Implemented a simple, reusable linked list structure. Supports single…

… and double linked lists plus circular (ring) variants. List has an integral sort using a recursive mergesort algorithm.

TODO: Some level of thread-safety would be nice.

doomsday/build/win32/doomsday_cl.rsp

@@ -15,6 +15,7 @@
  ./../../engine/portable/src/m_filehash.c
  ./../../engine/portable/src/m_bams.c
  ./../../engine/portable/src/m_args.c
+ ./../../engine/portable/src/m_linkedlist.c
  ./../../engine/portable/src/s_wav.c
  ./../../engine/portable/src/s_sfx.c
  ./../../engine/portable/src/s_mus.c

doomsday/build/win32/vs8/doomsday.vcproj

@@ -436,6 +436,10 @@
 				RelativePath="..\..\..\engine\portable\src\m_huffman.c"
 				>
 			</File>
+			<File
+				RelativePath="..\..\..\engine\portable\src\m_linkedlist.c"
+				>
+			</File>
 			<File
 				RelativePath="..\..\..\engine\portable\src\m_md5.c"
 				>
@@ -1383,6 +1387,10 @@
 				RelativePath="..\..\..\engine\portable\include\m_huffman.h"
 				>
 			</File>
+			<File
+				RelativePath="..\..\..\engine\portable\include\m_linkedlist.h"
+				>
+			</File>
 			<File
 				RelativePath="..\..\..\engine\portable\include\m_md5.h"
 				>

doomsday/engine/portable/include/de_misc.h

@@ -1,4 +1,4 @@
-/**\file
+/**\file
  *\section License
  * License: GPL
  * Online License Link: http://www.gnu.org/licenses/gpl.html
@@ -39,5 +39,6 @@
 #include "m_vector.h"
 #include "m_profiler.h"
 #include "m_md5.h"
+#include "m_linkedlist.h"
 
 #endif

doomsday/engine/portable/include/m_linkedlist.h

@@ -0,0 +1,128 @@
+/**\file
+ *\section License
+ * License: GPL
+ * Online License Link: http://www.gnu.org/licenses/gpl.html
+ *
+ *\author Copyright © 2007 Daniel Swanson <danij@dengine.net>
+ *
+ * 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., 51 Franklin St, Fifth Floor,
+ * Boston, MA  02110-1301  USA
+ */
+
+/*
+ * m_linkedlist.h: Linked lists.
+ */
+
+#ifndef __LINKEDLIST_H__
+#define __LINKEDLIST_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// The C_DECL macro, used with compare functions.
+#ifndef C_DECL
+#  if defined(WIN32)
+#    define C_DECL __cdecl
+#  elif defined(UNIX)
+#    define C_DECL
+#  endif
+#endif
+
+typedef int listindex_t;
+
+// Helper macro for defining list compare functions.
+#define COMPAREFUNC(name)   int C_DECL name(const void *a, const void *b)
+
+typedef int (C_DECL *comparefunc) (const void *a, const void *b);
+
+// Premade compare functions:
+COMPAREFUNC( compareInt );
+COMPAREFUNC( compareUInt );
+COMAPREFUNC( compareFloat );
+COMPAREFUNC( compareDouble );
+COMPAREFUNC( compareString );
+COMPAREFUNC( compareAddress );
+
+//
+// Linked lists.
+//
+typedef void* linklist_t;
+
+#define PTR_NOT_LIST        -1
+
+// Linked list errors:
+enum {
+    LL_NO_ERROR,
+    LL_ERROR_UNKNOWN,
+    LL_ERROR_OUT_OF_MEMORY,
+    LL_ERROR_UNDERFLOW,
+    LL_ERROR_OVERFLOW,
+    LL_ERROR_LAST
+};
+
+// List_Create flags:
+#define LCF_CIRCULAR        0x1 // The list forms a ring of items, as
+                                // opposed to the default linear list.
+
+// List_Iterate flags
+#define LIF_REVERSE         0x1 // Iteration will be tail > head.
+
+// Create/Destroy:
+linklist_t     *List_Create(void);
+linklist_t     *List_Create2(int createFlags, comparefunc func);
+void            List_Destroy(linklist_t *list);
+
+// Inserts:
+int             List_InsertFront(linklist_t *list, const void *data);
+int             List_InsertBack(linklist_t *list, const void *data);
+
+// Retrieves:
+void*           List_GetFront(const linklist_t *list);
+void*           List_GetBack(const linklist_t *list);
+void*           List_GetAt(const linklist_t *list, listindex_t position);
+
+// Extracts:
+void*           List_ExtractFront(linklist_t *list);
+void*           List_ExtractBack(linklist_t *list);
+void*           List_ExtractAt(linklist_t *list, listindex_t position);
+
+// Other:
+void            List_SetCompareFunc(linklist_t *list, comparefunc func);
+void            List_Clear(linklist_t *list);
+listindex_t     List_Find(const linklist_t *list, const void *data);
+int             List_Exchange(linklist_t *list, listindex_t positionA,
+                              listindex_t positionB);
+// Sorts:
+void            List_Sort(linklist_t *list);
+
+// State retrieval:
+listindex_t     List_Count(const linklist_t *list);
+int             List_GetError(const linklist_t *list);
+
+// Iteration:
+int             List_Iterate(const linklist_t *list, int iterateFlags,
+                             void *data,
+                             int (*callback) (void *element, void *data));
+// Debugging:
+#ifndef NDEBUG
+void            List_Test(void);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif