Default ConnectionConfig to no timeout and let ClientConfig ask for one

The neutral type should not carry an opinion about how long a connection is
worth waiting on, since it cannot know what the connection is for. A client
does know, so it is the one that names thirty seconds, and a server takes the
absence of a deadline as it comes.

Author: BlueCannonBall

polyweb.hpp

@@ -583,19 +583,19 @@ namespace pw {
     using TLSWSRoute = BasicWSRoute<pn::tcp::TLSConnection>;
 
     struct ConnectionConfig {
-        std::chrono::milliseconds send_timeout = std::chrono::seconds(30);
-        std::chrono::milliseconds recv_timeout = std::chrono::seconds(30);
+        // A connection may stay request and response, become a WebSocket, or become a long
+        // poll, and only the first of those tolerates a deadline, so none is imposed here
+        std::chrono::milliseconds send_timeout = {};
+        std::chrono::milliseconds recv_timeout = {};
         bool tcp_keep_alive = true; // Reaps peers that vanished without closing, not HTTP keep-alive
         bool tcp_no_delay = true;
 
         pn::Status apply(pn::tcp::Connection& conn) const;
     };
 
     struct ServerConfig {
-        // A server cannot know at accept time whether a connection will stay request and
-        // response, become a WebSocket, or become a long poll, so it waits rather than
-        // impose a deadline that is only right for one of them
-        ConnectionConfig tcp = {.send_timeout = {}, .recv_timeout = {}};
+        // A server cannot know at accept time which of those an accepted connection is
+        ConnectionConfig tcp;
         size_t buf_capacity = 4'000;
         MessageConfig http;
         WSConfig ws;
@@ -663,7 +663,9 @@ namespace pw {
 
     class ClientConfig {
     public:
-        ConnectionConfig tcp;
+        // A client makes one request and knows what it is waiting for, so unlike a server
+        // it can say how long that is worth waiting
+        ConnectionConfig tcp = {.send_timeout = std::chrono::seconds(30), .recv_timeout = std::chrono::seconds(30)};
 
         // Borrowed rather than owned, so one context may serve any number of requests.
         // When it is null a default trust store, built once on first use, is used instead

tests/http.cpp

@@ -370,6 +370,11 @@ TEST(a_connection_config_applies_the_options_it_names) {
 TEST(a_server_imposes_no_timeout_of_its_own) {
     // A WebSocket idles between messages by design, and handle_conn cannot tell an idle
     // keep-alive connection from a client that sent nothing, so a server waits instead
+    pw::ConnectionConfig config;
+    CHECK(config.recv_timeout == std::chrono::milliseconds(0));
+    CHECK(config.send_timeout == std::chrono::milliseconds(0));
+
+    // A server takes that as it comes, rather than overriding it the way a client does
     pw::ServerConfig server_config;
     CHECK(server_config.tcp.recv_timeout == std::chrono::milliseconds(0));
     CHECK(server_config.tcp.send_timeout == std::chrono::milliseconds(0));