RolledLogDeleter: do not sort on each candidate consideration.

proxy/logging/RolledLogDeleter.cc

@@ -73,6 +73,7 @@ RolledLogDeleter::register_log_type_for_deletion(std::string_view log_type, int
 
   deletingInfoList.push_back(std::move(deletingInfo));
   deleting_info.insert(deletingInfoPtr);
+  candidates_require_sorting = true;
 }
 
 bool
@@ -86,20 +87,31 @@ RolledLogDeleter::consider_for_candidacy(std::string_view log_path, int64_t file
   auto &candidates = iter->candidates;
   candidates.push_back(std::make_unique<LogDeleteCandidate>(log_path, file_size, modification_time));
   ++num_candidates;
-
-  std::sort(
-    candidates.begin(), candidates.end(),
-    [](std::unique_ptr<LogDeleteCandidate> const &a, std::unique_ptr<LogDeleteCandidate> const &b) { return a->mtime > b->mtime; });
-
+  candidates_require_sorting = true;
   return true;
 }
 
+void
+RolledLogDeleter::sort_candidates()
+{
+  deleting_info.apply([](LogDeletingInfo &info) {
+    std::sort(info.candidates.begin(), info.candidates.end(),
+              [](std::unique_ptr<LogDeleteCandidate> const &a, std::unique_ptr<LogDeleteCandidate> const &b) {
+                return a->mtime > b->mtime;
+              });
+  });
+  candidates_require_sorting = false;
+}
+
 std::unique_ptr<LogDeleteCandidate>
 RolledLogDeleter::take_next_candidate_to_delete()
 {
   if (!has_candidates()) {
     return nullptr;
   }
+  if (candidates_require_sorting) {
+    sort_candidates();
+  }
   // Select the highest priority type (diags.log, traffic.out, etc.) from which
   // to select a candidate.
   auto target_type =

proxy/logging/RolledLogDeleter.h

@@ -24,7 +24,7 @@
 #pragma once
 
 #include <cstdint>
-#include <list>
+#include <deque>
 #include <memory>
 #include <string>
 #include <string_view>
@@ -201,14 +201,27 @@ class RolledLogDeleter
    */
   void clear_candidates();
 
+private:
+  /** Sort all the assembled candidates for each LogDeletingInfo.
+   *
+   * After any additions to the @a deleting_info, this should be called before
+   * calling @a take_next_candidate_to_delete because the latter depends upon
+   * the candidate entries being sorted.
+   */
+  void sort_candidates();
+
 private:
   /** The owning references to the set of LogDeletingInfo added to the below
    * hash map. */
-  std::list<std::unique_ptr<LogDeletingInfo>> deletingInfoList;
+  std::deque<std::unique_ptr<LogDeletingInfo>> deletingInfoList;
 
   /** The set of candidates for deletion keyed by log_type. */
   IntrusiveHashMap<LogDeletingInfoDescriptor> deleting_info;
 
   /** The number of tracked candidates. */
   size_t num_candidates = 0;
+
+  /** Whether the candidates require sorting due to an addition to the
+   * deleting_info. */
+  bool candidates_require_sorting = true;
 };