Re^3: Unsigned 64-bit integer as Judy key

[Anonymous Monk]

so I changed that line #88 to

    if ( !SvIsUV($arg) && SvIOK($arg) && SvIV($arg) < 0 ) {

now Judy installs OK with its tests, and a test I posted in OP passes OK. Actually, it's all about 11148465 meditation; I knew Judy technology is amazing and just wanted to check this yet again. With latest llil2d.pl I get

llil2d start
get_properties : 10 secs
sort + output  : 21 secs
total          : 31 secs

and 2263M of htop's RES, with my Judy script:

my_test start
get_properties: 16 secs
sort + output: 21 secs
total: 37 secs

and 378M of htop's RES. And like I said (in my plan outline there) "words" are not stored in RAM (suppose they are long strings) but read again while writing output, hence relatively long time in 2nd row with almost instantaneous sort by Sort::Packed. I'll post to that thread later.

[ikegami]

I suspect that the changes doesn't make it stop considering 9223372036854775808 equal to -9223372036854775808.

[Anonymous Monk]

Of course not.

$ perl -MDevel::Peek -E 'Dump $_ for 1<<63,-(1<<63)'
SV = IV(0x559e408d8210) at 0x559e408d8220
  REFCNT = 1
  FLAGS = (IOK,pIOK,IsUV)
  UV = 9223372036854775808
SV = IV(0x559e408d83c0) at 0x559e408d83d0
  REFCNT = 1
  FLAGS = (IOK,pIOK)
  IV = -9223372036854775808

$ perl -MJudy::L=Set -E 'say Set($j, $_, 1) for 1<<63,-(1<<63),0'
94434583711008
Coercing -9223372036854775808 to 0. Can't use negative values as keys.
+ at -e line 1.
94434579767256
94434579767256

[ikegami]

You didn't retrieve any information from the data structure, so you didn't test it at all. Try this:

perl -Mv5.14  -MJudy::L=Get,Set -e'
   my $i = 1<<63;
   my $j = -$i;

   my $judy;

   Set( $judy, $i, 4 );
   Set( $judy, $j, 5 );

   say( ( Get( $judy, $i ) )[1] );
   say( ( Get( $judy, $j ) )[1] );
'

If you get different values, I was wrong. If you get the same value, each negative value is considered to the same as a very large positive value.

Without the hack, it outputs 5 twice. I suspect the hack only silences the warning.

Of course not.

No, it isn't obvious that the keys are 65 bits (or larger) in size. In fact, they pretty obviously aren't.