profile instant.xml save

This does clutter up stderr, but only because instant.xml is arguably
saved much too often (and it's not really instant :)

diff --git a/libs/pbd/stateful.cc b/libs/pbd/stateful.cc
index 8b8219f7e2243306f201f95257b035ec20b18cf0..59aa1f896a3e853da935e6f80fba695c682434f5 100644 (file)
--- a/libs/pbd/stateful.cc
+++ b/libs/pbd/stateful.cc
@@ -23,6 +23,7 @@
 #else
 #include <unistd.h>
 #endif
+#include <iomanip>  // std::setprecision
 
 #include <glibmm/fileutils.h>
 #include <glibmm/miscutils.h>
@@ -112,6 +113,9 @@ Stateful::save_extra_xml (const XMLNode& node)
 void
 Stateful::add_instant_xml (XMLNode& node, const std::string& directory_path)
 {
+#ifndef NDEBUG
+       const int64_t save_start_time = g_get_monotonic_time();
+#endif
        if (!Glib::file_test (directory_path, Glib::FILE_TEST_IS_DIR)) {
                if (g_mkdir_with_parents (directory_path.c_str(), 0755) != 0) {
                        error << string_compose(_("Error: could not create directory %1"), directory_path) << endmsg;
@@ -147,6 +151,10 @@ Stateful::add_instant_xml (XMLNode& node, const std::string& directory_path)
        if (!tree.write()) {
                error << string_compose(_("Error: could not write %1"), instant_xml_path) << endmsg;
        }
+#ifndef NDEBUG
+       const int64_t elapsed_time_us = g_get_monotonic_time() - save_start_time;
+       cerr << "saved '"<< instant_xml_path << "' in " << fixed << setprecision (1) << elapsed_time_us / 1000. << " ms\n";
+#endif
 }
 
 XMLNode *