Add function for flushing file buffers

src/emu/fileio.cpp

@@ -625,6 +625,17 @@ int emu_file::puts(const char *s)
 }
 
 
+//-------------------------------------------------
+//  vfprintf - vfprintf to a text file
+//-------------------------------------------------
+
+int emu_file::vprintf(const char *fmt, va_list va)
+{
+	// write the data if we can
+	return (m_file != nullptr) ? core_vfprintf(m_file, fmt, va) : 0;
+}
+
+
 //-------------------------------------------------
 //  printf - vfprintf to a text file
 //-------------------------------------------------
@@ -641,13 +652,14 @@ int CLIB_DECL emu_file::printf(const char *fmt, ...)
 
 
 //-------------------------------------------------
-//  mame_vfprintf - vfprintf to a text file
+//  flush - flush file buffers
 //-------------------------------------------------
 
-int emu_file::vprintf(const char *fmt, va_list va)
+void emu_file::flush()
 {
-	// write the data if we can
-	return (m_file != nullptr) ? core_vfprintf(m_file, fmt, va) : 0;
+	// flush the buffers if we can
+	if (m_file != nullptr)
+		core_fflush(m_file);
 }
 
 

src/emu/fileio.h

@@ -120,6 +120,8 @@ public:
 
 	// control
 	file_error compress(int compress);
+
+	// position
 	int seek(INT64 offset, int whence);
 	UINT64 tell();
 	bool eof();
@@ -137,6 +139,9 @@ public:
 	int vprintf(const char *fmt, va_list va);
 	int printf(const char *fmt, ...) ATTR_PRINTF(2,3);
 
+	// buffers
+	void flush();
+
 private:
 	bool compressed_file_ready(void);
 

src/lib/util/corefile.cpp

@@ -898,6 +898,16 @@ file_error core_truncate(core_file *f, UINT64 offset)
 }
 
 
+/*-------------------------------------------------
+    core_truncate - flush write buffer
+-------------------------------------------------*/
+
+file_error core_fflush(core_file *f)
+{
+	return osd_fflush(f->file);
+}
+
+
 
 /***************************************************************************
     FILENAME UTILITIES

src/lib/util/corefile.h

@@ -120,6 +120,9 @@ int CLIB_DECL core_fprintf(core_file *f, const char *fmt, ...) ATTR_PRINTF(2,3);
 /* file truncation */
 file_error core_truncate(core_file *f, UINT64 offset);
 
+/* flush file buffers */
+file_error core_fflush(core_file *f);
+
 
 
 /* ----- filename utilities ----- */

src/osd/osdcore.h

@@ -202,6 +202,21 @@ file_error osd_openpty(osd_file **file, char *name, size_t name_len);
 file_error osd_truncate(osd_file *file, UINT64 offset);
 
 
+/*-----------------------------------------------------------------------------
+    osd_fflus: flush file buffers
+
+    Parameters:
+
+        file - handle to a file previously opened via osd_open
+
+    Return value:
+
+        a file_error describing any error that occurred while writing to
+        the file, or FILERR_NONE if no error occurred
+-----------------------------------------------------------------------------*/
+file_error osd_fflush(osd_file *file);
+
+
 /*-----------------------------------------------------------------------------
     osd_rmfile: deletes a file
 

src/osd/osdmini/minifile.cpp

@@ -128,6 +128,22 @@ file_error osd_truncate(osd_file *file, UINT64 offset)
 	return FILERR_NONE;
 }
 
+//============================================================
+//  osd_fflush
+//============================================================
+
+file_error osd_fflush(osd_file *file)
+{
+	if (!file)
+		return FILERR_FAILURE;
+
+	int result = fflush((FILE *)file);
+	if (result == EOF)
+		return FILERR_FAILURE;
+
+	return FILERR_NONE;
+}
+
 
 //============================================================
 //  osd_rmfile

src/osd/sdl/sdlfile.cpp

@@ -369,6 +369,30 @@ file_error osd_truncate(osd_file *file, UINT64 offset)
 	}
 }
 
+//============================================================
+//  osd_truncate
+//============================================================
+
+file_error osd_fflush(osd_file *file)
+{
+	UINT32 result;
+
+	if (!file || !file->handle)
+		return FILERR_FAILURE;
+
+	switch (file->type)
+	{
+		case SDLFILE_FILE:
+			result = fflush(file->handle, offset);
+			if (result == EOF)
+				return error_to_file_error(errno);
+			return FILERR_NONE;
+
+		default:
+			return FILERR_FAILURE;
+	}
+}
+
 
 //============================================================
 //  osd_close

src/osd/windows/winfile.cpp

@@ -281,6 +281,31 @@ file_error osd_truncate(osd_file *file, UINT64 offset)
 	return FILERR_NONE;
 }
 
+//============================================================
+//  osd_fflush
+//============================================================
+
+file_error osd_fflush(osd_file *file)
+{
+	if (!file || !file->handle)
+		return FILERR_FAILURE;
+
+	switch (file->type)
+	{
+		case WINFILE_FILE:
+			// attempt to flush file buffers
+			if (!FlushFileBuffers(file->handle))
+				return win_error_to_mame_file_error(GetLastError());
+			break;
+		case WINFILE_SOCKET:
+			return FILERR_FAILURE;
+		case WINFILE_PTTY:
+			return FILERR_FAILURE;
+
+	}
+	return FILERR_NONE;
+}
+
 
 //============================================================
 //  osd_close