cairo-script-stack.c [plain text]
#include "cairo-script-private.h"
#include <limits.h>
#include <string.h>
csi_status_t
_csi_stack_init (csi_t *ctx, csi_stack_t *stack, csi_integer_t size)
{
csi_status_t status = CSI_STATUS_SUCCESS;
stack->len = 0;
stack->size = size;
stack->objects = _csi_alloc (ctx, size * sizeof (csi_object_t));
if (_csi_unlikely (stack->objects == NULL))
status = _csi_error (CSI_STATUS_NO_MEMORY);
return status;
}
void
_csi_stack_fini (csi_t *ctx, csi_stack_t *stack)
{
csi_integer_t n;
for (n = 0; n < stack->len; n++)
csi_object_free (ctx, &stack->objects[n]);
_csi_free (ctx, stack->objects);
}
csi_status_t
_csi_stack_roll (csi_t *ctx,
csi_stack_t *stack,
csi_integer_t mod, csi_integer_t n)
{
csi_object_t stack_copy[128];
csi_object_t *copy;
csi_integer_t last, i, len;
switch (mod) {
case 1:
last = stack->len - 1;
stack_copy[0] = stack->objects[last];
for (i = last; --n; i--)
stack->objects[i] = stack->objects[i-1];
stack->objects[i] = stack_copy[0];
return CSI_STATUS_SUCCESS;
case -1:
last = stack->len - 1;
stack_copy[0] = stack->objects[i = last - n + 1];
for (; --n; i++)
stack->objects[i] = stack->objects[i+1];
stack->objects[i] = stack_copy[0];
return CSI_STATUS_SUCCESS;
}
if (n > ARRAY_LENGTH (stack_copy)) {
if (_csi_unlikely ((unsigned) n > INT_MAX / sizeof (csi_object_t)))
return _csi_error (CSI_STATUS_NO_MEMORY);
copy = _csi_alloc (ctx, n * sizeof (csi_object_t));
if (copy == NULL)
return _csi_error (CSI_STATUS_NO_MEMORY);
} else
copy = stack_copy;
i = stack->len - n;
memcpy (copy, stack->objects + i, n * sizeof (csi_object_t));
mod = -mod;
if (mod < 0)
mod += n;
last = mod;
for (len = n; n--; i++) {
stack->objects[i] = copy[last];
if (++last == len)
last = 0;
}
if (copy != stack_copy)
_csi_free (ctx, copy);
return CSI_STATUS_SUCCESS;
}
csi_status_t
_csi_stack_grow (csi_t *ctx, csi_stack_t *stack, csi_integer_t cnt)
{
csi_integer_t newsize;
csi_object_t *newstack;
if (_csi_likely (cnt <= stack->size))
return CSI_STATUS_SUCCESS;
if (_csi_unlikely ((unsigned) cnt >= INT_MAX / sizeof (csi_object_t)))
return _csi_error (CSI_STATUS_NO_MEMORY);
newsize = stack->size;
do {
newsize *= 2;
} while (newsize <= cnt);
newstack = _csi_realloc (ctx,
stack->objects,
newsize * sizeof (csi_object_t));
if (_csi_unlikely (newstack == NULL))
return _csi_error (CSI_STATUS_NO_MEMORY);
stack->objects = newstack;
stack->size = newsize;
return CSI_STATUS_SUCCESS;
}
csi_status_t
_csi_stack_push_internal (csi_t *ctx, csi_stack_t *stack,
const csi_object_t *obj)
{
csi_status_t status;
status = _csi_stack_grow (ctx, stack, stack->size + 1);
if (_csi_unlikely (status))
return status;
stack->objects[stack->len++] = *obj;
return CSI_STATUS_SUCCESS;
}
csi_object_t *
_csi_stack_peek (csi_stack_t *stack, csi_integer_t i)
{
if (_csi_unlikely (stack->len < i))
return NULL;
return &stack->objects[stack->len - i -1];
}
void
_csi_stack_pop (csi_t *ctx, csi_stack_t *stack, csi_integer_t count)
{
if (_csi_unlikely (stack->len < count))
count = stack->len;
while (count--)
csi_object_free (ctx, &stack->objects[--stack->len]);
}
csi_status_t
_csi_stack_exch (csi_stack_t *stack)
{
csi_object_t tmp;
csi_integer_t n;
if (_csi_unlikely (stack->len < 2))
return _csi_error (CSI_STATUS_INVALID_SCRIPT);
n = stack->len - 1;
tmp = stack->objects[n];
stack->objects[n] = stack->objects[n - 1];
stack->objects[n - 1] = tmp;
return CSI_STATUS_SUCCESS;
}