBlock().getBody().getTransactions().size());
+
     return BlockAddedEvent.createForHeadAdvancement(
         blockWithReceipts.getBlock(),
         LogWithMetadata.generate(