From f7945918c6ffeb2f1757b8f1e6c2103f95267513 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Fri, 18 Dec 2020 03:25:16 -0800
Subject: [PATCH] ircd::stats: Use vector for item iteration; add name
 convenience member.

---
 include/ircd/stats.h |  3 ++-
 ircd/stats.cc        | 52 +++++++++++++++++++++++++++++---------------
 modules/console.cc   |  6 ++---
 modules/stats.cc     |  4 ++--
 4 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/include/ircd/stats.h b/include/ircd/stats.h
index 54b199571..bcea3a824 100644
--- a/include/ircd/stats.h
+++ b/include/ircd/stats.h
@@ -55,7 +55,7 @@ namespace ircd::stats
 	template<> struct item<uint16_t>;
 
 	extern const size_t NAME_MAX_LEN;
-	extern std::map<string_view, item<void> *> items;
+	extern std::vector<item<void> *> items;
 
 	string_view string(const mutable_buffer &, const item<void> &);
 	std::ostream &operator<<(std::ostream &, const item<void> &);
@@ -78,6 +78,7 @@ struct ircd::stats::item<void>
 {
 	std::type_index type {typeid(void)};
 	json::strung feature;
+	json::string name;
 
   public:
 	// Access features
diff --git a/ircd/stats.cc b/ircd/stats.cc
index 9f4f95d4d..9adc0b0e5 100644
--- a/ircd/stats.cc
+++ b/ircd/stats.cc
@@ -95,12 +95,11 @@ ircd::stats::item<void>::item(const std::type_index &type,
 {
 	opts
 }
+,name
+{
+	this->operator[]("name")
+}
 {
-	const json::string name
-	{
-		this->operator[]("name")
-	};
-
 	if(unlikely(!name))
 		throw invalid
 		{
@@ -116,32 +115,49 @@ ircd::stats::item<void>::item(const std::type_index &type,
 			NAME_MAX_LEN
 		};
 
-	if(unlikely(!items.emplace(name, this).second))
+	static const auto less
+	{
+		[](const auto &a, const auto &b)
+		{
+			return a->name < b->name;
+		}
+	};
+
+	const auto exists
+	{
+		std::binary_search(begin(items), end(items), this, less)
+	};
+
+	if(unlikely(exists))
 		throw invalid
 		{
 			"Stats item named '%s' already exists",
 			name
 		};
+
+	if(items.empty())
+		items.reserve(4096);
+
+	items.emplace_back(this);
+	std::sort(begin(items), end(items), less);
 }
 
 ircd::stats::item<void>::~item()
 noexcept
 {
-	const json::string name
+	if(!name)
+		return;
+
+	const auto eit
 	{
-		this->operator[]("name")
+		std::remove_if(begin(items), end(items), [this]
+		(const auto &item)
+		{
+			return item->name == this->name;
+		})
 	};
 
-	if(name)
-	{
-		const auto it
-		{
-			items.find(name)
-		};
-
-		assert(data(it->first) == data(name));
-		items.erase(it);
-	}
+	items.erase(eit, end(items));
 }
 
 ircd::string_view
diff --git a/modules/console.cc b/modules/console.cc
index f140c3305..606d7cd5b 100644
--- a/modules/console.cc
+++ b/modules/console.cc
@@ -1599,9 +1599,9 @@ console_cmd__stats(opt &out, const string_view &line)
 		param[0] == "-a"? param[1]: param[0]
 	};
 
-	for(const auto &[name_, item] : stats::items)
+	for(const auto &item : stats::items)
 	{
-		if(prefix && !startswith(name_, prefix))
+		if(prefix && !startswith(item->name, prefix))
 			continue;
 
 		assert(item);
@@ -1615,7 +1615,7 @@ console_cmd__stats(opt &out, const string_view &line)
 
 		const fmt::bsprintf<128> name
 		{
-			"%s ", trunc(name_, name_width)
+			"%s ", trunc(item->name, name_width)
 		};
 
 		out
diff --git a/modules/stats.cc b/modules/stats.cc
index 245a02bfd..4e93068c2 100644
--- a/modules/stats.cc
+++ b/modules/stats.cc
@@ -51,12 +51,12 @@ ircd::stats::get_stats(client &client,
 		ircd::time<milliseconds>()
 	};
 
-	for(const auto &[name_, item] : items)
+	for(const auto &item : items)
 	{
 		char buf[256], name[2][128], val[64];
 		const string_view _name
 		{
-			replace(name[0], name_, '.', '_')
+			replace(name[0], item->name, '.', '_')
 		};
 
 		const string_view line