END_TEST
START_TEST(test_upper_power_of_two)
{
/* check function */
static size_t test_pairs[][2] =
{
{ 0, 2 },
{ 1, 2 },
{ 7, 8 },
{ 100, 128 },
{ 1023, 1024 },
{ 1024, 1024 },
{ 1025, 2048 },
{ 32 * 1024, 32 * 1024 },
{ (32 * 1024) - 1, 32 * 1024 },
{ (32 * 1024) + 1, 64 * 1024 },
{ 64 * 1024, 64 * 1024 },
{ (64 * 1024) - 1, 64 * 1024 },
{ (64 * 1024) + 1, 128 * 1024 },
{ 0, 2 },
{ -1, -1 }
};
int i = 0;
while ( test_pairs[i][0] != -1 ) {
size_t testval = test_pairs[i][0];
size_t expected = test_pairs[i][1];
size_t actual = upper_power_of_two(testval);
fail_unless( actual == expected );
i++;
}
/* TODO: test overflow behaviour */
/* checks that BUFFER_MAX is defined as a power of 2 */
fail_unless(upper_power_of_two(BUFFER_MAX) == BUFFER_MAX);
}
static inline void pool_expand(size_t len)
{
list *newlist = NULL;
/* Check if we have enough memory already */
if (memory_pools->size - memory_pools->used >= len) {
return;
}
newlist = (list*) malloc(sizeof(list));
newlist->next = memory_pools;
memory_pools = newlist;
memory_pools->used = 0;
memory_pools->size = upper_power_of_two(3*memory_pools->next->size/2 + len); /* expand by 1.5x the old memory pool. More if we request a very large array. */
memory_pools->memory = malloc(memory_pools->size);
}
/*
Pairwise max - computes the pair maximums using recursive algorithm and by building binary tree
*arr - array pointer
startindex - starting index of the array
endindex - ending index of the array
return - root node
*/
node* pairmax(int *arr, int startIndex, int endIndex)
{
if(endIndex-startIndex == 1)
{
node *left = newNode(arr[startIndex],NULL,NULL);
node *right = newNode(arr[endIndex],NULL,NULL);
node *max = newNode(maximum(arr[startIndex], arr[endIndex]),left,right);
return max;
}
else if (endIndex-startIndex == 0)
{
node *right = newNode(arr[endIndex],NULL,NULL);
return right;
}
int m = upper_power_of_two((endIndex-startIndex)+1);
if( m == (endIndex-startIndex)+1)
{
m = ((endIndex-startIndex)+1)/2;
}
node *leftmax = pairmax(arr,startIndex,startIndex+m-1);
node *rightmax = pairmax(arr,startIndex+m,endIndex);
node *totalmax = newNode(maximum(leftmax->value, rightmax->value),leftmax,rightmax);
return totalmax;
}