[lintian] 01/01: r/html_reports: Optimise away some regex subst

[Niels Thykier <nthykier@moszumanska.debian.org>]

This is an automated email from the git hooks/post-receive script.

nthykier pushed a commit to branch master
in repository lintian.

commit 970ebdd27b3cb1034a2bba2d35fec699877983c7
Author: Niels Thykier <niels@thykier.net>
Date:   Mon Feb 3 22:14:55 2014 +0100

    r/html_reports: Optimise away some regex subst
    
    Use index() to skip some s/// invocations.  When profiling
    html_reports, this seems to reduce the runtime with about 30s.
    
    For reference, html_quote is called about 5.6 million times, but the
    "escapble" characters are only found in 9-10k, ~7k and ~7k of strings
    checked (respectively).  In other words, no more than 0.5% of the
    strings need any escaping (in practise).
    
    Signed-off-by: Niels Thykier <niels@thykier.net>
---
 reporting/html_reports | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/reporting/html_reports b/reporting/html_reports
index 23fe3a3..3432434 100755
--- a/reporting/html_reports
+++ b/reporting/html_reports
@@ -747,9 +747,18 @@ sub maintainer_url {
 sub html_quote {
     my ($text) = @_;
     $text ||= '';
-    $text =~ s/&/\&amp;/g;
-    $text =~ s/</\&lt;/g;
-    $text =~ s/>/\&gt;/g;
+    # Use index to do a quick check before we bother requesting a
+    # subst.  On average, this is cheaper than blindly s///'ing, since
+    # we rarely subst (all) of the characters below.
+    if (index($text, '&') > -1) {
+        $text =~ s/&/\&amp;/g;
+    }
+    if (index($text, '<') > -1) {
+        $text =~ s/</\&lt;/g;
+    }
+    if (index($text, '>') > -1) {
+        $text =~ s/>/\&gt;/g;
+    }
     return $text;
 }
 

-- 
Alioth's /usr/local/bin/git-commit-notice on /srv/git.debian.org/git/lintian/lintian.git