From 4579fa2f26f0d4f3c910722fda0b8e9d76c0af97 Mon Sep 17 00:00:00 2001
From: ethanlabelle <37966268+ethanlabelle@users.noreply.github.com>
Date: Wed, 29 Jun 2022 19:10:03 -0400
Subject: [PATCH] Use ledger close times for stale data warning (#194)

---
 src/etl/ReportingETL.cpp |  8 +++-----
 src/etl/ReportingETL.h   | 23 +++++++++++++++++++++++
 src/webserver/HttpBase.h |  4 ++--
 src/webserver/WsBase.h   |  5 ++---
 4 files changed, 30 insertions(+), 10 deletions(-)

diff --git a/src/etl/ReportingETL.cpp b/src/etl/ReportingETL.cpp
index 28f4ece2..ae8d2c36 100644
--- a/src/etl/ReportingETL.cpp
+++ b/src/etl/ReportingETL.cpp
@@ -147,11 +147,9 @@ ReportingETL::publishLedger(ripple::LedgerInfo const& lgrInfo)
         backend_->cache().update(diff, lgrInfo.seq);
         backend_->updateRange(lgrInfo.seq);
     }
-    auto now = std::chrono::duration_cast<std::chrono::seconds>(
-                   std::chrono::system_clock::now().time_since_epoch())
-                   .count();
-    auto closeTime = lgrInfo.closeTime.time_since_epoch().count();
-    auto age = now - (rippleEpochStart + closeTime);
+
+    setLastClose(lgrInfo.closeTime);
+    auto age = lastCloseAgeSeconds();
     // if the ledger closed over 10 minutes ago, assume we are still
     // catching up and don't publish
     if (age < 600)
diff --git a/src/etl/ReportingETL.h b/src/etl/ReportingETL.h
index 3c68d35d..3d43b409 100644
--- a/src/etl/ReportingETL.h
+++ b/src/etl/ReportingETL.h
@@ -139,6 +139,18 @@ private:
         lastPublish_ = std::chrono::system_clock::now();
     }
 
+    /// The time that the most recently published ledger was closed.
+    std::chrono::time_point<ripple::NetClock> lastCloseTime_;
+
+    mutable std::shared_mutex closeTimeMtx_;
+
+    void
+    setLastClose(std::chrono::time_point<ripple::NetClock> lastCloseTime)
+    {
+        std::unique_lock lck(closeTimeMtx_);
+        lastCloseTime_ = lastCloseTime;
+    }
+
     /// Download a ledger with specified sequence in full, via GetLedgerData,
     /// and write the data to the databases. This takes several minutes or
     /// longer.
@@ -334,6 +346,17 @@ public:
                    std::chrono::system_clock::now() - getLastPublish())
             .count();
     }
+
+    std::uint32_t
+    lastCloseAgeSeconds() const
+    {
+        std::shared_lock lck(closeTimeMtx_);
+        auto now = std::chrono::duration_cast<std::chrono::seconds>(
+                       std::chrono::system_clock::now().time_since_epoch())
+                       .count();
+        auto closeTime = lastCloseTime_.time_since_epoch().count();
+        return now - (rippleEpochStart + closeTime);
+    }
 };
 
 #endif
diff --git a/src/webserver/HttpBase.h b/src/webserver/HttpBase.h
index c4f4b25d..8e0d170c 100644
--- a/src/webserver/HttpBase.h
+++ b/src/webserver/HttpBase.h
@@ -422,8 +422,8 @@ handle_request(
             "This is a clio server. clio only serves validated data. If you "
             "want to talk to rippled, include 'ledger_index':'current' in your "
             "request");
-        auto lastPublishAge = context->etl->lastPublishAgeSeconds();
-        if (lastPublishAge >= 60)
+        auto lastCloseAge = context->etl->lastCloseAgeSeconds();
+        if (lastCloseAge >= 60)
             warnings.emplace_back("This server may be out of date");
         result["warnings"] = warnings;
         responseStr = boost::json::serialize(response);
diff --git a/src/webserver/WsBase.h b/src/webserver/WsBase.h
index 0931c5a4..5e537b3c 100644
--- a/src/webserver/WsBase.h
+++ b/src/webserver/WsBase.h
@@ -351,10 +351,9 @@ public:
             "want to talk to rippled, include 'ledger_index':'current' in your "
             "request");
 
-        auto lastPublishAge = etl_->lastPublishAgeSeconds();
-        if (lastPublishAge >= 60)
+        auto lastCloseAge = etl_->lastCloseAgeSeconds();
+        if (lastCloseAge >= 60)
             warnings.emplace_back("This server may be out of date");
-
         response["warnings"] = warnings;
         std::string responseStr = boost::json::serialize(response);
         if (!dosGuard_.add(*ip, responseStr.size()))