# HG changeset patch
# User jbe
# Date 1428353931 -7200
# Node ID ef552870f1b66648ce79e5ac6fb06b4f8d32b2da
# Parent  8a6e2a80fcada6806ff331b15f83a1a82c84b4a5
Implementation of read and read_nb in I/O module

diff -r 8a6e2a80fcad -r ef552870f1b6 moonbridge_io.c
--- a/moonbridge_io.c	Mon Apr 06 15:41:37 2015 +0200
+++ b/moonbridge_io.c	Mon Apr 06 22:58:51 2015 +0200
@@ -16,6 +16,7 @@
 #include <lualib.h>
 
 #define MOONBR_IO_MAXSTRERRORLEN 80
+#define MOONBR_IO_READBUFLEN 4096
 #define MOONBR_IO_WRITEBUFLEN 4096
 
 #define moonbr_io_errmsg() \
@@ -30,6 +31,8 @@
   int fd;
   int issocket;
   int nonblocking;
+  int readerr;
+  int readbufcnt;
   int writeerr;
   size_t writeleft;
 #if LUA_VERSION_NUM >= 503
@@ -41,6 +44,7 @@
 #endif
   size_t writeqoff;
   int writebufcnt;
+  char readbuf[MOONBR_IO_READBUFLEN];
   char writebuf[MOONBR_IO_WRITEBUFLEN];
 } moonbr_io_handle_t;
 
@@ -61,6 +65,77 @@
   }
 }
 
+static int moonbr_io_read_impl(lua_State *L, int nonblocking) {
+  moonbr_io_handle_t *handle;
+  lua_Integer maxread;
+  const char *terminatorstr;
+  size_t terminatorlen;
+  char terminator;
+  luaL_Buffer luabuf;
+  size_t luabufcnt = 0;
+  int restcnt;
+  char *terminatorpos;
+  ssize_t result;
+  handle = luaL_checkudata(L, 1, MOONBR_IO_HANDLE_MT_REGKEY);
+  maxread = luaL_optinteger(L, 2, 0);
+  terminatorstr = luaL_optlstring(L, 3, "", &terminatorlen);
+  if (terminatorlen) {
+    luaL_argcheck(L, terminatorlen == 1, 3, "single byte expected");
+    terminator = terminatorstr[0];
+  }
+  if (handle->fd < 0) luaL_error(L, "Attempt to read from a closed I/O handle");
+  if (handle->readerr) {
+    lua_pushnil(L);
+    lua_pushliteral(L, "Previous read error");
+    return 2;
+  }
+  moonbr_io_handle_set_nonblocking(L, handle, nonblocking);
+  luaL_buffinit(L, &luabuf);
+  while (1) {
+    restcnt = -1;
+    if (maxread > 0 && handle->readbufcnt >= maxread - luabufcnt) {
+      restcnt = maxread - luabufcnt;
+    } else if (terminatorlen) {
+      terminatorpos = memchr(handle->readbuf, terminator, handle->readbufcnt);
+      if (terminatorpos) restcnt = 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);
+      return 1;
+    }
+    luaL_addlstring(&luabuf, handle->readbuf, handle->readbufcnt);
+    luabufcnt += handle->readbufcnt;
+    handle->readbufcnt = 0;
+    do {
+      result = read(handle->fd, handle->readbuf, MOONBR_IO_READBUFLEN);
+    } while (result < 0 && (errno == EINTR));
+    if (result == 0 || (nonblocking && result < 0 && (errno == EAGAIN || errno == EWOULDBLOCK))) break;
+    if (result < 0) {
+      moonbr_io_errmsg();
+      handle->readerr = 1;
+      lua_pushnil(L);
+      lua_pushstring(L, errmsg);
+      return 2;
+    }
+    handle->readbufcnt += result;
+  }
+  luaL_addlstring(&luabuf, handle->readbuf, handle->readbufcnt);
+  handle->readbufcnt = 0;
+  luaL_pushresult(&luabuf);
+  return 1;
+}
+
+static int moonbr_io_read(lua_State *L) {
+  return moonbr_io_read_impl(L, 0);
+}
+
+static int moonbr_io_read_nb(lua_State *L) {
+  return moonbr_io_read_impl(L, 1);
+}
+
 static int moonbr_io_write_impl(lua_State *L, int nonblocking, int flush) {
   moonbr_io_handle_t *handle;
   int i, top;
@@ -221,6 +296,8 @@
   handle->fd = fd;
   handle->issocket = issocket;
   handle->nonblocking = -1;
+  handle->readerr = 0;
+  handle->readbufcnt = 0;
   handle->writeerr = 0;
   handle->writeleft = 0;
   handle->writeqin = 0;
@@ -271,17 +348,19 @@
 }
 
 static int moonbr_io_getdummy(lua_State *L) {
-  moonbr_io_pushhandle(L, 2, 0);
+  moonbr_io_pushhandle(L, 0, 0);
   return 1;
 }
 
 static const struct luaL_Reg moonbr_io_handle_methods[] = {
-  {"reset", moonbr_io_reset},
-  {"close", moonbr_io_close},
+  {"read", moonbr_io_read},
+  {"read_nb", moonbr_io_read_nb},
   {"write", moonbr_io_write},
   {"write_nb", moonbr_io_write_nb},
   {"flush", moonbr_io_flush},
   {"flush_nb", moonbr_io_flush_nb},
+  {"reset", moonbr_io_reset},
+  {"close", moonbr_io_close},
   {NULL, NULL}
 };