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DEFINE_STACK_OF(3ossl) OpenSSL DEFINE_STACK_OF(3ossl)
NAME
DEFINE_STACK_OF, DEFINE_STACK_OF_CONST, DEFINE_SPECIAL_STACK_OF,
DEFINE_SPECIAL_STACK_OF_CONST, sk_TYPE_num, sk_TYPE_value, sk_TYPE_new,
sk_TYPE_new_null, sk_TYPE_reserve, sk_TYPE_free, sk_TYPE_zero,
sk_TYPE_delete, sk_TYPE_delete_ptr, sk_TYPE_push, sk_TYPE_unshift,
sk_TYPE_pop, sk_TYPE_shift, sk_TYPE_pop_free, sk_TYPE_insert,
sk_TYPE_set, sk_TYPE_find, sk_TYPE_find_ex, sk_TYPE_find_all,
sk_TYPE_sort, sk_TYPE_is_sorted, sk_TYPE_dup, sk_TYPE_deep_copy,
sk_TYPE_set_cmp_func, sk_TYPE_new_reserve, OPENSSL_sk_deep_copy,
OPENSSL_sk_delete, OPENSSL_sk_delete_ptr, OPENSSL_sk_dup,
OPENSSL_sk_find, OPENSSL_sk_find_ex, OPENSSL_sk_find_all,
OPENSSL_sk_free, OPENSSL_sk_insert, OPENSSL_sk_is_sorted,
OPENSSL_sk_new, OPENSSL_sk_new_null, OPENSSL_sk_new_reserve,
OPENSSL_sk_num, OPENSSL_sk_pop, OPENSSL_sk_pop_free, OPENSSL_sk_push,
OPENSSL_sk_reserve, OPENSSL_sk_set, OPENSSL_sk_set_cmp_func,
OPENSSL_sk_shift, OPENSSL_sk_sort, OPENSSL_sk_unshift,
OPENSSL_sk_value, OPENSSL_sk_zero - stack container
SYNOPSIS
#include <openssl/safestack.h>
STACK_OF(TYPE)
DEFINE_STACK_OF(TYPE)
DEFINE_STACK_OF_CONST(TYPE)
DEFINE_SPECIAL_STACK_OF(FUNCTYPE, TYPE)
DEFINE_SPECIAL_STACK_OF_CONST(FUNCTYPE, TYPE)
typedef int (*sk_TYPE_compfunc)(const TYPE *const *a, const TYPE *const *b);
typedef TYPE * (*sk_TYPE_copyfunc)(const TYPE *a);
typedef void (*sk_TYPE_freefunc)(TYPE *a);
int sk_TYPE_num(const STACK_OF(TYPE) *sk);
TYPE *sk_TYPE_value(const STACK_OF(TYPE) *sk, int idx);
STACK_OF(TYPE) *sk_TYPE_new(sk_TYPE_compfunc compare);
STACK_OF(TYPE) *sk_TYPE_new_null(void);
int sk_TYPE_reserve(STACK_OF(TYPE) *sk, int n);
void sk_TYPE_free(const STACK_OF(TYPE) *sk);
void sk_TYPE_zero(const STACK_OF(TYPE) *sk);
TYPE *sk_TYPE_delete(STACK_OF(TYPE) *sk, int i);
TYPE *sk_TYPE_delete_ptr(STACK_OF(TYPE) *sk, TYPE *ptr);
int sk_TYPE_push(STACK_OF(TYPE) *sk, const TYPE *ptr);
int sk_TYPE_unshift(STACK_OF(TYPE) *sk, const TYPE *ptr);
TYPE *sk_TYPE_pop(STACK_OF(TYPE) *sk);
TYPE *sk_TYPE_shift(STACK_OF(TYPE) *sk);
void sk_TYPE_pop_free(STACK_OF(TYPE) *sk, sk_TYPE_freefunc freefunc);
int sk_TYPE_insert(STACK_OF(TYPE) *sk, TYPE *ptr, int idx);
TYPE *sk_TYPE_set(STACK_OF(TYPE) *sk, int idx, const TYPE *ptr);
int sk_TYPE_find(STACK_OF(TYPE) *sk, TYPE *ptr);
int sk_TYPE_find_ex(STACK_OF(TYPE) *sk, TYPE *ptr);
int sk_TYPE_find_all(STACK_OF(TYPE) *sk, TYPE *ptr, int *pnum);
void sk_TYPE_sort(const STACK_OF(TYPE) *sk);
int sk_TYPE_is_sorted(const STACK_OF(TYPE) *sk);
STACK_OF(TYPE) *sk_TYPE_dup(const STACK_OF(TYPE) *sk);
STACK_OF(TYPE) *sk_TYPE_deep_copy(const STACK_OF(TYPE) *sk,
sk_TYPE_copyfunc copyfunc,
sk_TYPE_freefunc freefunc);
inline functions that wrap around the utility OPENSSL_sk_ API. In the
description here, TTYYPPEE is used as a placeholder for any of the OpenSSL
datatypes, such as X509.
The STACK_OF() macro returns the name for a stack of the specified
TTYYPPEE. This is an opaque pointer to a structure declaration. This can
be used in every header file that references the stack. There are
several DEFINE... macros that create static inline functions for all of
the functions described on this page. This should normally be used in
one source file, and the stack manipulation is wrapped with
application-specific functions.
DEFINE_STACK_OF() creates set of functions for a stack of TTYYPPEE
elements. The type is referenced by STACK_OF(TTYYPPEE) and each function
name begins with sk_TTYYPPEE_. DEFINE_STACK_OF_CONST() is identical to
DEFINE_STACK_OF() except each element is constant.
/* DEFINE_STACK_OF(TYPE) */
TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
/* DEFINE_STACK_OF_CONST(TYPE) */
const TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
DEFINE_SPECIAL_STACK_OF() and DEFINE_SPECIAL_STACK_OF_CONST() are
similar except FUNCNAME is used in the function names:
/* DEFINE_SPECIAL_STACK_OF(TYPE, FUNCNAME) */
TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
/* DEFINE_SPECIAL_STACK_OF(TYPE, FUNCNAME) */
const TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
sk_TTYYPPEE_num() returns the number of elements in sk or -1 if sk is NULL.
sk_TTYYPPEE_value() returns element idx in sk, where idx starts at zero. If
idx is out of range then NULL is returned.
sk_TTYYPPEE_new() allocates a new empty stack using comparison function
compare. If compare is NULL then no comparison function is used. This
function is equivalent to sk_TTYYPPEE_new_reserve(compare, 0).
sk_TTYYPPEE_new_null() allocates a new empty stack with no comparison
function. This function is equivalent to sk_TTYYPPEE_new_reserve(NULL, 0).
sk_TTYYPPEE_reserve() allocates additional memory in the sk structure such
that the next n calls to sk_TTYYPPEE_insert(), sk_TTYYPPEE_push() or
sk_TTYYPPEE_unshift() will not fail or cause memory to be allocated or
reallocated. If n is zero, any excess space allocated in the sk
structure is freed. On error sk is unchanged.
sk_TTYYPPEE_new_reserve() allocates a new stack. The new stack will have
additional memory allocated to hold n elements if n is positive. The
next n calls to sk_TTYYPPEE_insert(), sk_TTYYPPEE_push() or sk_TTYYPPEE_unshift()
will not fail or cause memory to be allocated or reallocated. If n is
zero or less than zero, no memory is allocated. sk_TTYYPPEE_new_reserve()
also sets the comparison function compare to the newly created stack.
If compare is NULL then no comparison function is used.
sk_TTYYPPEE_set_cmp_func() sets the comparison function of sk to compare.
The previous comparison function is returned or NULL if there was no
previous comparison function.
sk_TTYYPPEE_pop_free() frees up all elements of sk and sk itself. The free
function freefunc() is called on each element to free it.
sk_TTYYPPEE_delete() deletes element i from sk. It returns the deleted
element or NULL if i is out of range.
sk_TTYYPPEE_delete_ptr() deletes element matching ptr from sk. It returns
the deleted element or NULL if no element matching ptr was found.
sk_TTYYPPEE_insert() inserts ptr into sk at position idx. Any existing
elements at or after idx are moved downwards. If idx is out of range
the new element is appended to sk. sk_TTYYPPEE_insert() either returns the
number of elements in sk after the new element is inserted or zero if
an error (such as memory allocation failure) occurred.
sk_TTYYPPEE_push() appends ptr to sk it is equivalent to:
sk_TYPE_insert(sk, ptr, -1);
sk_TTYYPPEE_unshift() inserts ptr at the start of sk it is equivalent to:
sk_TYPE_insert(sk, ptr, 0);
sk_TTYYPPEE_pop() returns and removes the last element from sk.
sk_TTYYPPEE_shift() returns and removes the first element from sk.
sk_TTYYPPEE_set() sets element idx of sk to ptr replacing the current
element. The new element value is returned or NULL if an error
occurred: this will only happen if sk is NULL or idx is out of range.
sk_TTYYPPEE_find() searches sk for the element ptr. In the case where no
comparison function has been specified, the function performs a linear
search for a pointer equal to ptr. The index of the first matching
element is returned or -1 if there is no match. In the case where a
comparison function has been specified, sk is sorted and sk_TTYYPPEE_find()
returns the index of a matching element or -1 if there is no match.
Note that, in this case the comparison function will usually compare
the values pointed to rather than the pointers themselves and the order
of elements in sk can change. Note that because the stack may be sorted
as the result of a sk_TTYYPPEE_find() call, if a lock is being used to
synchronise access to the stack across multiple threads, then that lock
must be a "write" lock.
sk_TTYYPPEE_find_ex() operates like sk_TTYYPPEE_find() except when a comparison
function has been specified and no matching element is found. Instead
of returning -1, sk_TTYYPPEE_find_ex() returns the index of the element
either before or after the location where ptr would be if it were
present in sk. The function also does not guarantee that the first
matching element in the sorted stack is returned.
sk_TTYYPPEE_find_all() operates like sk_TTYYPPEE_find() but it also sets the
*pnum to number of matching elements in the stack. In case no
comparison function has been specified the *pnum will be always set to
1 if matching element was found, 0 otherwise.
sk_TTYYPPEE_sort() sorts sk using the supplied comparison function.
sk_TTYYPPEE_is_sorted() returns 1 if sk is sorted and 0 otherwise.
performed by the supplied copyfunc() and freeing by freefunc(). The
function freefunc() is only called if an error occurs.
NOTES
Care should be taken when accessing stacks in multi-threaded
environments. Any operation which increases the size of a stack such
as sk_TTYYPPEE_insert() or sk_TTYYPPEE_push() can "grow" the size of an
internal array and cause race conditions if the same stack is accessed
in a different thread. Operations such as sk_TTYYPPEE_find() and
sk_TTYYPPEE_sort() can also reorder the stack.
Any comparison function supplied should use a metric suitable for use
in a binary search operation. That is it should return zero, a positive
or negative value if a is equal to, greater than or less than b
respectively.
Care should be taken when checking the return values of the functions
sk_TTYYPPEE_find() and sk_TTYYPPEE_find_ex(). They return an index to the
matching element. In particular 0 indicates a matching first element.
A failed search is indicated by a -1 return value.
STACK_OF(), DEFINE_STACK_OF(), DEFINE_STACK_OF_CONST(), and
DEFINE_SPECIAL_STACK_OF() are implemented as macros.
It is not an error to call sk_TTYYPPEE_num(), sk_TTYYPPEE_value(),
sk_TTYYPPEE_free(), sk_TTYYPPEE_zero(), sk_TTYYPPEE_pop_free(), sk_TTYYPPEE_delete(),
sk_TTYYPPEE_delete_ptr(), sk_TTYYPPEE_pop(), sk_TTYYPPEE_shift(), sk_TTYYPPEE_find(),
sk_TTYYPPEE_find_ex(), and sk_TTYYPPEE_find_all() on a NULL stack, empty stack,
or with an invalid index. An error is not raised in these conditions.
The underlying utility OPENSSL_sk_ API should not be used directly. It
defines these functions: OPENSSL_sk_deep_copy(), OPENSSL_sk_delete(),
OPENSSL_sk_delete_ptr(), OPENSSL_sk_dup(), OPENSSL_sk_find(),
OPENSSL_sk_find_ex(), OPENSSL_sk_find_all(), OPENSSL_sk_free(),
OPENSSL_sk_insert(), OPENSSL_sk_is_sorted(), OPENSSL_sk_new(),
OPENSSL_sk_new_null(), OPENSSL_sk_new_reserve(), OPENSSL_sk_num(),
OPENSSL_sk_pop(), OPENSSL_sk_pop_free(), OPENSSL_sk_push(),
OPENSSL_sk_reserve(), OPENSSL_sk_set(), OPENSSL_sk_set_cmp_func(),
OPENSSL_sk_shift(), OPENSSL_sk_sort(), OPENSSL_sk_unshift(),
OPENSSL_sk_value(), OPENSSL_sk_zero().
RETURN VALUES
sk_TTYYPPEE_num() returns the number of elements in the stack or -1 if the
passed stack is NULL.
sk_TTYYPPEE_value() returns a pointer to a stack element or NULL if the
index is out of range.
sk_TTYYPPEE_new(), sk_TTYYPP