5 DEFINE_STACK_OF, DEFINE_STACK_OF_CONST, DEFINE_SPECIAL_STACK_OF,
6 DEFINE_SPECIAL_STACK_OF_CONST,
7 sk_TYPE_num, sk_TYPE_value, sk_TYPE_new, sk_TYPE_new_null,
8 sk_TYPE_reserve, sk_TYPE_free, sk_TYPE_zero, sk_TYPE_delete,
9 sk_TYPE_delete_ptr, sk_TYPE_push, sk_TYPE_unshift, sk_TYPE_pop,
10 sk_TYPE_shift, sk_TYPE_pop_free, sk_TYPE_insert, sk_TYPE_set,
11 sk_TYPE_find, sk_TYPE_find_ex, sk_TYPE_sort, sk_TYPE_is_sorted,
12 sk_TYPE_dup, sk_TYPE_deep_copy, sk_TYPE_set_cmp_func, sk_TYPE_new_reserve
19 #include <openssl/safestack.h>
23 DEFINE_STACK_OF_CONST(TYPE)
24 DEFINE_SPECIAL_STACK_OF(FUNCTYPE, TYPE)
25 DEFINE_SPECIAL_STACK_OF_CONST(FUNCTYPE, TYPE)
27 typedef int (*sk_TYPE_compfunc)(const TYPE *const *a, const TYPE *const *b);
28 typedef TYPE * (*sk_TYPE_copyfunc)(const TYPE *a);
29 typedef void (*sk_TYPE_freefunc)(TYPE *a);
31 int sk_TYPE_num(const STACK_OF(TYPE) *sk);
32 TYPE *sk_TYPE_value(const STACK_OF(TYPE) *sk, int idx);
33 STACK_OF(TYPE) *sk_TYPE_new(sk_TYPE_compfunc compare);
34 STACK_OF(TYPE) *sk_TYPE_new_null(void);
35 int sk_TYPE_reserve(STACK_OF(TYPE) *sk, int n);
36 void sk_TYPE_free(const STACK_OF(TYPE) *sk);
37 void sk_TYPE_zero(const STACK_OF(TYPE) *sk);
38 TYPE *sk_TYPE_delete(STACK_OF(TYPE) *sk, int i);
39 TYPE *sk_TYPE_delete_ptr(STACK_OF(TYPE) *sk, TYPE *ptr);
40 int sk_TYPE_push(STACK_OF(TYPE) *sk, const TYPE *ptr);
41 int sk_TYPE_unshift(STACK_OF(TYPE) *sk, const TYPE *ptr);
42 TYPE *sk_TYPE_pop(STACK_OF(TYPE) *sk);
43 TYPE *sk_TYPE_shift(STACK_OF(TYPE) *sk);
44 void sk_TYPE_pop_free(STACK_OF(TYPE) *sk, sk_TYPE_freefunc freefunc);
45 int sk_TYPE_insert(STACK_OF(TYPE) *sk, TYPE *ptr, int idx);
46 TYPE *sk_TYPE_set(STACK_OF(TYPE) *sk, int idx, const TYPE *ptr);
47 int sk_TYPE_find(STACK_OF(TYPE) *sk, TYPE *ptr);
48 int sk_TYPE_find_ex(STACK_OF(TYPE) *sk, TYPE *ptr);
49 void sk_TYPE_sort(const STACK_OF(TYPE) *sk);
50 int sk_TYPE_is_sorted(const STACK_OF(TYPE) *sk);
51 STACK_OF(TYPE) *sk_TYPE_dup(const STACK_OF(TYPE) *sk);
52 STACK_OF(TYPE) *sk_TYPE_deep_copy(const STACK_OF(TYPE) *sk,
53 sk_TYPE_copyfunc copyfunc,
54 sk_TYPE_freefunc freefunc);
55 sk_TYPE_compfunc (*sk_TYPE_set_cmp_func(STACK_OF(TYPE) *sk,
56 sk_TYPE_compfunc compare));
57 STACK_OF(TYPE) *sk_TYPE_new_reserve(sk_TYPE_compfunc compare, int n);
61 Applications can create and use their own stacks by placing any of the macros
62 described below in a header file. These macros define typesafe inline
63 functions that wrap around the utility B<OPENSSL_sk_> API.
64 In the description here, I<TYPE> is used
65 as a placeholder for any of the OpenSSL datatypes, such as I<X509>.
67 STACK_OF() returns the name for a stack of the specified B<TYPE>.
68 DEFINE_STACK_OF() creates set of functions for a stack of B<TYPE>. This
69 will mean that type B<TYPE> is stored in each stack, the type is referenced by
70 STACK_OF(TYPE) and each function name begins with I<sk_TYPE_>. For example:
72 TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
74 DEFINE_STACK_OF_CONST() is identical to DEFINE_STACK_OF() except
75 each element is constant. For example:
77 const TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
79 DEFINE_SPECIAL_STACK_OF() defines a stack of B<TYPE> but
80 each function uses B<FUNCNAME> in the function name. For example:
82 TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
84 DEFINE_SPECIAL_STACK_OF_CONST() is similar except that each element is
87 const TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
89 sk_TYPE_num() returns the number of elements in B<sk> or -1 if B<sk> is
92 sk_TYPE_value() returns element B<idx> in B<sk>, where B<idx> starts at
93 zero. If B<idx> is out of range then B<NULL> is returned.
95 sk_TYPE_new() allocates a new empty stack using comparison function B<compare>.
96 If B<compare> is B<NULL> then no comparison function is used. This function is
97 equivalent to sk_TYPE_new_reserve(compare, 0).
99 sk_TYPE_new_null() allocates a new empty stack with no comparison function. This
100 function is equivalent to sk_TYPE_new_reserve(NULL, 0).
102 sk_TYPE_reserve() allocates additional memory in the B<sk> structure
103 such that the next B<n> calls to sk_TYPE_insert(), sk_TYPE_push()
104 or sk_TYPE_unshift() will not fail or cause memory to be allocated
105 or reallocated. If B<n> is zero, any excess space allocated in the
106 B<sk> structure is freed. On error B<sk> is unchanged.
108 sk_TYPE_new_reserve() allocates a new stack. The new stack will have additional
109 memory allocated to hold B<n> elements if B<n> is positive. The next B<n> calls
110 to sk_TYPE_insert(), sk_TYPE_push() or sk_TYPE_unshift() will not fail or cause
111 memory to be allocated or reallocated. If B<n> is zero or less than zero, no
112 memory is allocated. sk_TYPE_new_reserve() also sets the comparison function
113 B<compare> to the newly created stack. If B<compare> is B<NULL> then no
114 comparison function is used.
116 sk_TYPE_set_cmp_func() sets the comparison function of B<sk> to B<compare>.
117 The previous comparison function is returned or B<NULL> if there was
118 no previous comparison function.
120 sk_TYPE_free() frees up the B<sk> structure. It does B<not> free up any
121 elements of B<sk>. After this call B<sk> is no longer valid.
123 sk_TYPE_zero() sets the number of elements in B<sk> to zero. It does not free
124 B<sk> so after this call B<sk> is still valid.
126 sk_TYPE_pop_free() frees up all elements of B<sk> and B<sk> itself. The
127 free function freefunc() is called on each element to free it.
129 sk_TYPE_delete() deletes element B<i> from B<sk>. It returns the deleted
130 element or B<NULL> if B<i> is out of range.
132 sk_TYPE_delete_ptr() deletes element matching B<ptr> from B<sk>. It returns
133 the deleted element or B<NULL> if no element matching B<ptr> was found.
135 sk_TYPE_insert() inserts B<ptr> into B<sk> at position B<idx>. Any existing
136 elements at or after B<idx> are moved downwards. If B<idx> is out of range
137 the new element is appended to B<sk>. sk_TYPE_insert() either returns the
138 number of elements in B<sk> after the new element is inserted or zero if
139 an error (such as memory allocation failure) occurred.
141 sk_TYPE_push() appends B<ptr> to B<sk> it is equivalent to:
143 sk_TYPE_insert(sk, ptr, -1);
145 sk_TYPE_unshift() inserts B<ptr> at the start of B<sk> it is equivalent to:
147 sk_TYPE_insert(sk, ptr, 0);
149 sk_TYPE_pop() returns and removes the last element from B<sk>.
151 sk_TYPE_shift() returns and removes the first element from B<sk>.
153 sk_TYPE_set() sets element B<idx> of B<sk> to B<ptr> replacing the current
154 element. The new element value is returned or B<NULL> if an error occurred:
155 this will only happen if B<sk> is B<NULL> or B<idx> is out of range.
157 sk_TYPE_find() searches B<sk> for the element B<ptr>. In the case
158 where no comparison function has been specified, the function performs
159 a linear search for a pointer equal to B<ptr>. The index of the first
160 matching element is returned or B<-1> if there is no match. In the case
161 where a comparison function has been specified, B<sk> is sorted then
162 sk_TYPE_find() returns the index of a matching element or B<-1> if there
163 is no match. Note that, in this case, the matching element returned is
164 not guaranteed to be the first; the comparison function will usually
165 compare the values pointed to rather than the pointers themselves and
166 the order of elements in B<sk> could change.
168 sk_TYPE_find_ex() operates like sk_TYPE_find() except when a comparison
169 function has been specified and no matching element is found. Instead
170 of returning B<-1>, sk_TYPE_find_ex() returns the index of the element
171 either before or after the location where B<ptr> would be if it were
174 sk_TYPE_sort() sorts B<sk> using the supplied comparison function.
176 sk_TYPE_is_sorted() returns B<1> if B<sk> is sorted and B<0> otherwise.
178 sk_TYPE_dup() returns a copy of B<sk>. Note the pointers in the copy
179 are identical to the original.
181 sk_TYPE_deep_copy() returns a new stack where each element has been copied.
182 Copying is performed by the supplied copyfunc() and freeing by freefunc(). The
183 function freefunc() is only called if an error occurs.
187 Care should be taken when accessing stacks in multi-threaded environments.
188 Any operation which increases the size of a stack such as sk_TYPE_insert() or
189 sk_push() can "grow" the size of an internal array and cause race conditions
190 if the same stack is accessed in a different thread. Operations such as
191 sk_find() and sk_sort() can also reorder the stack.
193 Any comparison function supplied should use a metric suitable
194 for use in a binary search operation. That is it should return zero, a
195 positive or negative value if B<a> is equal to, greater than
196 or less than B<b> respectively.
198 Care should be taken when checking the return values of the functions
199 sk_TYPE_find() and sk_TYPE_find_ex(). They return an index to the
200 matching element. In particular B<0> indicates a matching first element.
201 A failed search is indicated by a B<-1> return value.
203 STACK_OF(), DEFINE_STACK_OF(), DEFINE_STACK_OF_CONST(), and
204 DEFINE_SPECIAL_STACK_OF() are implemented as macros.
206 The underlying utility B<OPENSSL_sk_> API should not be used directly.
207 It defines these functions: OPENSSL_sk_deep_copy(),
208 OPENSSL_sk_delete(), OPENSSL_sk_delete_ptr(), OPENSSL_sk_dup(),
209 OPENSSL_sk_find(), OPENSSL_sk_find_ex(), OPENSSL_sk_free(),
210 OPENSSL_sk_insert(), OPENSSL_sk_is_sorted(), OPENSSL_sk_new(),
211 OPENSSL_sk_new_null(), OPENSSL_sk_num(), OPENSSL_sk_pop(),
212 OPENSSL_sk_pop_free(), OPENSSL_sk_push(), OPENSSL_sk_reserve(),
213 OPENSSL_sk_set(), OPENSSL_sk_set_cmp_func(), OPENSSL_sk_shift(),
214 OPENSSL_sk_sort(), OPENSSL_sk_unshift(), OPENSSL_sk_value(),
219 sk_TYPE_num() returns the number of elements in the stack or B<-1> if the
220 passed stack is B<NULL>.
222 sk_TYPE_value() returns a pointer to a stack element or B<NULL> if the
223 index is out of range.
225 sk_TYPE_new(), sk_TYPE_new_null() and sk_TYPE_new_reserve() return an empty
226 stack or B<NULL> if an error occurs.
228 sk_TYPE_reserve() returns B<1> on successful allocation of the required memory
231 sk_TYPE_set_cmp_func() returns the old comparison function or B<NULL> if
232 there was no old comparison function.
234 sk_TYPE_free(), sk_TYPE_zero(), sk_TYPE_pop_free() and sk_TYPE_sort() do
237 sk_TYPE_pop(), sk_TYPE_shift(), sk_TYPE_delete() and sk_TYPE_delete_ptr()
238 return a pointer to the deleted element or B<NULL> on error.
240 sk_TYPE_insert(), sk_TYPE_push() and sk_TYPE_unshift() return the total
241 number of elements in the stack and 0 if an error occurred.
243 sk_TYPE_set() returns a pointer to the replacement element or B<NULL> on
246 sk_TYPE_find() and sk_TYPE_find_ex() return an index to the found element
249 sk_TYPE_is_sorted() returns B<1> if the stack is sorted and B<0> if it is
252 sk_TYPE_dup() and sk_TYPE_deep_copy() return a pointer to the copy of the
257 Before OpenSSL 1.1.0, this was implemented via macros and not inline functions
258 and was not a public API.
260 sk_TYPE_reserve() and sk_TYPE_new_reserve() were added in OpenSSL 1.1.1.
264 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
266 Licensed under the OpenSSL license (the "License"). You may not use
267 this file except in compliance with the License. You can obtain a copy
268 in the file LICENSE in the source distribution or at
269 L<https://www.openssl.org/source/license.html>.