Commit a1c7c58f authored by Daniel Verkamp's avatar Daniel Verkamp Committed by Jim Harris
Browse files

util/bit_array: add functions to count 0/1 bits 



Change-Id: I7c1ad078982a19c4093e787731974986011f535b
Signed-off-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/413295


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent 72800826

include/spdk/bit_array.h

+18 −0
Original line number Diff line number Diff line
@@ -155,6 +155,24 @@ uint32_t spdk_bit_array_find_first_set(const struct spdk_bit_array *ba, uint32_t 
 */

uint32_t spdk_bit_array_find_first_clear(const struct spdk_bit_array *ba, uint32_t start_bit_index);



/**

 * Count the number of set bits in the array.

 *

 * \param ba The bit array to search.

 *

 * \return the number of bits set in the array.

 */

uint32_t spdk_bit_array_count_set(const struct spdk_bit_array *ba);



/**

 * Count the number of cleared bits in the array.

 *

 * \param ba The bit array to search.

 *

 * \return the number of bits cleared in the array.

 */

uint32_t spdk_bit_array_count_clear(const struct spdk_bit_array *ba);



#ifdef __cplusplus

}

#endif

lib/util/bit_array.c

+25 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ 


typedef uint64_t spdk_bit_array_word;

#define SPDK_BIT_ARRAY_WORD_TZCNT(x)	(__builtin_ctzll(x))

#define SPDK_BIT_ARRAY_WORD_POPCNT(x)	(__builtin_popcountll(x))

#define SPDK_BIT_ARRAY_WORD_C(x)	((spdk_bit_array_word)(x))

#define SPDK_BIT_ARRAY_WORD_BYTES	sizeof(spdk_bit_array_word)

#define SPDK_BIT_ARRAY_WORD_BITS	(SPDK_BIT_ARRAY_WORD_BYTES * 8)
@@ -270,3 +271,27 @@ spdk_bit_array_find_first_clear(const struct spdk_bit_array *ba, uint32_t start_ 
{

	return _spdk_bit_array_find_first(ba, start_bit_index, SPDK_BIT_ARRAY_WORD_C(-1));

}



uint32_t

spdk_bit_array_count_set(const struct spdk_bit_array *ba)

{

	const spdk_bit_array_word *cur_word = ba->words;

	uint32_t word_count = spdk_bit_array_word_count(ba->bit_count);

	uint32_t set_count = 0;



	while (word_count--) {

		/*

		 * No special treatment is needed for the last (potentially partial) word, since

		 * spdk_bit_array_resize() makes sure the bits past bit_count are cleared.

		 */

		set_count += SPDK_BIT_ARRAY_WORD_POPCNT(*cur_word++);

	}



	return set_count;

}



uint32_t

spdk_bit_array_count_clear(const struct spdk_bit_array *ba)

{

	return ba->bit_count - spdk_bit_array_count_set(ba);

}

test/unit/lib/util/bit_array.c/bit_array_ut.c

+55 −1
Original line number Diff line number Diff line
@@ -236,6 +236,59 @@ test_errors(void) 
	spdk_bit_array_free(NULL);

}



static void

test_count(void)

{

	struct spdk_bit_array *ba;

	uint32_t i;



	/* 0-bit array should have 0 bits set and 0 bits clear */

	ba = spdk_bit_array_create(0);

	SPDK_CU_ASSERT_FATAL(ba != NULL);

	CU_ASSERT(spdk_bit_array_count_set(ba) == 0);

	CU_ASSERT(spdk_bit_array_count_clear(ba) == 0);

	spdk_bit_array_free(&ba);



	/* 1-bit array */

	ba = spdk_bit_array_create(1);

	SPDK_CU_ASSERT_FATAL(ba != NULL);

	CU_ASSERT(spdk_bit_array_count_set(ba) == 0);

	CU_ASSERT(spdk_bit_array_count_clear(ba) == 1);

	spdk_bit_array_set(ba, 0);

	CU_ASSERT(spdk_bit_array_count_set(ba) == 1);

	CU_ASSERT(spdk_bit_array_count_clear(ba) == 0);

	spdk_bit_array_free(&ba);



	/* 65-bit array */

	ba = spdk_bit_array_create(65);

	SPDK_CU_ASSERT_FATAL(ba != NULL);

	CU_ASSERT(spdk_bit_array_count_set(ba) == 0);

	CU_ASSERT(spdk_bit_array_count_clear(ba) == 65);

	spdk_bit_array_set(ba, 0);

	CU_ASSERT(spdk_bit_array_count_set(ba) == 1);

	CU_ASSERT(spdk_bit_array_count_clear(ba) == 64);

	spdk_bit_array_set(ba, 5);

	CU_ASSERT(spdk_bit_array_count_set(ba) == 2);

	CU_ASSERT(spdk_bit_array_count_clear(ba) == 63);

	spdk_bit_array_set(ba, 13);

	CU_ASSERT(spdk_bit_array_count_set(ba) == 3);

	CU_ASSERT(spdk_bit_array_count_clear(ba) == 62);

	spdk_bit_array_clear(ba, 0);

	CU_ASSERT(spdk_bit_array_count_set(ba) == 2);

	CU_ASSERT(spdk_bit_array_count_clear(ba) == 63);

	for (i = 0; i < 65; i++) {

		spdk_bit_array_set(ba, i);

	}

	CU_ASSERT(spdk_bit_array_count_set(ba) == 65);

	CU_ASSERT(spdk_bit_array_count_clear(ba) == 0);

	for (i = 0; i < 65; i++) {

		spdk_bit_array_clear(ba, i);

		CU_ASSERT(spdk_bit_array_count_set(ba) == 65 - i - 1);

		CU_ASSERT(spdk_bit_array_count_clear(ba) == i + 1);

	}

	spdk_bit_array_free(&ba);

}



int

main(int argc, char **argv)

{
@@ -257,7 +310,8 @@ main(int argc, char **argv) 
		CU_add_test(suite, "test_64bit", test_64bit) == NULL ||

		CU_add_test(suite, "test_find", test_find) == NULL ||

		CU_add_test(suite, "test_resize", test_resize) == NULL ||

		CU_add_test(suite, "test_errors", test_errors) == NULL) {

		CU_add_test(suite, "test_errors", test_errors) == NULL ||

		CU_add_test(suite, "test_count", test_count) == NULL) {

		CU_cleanup_registry();

		return CU_get_error();

	}