From 8b97a4e3e8b71d1dda384dccdff35949e64f7dec Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Tue, 20 Jun 2023 21:09:32 +0100
Subject: [PATCH] mason/.perl-lib/TrivGal.pm (Image): Use `Image::Size' to find
 image size.

Using `Image::Imlib2' means that we don't learn the size without fully
decoding the image and using up lots of memory.  The `Image::Size'
package will determine the image size by reading it out of the file
without decoding, so it's much faster.

Of course, that doesn't matter much yet, because we're only using it
/after/ we decode the image.  Hmm...
---
 mason/.perl-lib/TrivGal.pm | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/mason/.perl-lib/TrivGal.pm b/mason/.perl-lib/TrivGal.pm
index fc93772..d6d3afb 100644
--- a/mason/.perl-lib/TrivGal.pm
+++ b/mason/.perl-lib/TrivGal.pm
@@ -32,6 +32,7 @@ use Exporter qw{import};
 use File::stat;
 use Image::ExifTool qw{};
 use Image::Imlib2;
+use Image::Size qw{};
 use User::pwent;
 use POSIX;
 
@@ -215,10 +216,24 @@ package TrivGal::Image {
     return bless {
       path => $path, imgpath => $imgpath,
       mtime => $st->mtime,
-      img => undef
+      img => undef,
+      _wd => undef, _ht => undef,
+      sz => undef
     }, $cls;
   }
 
+  sub _getsz ($) {
+    my ($me) = @_;
+    return if defined $me->{_wd};
+
+    my ($wd, $ht, $err) = Image::Size::imgsize $me->{imgpath};
+    defined $wd or die "failed to read size of `$me->{path}': $err";
+    my $sz = $wd; if ($sz < $ht) { $sz = $ht; }
+    @$me{"_wd", "_ht", "sz"} = ($wd, $ht, $sz);
+  }
+
+  sub sz ($) { my ($me) = @_; $me->_getsz; return $me->{sz}; }
+
   sub scale ($$;$) {
     my ($me, $scale, $forcep) = @_;
     my $m = HTML::Mason::Request->instance;
@@ -250,11 +265,9 @@ package TrivGal::Image {
       }
     }
 
-    my ($wd, $ht) = ($img->width, $img->height);
-    my $max = $wd > $ht ? $wd : $ht;
-    if ($max <= $sz)
+    if ($me->sz <= $sz)
       { return $m->interp->apply_escapes("$IMGURL/$path", "u"); }
-    my $sc = $sz/$max;
+    my $sc = $sz/$me->sz;
     my $scaled = $img->create_scaled_image($sc*$wd, $sc*$ht);
 
     $scaled->image_set_format($ty->imlibfmt);
-- 
2.11.0