# HG changeset patch
# User jbe
# Date 1428189426 -7200
# Node ID 38e7bd13200ddb8fd050e4a4da24844e4a941152
# Parent  d4265136ce8860eed90a410a627dcdfb7c4e4d88
Use write instead of fwrite for non-blocking I/O

diff -r d4265136ce88 -r 38e7bd13200d moonbridge.c
--- a/moonbridge.c	Sun Apr 05 00:35:11 2015 +0200
+++ b/moonbridge.c	Sun Apr 05 01:17:06 2015 +0200
@@ -2484,38 +2484,36 @@
 
 /* New methods for Lua file objects: non-blocking writing */
 static int moonbr_io_write_nb_impl(lua_State *L) {
-  luaL_Stream *stream;
-  FILE *file;
-  int argc, i;
+  int fd, argc, i;
   const char *str;
   size_t strlen;
-  size_t written;
-  stream = luaL_checkudata(L, 1, LUA_FILEHANDLE);
-  file = stream->f;
+  ssize_t written;
+  luaL_Buffer buf;
+  fd = lua_tointeger(L, 1);
   argc = lua_gettop(L) - 1;
   for (i=0; i<argc; i++) {
     str = luaL_checklstring(L, 2+i, &strlen);
-    written = fwrite(str, 1, strlen, file);
-    if (written < strlen) {
-      if (errno == EAGAIN) {
-        luaL_Buffer buf;
-        clearerr(file);
-        luaL_buffinit(L, &buf);
-        luaL_addlstring(&buf, str+written, strlen-written);
-        for (i=i+1; i<argc; i++) {
-          luaL_checkstring(L, 2+i);
-          lua_pushvalue(L, 2+i);
-          luaL_addvalue(&buf);
-        }
-        luaL_pushresult(&buf);
-        return 1;
-      } else {
+    written = write(fd, str, strlen);
+    if (written < 0) {
+      if (errno != EAGAIN) {
         char errmsg[MOONBR_MAXSTRERRORLEN];
         strerror_r(errno, errmsg, MOONBR_MAXSTRERRORLEN);  /* use thread-safe call in case child created threads */
         lua_pushnil(L);
         lua_pushstring(L, errmsg);
         return 2;
       }
+      written = 0;
+    }
+    if (written < strlen) {
+      luaL_buffinit(L, &buf);
+      luaL_addlstring(&buf, str+written, strlen-written);
+      for (i=i+1; i<argc; i++) {
+        luaL_checkstring(L, 2+i);
+        lua_pushvalue(L, 2+i);
+        luaL_addvalue(&buf);
+      }
+      luaL_pushresult(&buf);
+      return 1;
     }
   }
   lua_pushliteral(L, "");
@@ -2527,24 +2525,22 @@
   int fd, flags;
   stream = luaL_checkudata(L, 1, LUA_FILEHANDLE);
   if (!stream->closef) luaL_error(L, "attempt to use a closed file");
+  file = stream->f;
+  if (fflush(file)) goto moonbr_io_write_nb_error;
   lua_pushcfunction(L, moonbr_io_write_nb_impl);
-  lua_insert(L, 1);
-  file = stream->f;
-  if (ferror(file)) {
-    lua_pushnil(L);
-    lua_pushliteral(L, "Previous error condition on file handle");
-    return 2;
-  }
+  lua_insert(L, 2);
   fd = fileno(file);
+  lua_pushinteger(L, fd);
+  lua_insert(L, 3);
   flags = fcntl(fd, F_GETFL, 0);
   if (flags == -1) goto moonbr_io_write_nb_error;
   if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) goto moonbr_io_write_nb_error;
-  if (lua_pcall(L, lua_gettop(L) - 1, LUA_MULTRET, 0)) {
+  if (lua_pcall(L, lua_gettop(L) - 2, LUA_MULTRET, 0)) {
     fcntl(fd, F_SETFL, flags);
     return lua_error(L);
   }
   if (fcntl(fd, F_SETFL, flags) == -1) goto moonbr_io_write_nb_error;
-  return lua_gettop(L);
+  return lua_gettop(L) - 1;
   moonbr_io_write_nb_error:
   {
     char errmsg[MOONBR_MAXSTRERRORLEN];
diff -r d4265136ce88 -r 38e7bd13200d reference.txt
--- a/reference.txt	Sun Apr 05 00:35:11 2015 +0200
+++ b/reference.txt	Sun Apr 05 01:17:06 2015 +0200
@@ -57,7 +57,8 @@
 
 Alternatively to file descriptors, the tables may contain file handles, in
 which case the file descriptor is automatically extracted from the file handle
-and the file handle's buffer is additionally tested for pending data.
+and, in case of waiting for reading, the file handle's buffer is additionally
+tested for pending data.
 
 Please note that support for non-blocking I/O operations is limited if you use
 ordinary file handles (as Moonbridge does). It is possible, however, to wait
@@ -194,6 +195,11 @@
 In case of an I/O error, nil (as first result value) and an error message (as
 second result value) are returned.
 
+Note: Using this method will automatically flush any unflushed data written
+through previous socket.output:write(...) calls. Thus, if any data was
+previously written in a blocking fashion and has not been flushed, then the
+socket.output:write_nb(...) call may block.
+
 This method is also available for any other Lua file handle.