From cd93fa83ba632588b357b190f47809205b9a5d91 Mon Sep 17 00:00:00 2001
From: Arne Georg Gleditsch <argggh@lxr.linpro.no>
Date: Tue, 12 Feb 2008 22:53:01 +0100
Subject: Change line number layout and caching mechanism.

---
 lib/LXRng/Markup/File.pm          |   6 +-
 lib/LXRng/Web.pm                  | 140 +++++++++++++++++++++++++++-----------
 webroot/.static/css/lxrng.css     |  34 ++-------
 webroot/.static/js/lxrng-funcs.js |  79 ++++++++++++++-------
 4 files changed, 164 insertions(+), 95 deletions(-)

diff --git a/lib/LXRng/Markup/File.pm b/lib/LXRng/Markup/File.pm
index 9bd811c..d94952c 100644
--- a/lib/LXRng/Markup/File.pm
+++ b/lib/LXRng/Markup/File.pm
@@ -49,9 +49,9 @@ sub make_format_newline {
 	$line++;
 	$nl = safe_html($nl);
 
-	return qq{</span>$nl<li>}.
-	    qq{<a href="$name#L$line" class="line"><span></span></a>}.
-	    qq{<a id="L$line" name="L$line"></a><span class="line">};
+	return qq{$nl}.
+	    qq{<a href="$name#L$line" class="line">$line</a>}.
+	    qq{<a id="L$line" name="L$line"></a>};
     }
 }
 
diff --git a/lib/LXRng/Web.pm b/lib/LXRng/Web.pm
index 4334981..d7f9be4 100644
--- a/lib/LXRng/Web.pm
+++ b/lib/LXRng/Web.pm
@@ -34,13 +34,17 @@ use IO::Handle;
 use Digest::SHA1 qw(sha1_hex);
 use CGI::Ajax;
 use File::Temp qw(tempdir tempfile);
+use File::Path qw(mkpath);
 use POSIX qw(waitpid);
 
 use constant PDF_LINELEN => 95;
 use constant PDF_CHARPTS => 6.6;
 
+# Cache must be purged if this is changed.
+use constant FRAGMENT_SIZE => 250;
+
 use vars qw($has_gzip_io);
-# eval { require PerlIO::gzip; $has_gzip_io = 1; };
+eval { require PerlIO::gzip; $has_gzip_io = 1; };
 
 # Return 1 if gzip compression of html is desired.
 
@@ -77,39 +81,49 @@ sub print_markedup_file {
 	return;
     }
     else {
-	# Grmble.  We assume the identifiers to markup are identical
-	# from one version to another, but if the same revision of a
-	# file exists both in an indexed and un-indexed release, one
-	# of them will have its identifiers highlighted and the other
-	# not.  So we can't share a cache slot across releases without
-	# adding some extra logic here.  Bummer.
-	# TODO: Resolve by caching only accesses to releases that are
-	# is_indexed.
+	my $line   = 0;
+	my $focus  = 1;
+	my $fline  = $context->param('line');
+
+	$focus = $fline < 100 if defined($fline);
+    
 	my $shaid = sha1_hex(join("\0", $node->name, $node->revision,
 				  $context->release));
 	my $cfile;
+	$shaid =~ s,^(..)(..),$1/$2/,;
 	$cfile = $context->config->{'cache'}.'/'.$shaid
 	    if exists $context->config->{'cache'};
 
-	if ($cfile and -e $cfile) {
-	    open(my $cache, '<', $cfile);
-
-	    my $focus = $context->param('line') || 0;
-	    $focus = 0 if $context->param('full');
-	    my $class = $focus ? 'partial' : 'full';
-	    my $start = $focus > 5 ? " start=".($focus - 5) : "";
-	    print("<pre id=\"file_contents\" class=\"$class\"><ol$start><span>");
-	    while (<$cache>) {
-		next if $focus and $. < $focus - 5;
-		print($_);
-		last if $focus and $. > $focus + 70;
+	if ($cfile and -d $cfile) {
+	    print("<pre id=\"file_contents\">");
+	    while (-r "$cfile/$line") {
+		print("<div class=\"".($focus ? "done" : "pending").
+		      "\" id=\"$shaid/$line\">");
+		if ($focus) {
+		    open(my $cache, '<', "$cfile/$line");
+		    my $buf;
+		    while (read($cache, $buf, 16384) > 0) {
+			print($buf);
+		    }
+		    close($cache);
+		}
+		else {
+		    print("\n" x FRAGMENT_SIZE);
+		}
+		print("</div>");
+		$line += FRAGMENT_SIZE;
+
+		if (defined($fline)) {
+		    $focus = ($line <= ($fline + 100)
+			      and $line > ($fline - FRAGMENT_SIZE));
+		}
 	    }
-	    print("</span></ol></pre>");
-	    close($cache);
+	    print("</pre>\n");
 	}
 	else {
 	    my $cache;
-	    open($cache, '>', $cfile) if $cfile;
+	    mkpath($cfile, 0, 0777);
+	    open($cache, '>', "$cfile/0") if $cfile;
 	    my $handle = $node->handle();
 	    LXRng::Lang->init($context);
 	    my $lang   = LXRng::Lang->new($node);
@@ -117,21 +131,39 @@ sub print_markedup_file {
 						   @{$lang->parsespec});
 	    my $markup = LXRng::Markup::File->new('context' => $context);
 	    my $subst  = $lang->markuphandlers($context, $node, $markup);
-    
-	    # Possible optimization: store cached file also as .gz,
-	    # and pass that on if the client accepts gzip-encoded
-	    # data.  Saves us from compressing the cached file each
-	    # time it's needed, but requires a bit of fiddling with
-	    # perlio and the streams to get right.  Also messes up
-	    # partial transfers.
-	    print("<pre id=\"file_contents\" class=\"full\"><ol><span>");
+
+	    print("<pre id=\"file_contents\">".
+		  "<div class=\"".($focus ? "done" : "pending").
+		  "\" id=\"$shaid/0\">");
 	    while (1) {
-		my @frags = $markup->markupfile($subst, $parse);
+		my @frags = map { split(/(?<=\n)/, $_) }
+				  $markup->markupfile($subst, $parse);
 		last unless @frags;
-		print(@frags);
-		print($cache @frags) if $cache;
+		foreach my $f (@frags) {
+		    print($f) if $focus;
+		    print($cache $f) if $cache;
+		    if ($f =~ /\n$/s) {
+			$line++;
+			if ($line % FRAGMENT_SIZE == 0) {
+			    print("\n" x FRAGMENT_SIZE) unless $focus;
+			    if (defined($fline)) {
+				$focus = ($line <= ($fline + 100)
+					  and $line > ($fline - FRAGMENT_SIZE));
+			    }
+			    print("</div>".
+				  "<div class=\"".
+				  ($focus ? "done" : "pending").
+				  "\" id=\"$shaid/$line\">");
+			    if ($cache) {
+				close($cache);
+				open($cache, '>', "$cfile/$line");
+			    }
+			}
+		    }
+		}
 	    }
-	    print("</span></ol></pre>\n");
+	    print("</div></pre>\n");
+	    close($cache) if $cache;
 	}
 	return $shaid;
     }
@@ -161,6 +193,7 @@ sub source {
 
     my $pjx = CGI::Ajax->new('pjx_search' => '',
 			     'pjx_load_file' => '',
+			     'pjx_load_fragment' => '',
 			     'pjx_releases' => '');
     $pjx->js_encode_function('escape');
 
@@ -181,10 +214,17 @@ sub source {
 		my $base = $context->base_url(1);
 		$base =~ s,/*$,/ajax+*/,;
 
+		# This is a bit fragile, but only covers a relatively
+		# esoteric corner case.  (CGI::Ajax splits results on
+		# __pjx__, and there doesn't seem to be any provisions
+		# for escaping any randomly occurring split markers.)
+		my $js = $pjx->show_javascript();
+		$js =~ s/var splitval.*var data[^;]+/var data = rsp/;
+
 		$template->process('main.tt2',
 				   {'context'    => $context,
 				    'base_url'   => $base,
-				    'javascript' => $pjx->show_javascript(),
+				    'javascript' => $js,
 				    'is_ajax' => 1})
 		    or die $template->error();
 	    }
@@ -443,11 +483,13 @@ sub handle_ajax_request {
     my $gzip = do_compress_response($query);
     
     # $query->no_cache(1); FIXME -- not available with CGI.pm.
-    print($query->header(-type => 'text/html',
-			 -charset => 'utf-8',
-			 -cache-control => 'no-store, no-cache, must-revalidate',
-			 $gzip ? (-content_encoding => 'gzip') : ()));
+    my %headers = (-type => 'text/html',
+		   -charset => 'utf-8');
+    $headers{'-cache-control'} = 'no-store, no-cache, must-revalidate'
+	unless $context->param('fname') eq 'pjx_load_fragment';
+    $headers{'-content_encoding'} = 'gzip' if $gzip;
 
+    print($query->header(%headers));
     binmode(\*STDOUT, ":gzip") if $gzip;
 
     if ($context->param('fname') eq 'pjx_load_file') {
@@ -456,6 +498,22 @@ sub handle_ajax_request {
 	print_markedup_file($context, $template, $node);
 	
     }
+    elsif ($context->param('fname') eq 'pjx_load_fragment') {
+	my $shaid = $context->param('frag');
+	return unless $shaid =~ 
+	    m|^[0-9a-z]{2}/[0-9a-z]{2}/[0-9a-z]{36}/[0-9]+$|;
+	return unless exists $context->config->{'cache'};
+	my $cfile = $context->config->{'cache'}.'/'.$shaid;
+	return unless -e $cfile;
+	open(my $cache, '<', $cfile) or return;
+	
+	print($shaid.'|');
+	my $buf;
+	while (read($cache, $buf, 16384) > 0) {
+	    print($buf);
+	}
+	close($cache);
+    }
     elsif ($context->param('fname') eq 'pjx_search') {
 	if ($context->param('ajax_lookup') =~
 	    /^[+ ](code|ident|file|text|ambig)=(.*)/)
diff --git a/webroot/.static/css/lxrng.css b/webroot/.static/css/lxrng.css
index f5d84c0..3b6ff2b 100644
--- a/webroot/.static/css/lxrng.css
+++ b/webroot/.static/css/lxrng.css
@@ -150,6 +150,10 @@ span.close-button {
 	content: attr(id);
 } */
 
+pre {
+	margin-left: 3.8em;
+}
+
 a.line {
 	position: absolute;
 	top: auto;
@@ -157,39 +161,13 @@ a.line {
 	height: 2ex;
 	width: 3em;
 	text-align: right;
+	padding-right: 3px;
 
 	border: solid;
 	border-width: 1px;
 	border-color: #000000;
 	margin-left: 3px;
-}
-
-a.line span { 
-	position: absolute;
-	top: auto;
-	height: 2ex;
-	left: 0px;
-	background: #6c6c6c;
-	filter: alpha(opacity=10);
-	moz-opacity: .10;
-	opacity: .10;
-	width: 3em;
-}
-
-
-pre#file_contents li { 
-	color: blue;
-}
-
-span.line {
-	position: absolute;
-	left: 4em;
-	color: black;
-	white-space: pre;
-}
-
-pre {
-	margin-left: 0.7em;
+	background: #F0F0F0;
 }
 
 a img { 
diff --git a/webroot/.static/js/lxrng-funcs.js b/webroot/.static/js/lxrng-funcs.js
index 0aa4237..939eefd 100644
--- a/webroot/.static/js/lxrng-funcs.js
+++ b/webroot/.static/js/lxrng-funcs.js
@@ -190,6 +190,59 @@ function load_file(tree, file, ver, line) {
 	return false;
 }
 
+
+function ajaxify_link_handlers(links) {
+	var i;
+	for (i = 0; i < links.length; i++) {
+		if (links[i].className == 'fref') {
+			links[i].onclick = ajax_nav;
+		}
+		else if (links[i].className == 'line') {
+			links[i].onclick = ajax_jumpto_line;
+		}
+		else if (links[i].className == 'sref' || 
+		    links[i].className == 'falt')
+		{
+			links[i].onclick = ajax_lookup_anchor; 
+		}
+
+	}
+}
+
+function load_next_pending_fragment() {
+	var pre = document.getElementById('file_contents');
+	if (!pre)
+		return;
+
+	for (var i = 0; i < pre.childNodes.length; i++) {
+		if ((pre.childNodes[i].nodeName == 'DIV') &&
+		    (pre.childNodes[i].className == 'pending'))
+		{
+			pjx_load_fragment(['tree__' + pending_tree,
+					   'frag__' + pre.childNodes[i].id],
+					  [load_fragment_finalize]);
+			return;
+		}
+	}
+}
+
+function load_fragment_finalize(content) {
+	var split = content.indexOf('|');
+	var div = document.getElementById(content.substr(0, split));
+	if (!div)
+		return;
+
+	div.innerHTML = content.substr(split+1);
+	div.className = 'done';
+
+	var links = div.getElementsByTagName('a');
+	ajaxify_link_handlers(links);
+	load_next_pending_fragment();
+
+//	if (location.hash)
+//		location.hash = location.hash;
+}
+
 function load_file_finalize(content) {
 	var res = document.getElementById('content');
 	res.innerHTML = 'Done';
@@ -198,7 +251,7 @@ function load_file_finalize(content) {
 	head.innerHTML = '<a class=\"fref\" href=\".\">' + pending_tree + '</a>';
 	var path_walked = '';
 	var elems = pending_file.split(/\//);
-	for (var i=0; i<elems.length; i++) {
+	for (var i = 0; i < elems.length; i++) {
 		if (elems[i] != '') {
 			head.innerHTML = head.innerHTML + '/' +
 				'<a class=\"fref\" href=\"' + path_walked + elems[i] +
@@ -214,13 +267,6 @@ function load_file_finalize(content) {
 	}
 	var full_path = full_tree + '/' + pending_file.replace(/^\/?/, '');
 
-	var pre = document.getElementById('file_contents');
-	if (pre && pre.className == 'partial') {
-		pjx_load_file(['tree__' + pending_tree, 'file__' + pending_file,
-			       'v__' + pending_ver, 'full__1', 'NO_CACHE'],
-			      [load_file_finalize]);
-	}
-
 	var print = document.getElementById('lxr_print');
 	var dirlist = document.getElementById('content_dir');
 	if (dirlist) {
@@ -257,22 +303,9 @@ function load_file_finalize(content) {
 	loaded_ver = pending_ver;
 	hash_check = setTimeout('check_hash_navigation()', 50);
 
-//	TODO: This really takes oodles of time.  Consider coding into html.
-	var i;
-	for (i = 0; i < document.links.length; i++) {
-		if (document.links[i].className == 'fref') {
-			document.links[i].onclick = ajax_nav;
-		}
-		else if (document.links[i].className == 'line') {
-			document.links[i].onclick = ajax_jumpto_line;
-		}
-		else if (document.links[i].className == 'sref' || 
-		    document.links[i].className == 'falt')
-		{
-			document.links[i].onclick = ajax_lookup_anchor; 
-		}
+	ajaxify_link_handlers(document.links);
 
-	}
+	load_next_pending_fragment();
 }
 
 function load_content() {
-- 
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