just serve: Implement a progress reporting infrastructure

This commit simply defines the logic needed for progress reporting.

1 files changed, 55 insertions, 0 deletions

diff --git a/src/buildtool/serve_api/progress_reporting/statistics.hpp b/src/buildtool/serve_api/progress_reporting/statistics.hpp
new file mode 100644
index 00000000..6c1aa352
--- /dev/null
+++ b/src/buildtool/serve_api/progress_reporting/statistics.hpp
@@ -0,0 +1,55 @@
+// Copyright 2023 Huawei Cloud Computing Technology Co., Ltd.
+//
+// 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.
+
+#ifndef INCLUDED_SRC_BUILDTOOL_SERVE_API_PROGRESS_REPORTING_STATISTICS_HPP
+#define INCLUDED_SRC_BUILDTOOL_SERVE_API_PROGRESS_REPORTING_STATISTICS_HPP
+
+#include <atomic>
+
+class ServeServiceStatistics {
+  public:
+    [[nodiscard]] static auto Instance() noexcept -> ServeServiceStatistics& {
+        static ServeServiceStatistics instance{};
+        return instance;
+    }
+
+    void Reset() noexcept {
+        num_cache_hits_ = 0;
+        num_dispatched_ = 0;
+        num_served_ = 0;
+    }
+    void IncrementCacheHitsCounter() noexcept { ++num_cache_hits_; }
+    void IncrementDispatchedCounter() noexcept { ++num_dispatched_; }
+    void IncrementServedCounter() noexcept { ++num_served_; }
+
+    [[nodiscard]] auto CacheHitsCounter() const noexcept -> int {
+        return num_cache_hits_;
+    }
+    [[nodiscard]] auto DispatchedCounter() const noexcept -> int {
+        return num_dispatched_;
+    }
+    [[nodiscard]] auto ServedCounter() const noexcept -> int {
+        return num_served_;
+    }
+
+  private:
+    // locally cached export targets
+    std::atomic<int> num_cache_hits_{};
+    // export targets for which we have queried just serve
+    std::atomic<int> num_dispatched_{};
+    // export targets for which just serve responded
+    std::atomic<int> num_served_{};
+};
+
+#endif  // INCLUDED_SRC_BUILDTOOL_SERVE_API_PROGRESS_REPORTING_STATISTICS_HPP