Bug 498309: Speed up show_bug.cgi when there are many comments by caching

Bugzilla/Template.pm

@@ -236,7 +236,7 @@ sub quoteUrls {
     # we have to do this in one pattern, and so this is semi-messy.
     # Also, we can't use $bug_re?$comment_re? because that will match the
     # empty string
-    my $bug_word = get_text('term', { term => 'bug' });
+    my $bug_word = template_var('terms')->{bug};
     my $bug_re = qr/\Q$bug_word\E\s*\#?\s*(\d+)/i;
     my $comment_re = qr/comment\s*\#?\s*(\d+)/i;
     $text =~ s~\b($bug_re(?:\s*,?\s*$comment_re)?|$comment_re)
@@ -774,6 +774,11 @@ sub create {
 
             'feature_enabled' => sub { return Bugzilla->feature(@_); },
 
+            # field_descs can be somewhat slow to generate, so we generate
+            # it only once per-language no matter how many times
+            # $template->process() is called.
+            'field_descs' => sub { return template_var('field_descs') },
+
             'install_string' => \&Bugzilla::Install::Util::install_string,
 
             # These don't work as normal constants.

Bugzilla/Util.pm

@@ -44,7 +44,7 @@ use base qw(Exporter);
                              file_mod_time is_7bit_clean
                              bz_crypt generate_random_password
                              validate_email_syntax clean_text
-                             get_text disable_utf8);
+                             get_text template_var disable_utf8);
 
 use Bugzilla::Constants;
 
@@ -621,6 +621,26 @@ sub get_text {
     return $message;
 }
 
+sub template_var {
+    my $name = shift;
+    my $cache = Bugzilla->request_cache->{util_template_var} ||= {};
+    my $template = Bugzilla->template_inner;
+    my $lang = $template->context->{bz_language};
+    return $cache->{$lang}->{$name} if defined $cache->{$lang};
+    my %vars;
+    # Note: If we suddenly start needing a lot of template_var variables,
+    # they should move into their own template, not field-descs.
+    my $result = $template->process('global/field-descs.none.tmpl', 
+                                    { vars => \%vars, in_template_var => 1 });
+    # Bugzilla::Error can't be "use"d in Bugzilla::Util.
+    if (!$result) {
+        require Bugzilla::Error;
+        Bugzilla::Error::ThrowTemplateError($template->error);
+    }
+    $cache->{$lang} = \%vars;
+    return $vars{$name};
+}
+
 sub disable_utf8 {
     if (Bugzilla->params->{'utf8'}) {
         binmode STDOUT, ':bytes'; # Turn off UTF8 encoding.
@@ -902,6 +922,14 @@ A string.
 
 =back
 
+
+=item C<template_var>
+
+This is a method of getting the value of a variable from a template in
+Perl code. The available variables are in the C<global/field-descs.none.tmpl>
+template. Just pass in the name of the variable that you want the value of.
+
+
 =back
 
 =head2 Formatting Time

extensions/Voting/template/en/default/hook/global/field-descs-end.none.tmpl

@@ -18,5 +18,6 @@
   #   Max Kanat-Alexander <mkanat@bugzilla.org>
   #%]
 
-[% field_descs.votes = "Votes" %]
-
+[% IF in_template_var %]
+  [% vars.field_descs.votes = "Votes" %]
+[% END %]

template/en/default/global/field-descs.none.tmpl

@@ -23,7 +23,79 @@
 
 [% PROCESS global/variables.none.tmpl %]
 
-[% field_descs = { "[Bug creation]"          => "[$terms.Bug creation]",
+[% SET search_descs = {
+  "noop"           => "---",
+  "equals"         => "is equal to",
+  "notequals"      => "is not equal to",
+  "anyexact"       => "is equal to any of the strings",
+  "substring"      => "contains the string",
+  "casesubstring"  => "contains the string (exact case)",
+  "notsubstring"   => "does not contain the string",
+  "anywordssubstr" => "contains any of the strings",
+  "allwordssubstr" => "contains all of the strings",
+  "nowordssubstr"  => "contains none of the strings",
+  "regexp"         => "matches regular expression",
+  "notregexp"      => "does not match regular expression",
+  "lessthan"       => "is less than",
+  "lessthaneq"     => "is less than or equal to",
+  "greaterthan"    => "is greater than",
+  "greaterthaneq"  => "is greater than or equal to",
+  "anywords"       => "contains any of the words",
+  "allwords"       => "contains all of the words",
+  "nowords"        => "contains none of the words",
+  "changedbefore"  => "changed before",
+  "changedafter"   => "changed after",
+  "changedfrom"    => "changed from",
+  "changedto"      => "changed to",
+  "changedby"      => "changed by",
+  "matches"        => "matches",
+} %]
+
+[% field_types = { ${constants.FIELD_TYPE_UNKNOWN}       => "Unknown Type",
+                   ${constants.FIELD_TYPE_FREETEXT}      => "Free Text",
+                   ${constants.FIELD_TYPE_SINGLE_SELECT} => "Drop Down",
+                   ${constants.FIELD_TYPE_MULTI_SELECT}  => "Multiple-Selection Box",
+                   ${constants.FIELD_TYPE_TEXTAREA}      => "Large Text Box",
+                   ${constants.FIELD_TYPE_DATETIME}      => "Date/Time",
+                   ${constants.FIELD_TYPE_BUG_ID}        => "$terms.Bug ID",
+                } %]
+
+[%# You can use this hash to localize (translate) the values displayed
+  # for drop-down and multiple-select fields. Lines starting with "#"
+  # are comments.
+  #%]
+[% value_descs = {
+  "bug_status" => {
+    # "UNCONFIRMED" => "UNCO",
+    # "NEW"         => "NEWISH",
+  },
+
+  "resolution" => {
+    ""        => "---",
+    # "FIXED" => "NO LONGER AN ISSUE",
+    # "MOVED" => "BYE-BYE",
+  },
+} %]
+
+[%# We use "FILTER none" here because only the caller can know how to
+  # filter the result appropriately. 
+  #%]
+[% MACRO display_value(field_name, value_name) BLOCK %][% FILTER trim %]
+  [% IF value_descs.${field_name}.${value_name}.defined %]
+    [% value_descs.${field_name}.${value_name} FILTER none %]
+  [% ELSE %]
+    [% value_name FILTER none %]
+  [% END %]
+[% END %][% END %]
+
+[% IF in_template_var %]
+  [% vars.terms = terms %]
+
+  [%# field_descs is loaded as a global template variable and cached
+    # across all templates--see VARIABLES in Bugzilla/Template.pm.
+    #%]
+  [% vars.field_descs = {
+    "[Bug creation]"          => "[$terms.Bug creation]",
      "actual_time"             => "Actual Hours",
      "alias"                   => "Alias",
      "assigned_to"             => "Assignee",
@@ -84,82 +156,19 @@
      "status_whiteboard"       => "Whiteboard",
      "target_milestone"        => "Target Milestone",
      "version"                 => "Version",
-                   "work_time"               => "Hours Worked"} %]
+     "work_time"               => "Hours Worked",
+  } %]
 
-[%# Also include any custom fields or fields which don't have a
+  [%# Also include any custom fields or fields which don't have a
       Description here, by copying their Description from the
       database. If you want to override this for your language
       or your installation, just use a hook. %]
-[% UNLESS Param('shutdownhtml') %]
+  [% UNLESS Param('shutdownhtml') %]
     [% FOREACH bz_field = bug_fields.values %]
-    [% SET field_descs.${bz_field.name} = bz_field.description
-       IF !field_descs.${bz_field.name}.defined %]
+      [% SET vars.field_descs.${bz_field.name} = bz_field.description
+         IF !vars.field_descs.${bz_field.name}.defined %]
     [% END %]
-[% END %]
-
-[% SET search_descs = {
-  "noop"           => "---",
-  "equals"         => "is equal to",
-  "notequals"      => "is not equal to",
-  "anyexact"       => "is equal to any of the strings",
-  "substring"      => "contains the string",
-  "casesubstring"  => "contains the string (exact case)",
-  "notsubstring"   => "does not contain the string",
-  "anywordssubstr" => "contains any of the strings",
-  "allwordssubstr" => "contains all of the strings",
-  "nowordssubstr"  => "contains none of the strings",
-  "regexp"         => "matches regular expression",
-  "notregexp"      => "does not match regular expression",
-  "lessthan"       => "is less than",
-  "lessthaneq"     => "is less than or equal to",
-  "greaterthan"    => "is greater than",
-  "greaterthaneq"  => "is greater than or equal to",
-  "anywords"       => "contains any of the words",
-  "allwords"       => "contains all of the words",
-  "nowords"        => "contains none of the words",
-  "changedbefore"  => "changed before",
-  "changedafter"   => "changed after",
-  "changedfrom"    => "changed from",
-  "changedto"      => "changed to",
-  "changedby"      => "changed by",
-  "matches"        => "matches",
-} %]
-
-[% field_types = { ${constants.FIELD_TYPE_UNKNOWN}       => "Unknown Type",
-                   ${constants.FIELD_TYPE_FREETEXT}      => "Free Text",
-                   ${constants.FIELD_TYPE_SINGLE_SELECT} => "Drop Down",
-                   ${constants.FIELD_TYPE_MULTI_SELECT}  => "Multiple-Selection Box",
-                   ${constants.FIELD_TYPE_TEXTAREA}      => "Large Text Box",
-                   ${constants.FIELD_TYPE_DATETIME}      => "Date/Time",
-                   ${constants.FIELD_TYPE_BUG_ID}        => "$terms.Bug ID",
-                } %]
-
-[%# You can use this hash to localize (translate) the values displayed
-  # for drop-down and multiple-select fields. Lines starting with "#"
-  # are comments.
-  #%]
-[% value_descs = {
-  "bug_status" => {
-    # "UNCONFIRMED" => "UNCO",
-    # "NEW"         => "NEWISH",
-  },
-
-  "resolution" => {
-    ""        => "---",
-    # "FIXED" => "NO LONGER AN ISSUE",
-    # "MOVED" => "BYE-BYE",
-  },
-} %]
-
-[%# We use "FILTER none" here because only the caller can know how to
-  # filter the result appropriately. 
-  #%]
-[% MACRO display_value(field_name, value_name) BLOCK %][% FILTER trim %]
-  [% IF value_descs.${field_name}.${value_name}.defined %]
-    [% value_descs.${field_name}.${value_name} FILTER none %]
-  [% ELSE %]
-    [% value_name FILTER none %]
   [% END %]
-[% END %][% END %]
+[% END %]
 
 [% Hook.process("end") %]