Merge branch 'b-3.6.1' of ../kivitendo-erp_20220811

[kivitendo-erp.git] / SL / System / ResourceCache.pm

diff --git a/SL/System/ResourceCache.pm b/SL/System/ResourceCache.pm
new file mode 100644 (file)
index 0000000..be7a1d4
--- /dev/null
+++ b/SL/System/ResourceCache.pm
@@ -0,0 +1,79 @@
+package SL::System::ResourceCache;
+
+use strict;
+use File::stat;
+use File::Find;
+
+our @paths = qw(image css);
+our $cache;
+
+sub generate_data {
+  return if $cache;
+
+  $cache = {};
+
+  File::Find::find(sub {
+    $cache->{ $File::Find::name =~ s{^\./}{}r } = stat($_);
+  }, @paths);
+}
+
+sub get {
+  my ($class, $file) = @_;
+  no warnings 'once';
+
+  return stat($file) if ($::dispatcher // { interface => 'cgi' })->{interface} eq 'cgi';
+
+  $class->generate_data;
+  $cache->{$file};
+}
+
+1;
+
+
+__END__
+
+=encoding utf-8
+
+=head1 NAME
+
+SL::System::ResourceCache - provides access to resource files without having to access the filesystem all the time
+
+=head1 SYNOPSIS
+
+  use SL::System::ResourceCache;
+
+  SL::System::ResourceCache->get($filename);
+
+=head1 DESCRIPTION
+
+This will stat() all files in the configured paths at startup once, so that
+subsequent calls can use the cached values. Particularly useful for icons in
+the menu, which would otherwise generate a few hundred file sytem accesses per
+request.
+
+The caching will not happen in CGI and script environments.
+
+=head1 FUNCTIONS
+
+=over 4
+
+=item * C<get FILENAME>
+
+If the file exists, returns a L<File::stat> object. If it doesn't exists, returns undef.
+
+=back
+
+=head1 BUGS
+
+None yet :)
+
+=head1 TODO
+
+Make into instance cache and keep it as system wide object
+
+=head1 AUTHOR
+
+Sven Schöling E<lt>sven.schoeling@googlemail.comE<gt>
+
+=cut
+