# HG changeset patch
# User jbe
# Date 1428360450 -7200
# Node ID 9fa3a36733ff7e9a48c4e4877824dce873e69f03
# Parent  ef552870f1b66648ce79e5ac6fb06b4f8d32b2da
New I/O methods drain and drain_nb

diff -r ef552870f1b6 -r 9fa3a36733ff moonbridge_io.c
--- a/moonbridge_io.c	Mon Apr 06 22:58:51 2015 +0200
+++ b/moonbridge_io.c	Tue Apr 07 00:47:30 2015 +0200
@@ -4,9 +4,6 @@
 #include <stdint.h>
 #include <errno.h>
 #include <string.h>
-#include <stdio.h>
-#include <time.h>
-#include <sys/time.h>
 #include <sys/socket.h>
 #include <sys/select.h>
 #include <fcntl.h>
@@ -23,7 +20,6 @@
   char errmsg[MOONBR_IO_MAXSTRERRORLEN]; \
   strerror_r(errno, errmsg, MOONBR_IO_MAXSTRERRORLEN)
 
-
 #define MOONBR_IO_HANDLE_MT_REGKEY "moonbridge_io_handle"
 #define MOONBR_IO_HANDLE_PUBLIC_MT_REGKEY "moonbridge_io_handle_public"
 
@@ -65,7 +61,7 @@
   }
 }
 
-static int moonbr_io_read_impl(lua_State *L, int nonblocking) {
+static int moonbr_io_read_impl(lua_State *L, int nonblocking, int drain) {
   moonbr_io_handle_t *handle;
   lua_Integer maxread;
   const char *terminatorstr;
@@ -73,7 +69,7 @@
   char terminator;
   luaL_Buffer luabuf;
   size_t luabufcnt = 0;
-  int restcnt;
+  int endcnt;
   char *terminatorpos;
   ssize_t result;
   handle = luaL_checkudata(L, 1, MOONBR_IO_HANDLE_MT_REGKEY);
@@ -83,6 +79,7 @@
     luaL_argcheck(L, terminatorlen == 1, 3, "single byte expected");
     terminator = terminatorstr[0];
   }
+  lua_settop(L, 1);  /* return handle on drain, terminator string may be garbage collected */
   if (handle->fd < 0) luaL_error(L, "Attempt to read from a closed I/O handle");
   if (handle->readerr) {
     lua_pushnil(L);
@@ -90,23 +87,25 @@
     return 2;
   }
   moonbr_io_handle_set_nonblocking(L, handle, nonblocking);
-  luaL_buffinit(L, &luabuf);
+  if (!drain) luaL_buffinit(L, &luabuf);
   while (1) {
-    restcnt = -1;
+    endcnt = -1;
     if (maxread > 0 && handle->readbufcnt >= maxread - luabufcnt) {
-      restcnt = maxread - luabufcnt;
+      endcnt = maxread - luabufcnt;
     } else if (terminatorlen) {
       terminatorpos = memchr(handle->readbuf, terminator, handle->readbufcnt);
-      if (terminatorpos) restcnt = 1 + (terminatorpos - handle->readbuf);
+      if (terminatorpos) endcnt = 1 + (terminatorpos - handle->readbuf);
     }
-    if (restcnt >= 0) {
-      luaL_addlstring(&luabuf, handle->readbuf, restcnt);
-      handle->readbufcnt -= restcnt;
-      memmove(handle->readbuf, handle->readbuf + restcnt, handle->readbufcnt);
-      luaL_pushresult(&luabuf);
+    if (endcnt >= 0) {
+      if (!drain) {
+        luaL_addlstring(&luabuf, handle->readbuf, endcnt);
+        luaL_pushresult(&luabuf);
+      }
+      handle->readbufcnt -= endcnt;
+      memmove(handle->readbuf, handle->readbuf + endcnt, handle->readbufcnt);
       return 1;
     }
-    luaL_addlstring(&luabuf, handle->readbuf, handle->readbufcnt);
+    if (!drain) luaL_addlstring(&luabuf, handle->readbuf, handle->readbufcnt);
     luabufcnt += handle->readbufcnt;
     handle->readbufcnt = 0;
     do {
@@ -122,18 +121,28 @@
     }
     handle->readbufcnt += result;
   }
-  luaL_addlstring(&luabuf, handle->readbuf, handle->readbufcnt);
+  if (!drain) {
+    luaL_addlstring(&luabuf, handle->readbuf, handle->readbufcnt);
+    luaL_pushresult(&luabuf);
+  }
   handle->readbufcnt = 0;
-  luaL_pushresult(&luabuf);
   return 1;
 }
 
 static int moonbr_io_read(lua_State *L) {
-  return moonbr_io_read_impl(L, 0);
+  return moonbr_io_read_impl(L, 0, 0);
 }
 
 static int moonbr_io_read_nb(lua_State *L) {
-  return moonbr_io_read_impl(L, 1);
+  return moonbr_io_read_impl(L, 1, 0);
+}
+
+static int moonbr_io_drain(lua_State *L) {
+  return moonbr_io_read_impl(L, 0, 1);
+}
+
+static int moonbr_io_drain_nb(lua_State *L) {
+  return moonbr_io_read_impl(L, 1, 1);
 }
 
 static int moonbr_io_write_impl(lua_State *L, int nonblocking, int flush) {
@@ -355,6 +364,8 @@
 static const struct luaL_Reg moonbr_io_handle_methods[] = {
   {"read", moonbr_io_read},
   {"read_nb", moonbr_io_read_nb},
+  {"drain", moonbr_io_drain},
+  {"drain_nb", moonbr_io_drain_nb},
   {"write", moonbr_io_write},
   {"write_nb", moonbr_io_write_nb},
   {"flush", moonbr_io_flush},