implement support for DEPEND_EXISTS

Preliminary support, anyway.

If a dependency only includes DEPEND_EXISTS, then only changes that
involved adding or deleting a page can trigger it.

This is complicated by internal pages, since the code did not previously
differentiate between add, delete, and change of internal pages.
Now it tracks change separately from add+delete, so DEPEND_EXISTS pagespecs
that actually match internal pages (which will probably be quite rare in
practice) should work.

diff --git a/IkiWiki/Render.pm b/IkiWiki/Render.pm
index 246c2260d7748e9fe2b3522d73035564e0fb6754..9e00428c2127376182a304bdb34c4f8383b04880 100644 (file)
--- a/IkiWiki/Render.pm
+++ b/IkiWiki/Render.pm
@@ -342,7 +342,7 @@ sub refresh () {
        run_hooks(refresh => sub { shift->() });
        my ($files, $exists)=find_src_files();
 
-       my (%rendered, @add, @del, @internal);
+       my (%rendered, @add, @del, @internal, @internal_change);
        # check for added or removed pages
        foreach my $file (@$files) {
                my $page=pagename($file);
@@ -407,7 +407,7 @@ sub refresh () {
                    $forcerebuild{$page}) {
                        $pagemtime{$page}=$stat[9];
                        if (isinternal($page)) {
-                               push @internal, $file;
+                               push @internal_change, $file;
                                # Preprocess internal page in scan-only mode.
                                preprocess($page, $page, readfile($srcfile), 1);
                        }
@@ -429,7 +429,7 @@ sub refresh () {
                render($file);
                $rendered{$file}=1;
        }
-       foreach my $file (@internal) {
+       foreach my $file (@internal, @internal_change) {
                # internal pages are not rendered
                my $page=pagename($file);
                delete $depends{$page};
@@ -454,10 +454,12 @@ sub refresh () {
                }
        }
 
-       if (%rendered || @del || @internal) {
+       if (%rendered || @del || @internal || @internal_change) {
                my @changed=(keys %rendered, @del);
+               my @exists_changed=(@add, @del);
 
-               my %lcchanged = map { lc(pagename($_)) => 1 } @changed;
+               my %lc_changed = map { lc(pagename($_)) => 1 } @changed;
+               my %lc_exists_changed = map { lc(pagename($_)) => 1 } @exists_changed;
  
                # rebuild dependant pages
                foreach my $f (@$files) {
@@ -467,7 +469,13 @@ sub refresh () {
 
                        if (exists $depends_simple{$p}) {
                                foreach my $d (keys %{$depends_simple{$p}}) {
-                                       if (exists $lcchanged{$d}) {
+                                       if ($depends_simple{$p}{$d} == $IkiWiki::DEPEND_EXISTS) {
+                                               if (exists $lc_exists_changed{$d}) {
+                                                       $reason = $d;
+                                                       last;
+                                               }
+                                       }
+                                       elsif (exists $lc_changed{$d}) {
                                                $reason = $d;
                                                last;
                                        }
@@ -479,10 +487,26 @@ sub refresh () {
                                        my $sub=pagespec_translate($d);
                                        next if $@ || ! defined $sub;
 
+                                       my @candidates;
+                                       if ($depends{$p}{$d} == $IkiWiki::DEPEND_EXISTS) {
+                                               @candidates=@exists_changed;
+                                       }
+                                       else {
+                                               @candidates=@changed;
+                                       }
                                        # only consider internal files
                                        # if the page explicitly depends
                                        # on such files
-                                       foreach my $file (@changed, $d =~ /internal\(/ ? @internal : ()) {
+                                       if ($d =~ /internal\(/) {
+                                               if ($depends{$p}{$d} == $IkiWiki::DEPEND_EXISTS) {
+                                                       push @candidates, @internal;
+                                               }
+                                               else {
+                                                       push @candidates, @internal, @internal_change;
+                                               }
+                                       }
+
+                                       foreach my $file (@candidates) {
                                                next if $file eq $f;
                                                my $page=pagename($file);
                                                if ($sub->($page, location => $p)) {