Add a counter for requests containing ledger_hash

Author: kuznetsss

.gitignore

@@ -10,3 +10,5 @@
 .sanitizer-report
 CMakeUserPresets.json
 config.json
+CLAUDE.md
+.claude/**

src/rpc/Counters.cpp

@@ -152,6 +152,13 @@ Counters::Counters(Reportable const& wq)
               "Age of requested ledgers in ledger count"
           )
       )
+    , ledgerHashRequestsCounter_(
+          PrometheusService::counterInt(
+              "rpc_ledger_hash_requests_total_number",
+              Labels{},
+              "Total number of successful requests containing ledger_hash field"
+          )
+      )
     , workQueue_(std::cref(wq))
     , startupTime_{std::chrono::system_clock::now()}
 {
@@ -234,7 +241,12 @@ Counters::onInternalError()
 void
 Counters::recordLedgerRequest(boost::json::object const& params, std::uint32_t currentLedgerSequence)
 {
-    if (not params.contains("ledger_index")) {
+    if (params.contains(JS(ledger_hash))) {
+        ++ledgerHashRequestsCounter_.get();
+        return;
+    }
+
+    if (not params.contains(JS(ledger_index))) {
         ledgerAgeLedgersHistogram_.get().observe(0);
         return;
     }

src/rpc/Counters.hpp

@@ -69,6 +69,7 @@ class Counters {
     CounterType internalErrorCounter_;
 
     std::reference_wrapper<util::prometheus::HistogramInt> ledgerAgeLedgersHistogram_;
+    CounterType ledgerHashRequestsCounter_;
 
     std::reference_wrapper<Reportable const> workQueue_;
     std::chrono::time_point<std::chrono::system_clock> startupTime_;

tests/unit/rpc/CountersTests.cpp

@@ -259,3 +259,28 @@ TEST_F(RPCCountersMockPrometheusRecotdLedgerRequestTest, zeroAgeLedger)
     params["ledger_index"] = 1000;  // Same as current
     counters.recordLedgerRequest(params, 1000);
 }
+
+TEST_F(RPCCountersMockPrometheusRecotdLedgerRequestTest, ledgerHashRequest)
+{
+    auto& ledgerHashCounterMock = makeMock<CounterInt>("rpc_ledger_hash_requests_total_number", "");
+
+    EXPECT_CALL(ledgerHashCounterMock, add(1));
+
+    boost::json::object params;
+    params["ledger_hash"] = "ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789";
+    counters.recordLedgerRequest(params, 1000);
+}
+
+TEST_F(RPCCountersMockPrometheusRecotdLedgerRequestTest, ledgerHashWithIndexIgnoresIndex)
+{
+    auto& ledgerHashCounterMock = makeMock<CounterInt>("rpc_ledger_hash_requests_total_number", "");
+
+    // When both ledger_hash and ledger_index are present, only ledger_hash counter should be incremented
+    EXPECT_CALL(ledgerHashCounterMock, add(1));
+    // No histogram call should be made
+
+    boost::json::object params;
+    params["ledger_hash"] = "ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789";
+    params["ledger_index"] = 900;  // This should be ignored
+    counters.recordLedgerRequest(params, 1000);
+}