[Lldb-commits] [lldb] [LLDB][Data Formatters] Calculate average and total time for summary providers within lldb (PR #102708)

[Jacob Lalonde via lldb-commits]

================
@@ -174,6 +176,83 @@ struct StatisticsOptions {
   std::optional<bool> m_include_transcript;
 };
 
+/// A class that represents statistics about a TypeSummaryProviders invocations
+class SummaryStatistics {
+public:
+  SummaryStatistics() = default;
+  SummaryStatistics(lldb_private::ConstString name) : 
+    m_total_time(), m_name(name), m_summary_count(0) {}
+
+  SummaryStatistics(const SummaryStatistics &&rhs)
+      : m_total_time(), m_name(rhs.m_name), m_summary_count(rhs.m_summary_count.load(std::memory_order_relaxed)) {}
+
+  lldb_private::ConstString GetName() const { return m_name; };
+  double GetAverageTime() const {
+    return m_total_time.get().count() / m_summary_count.load(std::memory_order_relaxed);
+  }
+
+  double GetTotalTime() const {
+    return m_total_time.get().count();
+  }
+
+  uint64_t GetSummaryCount() const {
+    return m_summary_count.load(std::memory_order_relaxed);
+  }
+
+  StatsDuration& GetDurationReference() {
+    return m_total_time;
+  }
+
+  llvm::json::Value ToJSON() const;
+
+  // Basic RAII class to increment the summary count when the call is complete.
+  // In the future this can be extended to collect information about the 
+  // elapsed time for a single request.
+  class SummaryInvocation {
+  public:
+    SummaryInvocation(SummaryStatistics &summary) : m_summary(summary) {}
+    ~SummaryInvocation() {
+      m_summary.OnInvoked();
+    }
+  private:
+    SummaryStatistics &m_summary;
+  };
+
+private:
+  /// Called when Summary Invocation is destructed.
+  void OnInvoked() {
+    m_summary_count.fetch_add(1, std::memory_order_relaxed);
+  }
+
+  lldb_private::StatsDuration m_total_time;
+  lldb_private::ConstString m_name;
+  std::atomic<uint64_t> m_summary_count;
+};
+
+/// A class that wraps a std::map of SummaryStatistics objects behind a mutex.
+class SummaryStatisticsCache {
+public:
+  SummaryStatisticsCache() = default;
+  /// Get the SummaryStatistics object for a given provider name, or insert
+  /// if statistics for that provider is not in the map.
+  lldb_private::SummaryStatistics &GetSummaryStatisticsForProviderName(lldb_private::ConstString summary_provider_name) {
+    m_map_mutex.lock();
+    if (m_summary_stats_map.count(summary_provider_name) == 0) {
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Jlalond wrote:

I prefer the type name being included in the object so in the future if we want to warn, or give any other related data that isn't just exported to statistics dump don't need to depend on accessing the map.

https://github.com/llvm/llvm-project/pull/102708