m_spanningtree Changes to TreeSocket::WriteLine() to avoid string copies

- Change argument type to a reference to avoid copies of the string object
- If the std::string implementation is using copy-on-write then calling operator[] on a mutable string results in a copy; avoid this by calling .c_str() instead

2 files changed, 12 insertions, 6 deletions

diff --git a/src/modules/m_spanningtree/compat.cpp b/src/modules/m_spanningtree/compat.cpp
index 0fc837beb..a9e48a10c 100644
--- a/src/modules/m_spanningtree/compat.cpp
+++ b/src/modules/m_spanningtree/compat.cpp
@@ -24,17 +24,19 @@
 
 static std::string newline("\n");
 
-void TreeSocket::WriteLine(std::string line)
+void TreeSocket::WriteLine(const std::string& original_line)
 {
 	if (LinkState == CONNECTED)
 	{
-		if (line[0] != ':')
+		if (original_line.c_str()[0] != ':')
 		{
 			ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Sending line without server prefix!");
-			line = ":" + ServerInstance->Config->GetSID() + " " + line;
+			WriteLine(":" + ServerInstance->Config->GetSID() + " " + original_line);
+			return;
 		}
 		if (proto_version != ProtocolVersion)
 		{
+			std::string line = original_line;
 			std::string::size_type a = line.find(' ');
 			std::string::size_type b = line.find(' ', a + 1);
 			std::string command = line.substr(a + 1, b-a-1);
@@ -159,11 +161,15 @@ void TreeSocket::WriteLine(std::string line)
 					}
 				}
 			}
+			ServerInstance->Logs->Log(MODNAME, LOG_RAWIO, "S[%d] O %s", this->GetFd(), line.c_str());
+			this->WriteData(line);
+			this->WriteData(newline);
+			return;
 		}
 	}
 
-	ServerInstance->Logs->Log(MODNAME, LOG_RAWIO, "S[%d] O %s", this->GetFd(), line.c_str());
-	this->WriteData(line);
+	ServerInstance->Logs->Log(MODNAME, LOG_RAWIO, "S[%d] O %s", this->GetFd(), original_line.c_str());
+	this->WriteData(original_line);
 	this->WriteData(newline);
 }
 
diff --git a/src/modules/m_spanningtree/treesocket.h b/src/modules/m_spanningtree/treesocket.h
index 47bdef884..6d79711cc 100644
--- a/src/modules/m_spanningtree/treesocket.h
+++ b/src/modules/m_spanningtree/treesocket.h
@@ -237,7 +237,7 @@ class TreeSocket : public BufferedSocket
 
 	/** Send one or more complete lines down the socket
 	 */
-	void WriteLine(std::string line);
+	void WriteLine(const std::string& line);
 
 	/** Handle ERROR command */
 	void Error(parameterlist &params);