feat: Graceful shutdown with old web server (#2786)

- Stop accepting connections during graceful shutdown in the old web server
- Stop all the services before Clio exits
- Move cache saving into stop callback

src/data/LedgerCacheSaver.cpp

@@ -0,0 +1,70 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2025, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "data/LedgerCacheSaver.hpp"
+
+#include "data/LedgerCacheInterface.hpp"
+#include "util/Assert.hpp"
+#include "util/Profiler.hpp"
+#include "util/log/Logger.hpp"
+
+#include <string>
+#include <thread>
+
+namespace data {
+
+LedgerCacheSaver::LedgerCacheSaver(util::config::ClioConfigDefinition const& config, LedgerCacheInterface const& cache)
+    : cacheFilePath_(config.maybeValue<std::string>("cache.file.path")), cache_(cache)
+{
+}
+
+LedgerCacheSaver::~LedgerCacheSaver()
+{
+    waitToFinish();
+}
+
+void
+LedgerCacheSaver::save()
+{
+    ASSERT(not savingThread_.has_value(), "Multiple save() calls are not allowed");
+    savingThread_ = std::thread([this]() {
+        if (not cacheFilePath_.has_value()) {
+            return;
+        }
+
+        LOG(util::LogService::info()) << "Saving ledger cache to " << *cacheFilePath_;
+        if (auto const [success, durationMs] = util::timed([&]() { return cache_.get().saveToFile(*cacheFilePath_); });
+            success.has_value()) {
+            LOG(util::LogService::info()) << "Successfully saved ledger cache in " << durationMs << " ms";
+        } else {
+            LOG(util::LogService::error()) << "Error saving LedgerCache to file";
+        }
+    });
+}
+
+void
+LedgerCacheSaver::waitToFinish()
+{
+    if (savingThread_.has_value() and savingThread_->joinable()) {
+        savingThread_->join();
+    }
+    savingThread_.reset();
+}
+
+}  // namespace data