ircd::db: Elaborate interface to the rocksdb perf_context.

include/ircd/db/database/rocksdb.h

@@ -31,6 +31,7 @@ namespace rocksdb
 	struct Slice;
 	struct Checkpoint;
 	struct SstFileManager;
+	struct PerfContext;
 }
 
 //

include/ircd/db/db.h

@@ -87,7 +87,10 @@ namespace ircd::db
 	std::string path(const std::string &name);
 	std::vector<std::string> available();
 
-	void log_rdb_perf_context(const bool &all = true);
+	uint perf_level();
+	void perf_level(const uint &);
+	const rocksdb::PerfContext &perf_current();
+	std::string string(const rocksdb::PerfContext &, const bool &all = false);
 
 	string_view reflect(const pos &);
 }

ircd/db.cc

@@ -1304,17 +1304,49 @@ catch(const std::exception &e)
 // database::stats
 //
 
-void
-ircd::db::log_rdb_perf_context(const bool &all)
+std::string
+ircd::db::string(const rocksdb::PerfContext &pc,
+                 const bool &all)
 {
-	const auto pc
+	const bool exclude_zeros(!all);
+	return pc.ToString(exclude_zeros);
+}
+
+const rocksdb::PerfContext &
+ircd::db::perf_current()
+{
+	const auto *const &ret
 	{
 		rocksdb::get_perf_context()
 	};
 
-	assert(pc);
-	const bool exclude_zeros(!all);
-	log.debug("%s", pc->ToString(exclude_zeros));
+	if(unlikely(!ret))
+		throw error
+		{
+			"Performance counters are not available on this thread."
+		};
+
+	return *ret;
+}
+
+void
+ircd::db::perf_level(const uint &level)
+{
+	if(level >= rocksdb::PerfLevel::kOutOfBounds)
+		throw error
+		{
+			"Perf level of '%u' is invalid; maximum is '%u'",
+			level,
+			uint(rocksdb::PerfLevel::kOutOfBounds)
+		};
+
+	rocksdb::SetPerfLevel(rocksdb::PerfLevel(level));
+}
+
+uint
+ircd::db::perf_level()
+{
+	return rocksdb::GetPerfLevel();
 }
 
 uint32_t

modules/console.cc

@@ -1130,6 +1130,47 @@ catch(const std::out_of_range &e)
 	return true;
 }
 
+bool
+console_cmd__db__perf(opt &out, const string_view &line)
+{
+	const auto &pc
+	{
+		db::perf_current()
+	};
+
+	out << db::string(pc) << std::endl;
+	return true;
+}
+
+bool
+console_cmd__db__perf__level(opt &out, const string_view &line)
+{
+	const params param{line, " ",
+	{
+		"[level]"
+	}};
+
+	if(!param.count())
+	{
+		const auto &level
+		{
+			db::perf_level()
+		};
+
+		out << "Current level is: " << level << std::endl;
+		return true;
+	}
+
+	const auto &level
+	{
+		param.at<uint>(0)
+	};
+
+	db::perf_level(level);
+	out << "Set level to: " << level << std::endl;
+	return true;
+}
+
 bool
 console_cmd__db__prop(opt &out, const string_view &line)
 try