simon987/pg_hamming
1
0
Fork 0
mirror of https://github.com/simon987/pg_hamming.git synced 2025-04-17 17:26:43 +00:00
Code Issues Projects Releases Wiki Activity

bugfix

Browse Source
This commit is contained in:
simon 2019-07-23 15:50:18 -04:00
parent 95749d6a28
commit a7c41e4959
1 changed files with 9 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
hamming.c
View File

@ -14,7 +14,7 @@ PG_FUNCTION_INFO_V1(hash_is_within_distance);
* Import with
CREATE OR REPLACE FUNCTION hash_is_within_distance(bytea, bytea, integer) RETURNS boolean
AS '/path/to/libhamming.so', 'hash_is_within_distance'
LANGUAGE C STRICT;'
LANGUAGE C STRICT;
*
* @return the hamming distance between the two arrays
*/
@ -55,7 +55,7 @@ PG_FUNCTION_INFO_V1(hash_distance);
* Import with
CREATE OR REPLACE FUNCTION hash_distance(bytea, bytea) RETURNS integer
AS '/path/to/libhamming.so', 'hash_distance'
LANGUAGE C STRICT;'
LANGUAGE C STRICT;
*
* @return the hamming distance between the two arrays
*/
@ -92,7 +92,7 @@ PG_FUNCTION_INFO_V1(hash_is_within_distance_any);
* Import with
CREATE OR REPLACE FUNCTION hash_is_within_distance_any(bytea, bytea, integer) RETURNS bool
AS '/path/to/libhamming.so', 'hash_is_within_distance_any'
LANGUAGE C STRICT;'
LANGUAGE C STRICT;
*
* @return true if at least 1 hash matches
*/
@ -105,20 +105,20 @@ Datum hash_is_within_distance_any(PG_FUNCTION_ARGS) {
int distance;
for (int i = VARSIZE(h_bytea) - 18; i >= 0; i -= 18) {
h_arr += 18;
distance = 0;
for (int i = (VARSIZE(h_bytea) - VARHDRSZ) / 18 - 1; i >= 0; i--) {
distance += __builtin_popcountll(
distance = __builtin_popcountll(
*((uint64 *) h) ^ *((uint64 *) h_arr)
);
if (distance > max_distance) {
h_arr += 18;
continue;
}
distance += __builtin_popcountll(
*((uint64 *) h + 1) ^ *((uint64 *) h_arr + 1)
);
if (distance > max_distance) {
h_arr += 18;
continue;
}
distance += __builtin_popcount(
@ -128,6 +128,7 @@ Datum hash_is_within_distance_any(PG_FUNCTION_ARGS) {
if (distance <= max_distance) {
PG_RETURN_BOOL(true);
}
h_arr += 18;
}
PG_RETURN_BOOL(false);
@ -153,7 +154,7 @@ Datum hash_equ_any(PG_FUNCTION_ARGS) {
bytea *h_bytea = PG_GETARG_BYTEA_P(1);
char *h_arr = VARDATA(h_bytea);
for (int i = VARSIZE(h_bytea); i >= 0; i -= 18) {
for (int i = (VARSIZE(h_bytea) - VARHDRSZ) / 18 - 1; i >= 0; i--) {
// This is a bit faster than __builtin_memcmp
if (*((uint64 *) h) == *((uint64 *) h_arr) &&