Dashboard: oplog tree view (#217)

* Turned tables and progress bars and friends into "widgets!"

* A step to abstracting away a page's the internal DOM structure

* Folded sector creation into Page and pivoted it to a widget host

* Try and keep start/count as numbers regardless of input

* No need for the entry table to be defined up front now

* Add op count and log sixe to oplog list page

* Cache left side toolbar object

* Bounds count page start when building list of oplog entrie

* Start/end navigation tools

* Build rest of entry page while waiting for indexer to load

* Consistent naming with other pages

* Spacially consolidate fetching code

* Hide fetch latency to speed up index generation workers

* Extract dashboard structure from zen.js monolith

* Fix breadcrumbs after restructuring

* Add view link to actions cell of oplogs list

* Generator to enumerate names of entries in indexer

* Methods for simple traversal of component relations

* is() to check if a component is of a certain type

* Extend attr() to get and unset a component's attributes

* Unsetting all styles of anchor tags was underisrable

* Restore page name as id of container element

* A tree view of an oplog

* Move helper class out to private module scope

* Small tweak to use left var that already exists

* Changelog update

* Updated frontend .zip archive

2 files changed, 26 insertions, 8 deletions

diff --git a/src/zenserver/frontend/html/indexer/indexer.js b/src/zenserver/frontend/html/indexer/indexer.js
index 8e5003edf..5bbb7c352 100644
--- a/src/zenserver/frontend/html/indexer/indexer.js
+++ b/src/zenserver/frontend/html/indexer/indexer.js
@@ -48,6 +48,13 @@ class Indexer
 				if (name.indexOf(needle) >= 0)
 					yield name;
 	}
+
+	*enum_names()
+	{
+		for (const page of this._pages)
+			for (const [_, name] of page)
+				yield name;
+	}
 }
 
 
diff --git a/src/zenserver/frontend/html/indexer/worker.js b/src/zenserver/frontend/html/indexer/worker.js
index 581746d6c..b8183cc6f 100644
--- a/src/zenserver/frontend/html/indexer/worker.js
+++ b/src/zenserver/frontend/html/indexer/worker.js
@@ -21,19 +21,31 @@ export class Message
 ////////////////////////////////////////////////////////////////////////////////
 async function map_id_to_key(project_id, oplog, start, end, page_size, stride)
 {
+	if (start >= end)
+		return postMessage(Message.create(Message.MapDone));
+
 	const uri = "/prj/" + project_id + "/oplog/" + oplog + "/entries";
-	while (start < end)
-	{
-		performance.mark("fetch");
+
+	const fetch_page = async function(index) {
 		const cbo = new Fetcher()
 			.resource(uri)
-			.param("start", start)
+			.param("start", index)
 			.param("count", page_size)
 			.param("fieldfilter", "packagedata,key")
 			.cbo()
 
-		const entry_count = Math.min(page_size, -(start - end));
-		var result = new Array(entry_count);
+		const entry_count = Math.min(page_size, -(index - end));
+		return [await cbo, entry_count];
+	};
+
+	var fetch = fetch_page(start);
+	while (fetch !== undefined)
+	{
+		performance.mark("fetch");
+
+		const [cbo, entry_count] = await fetch;
+		start += stride;
+		fetch = (start < end) ? fetch_page(start) : undefined;
 
 		var entries = (await cbo).as_object().find("entries");
 		if (entries == undefined)
@@ -45,6 +57,7 @@ async function map_id_to_key(project_id, oplog, start, end, page_size, stride)
 
 		performance.mark("build");
 		var count = 0;
+		var result = new Array(entry_count);
 		for (var entry of entries)
 		{
 			if (!entry.is_object())
@@ -84,8 +97,6 @@ async function map_id_to_key(project_id, oplog, start, end, page_size, stride)
 			count++;
 		}
 
-		start += stride;
-
 		if (count == 0)
 			continue;