new link change detection method and general code rework

This new method for determining when links on pages
have changed should be more efficient, since it avoids
double calculation of the bestlinks.

It also allows collecting data about the old links, before
the scan pass, so the data is accurate when pages move around
and bestlinks change.

Also got some code back to a saner indent level.

diff --git a/IkiWiki/Render.pm b/IkiWiki/Render.pm
index 599bb26e2b382a7b139f3fc415db9442a11c195a..fe0b3138aaa9cc9f3c74d757a420d82f5d47a82e 100644 (file)
--- a/IkiWiki/Render.pm
+++ b/IkiWiki/Render.pm
@@ -58,52 +58,6 @@ sub backlinks ($) {
        return @links;
 }
 
-sub find_changed_links (@_) {
-       my %linkchanged;
-       my %linkchangers;
-       foreach my $file (@_) {
-               my $page=pagename($file);
-       
-               if (exists $links{$page}) {
-                       foreach my $l (@{$links{$page}}) {
-                               my $link=bestlink($page, $l);
-                               if (length $link) {
-                                       if (! exists $oldlinks{$page} ||
-                                           ! grep { bestlink($page, $_) eq $link } @{$oldlinks{$page}}) {
-                                               $linkchanged{$link}=1;
-                                               $linkchangers{lc($page)}=1;
-                                       }
-                               }
-                               else {
-                                       if (! grep { lc $_ eq lc $l } @{$oldlinks{$page}}) {
-                                               $linkchangers{lc($page)}=1
-                                       }
-                               }
-                               
-                       }
-               }
-               if (exists $oldlinks{$page}) {
-                       foreach my $l (@{$oldlinks{$page}}) {
-                               my $link=bestlink($page, $l);
-                               if (length $link) {
-                                       if (! exists $links{$page} || 
-                                           ! grep { bestlink($page, $_) eq $link } @{$links{$page}}) {
-                                               $linkchanged{$link}=1;
-                                               $linkchangers{lc($page)}=1;
-                                       }
-                               }
-                               else {
-                                       if (! grep { lc $_ eq lc $l } @{$links{$page}}) {
-                                               $linkchangers{lc($page)}=1
-                                       }
-                               }
-                       }
-               }
-       }
-
-       return \%linkchanged, \%linkchangers;
-}
-
 sub genpage ($$) {
        my $page=shift;
        my $content=shift;
@@ -389,6 +343,7 @@ sub refresh () {
        my ($files, $exists)=find_src_files();
 
        my (%rendered, @add, @del, @internal, @internal_change);
+
        # check for added or removed pages
        foreach my $file (@$files) {
                my $page=pagename($file);
@@ -452,10 +407,11 @@ sub refresh () {
                    $stat[9] > $pagemtime{$page} ||
                    $forcerebuild{$page}) {
                        $pagemtime{$page}=$stat[9];
+
                        if (isinternal($page)) {
-                               push @internal_change, $file;
                                # Preprocess internal page in scan-only mode.
                                preprocess($page, $page, readfile($srcfile), 1);
+                               push @internal_change, $file;
                        }
                        else {
                                push @needsbuild, $file;
@@ -464,7 +420,19 @@ sub refresh () {
        }
        run_hooks(needsbuild => sub { shift->(\@needsbuild) });
 
-       # scan and render files
+       # before scanning, make a note of where pages'
+       # old links pointed
+       my %oldlink_targets;
+       foreach my $file (@needsbuild, @del) {
+               my $page=pagename($file);
+               if (exists $oldlinks{$page}) {
+                       foreach my $l (@{$oldlinks{$page}}) {
+                               $oldlink_targets{$page}{$l}=bestlink($page, $l);
+                       }
+               }
+       }
+
+       # scan and render changed files
        foreach my $file (@needsbuild) {
                debug(sprintf(gettext("scanning %s"), $file));
                scan($file);
@@ -499,99 +467,121 @@ sub refresh () {
                        }
                }
        }
-
-       if (%rendered || @del || @internal || @internal_change) {
+       
+       # determine which links, on what pages, have changed
+       my %backlinkchanged;
+       my %linkchangers;
+       foreach my $file (@needsbuild, @del) {
+               my $page=pagename($file);
+               my %link_targets;
+               if (exists $links{$page}) {
+                       foreach my $l (@{$links{$page}}) {
+                               my $target=bestlink($page, $l);
+                               if (! exists $oldlink_targets{$page}{$l} ||
+                                   $target ne $oldlink_targets{$page}{$l}) {
+                                       $backlinkchanged{$l}=1;
+                                       $linkchangers{lc($page)}=1;
+                               }
+                               delete $oldlink_targets{$page}{$l};
+                       }
+               }
+               if (exists $oldlink_targets{$page} &&
+                   %{$oldlink_targets{$page}}) {
+                       foreach my $target (keys %{$oldlink_targets{$page}}) {
+                               $backlinkchanged{$target}=1;
+                       }
+                       $linkchangers{lc($page)}=1;
+               }
+       }
+       %oldlink_targets=();
+               
+       # rebuild dependant pages, recursively
+       my $deps=(@needsbuild || @del || @internal || @internal_change);
+       do {
+               $deps=0;
                my @changed=(keys %rendered, @del);
-               my ($linkchanged, $linkchangers)=find_changed_links(@changed);
-
-               my $unsettled;
-               do {
-                       $unsettled=0;
-                       @changed=(keys %rendered, @del);
-                       my @exists_changed=(@add, @del);
+               my @exists_changed=(@add, @del);
        
-                       my %lc_changed = map { lc(pagename($_)) => 1 } @changed;
-                       my %lc_exists_changed = map { lc(pagename($_)) => 1 } @exists_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) {
-                               next if $rendered{$f};
-                               my $p=pagename($f);
-                               my $reason = undef;
+               foreach my $f (@$files) {
+                       next if $rendered{$f};
+                       my $p=pagename($f);
+                       my $reason = undef;
        
-                               if (exists $depends_simple{$p}) {
-                                       foreach my $d (keys %{$depends_simple{$p}}) {
-                                               if (($depends_simple{$p}{$d} & $IkiWiki::DEPEND_CONTENT &&
-                                                    $lc_changed{$d})
-                                                   ||
-                                                   ($depends_simple{$p}{$d} & $IkiWiki::DEPEND_PRESENCE &&
-                                                    $lc_exists_changed{$d})
-                                                   ||
-                                                   ($depends_simple{$p}{$d} & $IkiWiki::DEPEND_LINKS &&
-                                                    $linkchangers->{$d})
-                                               ) {
-                                                       $reason = $d;
-                                                       last;
-                                               }
+                       if (exists $depends_simple{$p}) {
+                               foreach my $d (keys %{$depends_simple{$p}}) {
+                                       if (($depends_simple{$p}{$d} & $IkiWiki::DEPEND_CONTENT &&
+                                            $lc_changed{$d})
+                                           ||
+                                           ($depends_simple{$p}{$d} & $IkiWiki::DEPEND_PRESENCE &&
+                                            $lc_exists_changed{$d})
+                                           ||
+                                           ($depends_simple{$p}{$d} & $IkiWiki::DEPEND_LINKS &&
+                                            $linkchangers{$d})
+                                       ) {
+                                               $reason = $d;
+                                               last;
                                        }
                                }
+                       }
        
-                               if (exists $depends{$p} && ! defined $reason) {
-                                       D: foreach my $d (keys %{$depends{$p}}) {
-                                               my $sub=pagespec_translate($d);
-                                               next if $@ || ! defined $sub;
-       
-                                               # only consider internal files
-                                               # if the page explicitly depends
-                                               # on such files
-                                               my $internal_dep=$d =~ /internal\(/;
-
-                                               my @candidates;
-                                               if ($depends{$p}{$d} & $IkiWiki::DEPEND_PRESENCE) {
-                                                       @candidates=@exists_changed;
-                                                       push @candidates, @internal
-                                                               if $internal_dep;
-                                               }
-                                               if (($depends{$p}{$d} & ($IkiWiki::DEPEND_CONTENT | $IkiWiki::DEPEND_LINKS))) {
-                                                       @candidates=@changed;
-                                                       push @candidates, @internal, @internal_change
-                                                               if $internal_dep;
-                                               }
+                       if (exists $depends{$p} && ! defined $reason) {
+                               D: foreach my $d (keys %{$depends{$p}}) {
+                                       my $sub=pagespec_translate($d);
+                                       next if $@ || ! defined $sub;
+
+                                       # only consider internal files
+                                       # if the page explicitly depends
+                                       # on such files
+                                       my $internal_dep=$d =~ /internal\(/;
+
+                                       my @candidates;
+                                       if ($depends{$p}{$d} & $IkiWiki::DEPEND_PRESENCE) {
+                                               @candidates=@exists_changed;
+                                               push @candidates, @internal
+                                                       if $internal_dep;
+                                       }
+                                       if (($depends{$p}{$d} & ($IkiWiki::DEPEND_CONTENT | $IkiWiki::DEPEND_LINKS))) {
+                                               @candidates=@changed;
+                                               push @candidates, @internal, @internal_change
+                                                       if $internal_dep;
+                                       }
 
-                                               foreach my $file (@candidates) {
-                                                       next if $file eq $f;
-                                                       my $page=pagename($file);
-                                                       if ($sub->($page, location => $p)) {
-                                                               if ($depends{$p}{$d} & $IkiWiki::DEPEND_LINKS) {
-                                                                       next unless $linkchangers->{lc($page)};
-                                                               }
-                                                               $reason = $page;
-                                                               last D;
+                                       foreach my $file (@candidates) {
+                                               next if $file eq $f;
+                                               my $page=pagename($file);
+                                               if ($sub->($page, location => $p)) {
+                                                       if ($depends{$p}{$d} & $IkiWiki::DEPEND_LINKS) {
+                                                               next unless $linkchangers{lc($page)};
                                                        }
+                                                       $reason = $page;
+                                                       last D;
                                                }
                                        }
                                }
-       
-                               if (defined $reason) {
-                                       debug(sprintf(gettext("building %s, which depends on %s"), $f, $reason));
-                                       render($f);
-                                       $rendered{$f}=1;
-                                       $unsettled=1;
-                                       last;
-                               }
                        }
-               } while $unsettled;
-               
-               # update backlinks at end
-               foreach my $link (keys %{$linkchanged}) {
-                       my $linkfile=$pagesources{$link};
-                       if (defined $linkfile) {
-                               next if $rendered{$linkfile};
-                               debug(sprintf(gettext("building %s, to update its backlinks"), $linkfile));
-                               render($linkfile);
-                               $rendered{$linkfile}=1;
+       
+                       if (defined $reason) {
+                               debug(sprintf(gettext("building %s, which depends on %s"), $f, $reason));
+                               render($f);
+                               $rendered{$f}=1;
+                               $deps=1;
+                               last;
                        }
                }
+       } while $deps;
+
+       # update backlinks
+       foreach my $link (keys %backlinkchanged) {
+               my $linkfile=$pagesources{$link};
+               if (defined $linkfile) {
+                       next if $rendered{$linkfile};
+                       debug(sprintf(gettext("building %s, to update its backlinks"), $linkfile));
+                       render($linkfile);
+                       $rendered{$linkfile}=1;
+               }
        }
 
        # remove no longer rendered files