Commit 23ae8c63 authored by David Sterba's avatar David Sterba
Browse files

btrfs: heuristic: open code get_num callback of radix sort 



The callback is trivial and we don't need the abstraction for our
purposes. Let's open code it and also make the array types explicit.

Reviewed-by: default avatarTimofey Titovets <nefelim4ag@gmail.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 78f6beac

fs/btrfs/compression.c

+9 −16
Original line number Diff line number Diff line
@@ -1318,12 +1318,6 @@ static void copy_cell(void *dst, int dest_i, void *src, int src_i) 
	dstv[dest_i] = srcv[src_i];

}



static u64 get_num(const void *a, int i)

{

	struct bucket_item *av = (struct bucket_item *)a;

	return av[i].count;

}



/*

 * Use 4 bits as radix base

 * Use 16 u32 counters for calculating new possition in buf array
@@ -1332,12 +1326,11 @@ static u64 get_num(const void *a, int i) 
 * @array_buf - buffer array to store sorting results

 *              must be equal in size to @array

 * @num       - array size

 * @get_num   - function to extract number from array

 * @copy_cell - function to copy data from array to array_buf and vice versa

 * @get4bits  - function to get 4 bits from number at specified offset

 */

static void radix_sort(void *array, void *array_buf, int num,

		       u64 (*get_num)(const void *, int i),

static void radix_sort(struct bucket_item *array, struct bucket_item *array_buf,

		       int num,

		       void (*copy_cell)(void *dest, int dest_i,

					 void* src, int src_i),

		       u8 (*get4bits)(u64 num, int shift))
@@ -1355,9 +1348,9 @@ static void radix_sort(void *array, void *array_buf, int num, 
	 * Try avoid useless loop iterations for small numbers stored in big

	 * counters.  Example: 48 33 4 ... in 64bit array

	 */

	max_num = get_num(array, 0);

	max_num = array[0].count;

	for (i = 1; i < num; i++) {

		buf_num = get_num(array, i);

		buf_num = array[i].count;

		if (buf_num > max_num)

			max_num = buf_num;

	}
@@ -1370,7 +1363,7 @@ static void radix_sort(void *array, void *array_buf, int num, 
		memset(counters, 0, sizeof(counters));



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

			buf_num = get_num(array, i);

			buf_num = array[i].count;

			addr = get4bits(buf_num, shift);

			counters[addr]++;

		}
@@ -1379,7 +1372,7 @@ static void radix_sort(void *array, void *array_buf, int num, 
			counters[i] += counters[i - 1];



		for (i = num - 1; i >= 0; i--) {

			buf_num = get_num(array, i);

			buf_num = array[i].count;

			addr = get4bits(buf_num, shift);

			counters[addr]--;

			new_addr = counters[addr];
@@ -1397,7 +1390,7 @@ static void radix_sort(void *array, void *array_buf, int num, 
		memset(counters, 0, sizeof(counters));



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

			buf_num = get_num(array_buf, i);

			buf_num = array_buf[i].count;

			addr = get4bits(buf_num, shift);

			counters[addr]++;

		}
@@ -1406,7 +1399,7 @@ static void radix_sort(void *array, void *array_buf, int num, 
			counters[i] += counters[i - 1];



		for (i = num - 1; i >= 0; i--) {

			buf_num = get_num(array_buf, i);

			buf_num = array_buf[i].count;

			addr = get4bits(buf_num, shift);

			counters[addr]--;

			new_addr = counters[addr];
@@ -1444,7 +1437,7 @@ static int byte_core_set_size(struct heuristic_ws *ws) 
	struct bucket_item *bucket = ws->bucket;



	/* Sort in reverse order */

	radix_sort(ws->bucket, ws->bucket_b, BUCKET_SIZE, get_num, copy_cell,

	radix_sort(ws->bucket, ws->bucket_b, BUCKET_SIZE, copy_cell,

			get4bits);



	for (i = 0; i < BYTE_CORE_SET_LOW; i++)