Initial revision

circular.c

@@ -0,0 +1,122 @@
+/*-----------------------------------------------------------------------
+   Implementation file for a circular buffer facility.
+
+   Mark Koennecke, October 1999
+-------------------------------------------------------------------------*/
+#include <stdlib.h>
+#include <assert.h>
+#include "fortify.h"
+#include "circular.h"
+
+/*========================================================================
+        Definitions of Structures 
+*/
+
+  typedef struct __CircularItem {
+                                   void *pData;
+                                   struct __CircularItem *next;
+                                   struct __CircularItem *previous;
+                                 }CircularItem, *pCircularItem;
+
+
+  typedef struct __CIRCULAR {
+                             pCircularItem pPointer;
+                             CirKillFunc      killer;
+                            }Circular;
+
+/*=========================================================================
+   Functions for Birth and Death
+*/
+  pCircular createCircular(int iSize, CirKillFunc kf)
+  {
+     pCircular pNew = NULL;
+     pCircularItem pItem = NULL, pFirst = NULL;
+     int i;
+ 
+    
+     assert(iSize > 0);
+
+     /* create data structure */
+     pNew = (pCircular)malloc(sizeof(Circular));
+     if(!pNew)
+       return NULL;
+     memset(pNew,0,sizeof(Circular));
+
+     /* create all the members of the circular buffer */
+     pItem = (pCircularItem)malloc(sizeof(CircularItem));
+     if(!pItem)
+        return NULL;
+     memset(pItem,0,sizeof(CircularItem));
+     pNew->pPointer = pItem;
+     pFirst = pItem;
+     for(i = 1; i < iSize; i++)
+     {
+        pItem = (pCircularItem)malloc(sizeof(CircularItem));
+        if(!pItem)
+           return NULL;
+        memset(pItem,0,sizeof(CircularItem));
+        pItem->previous = pNew->pPointer;
+        pNew->pPointer->next = pItem;
+        pNew->pPointer = pItem;
+     }
+     pItem->next = pFirst;
+     pFirst->previous = pItem;
+     pNew->killer = kf;
+     return pNew;    
+  }
+/*---------------------------------------------------------------------*/
+  void deleteCircular(pCircular self)
+  {
+     pCircularItem pNext = NULL, pCurrent = NULL;
+
+     assert(self);
+
+     self->pPointer->previous->next = NULL;
+     pNext = self->pPointer;
+     while(pNext != NULL)
+     {
+        pCurrent = pNext;
+        pNext = pCurrent->next;
+        if(pCurrent->pData && self->killer)
+	{
+            self->killer(pCurrent->pData);
+        }
+        free(pCurrent);
+     }    
+     free(self);
+  } 
+/*========================================================================
+    Data Manipulation functions
+*/
+  void setCircular(pCircular self, void *pData)
+  {
+      assert(self);
+
+      /* delete if present */
+      if(self->pPointer->pData && self->killer)
+      {
+         self->killer(self->pPointer->pData);
+      }
+      self->pPointer->pData = pData;
+  }
+/*----------------------------------------------------------------------*/
+  void *getCircular(pCircular self)
+  {
+     assert(self);
+     return self->pPointer->pData;
+  }
+/*========================================================================
+  Pointer movement 
+*/
+  void nextCircular(pCircular self)
+  {
+     assert(self);
+     self->pPointer = self->pPointer->next;
+  }
+/*---------------------------------------------------------------------*/
+  void previousCircular(pCircular self)
+  {
+     assert(self);
+     self->pPointer = self->pPointer->previous;
+  }
+