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

[Michael Buch via lldb-commits]

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@@ -174,6 +176,82 @@ struct StatisticsOptions {
   std::optional<bool> m_include_transcript;
 };
 
+/// A class that represents statistics about a TypeSummaryProviders invocations
+class SummaryStatistics {
+public:
+  explicit SummaryStatistics(std::string name, std::string impl_type)
+      : m_total_time(), m_impl_type(impl_type), m_name(name), m_count(0) {}
+
+  std::string GetName() const { return m_name; };
+  double GetTotalTime() const { return m_total_time.get().count(); }
+
+  uint64_t GetSummaryCount() const {
+    return m_count.load(std::memory_order_relaxed);
+  }
+
+  StatsDuration &GetDurationReference() { return m_total_time; };
+
+  std::string GetSummaryKindName() const { return m_impl_type; }
+
+  llvm::json::Value ToJSON() const;
+
+  /// Basic RAII class to increment the summary count when the call is complete.
+  class SummaryInvocation {
+  public:
+    SummaryInvocation(std::shared_ptr<SummaryStatistics> summary_stats)
+        : m_stats(summary_stats),
+          m_elapsed_time(summary_stats->GetDurationReference()) {}
+    ~SummaryInvocation() { m_stats->OnInvoked(); }
+
+    /// Delete the copy constructor and assignment operator to prevent
+    /// accidental double counting.
+    /// @{
+    SummaryInvocation(const SummaryInvocation &) = delete;
+    SummaryInvocation &operator=(const SummaryInvocation &) = delete;
+    /// @}
+
+  private:
+    std::shared_ptr<SummaryStatistics> m_stats;
+    ElapsedTime m_elapsed_time;
+  };
+
+private:
+  void OnInvoked() noexcept { m_count.fetch_add(1, std::memory_order_relaxed); }
+  lldb_private::StatsDuration m_total_time;
+  const std::string m_impl_type;
+  const std::string m_name;
+  std::atomic<uint64_t> m_count;
+};
+
+typedef std::shared_ptr<SummaryStatistics> SummaryStatisticsSP;
+
+/// A class that wraps a std::map of SummaryStatistics objects behind a mutex.
+class SummaryStatisticsCache {
+public:
+  /// Get the SummaryStatistics object for a given provider name, or insert
+  /// if statistics for that provider is not in the map.
+  SummaryStatisticsSP
+  GetSummaryStatisticsForProviderName(lldb_private::TypeSummaryImpl &provider) {
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Michael137 wrote:

Yea it's mostly personal preference, thanks for addressing all the comments so far. But this approach seems fine to me too (though I've had enough time to let it sink in, not sure it'd be straightforward to reason about for someone new to this).

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