#include "test/jemalloc_test.h"

#include "jemalloc/internal/flat_bitmap.h"
#include "test/nbits.h"

static void
do_test_init(size_t nbits) {
	size_t sz = FB_NGROUPS(nbits) * sizeof(fb_group_t);
	fb_group_t *fb = malloc(sz);
	/* Junk fb's contents. */
	memset(fb, 99, sz);
	fb_init(fb, nbits);
	for (size_t i = 0; i < nbits; i++) {
		expect_false(fb_get(fb, nbits, i),
		    "bitmap should start empty");
	}
	free(fb);
}

TEST_BEGIN(test_fb_init) {
#define NB(nbits) \
	do_test_init(nbits);
	NBITS_TAB
#undef NB
}
TEST_END

static void
do_test_get_set_unset(size_t nbits) {
	size_t sz = FB_NGROUPS(nbits) * sizeof(fb_group_t);
	fb_group_t *fb = malloc(sz);
	fb_init(fb, nbits);
	/* Set the bits divisible by 3. */
	for (size_t i = 0; i < nbits; i++) {
		if (i % 3 == 0) {
			fb_set(fb, nbits, i);
		}
	}
	/* Check them. */
	for (size_t i = 0; i < nbits; i++) {
		expect_b_eq(i % 3 == 0, fb_get(fb, nbits, i),
		    "Unexpected bit at position %zu", i);
	}
	/* Unset those divisible by 5. */
	for (size_t i = 0; i < nbits; i++) {
		if (i % 5 == 0) {
			fb_unset(fb, nbits, i);
		}
	}
	/* Check them. */
	for (size_t i = 0; i < nbits; i++) {
		expect_b_eq(i % 3 == 0 && i % 5 != 0, fb_get(fb, nbits, i),
		    "Unexpected bit at position %zu", i);
	}
	free(fb);
}

TEST_BEGIN(test_get_set_unset) {
#define NB(nbits) \
	do_test_get_set_unset(nbits);
	NBITS_TAB
#undef NB
}
TEST_END

static ssize_t
find_3_5_compute(ssize_t i, size_t nbits, bool bit, bool forward) {
	for(; i < (ssize_t)nbits && i >= 0; i += (forward ? 1 : -1)) {
		bool expected_bit = i % 3 == 0 || i % 5 == 0;
		if (expected_bit == bit) {
			return i;
		}
	}
	return forward ? (ssize_t)nbits : (ssize_t)-1;
}

static void
do_test_search_simple(size_t nbits) {
	size_t sz = FB_NGROUPS(nbits) * sizeof(fb_group_t);
	fb_group_t *fb = malloc(sz);
	fb_init(fb, nbits);

	/* We pick multiples of 3 or 5. */
	for (size_t i = 0; i < nbits; i++) {
		if (i % 3 == 0) {
			fb_set(fb, nbits, i);
		}
		/* This tests double-setting a little, too. */
		if (i % 5 == 0) {
			fb_set(fb, nbits, i);
		}
	}
	for (size_t i = 0; i < nbits; i++) {
		size_t ffs_compute = find_3_5_compute(i, nbits, true, true);
		size_t ffs_search = fb_ffs(fb, nbits, i);
		expect_zu_eq(ffs_compute, ffs_search, "ffs mismatch at %zu", i);

		ssize_t fls_compute = find_3_5_compute(i, nbits, true, false);
		size_t fls_search = fb_fls(fb, nbits, i);
		expect_zu_eq(fls_compute, fls_search, "fls mismatch at %zu", i);

		size_t ffu_compute = find_3_5_compute(i, nbits, false, true);
		size_t ffu_search = fb_ffu(fb, nbits, i);
		expect_zu_eq(ffu_compute, ffu_search, "ffu mismatch at %zu", i);

		size_t flu_compute = find_3_5_compute(i, nbits, false, false);
		size_t flu_search = fb_flu(fb, nbits, i);
		expect_zu_eq(flu_compute, flu_search, "flu mismatch at %zu", i);
	}

	free(fb);
}

TEST_BEGIN(test_search_simple) {
#define NB(nbits) \
	do_test_search_simple(nbits);
	NBITS_TAB
#undef NB
}
TEST_END

static void
expect_exhaustive_results(fb_group_t *mostly_full, fb_group_t *mostly_empty,
    size_t nbits, size_t special_bit, size_t position) {
	if (position < special_bit) {
		expect_zu_eq(special_bit, fb_ffs(mostly_empty, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(-1, fb_fls(mostly_empty, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zu_eq(position, fb_ffu(mostly_empty, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(position, fb_flu(mostly_empty, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);

		expect_zu_eq(position, fb_ffs(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(position, fb_fls(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zu_eq(special_bit, fb_ffu(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(-1, fb_flu(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
	} else if (position == special_bit) {
		expect_zu_eq(special_bit, fb_ffs(mostly_empty, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(special_bit, fb_fls(mostly_empty, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zu_eq(position + 1, fb_ffu(mostly_empty, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(position - 1, fb_flu(mostly_empty, nbits,
		    position), "mismatch at %zu, %zu", position, special_bit);

		expect_zu_eq(position + 1, fb_ffs(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(position - 1, fb_fls(mostly_full, nbits,
		    position), "mismatch at %zu, %zu", position, special_bit);
		expect_zu_eq(position, fb_ffu(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(position, fb_flu(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
	} else {
		/* position > special_bit. */
		expect_zu_eq(nbits, fb_ffs(mostly_empty, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(special_bit, fb_fls(mostly_empty, nbits,
		    position), "mismatch at %zu, %zu", position, special_bit);
		expect_zu_eq(position, fb_ffu(mostly_empty, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(position, fb_flu(mostly_empty, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);

		expect_zu_eq(position, fb_ffs(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(position, fb_fls(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zu_eq(nbits, fb_ffu(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
		expect_zd_eq(special_bit, fb_flu(mostly_full, nbits, position),
		    "mismatch at %zu, %zu", position, special_bit);
	}
}

static void
do_test_search_exhaustive(size_t nbits) {
	/* This test is quadratic; let's not get too big. */
	if (nbits > 1000) {
		return;
	}
	size_t sz = FB_NGROUPS(nbits) * sizeof(fb_group_t);
	fb_group_t *empty = malloc(sz);
	fb_init(empty, nbits);
	fb_group_t *full = malloc(sz);
	fb_init(full, nbits);
	fb_set_range(full, nbits, 0, nbits);

	for (size_t i = 0; i < nbits; i++) {
		fb_set(empty, nbits, i);
		fb_unset(full, nbits, i);

		for (size_t j = 0; j < nbits; j++) {
			expect_exhaustive_results(full, empty, nbits, i, j);
		}
		fb_unset(empty, nbits, i);
		fb_set(full, nbits, i);
	}

	free(empty);
	free(full);
}

TEST_BEGIN(test_search_exhaustive) {
#define NB(nbits) \
	do_test_search_exhaustive(nbits);
	NBITS_TAB
#undef NB
}
TEST_END

TEST_BEGIN(test_range_simple) {
	/*
	 * Just pick a constant big enough to have nontrivial middle sizes, and
	 * big enough that usages of things like weirdnum (below) near the
	 * beginning fit comfortably into the beginning of the bitmap.
	 */
	size_t nbits = 64 * 10;
	size_t ngroups = FB_NGROUPS(nbits);
	fb_group_t *fb = malloc(sizeof(fb_group_t) * ngroups);
	fb_init(fb, nbits);
	for (size_t i = 0; i < nbits; i++) {
		if (i % 2 == 0) {
			fb_set_range(fb, nbits, i, 1);
		}
	}
	for (size_t i = 0; i < nbits; i++) {
		expect_b_eq(i % 2 == 0, fb_get(fb, nbits, i),
		    "mismatch at position %zu", i);
	}
	fb_set_range(fb, nbits, 0, nbits / 2);
	fb_unset_range(fb, nbits, nbits / 2, nbits / 2);
	for (size_t i = 0; i < nbits; i++) {
		expect_b_eq(i < nbits / 2, fb_get(fb, nbits, i),
		    "mismatch at position %zu", i);
	}

	static const size_t weirdnum = 7;
	fb_set_range(fb, nbits, 0, nbits);
	fb_unset_range(fb, nbits, weirdnum, FB_GROUP_BITS + weirdnum);
	for (size_t i = 0; i < nbits; i++) {
		expect_b_eq(7 <= i && i <= 2 * weirdnum + FB_GROUP_BITS - 1,
		    !fb_get(fb, nbits, i), "mismatch at position %zu", i);
	}
	free(fb);
}
TEST_END

static void
do_test_empty_full_exhaustive(size_t nbits) {
	size_t sz = FB_NGROUPS(nbits) * sizeof(fb_group_t);
	fb_group_t *empty = malloc(sz);
	fb_init(empty, nbits);
	fb_group_t *full = malloc(sz);
	fb_init(full, nbits);
	fb_set_range(full, nbits, 0, nbits);

	expect_true(fb_full(full, nbits), "");
	expect_false(fb_empty(full, nbits), "");
	expect_false(fb_full(empty, nbits), "");
	expect_true(fb_empty(empty, nbits), "");

	for (size_t i = 0; i < nbits; i++) {
		fb_set(empty, nbits, i);
		fb_unset(full, nbits, i);

		expect_false(fb_empty(empty, nbits), "error at bit %zu", i);
		if (nbits != 1) {
			expect_false(fb_full(empty, nbits),
			    "error at bit %zu", i);
			expect_false(fb_empty(full, nbits),
			    "error at bit %zu", i);
		} else {
			expect_true(fb_full(empty, nbits),
			    "error at bit %zu", i);
			expect_true(fb_empty(full, nbits),
			    "error at bit %zu", i);
		}
		expect_false(fb_full(full, nbits), "error at bit %zu", i);

		fb_unset(empty, nbits, i);
		fb_set(full, nbits, i);
	}

	free(empty);
	free(full);
}

TEST_BEGIN(test_empty_full) {
#define NB(nbits) \
	do_test_empty_full_exhaustive(nbits);
	NBITS_TAB
#undef NB
}
TEST_END

int
main(void) {
	return test_no_reentrancy(
	    test_fb_init,
	    test_get_set_unset,
	    test_search_simple,
	    test_search_exhaustive,
	    test_range_simple,
	    test_empty_full);
}