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[PATCH v4] popcount 2+ messages / 2 participants [nested] [flat]
* [PATCH v4] popcount @ 2020-12-30 10:51 David Fetter <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: David Fetter @ 2020-12-30 10:51 UTC (permalink / raw) Now it's accessible to SQL for the BIT VARYING and BYTEA types. diff --git doc/src/sgml/func.sgml doc/src/sgml/func.sgml index aa99665e2e..7626edeee7 100644 --- doc/src/sgml/func.sgml +++ doc/src/sgml/func.sgml @@ -4030,6 +4030,23 @@ SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three'); </para></entry> </row> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>count_set_bits</primary> + </indexterm> + <function>count_set_bits</function> ( <parameter>bytes</parameter> <type>bytea</type> ) + <returnvalue>bigint</returnvalue> + </para> + <para> + Counts the number of bits set in a binary string. + </para> + <para> + <literal>count_set_bits('\xdeadbeef'::bytea)</literal> + <returnvalue>24</returnvalue> + </para></entry> + </row> + <row> <entry role="func_table_entry"><para role="func_signature"> <indexterm> @@ -4830,6 +4847,23 @@ SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three'); </para></entry> </row> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>count_set_bits</primary> + </indexterm> + <function>count_set_bits</function> ( <parameter>bits</parameter> <type>bit</type> ) + <returnvalue>bigint</returnvalue> + </para> + <para> + Counts the bits set in a bit string. + </para> + <para> + <literal>count_set_bits(B'101010101010101010')</literal> + <returnvalue>9</returnvalue> + </para></entry> + </row> + <row> <entry role="func_table_entry"><para role="func_signature"> <indexterm> @@ -4869,6 +4903,7 @@ SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three'); <returnvalue>101010001010101010</returnvalue> </para></entry> </row> + </tbody> </tgroup> </table> diff --git src/include/catalog/pg_proc.dat src/include/catalog/pg_proc.dat index b5f52d4e4a..416ee0c2fb 100644 --- src/include/catalog/pg_proc.dat +++ src/include/catalog/pg_proc.dat @@ -1446,6 +1446,9 @@ { oid => '752', descr => 'substitute portion of string', proname => 'overlay', prorettype => 'bytea', proargtypes => 'bytea bytea int4', prosrc => 'byteaoverlay_no_len' }, +{ oid => '8436', descr => 'count set bits', + proname => 'count_set_bits', prorettype => 'int8', proargtypes => 'bytea', + prosrc => 'byteapopcount'}, { oid => '725', proname => 'dist_pl', prorettype => 'float8', proargtypes => 'point line', @@ -3865,6 +3868,9 @@ { oid => '3033', descr => 'set bit', proname => 'set_bit', prorettype => 'bit', proargtypes => 'bit int4 int4', prosrc => 'bitsetbit' }, +{ oid => '8435', descr => 'count set bits', + proname => 'count_set_bits', prorettype => 'int8', proargtypes => 'bit', + prosrc => 'bitpopcount'}, # for macaddr type support { oid => '436', descr => 'I/O', diff --git src/backend/utils/adt/varbit.c src/backend/utils/adt/varbit.c index 2235866244..c9c6c73422 100644 --- src/backend/utils/adt/varbit.c +++ src/backend/utils/adt/varbit.c @@ -36,6 +36,7 @@ #include "libpq/pqformat.h" #include "nodes/nodeFuncs.h" #include "nodes/supportnodes.h" +#include "port/pg_bitutils.h" #include "utils/array.h" #include "utils/builtins.h" #include "utils/varbit.h" @@ -1878,3 +1879,30 @@ bitgetbit(PG_FUNCTION_ARGS) else PG_RETURN_INT32(0); } + +/* + * bitpopcount + * + * Returns the number of bits set in a bit string. + * + */ +Datum +bitpopcount(PG_FUNCTION_ARGS) +{ + /* There's really no chance of an overflow here because + * to get to INT64_MAX set bits, an object would have to be + * an exbibyte long, exceeding what PostgreSQL can currently + * store by a factor of 2^28 + */ + int64 popcount; + VarBit *arg1 = PG_GETARG_VARBIT_P(0); + bits8 *p; + int len; + + p = VARBITS(arg1); + len = (VARBITLEN(arg1) + BITS_PER_BYTE - 1) / BITS_PER_BYTE; + + popcount = pg_popcount((char *)p, len); + + PG_RETURN_INT64(popcount); +} diff --git src/backend/utils/adt/varlena.c src/backend/utils/adt/varlena.c index 479ed9ae54..3f1179a0e8 100644 --- src/backend/utils/adt/varlena.c +++ src/backend/utils/adt/varlena.c @@ -3439,6 +3439,22 @@ bytea_overlay(bytea *t1, bytea *t2, int sp, int sl) return result; } +/* + * popcount + */ +Datum +byteapopcount(PG_FUNCTION_ARGS) +{ + bytea *t1 = PG_GETARG_BYTEA_PP(0); + int len; + int64 result; + + len = VARSIZE_ANY_EXHDR(t1); + result = pg_popcount(VARDATA_ANY(t1), len); + + PG_RETURN_INT64(result); +} + /* * byteapos - * Return the position of the specified substring. diff --git src/test/regress/expected/bit.out src/test/regress/expected/bit.out index a7f95b846d..1187076a8d 100644 --- src/test/regress/expected/bit.out +++ src/test/regress/expected/bit.out @@ -710,6 +710,19 @@ SELECT overlay(B'0101011100' placing '001' from 20); 0101011100001 (1 row) +-- Popcount +SELECT count_set_bits(B'0101011100'::bit(10)); + count_set_bits +---------------- + 5 +(1 row) + +SELECT count_set_bits(B'1111111111'::bit(10)); + count_set_bits +---------------- + 10 +(1 row) + -- This table is intentionally left around to exercise pg_dump/pg_upgrade CREATE TABLE bit_defaults( b1 bit(4) DEFAULT '1001', diff --git src/test/regress/expected/strings.out src/test/regress/expected/strings.out index 7c91afa6e4..e94e76000b 100644 --- src/test/regress/expected/strings.out +++ src/test/regress/expected/strings.out @@ -2179,3 +2179,10 @@ SELECT encode(overlay(E'Th\\000omas'::bytea placing E'\\002\\003'::bytea from 5 Th\000o\x02\x03 (1 row) +SET bytea_output TO hex; +SELECT count_set_bits(E'\\xdeadbeef'::bytea); + count_set_bits +---------------- + 24 +(1 row) + diff --git src/test/regress/sql/bit.sql src/test/regress/sql/bit.sql index ea01742c4a..8893d38b0d 100644 --- src/test/regress/sql/bit.sql +++ src/test/regress/sql/bit.sql @@ -215,6 +215,10 @@ SELECT overlay(B'0101011100' placing '101' from 6); SELECT overlay(B'0101011100' placing '001' from 11); SELECT overlay(B'0101011100' placing '001' from 20); +-- Popcount +SELECT count_set_bits(B'0101011100'::bit(10)); +SELECT count_set_bits(B'1111111111'::bit(10)); + -- This table is intentionally left around to exercise pg_dump/pg_upgrade CREATE TABLE bit_defaults( b1 bit(4) DEFAULT '1001', diff --git src/test/regress/sql/strings.sql src/test/regress/sql/strings.sql index ef4bfb008a..a4f7879b16 100644 --- src/test/regress/sql/strings.sql +++ src/test/regress/sql/strings.sql @@ -730,3 +730,6 @@ SELECT btrim(E'\\000trim\\000'::bytea, ''::bytea); SELECT encode(overlay(E'Th\\000omas'::bytea placing E'Th\\001omas'::bytea from 2),'escape'); SELECT encode(overlay(E'Th\\000omas'::bytea placing E'\\002\\003'::bytea from 8),'escape'); SELECT encode(overlay(E'Th\\000omas'::bytea placing E'\\002\\003'::bytea from 5 for 3),'escape'); + +SET bytea_output TO hex; +SELECT count_set_bits(E'\\xdeadbeef'::bytea); ^ permalink raw reply [nested|flat] 2+ messages in thread
* IPC::Run::time[r|out] vs our TAP tests @ 2024-04-04 21:24 Tom Lane <[email protected]> 0 siblings, 0 replies; 2+ messages in thread From: Tom Lane @ 2024-04-04 21:24 UTC (permalink / raw) To: [email protected] TIL that IPC::Run::timer is not the same as IPC::Run::timeout. With a timer object you have to check $timer->is_expired to see if the timeout has elapsed, but with a timeout object you don't because it will throw a Perl exception upon timing out, probably killing your test program. It appears that a good chunk of our TAP codebase has not read this memo, because I see plenty of places that are checking is_expired in the naive belief that they'll still have control after a timeout has fired. The particular thing that started me down this road was wondering why we are getting no useful failure details from buildfarm member tanager's struggles with the tab-completion test case added by commit 927332b95 [1]. Apparently it's not seeing a match to what it expects so it eventually times out, but all we get in the log is [03:03:42.595](0.002s) ok 82 - complete an interpolated psql variable name [03:03:42.597](0.002s) ok 83 - \\r works IPC::Run: timeout on timer #1 at /usr/share/perl5/IPC/Run.pm line 2944. # Postmaster PID for node "main" is 17308 ### Stopping node "main" using mode immediate We would have learned something useful if control had returned to pump_until, or even better 010_tab_completion.pl's check_completion, but it doesn't. A minimum fix that seems to make this work better is as attached, but I feel like somebody ought to examine all the IPC::Run::timer and IPC::Run::timeout calls and see which ones are mistaken. It's a little scary to convert a timeout to a timer because of the hazard that someplace that would need to be checking for is_expired isn't. Also, the debug printout code at the bottom of check_completion is quite useless, because control can never reach it since BackgroundPsql::query_until will "die" on failure. I think that that code worked when written, and I'm suspicious that 664d75753 broke it, but I've not dug deeply into the history. regards, tom lane [1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=tanager&dt=2024-04-04%2016%3A56%3A14 Attachments: [text/x-diff] use-timer-not-timeout-in-BackgroundPsql.patch (1.0K, ../../[email protected]/2-use-timer-not-timeout-in-BackgroundPsql.patch) download | inline diff: diff --git a/src/test/perl/PostgreSQL/Test/BackgroundPsql.pm b/src/test/perl/PostgreSQL/Test/BackgroundPsql.pm index 4091c311b8..72bb21e160 100644 --- a/src/test/perl/PostgreSQL/Test/BackgroundPsql.pm +++ b/src/test/perl/PostgreSQL/Test/BackgroundPsql.pm @@ -96,7 +96,7 @@ sub new "Forbidden caller of constructor: package: $package, file: $file:$line" unless $package->isa('PostgreSQL::Test::Cluster'); - $psql->{timeout} = IPC::Run::timeout( + $psql->{timeout} = IPC::Run::timer( defined($timeout) ? $timeout : $PostgreSQL::Test::Utils::timeout_default); diff --git a/src/test/perl/PostgreSQL/Test/Utils.pm b/src/test/perl/PostgreSQL/Test/Utils.pm index 42d5a50dc8..8fd0426d30 100644 --- a/src/test/perl/PostgreSQL/Test/Utils.pm +++ b/src/test/perl/PostgreSQL/Test/Utils.pm @@ -429,6 +429,7 @@ Pump until string is matched on the specified stream, or timeout occurs. sub pump_until { my ($proc, $timeout, $stream, $until) = @_; + die "timeout should be a timer" if defined($timeout->exception); $proc->pump_nb(); while (1) { ^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2024-04-04 21:24 UTC | newest] Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2020-12-30 10:51 [PATCH v4] popcount David Fetter <[email protected]> 2024-04-04 21:24 IPC::Run::time[r|out] vs our TAP tests Tom Lane <[email protected]>
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