1 /* Copyright (c) 2011, The Linux Foundation. All rights reserved.
2  *
3  * Redistribution and use in source and binary forms, with or without
4  * modification, are permitted provided that the following conditions are
5  * met:
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8  *     * Redistributions in binary form must reproduce the above
9  *       copyright notice, this list of conditions and the following
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12  *     * Neither the name of The Linux Foundation nor the names of its
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14  *       from this software without specific prior written permission.
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16  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
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27  */
28 #ifndef __LINKED_LIST_H__
29 #define __LINKED_LIST_H__
30 
31 #ifdef __cplusplus
32 extern "C" {
33 #endif /* __cplusplus */
34 
35 #include <stdbool.h>
36 #include <stdlib.h>
37 
38 /** Linked List Return Codes */
39 typedef enum
40 {
41   eLINKED_LIST_SUCCESS                             = 0,
42      /**< Request was successful. */
43   eLINKED_LIST_FAILURE_GENERAL                     = -1,
44      /**< Failed because of a general failure. */
45   eLINKED_LIST_INVALID_PARAMETER                   = -2,
46      /**< Failed because the request contained invalid parameters. */
47   eLINKED_LIST_INVALID_HANDLE                      = -3,
48      /**< Failed because an invalid handle was specified. */
49   eLINKED_LIST_UNAVAILABLE_RESOURCE                = -4,
50      /**< Failed because an there were not enough resources. */
51   eLINKED_LIST_INSUFFICIENT_BUFFER                 = -5,
52      /**< Failed because an the supplied buffer was too small. */
53 }linked_list_err_type;
54 
55 /*===========================================================================
56 FUNCTION    linked_list_init
57 
58 DESCRIPTION
59    Initializes internal structures for linked list.
60 
61    list_data: State of list to be initialized.
62 
63 DEPENDENCIES
64    N/A
65 
66 RETURN VALUE
67    Look at error codes above.
68 
69 SIDE EFFECTS
70    N/A
71 
72 ===========================================================================*/
73 linked_list_err_type linked_list_init(void** list_data);
74 
75 /*===========================================================================
76 FUNCTION    linked_list_destroy
77 
78 DESCRIPTION
79    Destroys internal structures for linked list.
80 
81    p_list_data: State of list to be destroyed.
82 
83 DEPENDENCIES
84    N/A
85 
86 RETURN VALUE
87    Look at error codes above.
88 
89 SIDE EFFECTS
90    N/A
91 
92 ===========================================================================*/
93 linked_list_err_type linked_list_destroy(void** list_data);
94 
95 /*===========================================================================
96 FUNCTION    linked_list_add
97 
98 DESCRIPTION
99    Adds an element to the head of the linked list. The passed in data pointer
100    is not modified or freed. Passed in data_obj is expected to live throughout
101    the use of the linked_list (i.e. data is not allocated internally)
102 
103    p_list_data:  List to add data to the head of.
104    data_obj:     Pointer to data to add into list
105    dealloc:      Function used to deallocate memory for this element. Pass NULL
106                  if you do not want data deallocated during a flush operation
107 
108 DEPENDENCIES
109    N/A
110 
111 RETURN VALUE
112    Look at error codes above.
113 
114 SIDE EFFECTS
115    N/A
116 
117 ===========================================================================*/
118 linked_list_err_type linked_list_add(void* list_data, void *data_obj, void (*dealloc)(void*));
119 
120 /*===========================================================================
121 FUNCTION    linked_list_remove
122 
123 DESCRIPTION
124    Retrieves data from the list tail. data_obj is the tail element from the list
125    passed in by linked_list_add.
126 
127    p_list_data:  List to remove the tail from.
128    data_obj:     Pointer to data removed from list
129 
130 DEPENDENCIES
131    N/A
132 
133 RETURN VALUE
134    Look at error codes above.
135 
136 SIDE EFFECTS
137    N/A
138 
139 ===========================================================================*/
140 linked_list_err_type linked_list_remove(void* list_data, void **data_obj);
141 
142 /*===========================================================================
143 FUNCTION    linked_list_empty
144 
145 DESCRIPTION
146    Tells whether the list currently contains any elements
147 
148    p_list_data:  List to check if empty.
149 
150 DEPENDENCIES
151    N/A
152 
153 RETURN VALUE
154    0/FALSE : List contains elements
155    1/TRUE  : List is Empty
156    Otherwise look at error codes above.
157 
158 SIDE EFFECTS
159    N/A
160 
161 ===========================================================================*/
162 int linked_list_empty(void* list_data);
163 
164 /*===========================================================================
165 FUNCTION    linked_list_flush
166 
167 DESCRIPTION
168    Removes all elements from the list and deallocates them using the provided
169    dealloc function while adding elements.
170 
171    p_list_data:  List to remove all elements from.
172 
173 DEPENDENCIES
174    N/A
175 
176 RETURN VALUE
177    Look at error codes above.
178 
179 SIDE EFFECTS
180    N/A
181 
182 ===========================================================================*/
183 linked_list_err_type linked_list_flush(void* list_data);
184 
185 /*===========================================================================
186 FUNCTION    linked_list_search
187 
188 DESCRIPTION
189    Searches for an element in the linked list.
190 
191    p_list_data:  List handle.
192    data_p:       to be stored with the data found; NUll if no match.
193                  if data_p passed in as NULL, then no write to it.
194    equal:        Function ptr takes in a list element, and returns
195                  indication if this the one looking for.
196    data_0:       The data being compared against.
197    rm_if_found:  Should data be removed if found?
198 
199 DEPENDENCIES
200    N/A
201 
202 RETURN VALUE
203    Look at error codes above.
204 
205 SIDE EFFECTS
206    N/A
207 
208 ===========================================================================*/
209 linked_list_err_type linked_list_search(void* list_data, void **data_p,
210                                         bool (*equal)(void* data_0, void* data),
211                                         void* data_0, bool rm_if_found);
212 
213 #ifdef __cplusplus
214 }
215 #endif /* __cplusplus */
216 
217 #endif /* __LINKED_LIST_H__ */
218