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-Replace native math for 64 bit timestamp manipulation with bigint

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git-svn-id: https://svn.code.sf.net/p/xcat/code/xcat-core/trunk@6169 8638fb3e-16cb-4fca-ae20-7b5d299a9bcd
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jbjohnso 2010-05-19 13:54:38 +00:00
parent 96d854d8cb
commit f9f17c1a5e
1 changed files with 34 additions and 25 deletions
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59
perl-xCAT/xCAT/Utils.pm
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@ -69,31 +69,40 @@ sub genUUID
#two identical UUIDs is 4 in 10 octillion.
my %args = @_;
if ($args{mac}) { #if a mac address was supplied, generate a uuidv1 instead
use Config;
if ($Config{use64bitint}) { #do it the simple way
no warnings 'portable';
use Time::HiRes qw/gettimeofday/;
my $sec;
my $usec;
($sec,$usec) = gettimeofday();
my $uuidtime=($sec*10000000)+($usec*10) + 0x01B21DD213814000;
my $timelow=$uuidtime&0xffffffff;# get lower 32bit
my $timemid=$uuidtime&0xffff00000000;
my $timehigh=$uuidtime&0xffff000000000000;
$timemid = $timemid>>32;
$timehigh=$timehigh>>48;
$timehigh = $timehigh | (1<<12); #add in version, don't bother stripping out the high bits since by the year 5236, none of this should matter
my $clockseq=rand(8191); #leave the top three bits alone. We could leave just top two bits, but it's unneeded
#also, randomness matters very little, as the time+mac is here
$clockseq = $clockseq | 0x8000; #RFC4122 variant
#time to assemble...
my $uuid=sprintf("%08x-%04x-%04x-%04x-",$timelow,$timemid,$timehigh,$clockseq);
my $mac = $args{mac};
$mac =~ s/://g;
$mac = lc($mac);
$uuid .= $mac;
return $uuid;
}
use Math::BigInt;
no warnings 'portable';
use Time::HiRes qw/gettimeofday/;
my $sec;
my $usec;
($sec,$usec) = gettimeofday();
my $uuidtime = Math::BigInt->new($sec);
$uuidtime->bmuladd('10000000',$usec*10);
$uuidtime->badd('0x01B21DD213814000');
my $timelow=$uuidtime->copy();
$timelow.band('0xffffffff');# get lower 32bit
my $timemid=$uuidtime->copy();
$timemid.band('0xffff00000000');
my $timehigh=$uuidtime->copy();
$timehigh.band('0xffff000000000000');
$timemid.brsft(32);
$timehigh.brsft(48);
$timehigh.bior('0x1000'); #add in version, don't bother stripping out the high bits since by the year 5236, none of this should matter
my $clockseq=rand(8191); #leave the top three bits alone. We could leave just top two bits, but it's unneeded
#also, randomness matters very little, as the time+mac is here
$clockseq = $clockseq | 0x8000; #RFC4122 variant
#time to assemble...
$timelow = $timelow->bstr();
$timelow == 0; # doing numeric comparison induces perl to 'int'-ify it. Safe at this point as the subpieces are all sub-32 bit now
$timemid = $timemid->bstr();
$timemid == 0;
$timehigh = $timehigh->bstr()
$timehigh == 0;
my $uuid=sprintf("%08x-%04x-%04x-%04x-",$timelow,$timemid,$timehigh,$clockseq);
my $mac = $args{mac};
$mac =~ s/://g;
$mac = lc($mac);
$uuid .= $mac;
return $uuid;
}
srand(); #Many note this as bad practice, however, forks are going on..
my $uuid;