Add WAD I/O abstraction layer - first step for mmapped WAD access.

Subversion-branch: /trunk/chocolate-doom
Subversion-revision: 1133

1 files changed, 88 insertions, 0 deletions

diff --git a/src/w_file.h b/src/w_file.h
new file mode 100644
index 00000000..2eb0d492
--- /dev/null
+++ b/src/w_file.h
@@ -0,0 +1,88 @@
+// Emacs style mode select   -*- C++ -*- 
+//-----------------------------------------------------------------------------
+//
+// Copyright(C) 1993-1996 Id Software, Inc.
+// Copyright(C) 2008 Simon Howard
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+// 02111-1307, USA.
+//
+// DESCRIPTION:
+//	WAD I/O functions.
+//
+//-----------------------------------------------------------------------------
+
+
+#ifndef __W_FILE__
+#define __W_FILE__
+
+#include <stdio.h>
+#include "doomtype.h"
+
+typedef struct _wad_file_s wad_file_t;
+
+typedef struct
+{
+    // Open a file for reading.
+
+    wad_file_t *(*OpenFile)(char *path);
+
+    // Close the specified file.
+
+    void (*CloseFile)(wad_file_t *file);
+
+    // Read data from the specified position in the file into the 
+    // provided buffer.  Returns the number of bytes read.
+
+    size_t (*Read)(wad_file_t *file, unsigned int offset,
+                   void *buffer, size_t buffer_len);
+
+} wad_file_class_t;
+
+struct _wad_file_s
+{
+    // Class of this file.
+
+    wad_file_class_t *file_class;
+
+    // If this is NULL, the file cannot be mapped into memory.  If this
+    // is non-NULL, it is a pointer to the mapped file.
+
+    byte *mapped;
+
+    // Length of the file, in bytes.
+
+    unsigned int length;
+};
+
+// Open the specified file. Returns a pointer to a new wad_file_t 
+// handle for the WAD file, or NULL if it could not be opened.
+
+wad_file_t *W_OpenFile(char *path);
+
+// Close the specified WAD file.
+
+void W_CloseFile(wad_file_t *wad);
+
+// Read data from the specified file into the provided buffer.  The
+// data is read from the specified offset from the start of the file.
+// Returns the number of bytes read.
+
+size_t W_Read(wad_file_t *wad, unsigned int offset,
+              void *buffer, size_t buffer_len);
+
+#endif /* #ifndef __W_FILE__ */
+
+