Turn off Nagle algorithm to decrease latency.

This is safe because of the way writes are performed: for each transmission,
all outgoing messages are concatenated in memory and only a single write()
syscall is made.

src/tcpsockets/TCPStream.cpp

@@ -27,6 +27,7 @@
 #include <WinSock2.h>
 #else
 #include <arpa/inet.h>
+#include <netinet/tcp.h>
 #include <unistd.h>
 #endif
 
@@ -136,6 +137,11 @@ llvm::StringRef TCPStream::getPeerIP() const { return m_peerIP; }
 
 int TCPStream::getPeerPort() const { return m_peerPort; }
 
+void TCPStream::setNoDelay() {
+  int optval = 1;
+  setsockopt(m_sd, IPPROTO_TCP, TCP_NODELAY, (char*)&optval, sizeof optval);
+}
+
 bool TCPStream::WaitForReadEvent(int timeout) {
   fd_set sdset;
   struct timeval tv;