1 #ifndef _LIST_H_
2 #define _LIST_H_
3 
4 #include <stdbool.h>
5 #include <stddef.h>
6 struct list_node_t;
7 typedef struct list_node_t list_node_t;
8 
9 struct list_t;
10 typedef struct list_t list_t;
11 
12 typedef void (*list_free_cb)(void *data);
13 typedef bool (*list_iter_cb)(void *data, void *context);
14 
15 // Returns a new, empty list. Returns NULL if not enough memory could be allocated
16 // for the list structure. The returned list must be freed with |list_free|. The
17 // |callback| specifies a function to be called whenever a list element is removed
18 // from the list. It can be used to release resources held by the list element, e.g.
19 // memory or file descriptor. |callback| may be NULL if no cleanup is necessary on
20 // element removal.
21 list_t *list_new(list_free_cb callback);
22 
23 
24 list_node_t *list_free_node(list_t *list, list_node_t *node);
25 
26 // similar with list_free_node, this function doesn't free the node data
27 list_node_t *list_delete_node(list_t *list, list_node_t *node);
28 
29 // Frees the list. This function accepts NULL as an argument, in which case it
30 // behaves like a no-op.
31 void list_free(list_t *list);
32 
33 // Returns true if |list| is empty (has no elements), false otherwise.
34 // |list| may not be NULL.
35 bool list_is_empty(const list_t *list);
36 
37 // Returns true if the list contains |data|, false otherwise.
38 // |list| may not be NULL.
39 bool list_contains(const list_t *list, const void *data);
40 
41 // Returns list_node which contains |data|, NULL otherwise.
42 // |list| may not be NULL.
43 list_node_t *list_get_node(const list_t *list, const void *data);
44 
45 // Returns the length of the |list|. |list| may not be NULL.
46 size_t list_length(const list_t *list);
47 
48 // Returns the first element in the list without removing it. |list| may not
49 // be NULL or empty.
50 void *list_front(const list_t *list);
51 
52 // Returns the last element in the list without removing it. |list| may not
53 // be NULL or empty.
54 void *list_back(const list_t *list);
55 list_node_t *list_back_node(const list_t *list);
56 
57 // Inserts |data| after |prev_node| in |list|. |data|, |list|, and |prev_node|
58 // may not be NULL. This function does not make a copy of |data| so the pointer
59 // must remain valid at least until the element is removed from the list or the
60 // list is freed. Returns true if |data| could be inserted, false otherwise
61 // (e.g. out of memory).
62 bool list_insert_after(list_t *list, list_node_t *prev_node, void *data);
63 
64 // Inserts |data| at the beginning of |list|. Neither |data| nor |list| may be NULL.
65 // This function does not make a copy of |data| so the pointer must remain valid
66 // at least until the element is removed from the list or the list is freed.
67 // Returns true if |data| could be inserted, false otherwise (e.g. out of memory).
68 bool list_prepend(list_t *list, void *data);
69 
70 // Inserts |data| at the end of |list|. Neither |data| nor |list| may be NULL.
71 // This function does not make a copy of |data| so the pointer must remain valid
72 // at least until the element is removed from the list or the list is freed.
73 // Returns true if |data| could be inserted, false otherwise (e.g. out of memory).
74 bool list_append(list_t *list, void *data);
75 
76 // Removes |data| from the list. Neither |list| nor |data| may be NULL. If |data|
77 // is inserted multiple times in the list, this function will only remove the first
78 // instance. If a free function was specified in |list_new|, it will be called back
79 // with |data|. This function returns true if |data| was found in the list and removed,
80 // false otherwise.
81 //list_node_t list_remove_node(list_t *list, list_node_t *prev_node, list_node_t *node);
82 //list_node_t list_insert_node(list_t *list, list_node_t *prev_node, list_node_t *node);
83 
84 bool list_remove(list_t *list, void *data);
85 
86 // similar with list_remove, but do not free the node data
87 bool list_delete(list_t *list, void *data);
88 
89 // Removes all elements in the list. Calling this function will return the list to the
90 // same state it was in after |list_new|. |list| may not be NULL.
91 void list_clear(list_t *list);
92 
93 // Iterates through the entire |list| and calls |callback| for each data element.
94 // If the list is empty, |callback| will never be called. It is safe to mutate the
95 // list inside the callback. If an element is added before the node being visited,
96 // there will be no callback for the newly-inserted node. Neither |list| nor
97 // |callback| may be NULL.
98 list_node_t *list_foreach(const list_t *list, list_iter_cb callback, void *context);
99 
100 // Returns an iterator to the first element in |list|. |list| may not be NULL.
101 // The returned iterator is valid as long as it does not equal the value returned
102 // by |list_end|.
103 list_node_t *list_begin(const list_t *list);
104 
105 // Returns an iterator that points past the end of the list. In other words,
106 // this function returns the value of an invalid iterator for the given list.
107 // When an iterator has the same value as what's returned by this function, you
108 // may no longer call |list_next| with the iterator. |list| may not be NULL.
109 list_node_t *list_end(const list_t *list);
110 
111 // Given a valid iterator |node|, this function returns the next value for the
112 // iterator. If the returned value equals the value returned by |list_end|, the
113 // iterator has reached the end of the list and may no longer be used for any
114 // purpose.
115 list_node_t *list_next(const list_node_t *node);
116 
117 // Returns the value stored at the location pointed to by the iterator |node|.
118 // |node| must not equal the value returned by |list_end|.
119 void *list_node(const list_node_t *node);
120 
121 #endif /* _LIST_H_ */
122