# HG changeset patch
# User jbe
# Date 1428448323 -7200
# Node ID 719f83c7fea412b405b84ab81750f308b851bb2c
# Parent  de3982f17d05c971dca42f2a2f3bdcf5fe3be6be
Correctly cache nonblocking status of socket in I/O library; Use TCP_NOPUSH/TCP_CORK when applicable

diff -r de3982f17d05 -r 719f83c7fea4 moonbridge_io.c
--- a/moonbridge_io.c	Tue Apr 07 22:17:13 2015 +0200
+++ b/moonbridge_io.c	Wed Apr 08 01:12:03 2015 +0200
@@ -7,6 +7,8 @@
 #include <sys/socket.h>
 #include <sys/select.h>
 #include <fcntl.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
 
 #include <lua.h>
 #include <lauxlib.h>
@@ -25,10 +27,11 @@
 
 typedef struct {
   int fd;
-  int useshutdown;
+  int isnetwork;
   int finished;
   int closed;
   int nonblocking;
+  int nopush;
   int readerr;
   int readbufcnt;
   int writeerr;
@@ -47,35 +50,55 @@
 } moonbr_io_handle_t;
 
 static void moonbr_io_handle_set_nonblocking(lua_State *L, moonbr_io_handle_t *handle, int nonblocking) {
-  if (handle->nonblocking != nonblocking) {
-    int flags;
-    flags = fcntl(handle->fd, F_GETFL, 0);
-    if (flags == -1) {
-      moonbr_io_errmsg();
-      luaL_error(L, "Unexpected error in fcntl call: %s", errmsg);
-    }
-    if (nonblocking) flags |= O_NONBLOCK;
-    else flags &= ~O_NONBLOCK;
-    if (fcntl(handle->fd, F_SETFL, flags) == -1) {
-      moonbr_io_errmsg();
-      luaL_error(L, "Unexpected error in fcntl call: %s", errmsg);
-    }
+  int flags;
+  if (handle->nonblocking == nonblocking) return;
+  flags = fcntl(handle->fd, F_GETFL, 0);
+  if (flags == -1) {
+    moonbr_io_errmsg();
+    handle->nonblocking = -1;
+    luaL_error(L, "Unexpected error in fcntl call: %s", errmsg);
   }
+  if (nonblocking) flags |= O_NONBLOCK;
+  else flags &= ~O_NONBLOCK;
+  if (fcntl(handle->fd, F_SETFL, flags) == -1) {
+    moonbr_io_errmsg();
+    handle->nonblocking = -1;
+    luaL_error(L, "Unexpected error in fcntl call: %s", errmsg);
+  }
+  handle->nonblocking = nonblocking;
 }
 
 static void moonbr_io_handle_set_linger(lua_State *L, moonbr_io_handle_t *handle, int timeout) {
   struct linger lingerval = { 0, };
-  if (!handle->useshutdown) return;
+  if (!handle->isnetwork) return;
   if (timeout >= 0) {
     lingerval.l_onoff = 1;
     lingerval.l_linger = timeout;
   }
   if (setsockopt(handle->fd, SOL_SOCKET, SO_LINGER, &lingerval, sizeof(lingerval))) {
     moonbr_io_errmsg();
-    luaL_error(L, "Unexpected error in setsockopt call: %s", errmsg);
+    luaL_error(L, "Unexpected error while setting SO_LINGER with setsockopt: %s", errmsg);
   }
 }
 
+static void moonbr_io_handle_set_nopush(lua_State *L, moonbr_io_handle_t *handle, int nopush) {
+  if (!handle->isnetwork || handle->nopush == nopush) return;
+#if defined(TCP_CORK) && !defined(TCP_NOPUSH)
+  if (setsockopt(handle->fd, IPPROTO_TCP, TCP_CORK, &nopush, sizeof(nopush))) {
+    moonbr_io_errmsg();
+    handle->nopush = -1;
+    luaL_error(L, "Unexpected error while setting TCP_CORK with setsockopt: %s", errmsg);
+  }
+#else
+  if (setsockopt(handle->fd, IPPROTO_TCP, TCP_NOPUSH, &nopush, sizeof(nopush))) {
+    moonbr_io_errmsg();
+    handle->nopush = -1;
+    luaL_error(L, "Unexpected error while setting TCP_NOPUSH with setsockopt: %s", errmsg);
+  }
+#endif
+  handle->nopush = nopush;
+}
+
 static int moonbr_io_read_impl(lua_State *L, int nonblocking, int drain) {
   moonbr_io_handle_t *handle;
   lua_Integer maxread;
@@ -210,6 +233,10 @@
         handle->writebufcnt += strlen - handle->writeqoff;
         break;
       } else {
+        moonbr_io_handle_set_nopush(L, handle,
+          (flush || handle->writeleft == MOONBR_IO_WRITEBUFLEN) ?
+          0 : 1
+        );
         written = 0;
         memcpy(handle->writebuf + handle->writebufcnt, str + handle->writeqoff, MOONBR_IO_WRITEBUFLEN - handle->writebufcnt);
         handle->writeqoff += MOONBR_IO_WRITEBUFLEN - handle->writebufcnt;
@@ -309,7 +336,7 @@
     }
   }
   handle->finished = 1;
-  if (handle->useshutdown) {
+  if (handle->isnetwork) {
     if (shutdown(handle->fd, SHUT_WR)) {
       moonbr_io_errmsg();
       lua_pushnil(L);
@@ -393,14 +420,15 @@
   }
 }
 
-void moonbr_io_pushhandle(lua_State *L, int fd, int useshutdown) {
+void moonbr_io_pushhandle(lua_State *L, int fd, int isnetwork) {
   moonbr_io_handle_t *handle;
   handle = lua_newuserdata(L, sizeof(moonbr_io_handle_t));
   handle->fd = fd;
-  handle->useshutdown = useshutdown;
+  handle->isnetwork = isnetwork;
   handle->finished = 0;
   handle->closed = 0;
   handle->nonblocking = -1;
+  handle->nopush = -1;
   handle->readerr = 0;
   handle->readbufcnt = 0;
   handle->writeerr = 0;