"Chandra Pratap via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes:
> diff --git a/t/unit-tests/t-prio-queue.c b/t/unit-tests/t-prio-queue.c
> new file mode 100644
> index 00000000000..07b112f5894
> --- /dev/null
> +++ b/t/unit-tests/t-prio-queue.c
> @@ -0,0 +1,99 @@
> +#include "test-lib.h"
> +#include "prio-queue.h"
> +
> +static int intcmp(const void *va, const void *vb, void *data UNUSED)
> +{
> + const int *a = va, *b = vb;
> + return *a - *b;
> +}
This came from the original and looks obviously OK.
> +static int show(int *v)
> +{
> + int ret = -1;
> + if (v)
> + ret = *v;
> + free(v);
> + return ret;
> +}
The original allowed us to differentiate "prio queue did not yield
anything" case and "the integer obtained from the queue happened to
be negative" cases, but with this, -1 is taken.
It is not a huge loss, as the tests can limit themselves to a subset
of "int" (say, positive integers only). But this realization can
lead to further simplfication.
> +static int test_prio_queue(const char **input, int *result)
This takes an array of strings, but it does not have to. Make it
take an array of "int" and then with something like
#define MISSING -1
#define GET -2
#define DUMP -3
#define STACK -4
you can get rid of strcmp(), atoi(), and xmalloc(), like so:
while (*input) {
int val = *input++;
switch (val) {
case GET:
void *peek = prio_queue_peek(&pq);
...
result[i++] = peek ? (*(int*)peek) : MISSING;
break;
... other "commands" here ...
default:
prio_queue_put(&pq, val);
break;
}
}
I inlined the show() in the above illustration, but you can keep it
as a separate small helper function. The point is that it makes it
far easier to follow by using the MISSING symbolic constant either
way.
> +{
> + struct prio_queue pq = { intcmp };
> + int i = 0;
> +
> + while (*input) {
> + if (!strcmp(*input, "get")) {
> + void *peek = prio_queue_peek(&pq);
> + void *get = prio_queue_get(&pq);
> + if (peek != get)
> + BUG("peek and get results do not match");
> + result[i++] = show(get);
> + } else if (!strcmp(*input, "dump")) {
> + void *peek;
> + void *get;
> + while ((peek = prio_queue_peek(&pq))) {
> + get = prio_queue_get(&pq);
> + if (peek != get)
> + BUG("peek and get results do not match");
> + result[i++] = show(get);
> + }
> + } else if (!strcmp(*input, "stack")) {
> + pq.compare = NULL;
> + } else if (!strcmp(*input, "reverse")) {
> + prio_queue_reverse(&pq);
> + } else {
> + int *v = xmalloc(sizeof(*v));
> + *v = atoi(*input);
> + prio_queue_put(&pq, v);
> + }
> + input++;
> + }
> +
> + clear_prio_queue(&pq);
> +
> + return 0;
> +}
> +
> +#define INPUT_SIZE 6
You do not need this (see below)
> +#define BASIC_INPUT "1", "2", "3", "4", "5", "5", "dump"
> +#define BASIC_EXPECTED 1, 2, 3, 4, 5, 5
> +
> +#define MIXED_PUT_GET_INPUT "6", "2", "4", "get", "5", "3", "get", "get", "1", "dump"
> +#define MIXED_PUT_GET_EXPECTED 2, 3, 4, 1, 5, 6
> +
> +#define EMPTY_QUEUE_INPUT "1", "2", "get", "get", "get", "1", "2", "get", "get", "get"
> +#define EMPTY_QUEUE_EXPECTED 1, 2, -1, 1, 2, -1
And these input and expectation can become all integers, i.e.
#define EMPTY_QUEUE_INPUT 1, 2, GET, GET, GET, 1, 2, GET, GET, GET
#define EMPTY_QUEUE_EXPECTED 1, 2, MISSING, 1, 2, MISSING
> +
> +#define STACK_INPUT "stack", "1", "5", "4", "6", "2", "3", "dump"
> +#define STACK_EXPECTED 3, 2, 6, 4, 5, 1
> +
> +#define REVERSE_STACK_INPUT "stack", "1", "2", "3", "4", "5", "6", "reverse", "dump"
> +#define REVERSE_STACK_EXPECTED 1, 2, 3, 4, 5, 6
> +
> +#define TEST_INPUT(INPUT, EXPECTED, name) \
> + static void test_##name(void) \
> +{ \
> + const char *input[] = {INPUT}; \
> + int expected[] = {EXPECTED}; \
> + int result[INPUT_SIZE]; \
This can be written more like
int result[ARRAY_SIZE(expected)]
so that you can freely extend each test without having to worry
about increasing the hardcoded limit.
> + test_prio_queue(input, result); \
> + check(!memcmp(expected, result, sizeof(expected))); \
> +}
> +
> +TEST_INPUT(BASIC_INPUT, BASIC_EXPECTED, basic)
> +TEST_INPUT(MIXED_PUT_GET_INPUT, MIXED_PUT_GET_EXPECTED, mixed)
> +TEST_INPUT(EMPTY_QUEUE_INPUT, EMPTY_QUEUE_EXPECTED, empty)
> +TEST_INPUT(STACK_INPUT, STACK_EXPECTED, stack)
> +TEST_INPUT(REVERSE_STACK_INPUT, REVERSE_STACK_EXPECTED, reverse)
> +
> +int cmd_main(int argc, const char **argv)
> +{
> + TEST(test_basic(), "prio-queue works for basic input");
> + TEST(test_mixed(), "prio-queue works for mixed put & get commands");
> + TEST(test_empty(), "prio-queue works when queue is empty");
> + TEST(test_stack(), "prio-queue works when used as a LIFO stack");
> + TEST(test_reverse(), "prio-queue works when LIFO stack is reversed");
> +
> + return test_done();
> +}
>
> base-commit: 1a87c842ece327d03d08096395969aca5e0a6996
