add Spot.pm with disabled $readback

It turns out that using tac to read backwards isn't really worth it
for spot files, but I'm leaving the code there for any future
use cases.

diff --git a/perl/Spot.pm b/perl/Spot.pm
index f29ecef804fd2703275e97a57f96b4c98247e145..74b3f77319decf08c9f004a471d7cc34b46161e4 100644 (file)
--- a/perl/Spot.pm
+++ b/perl/Spot.pm
@@ -56,6 +56,14 @@ $filterdef = bless ([
 $totalspots = $hfspots = $vhfspots = 0;
 $use_db_for_search = 0;
 
+our $usetac = 0;
+our $readback;
+
+if ($usetac) {
+       $readback = `which tac`;
+       chomp $readback;
+}
+
 # create a Spot Object
 sub new
 {
@@ -302,29 +310,46 @@ sub search
                           }
                           my \$c;
                           my \$ref;
-                          for (\$c = \$#spots; \$c >= 0; \$c--) {
-                                       \$ref = \$spots[\$c];
-                                       if ($expr) {
-                                               \$count++;
-                                               next if \$count < \$from; # wait until from 
-                                               push(\@out, \$ref);
-                                               last if \$count >= \$to; # stop after to
-                                       }
-                               }
+               if (\$readback) {
+                   foreach \$ref (\@spots) {
+                              if ($expr) {
+                                                  \$count++;
+                                                  next if \$count < $from; # wait until from 
+                                                  push(\@out, \$ref);
+                                                  last if \$count >= $to; # stop after to
+                                  }         
+                   }
+               } else {
+                             for (\$c = \$#spots; \$c >= 0; \$c--) {
+                                          \$ref = \$spots[\$c];
+                                          if ($expr) {
+                                                  \$count++;
+                                                  next if \$count < $from; # wait until from 
+                                                  push(\@out, \$ref);
+                                                  last if \$count >= $to; # stop after to
+                                          }
+                                  }
+               }
                          );
+                
        
     
        dbg("Spot eval: $eval") if isdbg('searcheval');
        
-
-       $fp->close;                                     # close any open files
-
+       my $fh;
+       my $now = $fromdate;
        for ($i = $count = 0; $i < $maxdays; ++$i) {    # look thru $maxdays worth of files only
-               my $now = $fromdate->sub($i); # but you can pick which $maxdays worth
-               last if $now->cmp($todate) <= 0;         
-       
-               my @spots = ();
-               my $fh = $fp->open($now); # get the next file
+               my @spots;
+               last if $now->cmp($todate) <= 0;
+               
+               if ($readback) {
+                       my $fn = $fp->fn($now->sub($i));
+                       dbg("search using tac fn: $fn $i") if isdbg('search');
+                       $fh = IO::File->new("$readback $fn |");
+               } else {
+                       $fh = $fp->open($now->sub($i));      # get the next file
+                       dbg("search fn: $fp->{fn} $i") if isdbg('search');
+               }
                if ($fh) {
                        my $in;
                        eval $eval;                     # do the search on this file