xref: /btstack/src/btstack_linked_list.h (revision 2fca4dad957cd7b88f4657ed51e89c12615dda72)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
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37 
38 /**
39  * @title Linked List
40  *
41  */
42 
43 #ifndef BTSTACK_LINKED_LIST_H
44 #define BTSTACK_LINKED_LIST_H
45 
46 #include "btstack_bool.h"
47 
48 #if defined __cplusplus
49 extern "C" {
50 #endif
51 
52 /* API_START */
53 
54 typedef struct btstack_linked_item {
55     struct btstack_linked_item *next; // <-- next element in list, or NULL
56 } btstack_linked_item_t;
57 
58 typedef btstack_linked_item_t * btstack_linked_list_t;
59 
60 typedef struct {
61 	int advance_on_next;
62     btstack_linked_item_t * prev;	// points to the item before the current one
63     btstack_linked_item_t * curr;	// points to the current item (to detect item removal)
64 } btstack_linked_list_iterator_t;
65 
66 
67 /**
68  * @brief Test if list is empty.
69  * @param list
70  * @return true if list is empty
71  */
72 bool btstack_linked_list_empty(btstack_linked_list_t * list);
73 
74 /**
75  * @brief Add item to list as first element.
76  * @param list
77  * @param item
78  * @return true if item was added, false if item already in list
79  */
80 bool btstack_linked_list_add(btstack_linked_list_t * list, btstack_linked_item_t *item);
81 
82 /**
83  * @brief Add item to list as last element.
84  * @param list
85  * @param item
86  * @return true if item was added, false if item already in list
87  */
88 bool btstack_linked_list_add_tail(btstack_linked_list_t * list, btstack_linked_item_t *item);
89 
90 /**
91  * @brief Pop (get + remove) first element.
92  * @param list
93  * @return first element or NULL if list is empty
94  */
95 btstack_linked_item_t * btstack_linked_list_pop(btstack_linked_list_t * list);
96 
97 /**
98  * @brief Remove item from list
99  * @param list
100  * @param item
101  * @return true if item was removed, false if it is no't in list
102  */
103 bool btstack_linked_list_remove(btstack_linked_list_t * list, btstack_linked_item_t *item);
104 
105 /**
106  * @brief Get first element.
107  * @param list
108  * @return first element or NULL if list is empty
109  */
110 btstack_linked_item_t * btstack_linked_list_get_first_item(btstack_linked_list_t * list);
111 
112 /**
113  * @brief Get last element.
114  * @param list
115  * @return first element or NULL if list is empty
116  */
117 btstack_linked_item_t * btstack_linked_list_get_last_item(btstack_linked_list_t * list);
118 
119 /**
120  * @brief Counts number of items in list
121  * @return number of items in list
122  */
123 int btstack_linked_list_count(btstack_linked_list_t * list);
124 
125 
126 
127 /**
128  * @brief Initialize Linked List Iterator
129  * @note robust against removal of current element by btstack_linked_list_remove
130  * @param it iterator context
131  * @param list
132  */
133 void btstack_linked_list_iterator_init(btstack_linked_list_iterator_t * it, btstack_linked_list_t * list);
134 
135 /**
136  * @brief Has next element
137  * @param it iterator context
138  * @return true if next element is available
139  */
140 bool btstack_linked_list_iterator_has_next(btstack_linked_list_iterator_t * it);
141 
142 /**
143  * @brief Get next list eleemnt
144  * @param it iterator context
145  * @return list element
146  */
147 btstack_linked_item_t * btstack_linked_list_iterator_next(btstack_linked_list_iterator_t * it);
148 
149 /**
150  * @brief Remove current list element from list
151  * @param it iterator context
152  */
153 void btstack_linked_list_iterator_remove(btstack_linked_list_iterator_t * it);
154 
155 /* API_END */
156 
157 void test_linked_list(void);
158 
159 
160 #if defined __cplusplus
161 }
162 #endif
163 
164 #endif // BTSTACK_LINKED_LIST_H
165