Postpone allocation of STACK internal storage ... until a first push(),

insert() or an explicit call to OPENSSL_sk_reserve

Factorise STACK item deletion code

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4379)
This commit is contained in:
FdaSilvaYY 2017-09-28 22:03:26 +02:00 committed by Andy Polyakov
parent 2dbfa8444b
commit 8e8e507ed7

View file

@ -55,6 +55,13 @@ OPENSSL_STACK *OPENSSL_sk_dup(const OPENSSL_STACK *sk)
/* direct structure assignment */
*ret = *sk;
if (sk->num == 0) {
/* postpone |ret->data| allocation */
ret->data = NULL;
ret->num_alloc = 0;
return ret;
}
/* duplicate |sk->data| content */
if ((ret->data = OPENSSL_malloc(sizeof(*ret->data) * sk->num_alloc)) == NULL)
goto err;
memcpy(ret->data, sk->data, sizeof(void *) * sk->num);
@ -80,6 +87,13 @@ OPENSSL_STACK *OPENSSL_sk_deep_copy(const OPENSSL_STACK *sk,
/* direct structure assignment */
*ret = *sk;
if (sk->num == 0) {
/* postpone |ret| data allocation */
ret->data = NULL;
ret->num_alloc = 0;
return ret;
}
ret->num_alloc = sk->num > min_nodes ? sk->num : min_nodes;
ret->data = OPENSSL_zalloc(sizeof(*ret->data) * ret->num_alloc);
if (ret->data == NULL) {
@ -103,41 +117,35 @@ OPENSSL_STACK *OPENSSL_sk_deep_copy(const OPENSSL_STACK *sk,
OPENSSL_STACK *OPENSSL_sk_new_null(void)
{
return OPENSSL_sk_new((OPENSSL_sk_compfunc)NULL);
return OPENSSL_zalloc(sizeof(OPENSSL_STACK));
}
OPENSSL_STACK *OPENSSL_sk_new(OPENSSL_sk_compfunc c)
{
OPENSSL_STACK *ret;
OPENSSL_STACK *ret = OPENSSL_sk_new_null();
if ((ret = OPENSSL_zalloc(sizeof(*ret))) == NULL)
goto err;
if ((ret->data = OPENSSL_zalloc(sizeof(*ret->data) * min_nodes)) == NULL)
goto err;
ret->comp = c;
ret->num_alloc = min_nodes;
return (ret);
err:
OPENSSL_free(ret);
return (NULL);
if (ret != NULL)
ret->comp = c;
return ret;
}
/*
* Calculate the array growth based on the target size.
*
* The growth faction is a rational number and is defined by a numerator
* The growth fraction is a rational number and is defined by a numerator
* and a denominator. According to Andrew Koenig in his paper "Why Are
* Vectors Efficient?" from JOOP 11(5) 1998, this factor should be less
* than the golden ratio (1.618...).
*
* We use 3/2 = 1.5 for simplicty of calculation and overflow checking.
* We use 3/2 = 1.5 for simplicity of calculation and overflow checking.
* Another option 8/5 = 1.6 allows for slightly faster growth, although safe
* computation is more difficult.
*
* The limit to avoid overflow is spot on. The modulo three correction term
* ensures that the limit is the largest number than can be expanded by the
* growth factor without exceeding the hard limit.
*
* Do not call it with |current| lower than 2, or it will infinitely loop.
*/
static ossl_inline int compute_growth(int target, int current)
{
@ -154,6 +162,7 @@ static ossl_inline int compute_growth(int target, int current)
return current;
}
/* internal STACK storage allocation */
static int sk_reserve(OPENSSL_STACK *st, int n, int exact)
{
const void **tmpdata;
@ -168,6 +177,19 @@ static int sk_reserve(OPENSSL_STACK *st, int n, int exact)
if (num_alloc < min_nodes)
num_alloc = min_nodes;
/* If |st->data| allocation was postponed */
if (st->data == NULL) {
/*
* At this point, |st->num_alloc| and |st->num| are 0;
* so |num_alloc| value is |n| or |min_nodes| if greater than |n|.
*/
st->data = OPENSSL_zalloc(sizeof(void *) * num_alloc);
if (st->data == NULL)
return 0;
st->num_alloc = num_alloc;
return 1;
}
if (!exact) {
if (num_alloc <= st->num_alloc)
return 1;
@ -217,29 +239,34 @@ int OPENSSL_sk_insert(OPENSSL_STACK *st, const void *data, int loc)
return st->num;
}
static ossl_inline void *internal_delete(OPENSSL_STACK *st, int loc)
{
const void *ret = st->data[loc];
if (loc != st->num - 1)
memmove(&st->data[loc], &st->data[loc + 1],
sizeof(st->data[0]) * (st->num - loc - 1));
st->num--;
return (void *)ret;
}
void *OPENSSL_sk_delete_ptr(OPENSSL_STACK *st, const void *p)
{
int i;
for (i = 0; i < st->num; i++)
if (st->data[i] == p)
return OPENSSL_sk_delete(st, i);
return internal_delete(st, i);
return NULL;
}
void *OPENSSL_sk_delete(OPENSSL_STACK *st, int loc)
{
const void *ret;
if (st == NULL || loc < 0 || loc >= st->num)
return NULL;
ret = st->data[loc];
if (loc != st->num - 1)
memmove(&st->data[loc], &st->data[loc + 1],
sizeof(st->data[0]) * (st->num - loc - 1));
st->num--;
return (void *)ret;
return internal_delete(st, loc);
}
static int internal_find(OPENSSL_STACK *st, const void *data,
@ -248,7 +275,7 @@ static int internal_find(OPENSSL_STACK *st, const void *data,
const void *r;
int i;
if (st == NULL)
if (st == NULL || st->num == 0)
return -1;
if (st->comp == NULL) {
@ -279,7 +306,9 @@ int OPENSSL_sk_find_ex(OPENSSL_STACK *st, const void *data)
int OPENSSL_sk_push(OPENSSL_STACK *st, const void *data)
{
return (OPENSSL_sk_insert(st, data, st->num));
if (st == NULL)
return -1;
return OPENSSL_sk_insert(st, data, st->num);
}
int OPENSSL_sk_unshift(OPENSSL_STACK *st, const void *data)
@ -290,19 +319,19 @@ int OPENSSL_sk_unshift(OPENSSL_STACK *st, const void *data)
void *OPENSSL_sk_shift(OPENSSL_STACK *st)
{
if (st == NULL)
return (NULL);
return NULL;
if (st->num <= 0)
return (NULL);
return (OPENSSL_sk_delete(st, 0));
return NULL;
return internal_delete(st, 0);
}
void *OPENSSL_sk_pop(OPENSSL_STACK *st)
{
if (st == NULL)
return (NULL);
return NULL;
if (st->num <= 0)
return (NULL);
return (OPENSSL_sk_delete(st, st->num - 1));
return NULL;
return internal_delete(st, st->num - 1);
}
void OPENSSL_sk_zero(OPENSSL_STACK *st)
@ -360,7 +389,8 @@ void *OPENSSL_sk_set(OPENSSL_STACK *st, int i, const void *data)
void OPENSSL_sk_sort(OPENSSL_STACK *st)
{
if (st && !st->sorted && st->comp != NULL) {
qsort(st->data, st->num, sizeof(void *), st->comp);
if (st->data != NULL)
qsort(st->data, st->num, sizeof(void *), st->comp);
st->sorted = 1;
}
}