Add DiskFile:noBuffer()

The noBuffer function disables read and write buffering via setvbuf.

DiskFile.c

@@ -62,10 +62,18 @@ static int torch_DiskFile_longSize(lua_State *L)
   return 1;
 }
 
+static int torch_DiskFile_noBuffer(lua_State *L)
+{
+  THFile *self = luaT_checkudata(L, 1, "torch.DiskFile");
+  THDiskFile_noBuffer(self);
+  lua_settop(L, 1);
+  return 1;
+}
+
 static int torch_DiskFile___tostring__(lua_State *L)
 {
   THFile *self = luaT_checkudata(L, 1, "torch.DiskFile");
-  lua_pushfstring(L, "torch.DiskFile on <%s> [status: %s -- mode %c%c]", 
+  lua_pushfstring(L, "torch.DiskFile on <%s> [status: %s -- mode %c%c]",
                   THDiskFile_name(self),
                   (THFile_isOpened(self) ? "open" : "closed"),
                   (THFile_isReadable(self) ? 'r' : ' '),
@@ -80,6 +88,7 @@ static const struct luaL_Reg torch_DiskFile__ [] = {
   {"littleEndianEncoding", torch_DiskFile_littleEndianEncoding},
   {"bigEndianEncoding", torch_DiskFile_bigEndianEncoding},
   {"longSize", torch_DiskFile_longSize},
+  {"noBuffer", torch_DiskFile_noBuffer},
   {"__tostring__", torch_DiskFile___tostring__},
   {NULL, NULL}
 };
@@ -88,7 +97,7 @@ void torch_DiskFile_init(lua_State *L)
 {
   luaT_newmetatable(L, "torch.DiskFile", "torch.File",
                     torch_DiskFile_new, torch_DiskFile_free, NULL);
-  
+
   luaT_setfuncs(L, torch_DiskFile__, 0);
   lua_pop(L, 1);
 }

doc/diskfile.md

@@ -12,7 +12,7 @@ the [binary](file.md#torch.File.binary) mode, the default endian encoding is the
 computer one.
 
 The file might be open in read, write, or read-write mode, depending on the parameter
-`mode` (which can take the value `"r"`, `"w"` or `"rw"` respectively) 
+`mode` (which can take the value `"r"`, `"w"` or `"rw"` respectively)
 given to the [torch.DiskFile(fileName, mode)](#torch.DiskFile).
 
 <a name="torch.DiskFile"></a>
@@ -32,7 +32,7 @@ The file is opened in [ASCII](file.md#torch.File.ascii) mode by default.
 <a name="torch.DiskFile.bigEndianEncoding"></a>
 ### bigEndianEncoding() ###
 
-In [binary](file.md#torch.File.binary) mode, force encoding in _big endian_. 
+In [binary](file.md#torch.File.binary) mode, force encoding in _big endian_.
 (_big end first_: decreasing numeric significance with increasing memory
 addresses)
 
@@ -67,3 +67,8 @@ In [binary](file.md#torch.File.binary) mode, force encoding in _native endian_.
 
 Longs will be written and read from the file as `size` bytes long, which
 can be 0, 4 or 8. 0 means system default.
+
+<a name="torch.DiskFile.noBuffer"/></a>
+### noBuffer() ###
+
+Disables read and write buffering on the `DiskFile`.

lib/TH/THDiskFile.c

@@ -291,6 +291,15 @@ void THDiskFile_longSize(THFile *self, int size)
   dfself->longSize = size;
 }
 
+void THDiskFile_noBuffer(THFile *self)
+{
+  THDiskFile *dfself = (THDiskFile*)(self);
+  THArgCheck(dfself->handle != NULL, 1, "attempt to use a closed file");
+  if (setvbuf(dfself->handle, NULL, _IONBF, 0)) {
+    THError("error: cannot disable buffer");
+  }
+}
+
 static void THDiskFile_free(THFile *self)
 {
   THDiskFile *dfself = (THDiskFile*)(self);

lib/TH/THDiskFile.h

@@ -14,5 +14,6 @@ TH_API void THDiskFile_nativeEndianEncoding(THFile *self);
 TH_API void THDiskFile_littleEndianEncoding(THFile *self);
 TH_API void THDiskFile_bigEndianEncoding(THFile *self);
 TH_API void THDiskFile_longSize(THFile *self, int size);
+TH_API void THDiskFile_noBuffer(THFile *self);
 
 #endif