Some performance optimizations (#5424)

* Some performance optimizations

This is globally removing some memory useless copy

* use a const ref return on std::string Settings::get to prevent data copy on getters which doesn't need to copy it
 * pass some stack created strings to static const as they are not modified anywhere
 * Camera: return nametags per const ref instead of a list pointer, we only need to read it
 * INodeDefManager: getAll should be a result ref writer instead of a return copy
 * INodeDefManager: getAlias should return a const std::string ref
 * Minimap: unroll a Scolor creation in blitMinimapPixersToImageRadar to prvent many variable construct/destruct which are unneeded (we rewrite the content in the loop)
 * CNodeDefManager::updateAliases: prevent a idef getall copy
 * Profiler: constness
 * rollback_interface: create real_name later, and use const ref
 * MapBlockMesh updateFastFaceRow: unroll TileSpec next_tile, which has a cost of 1.8% CPU due to variable allocation/destruction,
 * MapBlockMesh updateFastFaceRow: copy next_tile to tile only if it's a different tilespec
 * MapBlockMesh updateFastFaceRow: use memcpy to copy next_lights to lights to do it in a single cpu operation

1 files changed, 1 insertions, 28 deletions

diff --git a/src/settings.cpp b/src/settings.cpp
index c4c3c9073..b4083264e 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -90,33 +90,6 @@ bool Settings::checkValueValid(const std::string &value)
 	return true;
 }
 
-
-std::string Settings::sanitizeName(const std::string &name)
-{
-	std::string n = trim(name);
-
-	for (const char *s = "=\"{}#"; *s; s++)
-		n.erase(std::remove(n.begin(), n.end(), *s), n.end());
-
-	return n;
-}
-
-
-std::string Settings::sanitizeValue(const std::string &value)
-{
-	std::string v(value);
-	size_t p = 0;
-
-	if (v.substr(0, 3) == "\"\"\"")
-		v.erase(0, 3);
-
-	while ((p = v.find("\n\"\"\"")) != std::string::npos)
-		v.erase(p, 4);
-
-	return v;
-}
-
-
 std::string Settings::getMultiline(std::istream &is, size_t *num_lines)
 {
 	size_t lines = 1;
@@ -398,7 +371,7 @@ Settings *Settings::getGroup(const std::string &name) const
 }
 
 
-std::string Settings::get(const std::string &name) const
+const std::string &Settings::get(const std::string &name) const
 {
 	const SettingsEntry &entry = getEntry(name);
 	if (entry.is_group)