From: Jesse F. Williamson <jfw@ibm.com>
Date: Mon, 10 Feb 2025 17:20:38 +0000 (-0800)
Subject: Try out boost::container::flat_map<>.
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=2df252ea3c6faa705cb6f67ece387ad2c644167b;p=ceph.git

Try out boost::container::flat_map<>.

We don't have C++23 available yet.

Signed-off-by: Jesse F. Williamson <jfw@ibm.com>
---

diff --git a/src/common/ceph_json.cc b/src/common/ceph_json.cc
index af29226a87a..5856b8635ff 100644
--- a/src/common/ceph_json.cc
+++ b/src/common/ceph_json.cc
@@ -1,10 +1,11 @@
 #include "common/ceph_json.h"
 #include "include/utime.h"
 
-#include <boost/algorithm/string.hpp>
+#include <include/types.h>
 #include <boost/tokenizer.hpp>
 #include <boost/lexical_cast.hpp>
-#include <include/types.h>
+#include <boost/algorithm/string.hpp>
+#include <boost/container/flat_map.hpp>
 
 /* Enable boost.json's header-only mode:
 	(see: "https://github.com/boostorg/json?tab=readme-ov-file#header-only"): */
@@ -44,7 +45,7 @@ void JSONObj::handle_value(boost::json::value v)
   if (auto op = v.if_object()) {
 	for (const auto& kvp : *op) {
 		auto child = std::make_unique<JSONObj>(this, kvp.key(), kvp.value());
-		children.insert(std::pair { kvp.key(), std::move(child) });
+		children.emplace(std::pair { kvp.key(), std::move(child) });
 	 }
 
 	return;
@@ -53,7 +54,7 @@ void JSONObj::handle_value(boost::json::value v)
  if (auto ap = v.if_array()) {
 	for (const auto& kvp : *ap) {
 		auto child = std::make_unique<JSONObj>(this, "", kvp);
-		children.insert(std::pair { child->get_name(), std::move(child) });
+		children.emplace(std::pair { child->get_name(), std::move(child) });
 	 }
  }
 
diff --git a/src/common/ceph_json.h b/src/common/ceph_json.h
index a52a602e036..643ab7d34cd 100644
--- a/src/common/ceph_json.h
+++ b/src/common/ceph_json.h
@@ -111,7 +111,7 @@ concept json_val_seq = requires
 
 class JSONObjIter final {
 
-  using map_iter_t = std::map<std::string, std::unique_ptr<JSONObj>, std::less<>>::iterator;
+  using map_iter_t = boost::container::flat_map<std::string, std::unique_ptr<JSONObj>, std::less<>>::iterator;
 
   map_iter_t cur;
   map_iter_t last;
@@ -147,10 +147,6 @@ class JSONObj
 {
   JSONObj *parent = nullptr;
 
-protected:
-  using children_multimap_t = std::multimap<std::string, std::unique_ptr<JSONObj>, std::less<>>;
-  using children_multimap_value_type = typename children_multimap_t::value_type;
-
 public:
   struct data_val {
     std::string str;
@@ -171,8 +167,8 @@ protected:
 
   bool data_quoted{false};
 
-  children_multimap_t children;
-  std::map<std::string, data_val, std::less<>> attr_map;
+  boost::container::flat_multimap<std::string, std::unique_ptr<JSONObj>, std::less<>> children;
+  boost::container::flat_map<std::string, data_val, std::less<>> attr_map;
 
   void handle_value(boost::json::value v);
 
@@ -640,7 +636,7 @@ public:
   };
 
 private:
-  std::map<std::type_index, HandlerBase *> handlers;
+  boost::container::flat_map<std::type_index, HandlerBase *> handlers;
 
 public:
   void register_type(HandlerBase *h) {