[dw-free] Fix MEDIUMINT jtalkid memcache storage

[mark]

[commit: http://hg.dwscoalition.org/dw-free/rev/acb4c85567e3]

Fix MEDIUMINT jtalkid memcache storage

We hit 2^24 comments in one of our communities, so this is an emergency fix
to address the memcache portion of the problem. The database fix will come
after this.

Patch by mark.

Files modified:

• cgi-bin/LJ/Talk.pm
• htdocs/admin/memcache_view.bml

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diff -r 53f644001e05 -r acb4c85567e3 cgi-bin/LJ/Talk.pm
--- a/cgi-bin/LJ/Talk.pm	Sat Apr 28 18:50:52 2012 +0000
+++ b/cgi-bin/LJ/Talk.pm	Sun Apr 29 00:18:57 2012 +0000
@@ -679,7 +679,10 @@
     my $ret = {};
 
     # check for data in memcache
-    my $DATAVER = "1";  # single character
+    my $DATAVER = "3";  # single character
+    my $PACK_FORMAT = "NNNNC"; ## $talkid, $parenttalkid, $poster, $time, $state
+    my $RECORD_SIZE = 17;   
+
     my $memkey = [$u->{'userid'}, "talk2:$u->{'userid'}:$nodetype:$nodeid"];
     my $lockkey = $memkey->[1];
     my $packed = LJ::MemCache::get($memkey);
@@ -750,15 +753,15 @@
 
     my $memcache_good = sub {
         return $packed && substr($packed,0,1) eq $DATAVER &&
-            length($packed) % 16 == 1;
+            length($packed) % $RECORD_SIZE == 1;
     };
 
     my $memcache_decode = sub {
-        my $n = (length($packed) - 1) / 16;
+        my $n = (length($packed) - 1) / $RECORD_SIZE;
         for (my $i=0; $i<$n; $i++) {
-            my ($f1, $par, $poster, $time) = unpack("NNNN",substr($packed,$i*16+1,16));
-            my $state = chr($f1 & 255);
-            my $talkid = $f1 >> 8;
+            my ( $talkid, $par, $poster, $time, $state ) =
+                unpack( $PACK_FORMAT, substr($packed, $i*$RECORD_SIZE+1, $RECORD_SIZE ) );
+            $state = chr($state);
             $ret->{$talkid} = {
                 talkid => $talkid,
                 state => $state,
@@ -824,11 +827,12 @@
             LJ::Talk::add_talk2row_memcache($u->id, $r->{talkid}, \%row_arg);
         }
 
-        $memval .= pack("NNNN",
-                        ($r->{'talkid'} << 8) + ord($r->{'state'}),
+        $memval .= pack($PACK_FORMAT,
+                        $r->{'talkid'},
                         $r->{'parenttalkid'},
                         $r->{'posterid'},
-                        $r->{'datepost_unix'});
+                        $r->{'datepost_unix'},
+                        ord($r->{'state'}));
 
         $rp_ourcount++ if $r->{'state'} eq "A";
     }
@@ -1412,7 +1416,7 @@
             foreach my $k (qw(userid width height flags picdate)) {
                 $ur->{$k} += 0;
             }
-            $ur->{location} = uc(substr($ur->{location}, 0, 1));
+            $ur->{location} = uc(substr($ur->{location} || '', 0, 1));
 
             $LJ::CACHE_USERPIC{$id} = $ur;
             LJ::MemCache::set([$id,"userpic.$id"], LJ::MemCache::hash_to_array("userpic", $ur));
diff -r 53f644001e05 -r acb4c85567e3 htdocs/admin/memcache_view.bml
--- a/htdocs/admin/memcache_view.bml	Sat Apr 28 18:50:52 2012 +0000
+++ b/htdocs/admin/memcache_view.bml	Sun Apr 29 00:18:57 2012 +0000
@@ -101,17 +101,19 @@
      # unpack packed data
      if ($key =~ /^talk2:/) {
          my $newval;
-         my $n = (length($val) - 1) / 16;
+         my $PACK_FORMAT = "NNNNC"; ## $talkid, $parenttalkid, $poster, $time, $state
+         my $RECORD_SIZE = 17;
+                     
+         my $n = (length($val) - 1) / $RECORD_SIZE;
          for (my $i=0; $i<$n; $i++) {
-             my ($f1, $par, $poster, $time) = unpack("NNNN",substr($val,$i*16+1,16));
-             my $state = chr($f1 & 255);
-             my $talkid = $f1 >> 8;
+             my ( $talkid, $parenttalkid, $poster, $time, $state ) =
+                 unpack( $PACK_FORMAT, substr( $val, $i*$RECORD_SIZE+1, $RECORD_SIZE ) );
              $newval->{$talkid} = {
                  talkid => $talkid,
-                 state => $state,
+                 state => chr($state),
                  posterid => $poster,
                  datepost => LJ::mysql_time($time),
-                 parenttalkid => $par,
+                 parenttalkid => $parenttalkid,
              };
          }
          $val = [substr($val,0,1), $newval];
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