# HG changeset patch
# User František Kučera <franta-hg@frantovo.cz>
# Date 1659792220 -7200
# Node ID e16fa75135ad06259a7904a216a905e75b8204b2
# Parent  b9dcb7aa75e1fab05fbbbcfffe2a52d087555056
UDP: add delay option
The other side might be too slow to receive all datagrams and might loose some.
We might slow down – add a delay between the messages.
The delay is specified in microseconds: e.g. --connection-option delay 800
However better solution is to increase the buffer size on the receiver side.

diff -r b9dcb7aa75e1 -r e16fa75135ad bash-completion.sh
--- a/bash-completion.sh	Sat Aug 06 12:12:46 2022 +0200
+++ b/bash-completion.sh	Sat Aug 06 15:23:40 2022 +0200
@@ -36,6 +36,7 @@
 		"host"
 		"port"
 		"path"
+		"delay"
 	)
 
 	PROTOCOLS=(
@@ -55,6 +56,13 @@
 		"datagram"
 	)
 
+	DELAYS=(
+		"100"
+		"200"
+		"400"
+		"800"
+	)
+
 	if   [[ "$w1" == "--relation"                      && "x$w0" == "x" ]];    then COMPREPLY=("''")
 	elif [[ "$w1" == "--connection-string"                              ]];    then COMPREPLY=($(compgen -W "${CONNECTION_STRINGS[*]}" -- "$w0"))
 	elif [[ "$w1" == "--connection-option"                              ]];    then COMPREPLY=($(compgen -W "${OPTIONS[*]}" -- "$w0"))
@@ -62,6 +70,7 @@
 	elif [[ "$w2" == "--connection-option" && "$w1" == "role"           ]];    then COMPREPLY=($(compgen -W "${ROLES[*]}" -- "$w0"))
 	elif [[ "$w2" == "--connection-option" && "$w1" == "mode"           ]];    then COMPREPLY=($(compgen -W "${MODES[*]}" -- "$w0"))
 	elif [[ "$w2" == "--connection-option" && "$w1" == "path"           ]];    then COMPREPLY=($(compgen -f -- "$w0"))
+	elif [[ "$w2" == "--connection-option" && "$w1" == "delay"          ]];    then COMPREPLY=($(compgen -W "${DELAYS[*]}" -- "$w0"))
 	else
 		OPTIONS=(
 			"--relation"
diff -r b9dcb7aa75e1 -r e16fa75135ad src/Socket.cpp
--- a/src/Socket.cpp	Sat Aug 06 12:12:46 2022 +0200
+++ b/src/Socket.cpp	Sat Aug 06 15:23:40 2022 +0200
@@ -124,7 +124,7 @@
 
 };
 
-template<class SocketClass> static std::shared_ptr<Socket> openClientSocket(const SocketOptions& options, int socketType, int protocol) {
+template<class SocketClass> static std::shared_ptr<SocketClass> openClientSocket(const SocketOptions& options, int socketType, int protocol) {
 	AddressInfos remoteAddresses = AddressInfos::getAddressInfos(
 			findOption(options, OPTION_HOST, true),
 			findOption(options, OPTION_PORT, true),
@@ -137,6 +137,7 @@
 class UDPClientSocket : public Socket {
 private:
 	AddressInfos::AddressInfo remoteAddress;
+	useconds_t delay = 0;
 
 public:
 
@@ -145,13 +146,16 @@
 
 	static std::shared_ptr<Socket> open(const SocketOptions& options) {
 		bool sctp = findOption(options, OPTION_PROTOCOL) == PROTOCOL_SCTP;
-		return openClientSocket<UDPClientSocket>(options, sctp ? SOCK_SEQPACKET : SOCK_DGRAM, sctp ? IPPROTO_SCTP : IPPROTO_UDP);
+		auto socket = openClientSocket<UDPClientSocket>(options, sctp ? SOCK_SEQPACKET : SOCK_DGRAM, sctp ? IPPROTO_SCTP : IPPROTO_UDP);
+		socket->delay = std::stol(findOption(options, OPTION_DELAY, false, "0"));
+		return socket;
 	}
 
 	void send(const std::string& message) override {
 		auto ai = remoteAddress.ai;
 		FD s(::socket(AF_INET, ai->ai_socktype, ai->ai_protocol));
 		sendto(s.getFD(), message.c_str(), message.size(), 0, ai->ai_addr, ai->ai_addrlen);
+		if (delay) usleep(delay);
 	}
 
 	const std::string receive() override {
diff -r b9dcb7aa75e1 -r e16fa75135ad src/Socket.h
--- a/src/Socket.h	Sat Aug 06 12:12:46 2022 +0200
+++ b/src/Socket.h	Sat Aug 06 15:23:40 2022 +0200
@@ -37,6 +37,7 @@
 static const char OPTION_HOST[] = "host";
 static const char OPTION_PORT[] = "port";
 static const char OPTION_PATH[] = "path";
+static const char OPTION_DELAY[] = "delay";
 
 static const char PROTOCOL_TCP[] = "tcp";
 static const char PROTOCOL_UDP[] = "udp";