改为双向链表, 使用哑头

AWList.c

@@ -3,146 +3,112 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-typedef enum
-{
-    TRUE  = 1,
-    FALSE = 0
-} BOOL;
+typedef enum { TRUE = 1, FALSE = 0 } BOOL;
 
 // ================> SOURCE CODE BELOW <================
-AWList* AWList_init(AWList* list)
-{
-    if (list == NULL)
-    {
+AWList* AWList_init(AWList* list) {
+  if (list == NULL) {
     list = calloc(1, sizeof(AWList));
 
     list->free_me = TRUE;
-    }
-    else
-    {
+  } else {
     list->free_me = FALSE;
   }
 
-    list->head = NULL;
-    list->tail = NULL;
-    list->curr = NULL;
+  list->head = calloc(1, sizeof(AWNode));
+  list->tail = list->head;
+  list->iter = list->head;
   list->cnt  = 0;
   return list;
 }
 
-void AWList_destroy(AWList* list)
-{
-    if (list)
-    {
-        for (; list->head; AWList_delete_node(list, list->head))
-            ;
+void AWList_destroy(AWList* list) {
+  AWList_clear(list);
 
-        if (list->free_me == TRUE)
-        {
-            free(list);
-            list = NULL;
-        }
-    }
+  free(list->head);
+  if (list->free_me) { free(list); }
 }
 
-void AWList_add_head(AWList* list, void* data, void (*delete_func)(void*))
-{
-    AWNode* node      = (AWNode*)malloc(sizeof(AWNode));
+void AWList_clear(AWList* list) {
+  if (!list) { return; }
+  for (; list->tail != list->head; AWList_delete_node(list, list->tail))
+    ;
+}
+
+AWNode* AWNode_init(void* data, void (*delete_func)(void*)) {
+  AWNode* node = malloc(sizeof(AWNode));
   node->data            = data;
   node->delete_func     = delete_func;
 
-    if (list->head == NULL)
-    {
+  node->prev = NULL;
   node->next = NULL;
 
-        list->tail = node;
-    }
-    else
-    {
-        node->next = list->head;
-    }
-    list->curr = list->head = node;
-    list->cnt += 1;
+  return node;
 }
 
-void AWList_add_tail(AWList* list, void* data, void (*delete_func)(void*))
-{
-    AWNode* node      = (AWNode*)malloc(sizeof(AWNode));
-    node->data        = data;
-    node->next        = NULL;
-    node->delete_func = delete_func;
+void AWNode_destroy(AWNode* node) {
+  if (node->next) { node->next->prev = node->prev; }
+  node->prev->next = node->next;
 
-    if (list->head == NULL)
-    {
-        list->curr = list->head = node;
-    }
-    else
-    {
-        list->tail->next = node;
-    }
-    list->tail = node;
+  if (node && node->delete_func) { node->delete_func(node->data); }
+  free(node);
+}
 
-    list->cnt += 1;
+void AWList_delete_node(AWList* list, AWNode* node) {
+  if (!list || !list->head || !node) return;
+
+  if (list->tail == node) { list->tail = node->prev; }
+  if (list->iter == node) { list->iter = node->prev; }
+
+  AWNode_destroy(node);
+  list->cnt -= 1;
 }
 
-void AWList_delete_node(AWList* list, AWNode* node)
-{
-    if (list->head == NULL || node == NULL || node->delete_func == NULL) return;
+void AWList_add_head(AWList* list, void* data, void (*delete_func)(void*)) {
+  if (!list || !list->head) return;
 
+  AWNode* node  = AWNode_init(data, delete_func);
+  AWNode* dummy = list->head;
 
-    if (list->head == node)
-    {
-        list->curr = list->head = list->head->next;
-    }
-    else
-    {
-        AWNode* tmp = list->head;
-        for (; tmp->next && tmp->next != node; tmp = tmp->next)
-        {
-        }
-        if (tmp->next == node)
-            tmp->next = node->next;
-        else
-            return;
-    }
+  node->prev = dummy;
+  node->next = dummy->next;
 
-    node->delete_func(node->data);
+  dummy->next->prev = node;
+  dummy->next       = node;
 
-    free(node);
-    node = NULL;
-    list->cnt -= 1;
+  list->iter = node;
+  list->cnt += 1;
 }
 
-void AWList_clear(AWList *list)
-{
-    int freeme = list->free_me;
-    list->free_me = FALSE;
+void AWList_add_tail(AWList* list, void* data, void (*delete_func)(void*)) {
+  AWNode* node = AWNode_init(data, delete_func);
 
-    AWList_destroy(list);
+  node->prev = list->tail;
+  node->next = NULL;
 
-    list->free_me = freeme;
+  list->tail->next = node;
+  list->tail       = node;
+
+  list->cnt += 1;
 }
 
-AWNode *AWList_find_node(AWList* list, void* data, int (*cmp_callback)(void*, void*))
-{
-    AWNode *node;
-    AWList_for_each(node, list)
-    {
-        if (cmp_callback(node->data, data) == 0)
-            return node;
+AWNode* AWList_find_node(AWList* list,
+                         void*   data,
+                         int (*cmp_callback)(void*, void*)) {
+  AWNode* node;
+  AWList_for_each(node, list) {
+    if (cmp_callback(node->data, data) == 0) return node;
   }
 
   return NULL;
 }
 
-AWNode* AWList_iterator(AWList* list)
-{
-    if (list->curr)
-    {
-        AWNode* curr = list->curr;
-        list->curr = list->curr->next;
-        return curr;
-    }
-    else
-        return NULL;
+AWNode* AWList_iterator(AWList* list) {
+  if (!list || list->iter == list->tail->next) return NULL;
+
+  if (list->iter == list->head) list->iter = list->head->next;
+
+  AWNode* iter = list->iter;
+  list->iter   = list->iter->next;
+  return iter;
 }

AWList.h

@@ -16,9 +16,9 @@
  * @param      data       data of node
  * @param      delete_func  function to free data
  */
-typedef struct _node
-{
+typedef struct _node {
   struct _node* next;
+  struct _node* prev;
   void*         data;
   void (*delete_func)(void*);
 } AWNode;
@@ -30,11 +30,10 @@ typedef struct _node
  * @param      curr     current position of list
  * @param      free_me  need to free itself or not
  */
-typedef struct _linked_list
-{
-    AWNode* head;
-    AWNode* tail;
-    AWNode* curr;
+typedef struct _linked_list {
+  AWNode* head; /* dummy node */
+  AWNode* tail; /* last node */
+  AWNode* iter; /* iterator */
   int     free_me;
   int     cnt;
 } AWList;
@@ -110,7 +109,8 @@ void AWList_add_tail(AWList* list, void* data, void (*delete_func)(void*));
  *
  * @return     the pointer of the node if exists, NULL if not found
  */
-AWNode* AWList_find_node(AWList* list, void* data,
+AWNode* AWList_find_node(AWList* list,
+                         void*   data,
                          int (*cmp_callback)(void*, void*));
 
 /**

tests.c

+#include <stdio.h>
+#include <stdlib.h>
+
+#include "AWList.h"
+
+static inline void mfree(void* arg) {
+  free(arg);
+  arg = NULL;
+}
+
+int main() {
+  AWList list = {0};
+  AWList_init(&list);
+
+  int* num[10] = {NULL};
+  for (int i = 0; i < 10; ++i) {
+    num[i]  = calloc(1, sizeof(int));
+    *num[i] = i;
+
+    AWList_add_tail(&list, num[i], mfree);
+  }
+
+  AWNode* node = NULL;
+  for (node = list.head->next; node != list.tail->next; node = node->next) {
+    printf("%d ", *(int*)node->data);
+  }
+  printf("\n");
+
+  AWList_clear(&list);
+  /* while ((node = AWList_iterator(&list))) { printf("%d ", *(int*)node->data); } */
+  /* printf("\n"); */
+
+  AWList_destroy(&list);
+}

valgrind.log

+==240== Memcheck, a memory error detector
+==240== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
+==240== Using Valgrind-3.16.0 and LibVEX; rerun with -h for copyright info
+==240== Command: ./tests
+==240== Parent PID: 84
+==240== 
+==240== 
+==240== HEAP SUMMARY:
+==240==     in use at exit: 0 bytes in 0 blocks
+==240==   total heap usage: 22 allocs, 22 frees, 1,416 bytes allocated
+==240== 
+==240== All heap blocks were freed -- no leaks are possible
+==240== 
+==240== For lists of detected and suppressed errors, rerun with: -s
+==240== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)