Make unbuffered log verbosity aware

include/util/log.hpp

@@ -53,10 +53,40 @@ class Log
     virtual ~Log();
     std::mutex &get_mutex();
 
-    template <typename T> inline std::ostream &operator<<(const T &data) { return stream << data; }
+    template <typename T> inline Log &operator<<(const T &data)
+    {
+        const auto &policy = LogPolicy::GetInstance();
+        if (!policy.IsMute() && level <= policy.GetLevel())
+        {
+            stream << data;
+        }
+        return *this;
+    }
+
+    template <typename T> inline Log &operator<<(const std::atomic<T> &data)
+    {
+        const auto &policy = LogPolicy::GetInstance();
+        if (!policy.IsMute() && level <= policy.GetLevel())
+        {
+            stream << T(data);
+        }
+        return *this;
+    }
+
+    typedef std::ostream &(manip)(std::ostream &);
+
+    inline Log &operator<<(manip &m)
+    {
+        const auto &policy = LogPolicy::GetInstance();
+        if (!policy.IsMute() && level <= policy.GetLevel())
+        {
+            stream << m;
+        }
+        return *this;
+    }
 
   protected:
-    LogLevel level;
+    const LogLevel level;
     std::ostringstream buffer;
     std::ostream &stream;
 };

include/util/percent.hpp

@@ -83,7 +83,7 @@ class Percent
             // When not on a TTY, print newlines after each progress indicator so
             // so that progress is visible to line-buffered logging systems
             if (!IsStdoutATTY())
-                log << "" << std::endl;
+                log << std::endl;
         }
     }
 };