IkiWiki/Render.pm



#!/usr/bin/perl

package IkiWiki;

use warnings;
use strict;
use IkiWiki;
use Encode;

my (%backlinks, %rendered);
our %brokenlinks;
my $links_calculated=0;

sub calculate_links () {
    return if $links_calculated;
    %backlinks=%brokenlinks=();
    foreach my $page (keys %links) {
        foreach my $link (@{$links{$page}}) {
            my $bestlink=bestlink($page, $link);
            if (length $bestlink) {
                $backlinks{$bestlink}{$page}=1
                    if $bestlink ne $page;
            }
            else {
                push @{$brokenlinks{$link}}, $page;
            }
        }
    }
    $links_calculated=1;
}

sub backlink_pages ($) {
    my $page=shift;

    calculate_links();

    return keys %{$backlinks{$page}};
}

sub backlinks ($) {
    my $page=shift;

    my @links;
    foreach my $p (backlink_pages($page)) {
        my $href=urlto($p, $page);
                
        # Trim common dir prefixes from both pages.
        my $p_trimmed=$p;
        my $page_trimmed=$page;
        my $dir;
        1 while (($dir)=$page_trimmed=~m!^([^/]+/)!) &&
                defined $dir &&
                $p_trimmed=~s/^\Q$dir\E// &&
                $page_trimmed=~s/^\Q$dir\E//;
                   
        push @links, { url => $href, page => pagetitle($p_trimmed) };
    }
    return @links;
}

sub genpage ($$) {
    my $page=shift;
    my $content=shift;
    
    run_hooks(postscan => sub {
        shift->(page => $page, content => $content);
    });

    my $templatefile;
    run_hooks(templatefile => sub {
        return if defined $templatefile;
        my $file=shift->(page => $page);
        if (defined $file && defined template_file($file)) {
            $templatefile=$file;
        }
    });
    my $template=template(defined $templatefile ? $templatefile : 'page.tmpl', blind_cache => 1);
    my $actions=0;

    if (length $config{cgiurl}) {
        $template->param(editurl => cgiurl(do => "edit", page => $page))
            if IkiWiki->can("cgi_editpage");
        $template->param(prefsurl => cgiurl(do => "prefs"))
            if exists $hooks{auth};
        $actions++;
    }
        
    if (defined $config{historyurl} && length $config{historyurl}) {
        my $u=$config{historyurl};
        $u=~s/\[\[file\]\]/$pagesources{$page}/g;
        $template->param(historyurl => $u);
        $actions++;
    }
    if ($config{discussion}) {
        if ($page !~ /.*\/\Q$config{discussionpage}\E$/ &&
           (length $config{cgiurl} ||
            exists $links{$page."/".$config{discussionpage}})) {
            $template->param(discussionlink => htmllink($page, $page, $config{discussionpage}, noimageinline => 1, forcesubpage => 1));
            $actions++;
        }
    }

    if ($actions) {
        $template->param(have_actions => 1);
    }

    my @backlinks=sort { $a->{page} cmp $b->{page} } backlinks($page);
    my ($backlinks, $more_backlinks);
    if (@backlinks <= $config{numbacklinks} || ! $config{numbacklinks}) {
        $backlinks=\@backlinks;
        $more_backlinks=[];
    }
    else {
        $backlinks=[@backlinks[0..$config{numbacklinks}-1]];
        $more_backlinks=[@backlinks[$config{numbacklinks}..$#backlinks]];
    }

    $template->param(
        title => $page eq 'index' 
            ? $config{wikiname} 
            : pagetitle(basename($page)),
        wikiname => $config{wikiname},
        content => $content,
        backlinks => $backlinks,
        more_backlinks => $more_backlinks,
        mtime => displaytime($pagemtime{$page}),
        ctime => displaytime($pagectime{$page}),
        baseurl => baseurl($page),
    );

    run_hooks(pagetemplate => sub {
        shift->(page => $page, destpage => $page, template => $template);
    });
    
    $content=$template->output;
    
    run_hooks(format => sub {
        $content=shift->(
            page => $page,
            content => $content,
        );
    });

    return $content;
}

sub scan ($) {
    my $file=shift;

    debug(sprintf(gettext("scanning %s"), $file));

    my $type=pagetype($file);
    if (defined $type) {
        my $srcfile=srcfile($file);
        my $content=readfile($srcfile);
        my $page=pagename($file);
        will_render($page, htmlpage($page), 1);

        if ($config{discussion}) {
            # Discussion links are a special case since they're
            # not in the text of the page, but on its template.
            $links{$page}=[ $page."/".lc($config{discussionpage}) ];
        }
        else {
            $links{$page}=[];
        }

        run_hooks(scan => sub {
            shift->(
                page => $page,
                content => $content,
            );
        });

        # Preprocess in scan-only mode.
        preprocess($page, $page, $content, 1);
    }
    else {
        will_render($file, $file, 1);
    }
}

sub fast_file_copy (@) {
    my $srcfile=shift;
    my $destfile=shift;
    my $srcfd=shift;
    my $destfd=shift;
    my $cleanup=shift;

    my $blksize = 16384;
    my ($len, $buf, $written);
    while ($len = sysread $srcfd, $buf, $blksize) {
        if (! defined $len) {
            next if $! =~ /^Interrupted/;
            error("failed to read $srcfile: $!", $cleanup);
        }
        my $offset = 0;
        while ($len) {
            defined($written = syswrite $destfd, $buf, $len, $offset)
                or error("failed to write $destfile: $!", $cleanup);
            $len -= $written;
            $offset += $written;
        }
    }
}

sub render ($$) {
    my $file=shift;
    return if $rendered{$file};
    debug(shift);
    $rendered{$file}=1;
    
    my $type=pagetype($file);
    my $srcfile=srcfile($file);
    if (defined $type) {
        my $page=pagename($file);
        delete $depends{$page};
        delete $depends_simple{$page};
        will_render($page, htmlpage($page), 1);
        return if $type=~/^_/;
        
        my $content=htmlize($page, $page, $type,
            linkify($page, $page,
            preprocess($page, $page,
            filter($page, $page,
            readfile($srcfile)))));
        
        my $output=htmlpage($page);
        writefile($output, $config{destdir}, genpage($page, $content));
    }
    else {
        delete $depends{$file};
        delete $depends_simple{$file};
        will_render($file, $file, 1);
        
        if ($config{hardlink}) {
            # only hardlink if owned by same user
            my @stat=stat($srcfile);
            if ($stat[4] == $>) {
                prep_writefile($file, $config{destdir});
                unlink($config{destdir}."/".$file);
                if (link($srcfile, $config{destdir}."/".$file)) {
                    return;
                }
            }
            # if hardlink fails, fall back to copying
        }
        
        my $srcfd=readfile($srcfile, 1, 1);
        writefile($file, $config{destdir}, undef, 1, sub {
            fast_file_copy($srcfile, $file, $srcfd, @_);
        });
    }
}

sub prune ($) {
    my $file=shift;

    unlink($file);
    my $dir=dirname($file);
    while (rmdir($dir)) {
        $dir=dirname($dir);
    }
}

sub srcdir_check () {
    # security check, avoid following symlinks in the srcdir path by default
    my $test=$config{srcdir};
    while (length $test) {
        if (-l $test && ! $config{allow_symlinks_before_srcdir}) {
            error(sprintf(gettext("symlink found in srcdir path (%s) -- set allow_symlinks_before_srcdir to allow this"), $test));
        }
        unless ($test=~s/\/+$//) {
            $test=dirname($test);
        }
    }
    
}

sub find_src_files () {
    my @files;
    my %pages;
    eval q{use File::Find};
    error($@) if $@;
    find({
        no_chdir => 1,
        wanted => sub {
            my $file=decode_utf8($_);
            $file=~s/^\Q$config{srcdir}\E\/?//;
            return if -l $_ || -d _ || ! length $file;
            my $page = pagename($file);
            if (! exists $pagesources{$page} &&
                file_pruned($file)) {
                $File::Find::prune=1;
                return;
            }

            my ($f) = $file =~ /$config{wiki_file_regexp}/; # untaint
            if (! defined $f) {
                warn(sprintf(gettext("skipping bad filename %s"), $file)."\n");
            }
            else {
                push @files, $f;
                if ($pages{$page}) {
                    debug(sprintf(gettext("%s has multiple possible source pages"), $page));
                }
                $pages{$page}=1;
            }
        },
    }, $config{srcdir});
    foreach my $dir (@{$config{underlaydirs}}, $config{underlaydir}) {
        find({
            no_chdir => 1,
            wanted => sub {
                my $file=decode_utf8($_);
                $file=~s/^\Q$dir\E\/?//;
                return if -l $_ || -d _ || ! length $file;
                my $page=pagename($file);
                if (! exists $pagesources{$page} &&
                    file_pruned($file)) {
                    $File::Find::prune=1;
                    return;
                }

                my ($f) = $file =~ /$config{wiki_file_regexp}/; # untaint
                if (! defined $f) {
                    warn(sprintf(gettext("skipping bad filename %s"), $file)."\n");
                }
                else {
                    # avoid underlaydir override
                    # attacks; see security.mdwn
                    if (! -l "$config{srcdir}/$f" && 
                        ! -e _) {
                        if (! $pages{$page}) {
                            push @files, $f;
                            $pages{$page}=1;
                        }
                    }
                }
            },
        }, $dir);
    };
    return \@files, \%pages;
}

sub find_new_files ($) {
    my $files=shift;
    my @new;
    my @internal_new;

    foreach my $file (@$files) {
        my $page=pagename($file);
        if (exists $pagesources{$page} && $pagesources{$page} ne $file) {
            # the page has changed its type
            $forcerebuild{$page}=1;
        }
        $pagesources{$page}=$file;
        if (! $pagemtime{$page}) {
            if (isinternal($page)) {
                push @internal_new, $file;
            }
            else {
                push @new, $file;
                if ($config{getctime} && -e "$config{srcdir}/$file") {
                    eval {
                        my $time=rcs_getctime("$config{srcdir}/$file");
                        $pagectime{$page}=$time;
                    };
                    if ($@) {
                        print STDERR $@;
                    }
                }
            }
            $pagecase{lc $page}=$page;
            if (! exists $pagectime{$page}) {
                $pagectime{$page}=(srcfile_stat($file))[10];
            }
        }
    }

    return \@new, \@internal_new;
}

sub find_del_files ($) {
    my $pages=shift;
    my @del;
    my @internal_del;

    foreach my $page (keys %pagemtime) {
        if (! $pages->{$page}) {
            if (isinternal($page)) {
                push @internal_del, $pagesources{$page};
            }
            else {
                push @del, $pagesources{$page};
            }
            $links{$page}=[];
            $renderedfiles{$page}=[];
            $pagemtime{$page}=0;
        }
    }

    return \@del, \@internal_del;
}

sub remove_del (@) {
    foreach my $file (@_) {
        my $page=pagename($file);
        if (isinternal($page)) {
            debug(sprintf(gettext("removing old page %s"), $page));
        }
    
        foreach my $old (@{$oldrenderedfiles{$page}}) {
            prune($config{destdir}."/".$old);
        }

        foreach my $source (keys %destsources) {
            if ($destsources{$source} eq $page) {
                delete $destsources{$source};
            }
        }
    
        delete $pagecase{lc $page};
        delete $pagesources{$page};
    }
}

sub find_changed ($) {
    my $files=shift;
    my @changed;
    my @internal_changed;
    foreach my $file (@$files) {
        my $page=pagename($file);
        my ($srcfile, @stat)=srcfile_stat($file);
        if (! exists $pagemtime{$page} ||
            $stat[9] > $pagemtime{$page} ||
                $forcerebuild{$page}) {
            $pagemtime{$page}=$stat[9];

            if (isinternal($page)) {
                # Preprocess internal page in scan-only mode.
                preprocess($page, $page, readfile($srcfile), 1);
                push @internal_changed, $file;
            }
            else {
                push @changed, $file;
            }
        }
    }
    return \@changed, \@internal_changed;
}

sub calculate_old_links ($$) {
    my ($changed, $del)=@_;
    my %oldlink_targets;
    foreach my $file (@$changed, @$del) {
        my $page=pagename($file);
        if (exists $oldlinks{$page}) {
            foreach my $l (@{$oldlinks{$page}}) {
                $oldlink_targets{$page}{$l}=bestlink($page, $l);
            }
        }
    }
    return \%oldlink_targets;
}

sub derender_internal ($) {
    my $file=shift;
    my $page=pagename($file);
    delete $depends{$page};
    delete $depends_simple{$page};
    foreach my $old (@{$renderedfiles{$page}}) {
        delete $destsources{$old};
    }
    $renderedfiles{$page}=[];
}

sub render_linkers ($) {
    my $f=shift;
    my $p=pagename($f);
    foreach my $page (keys %{$backlinks{$p}}) {
        my $file=$pagesources{$page};
        render($file, sprintf(gettext("building %s, which links to %s"), $file, $p));
    }
}

sub remove_unrendered () {
    foreach my $src (keys %rendered) {
        my $page=pagename($src);
        foreach my $file (@{$oldrenderedfiles{$page}}) {
            if (! grep { $_ eq $file } @{$renderedfiles{$page}}) {
                debug(sprintf(gettext("removing %s, no longer built by %s"), $file, $page));
                prune($config{destdir}."/".$file);
            }
        }
    }
}

sub calculate_changed_links ($$$) {
    my ($changed, $del, $oldlink_targets)=@_;

    my (%backlinkchanged, %linkchangers);

    foreach my $file (@$changed, @$del) {
        my $page=pagename($file);

        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}) {
                    $backlinkchanged{$target}=1;
                    $linkchangers{lc($page)}=1;
                }
                delete $oldlink_targets->{$page}{$l};
            }
        }
        if (exists $oldlink_targets->{$page} &&
            %{$oldlink_targets->{$page}}) {
            foreach my $target (values %{$oldlink_targets->{$page}}) {
                $backlinkchanged{$target}=1;
            }
            $linkchangers{lc($page)}=1;
        }
    }

    return \%backlinkchanged, \%linkchangers;
}

sub render_dependent ($$$$$$$) {
    my ($files, $new, $internal_new, $del, $internal_del,
        $internal_changed, $linkchangers)=@_;

    my @changed=(keys %rendered, @$del);
    my @exists_changed=(@$new, @$del);
    
    my %lc_changed = map { lc(pagename($_)) => 1 } @changed;
    my %lc_exists_changed = map { lc(pagename($_)) => 1 } @exists_changed;
     
    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 $depends{$p} && ! defined $reason) {
            foreach my $dep (keys %{$depends{$p}}) {
                my $sub=pagespec_translate($dep);
                next if $@ || ! defined $sub;

                # only consider internal files
                # if the page explicitly depends
                # on such files
                my $internal_dep=$dep =~ /internal\(/;

                my $in=sub {
                    my $list=shift;
                    my $type=shift;
                    foreach my $file (@$list) {
                        next if $file eq $f;
                        my $page=pagename($file);
                        if ($sub->($page, location => $p)) {
                            if ($type == $IkiWiki::DEPEND_LINKS) {
                                next unless $linkchangers->{lc($page)};
                            }
                            return $page;
                        }
                    }
                    return undef;
                };

                if ($depends{$p}{$dep} & $IkiWiki::DEPEND_CONTENT) {
                    last if $reason =
                        $in->(\@changed, $IkiWiki::DEPEND_CONTENT);
                    last if $internal_dep && ($reason =
                        $in->($internal_new, $IkiWiki::DEPEND_CONTENT) ||
                        $in->($internal_del, $IkiWiki::DEPEND_CONTENT) ||
                        $in->($internal_changed, $IkiWiki::DEPEND_CONTENT));
                }
                if ($depends{$p}{$dep} & $IkiWiki::DEPEND_PRESENCE) {
                    last if $reason = 
                        $in->(\@exists_changed, $IkiWiki::DEPEND_PRESENCE);
                    last if $internal_dep && ($reason =
                        $in->($internal_new, $IkiWiki::DEPEND_PRESENCE) ||
                        $in->($internal_del, $IkiWiki::DEPEND_PRESENCE));
                }
                if ($depends{$p}{$dep} & $IkiWiki::DEPEND_LINKS) {
                    last if $reason =
                        $in->(\@changed, $IkiWiki::DEPEND_LINKS);
                    last if $internal_dep && ($reason =
                        $in->($internal_new, $IkiWiki::DEPEND_LINKS) ||
                        $in->($internal_del, $IkiWiki::DEPEND_LINKS) ||
                        $in->($internal_changed, $IkiWiki::DEPEND_LINKS));
                }
            }
        }
    
        if (defined $reason) {
            render($f, sprintf(gettext("building %s, which depends on %s"), $f, $reason));
            return 1;
        }
    }

    return 0;
}

sub render_backlinks ($) {
    my $backlinkchanged=shift;
    foreach my $link (keys %$backlinkchanged) {
        my $linkfile=$pagesources{$link};
        if (defined $linkfile) {
            render($linkfile, sprintf(gettext("building %s, to update its backlinks"), $linkfile));
        }
    }
}

sub refresh () {
    srcdir_check();
    run_hooks(refresh => sub { shift->() });
    my ($files, $pages)=find_src_files();
    my ($new, $internal_new)=find_new_files($files);
    my ($del, $internal_del)=find_del_files($pages);
    my ($changed, $internal_changed)=find_changed($files);
    run_hooks(needsbuild => sub { shift->($changed) });
    my $oldlink_targets=calculate_old_links($changed, $del);

    foreach my $file (@$changed) {
        scan($file);
    }

    calculate_links();
    
    remove_del(@$del, @$internal_del);

    foreach my $file (@$changed) {
        render($file, sprintf(gettext("building %s"), $file));
    }
    foreach my $file (@$internal_new, @$internal_del, @$internal_changed) {
        derender_internal($file);
    }

    my ($backlinkchanged, $linkchangers)=calculate_changed_links($changed,
        $del, $oldlink_targets);

    foreach my $file (@$new, @$del) {
        render_linkers($file);
    }
    
    if (@$changed || @$internal_changed ||
        @$del || @$internal_del || @$internal_new) {
        1 while render_dependent($files, $new, $internal_new,
            $del, $internal_del, $internal_changed,
            $linkchangers);
    }

    render_backlinks($backlinkchanged);
    remove_unrendered();

    if (@$del) {
        run_hooks(delete => sub { shift->(@$del) });
    }
    if (%rendered) {
        run_hooks(change => sub { shift->(keys %rendered) });
    }
}

sub commandline_render () {
    lockwiki();
    loadindex();
    unlockwiki();

    my $srcfile=possibly_foolish_untaint($config{render});
    my $file=$srcfile;
    $file=~s/\Q$config{srcdir}\E\/?//;

    my $type=pagetype($file);
    die sprintf(gettext("ikiwiki: cannot build %s"), $srcfile)."\n" unless defined $type;
    my $content=readfile($srcfile);
    my $page=pagename($file);
    $pagesources{$page}=$file;
    $content=filter($page, $page, $content);
    $content=preprocess($page, $page, $content);
    $content=linkify($page, $page, $content);
    $content=htmlize($page, $page, $type, $content);
    $pagemtime{$page}=(stat($srcfile))[9];
    $pagectime{$page}=$pagemtime{$page} if ! exists $pagectime{$page};

    print genpage($page, $content);
    exit 0;
}

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