From a5bd905f18ca6cea99f2cb4cd902ed130c03e8b7 Mon Sep 17 00:00:00 2001
From: gconsidine <greg@gregconsidine.com>
Date: Mon, 26 Feb 2018 11:18:02 -0500
Subject: [PATCH] [WIP] Add event buffering on scroll/resume

---
 .../features/output/index.controller.js       | 37 +++++++++++--------
 awx/ui/client/features/output/index.js        |  5 ++-
 2 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/awx/ui/client/features/output/index.controller.js b/awx/ui/client/features/output/index.controller.js
index 66f3171dd7..c6ceacea41 100644
--- a/awx/ui/client/features/output/index.controller.js
+++ b/awx/ui/client/features/output/index.controller.js
@@ -106,33 +106,32 @@ function JobsIndexController (
 }
 
 function processWebSocketEvents (scope, data) {
-    vm.scroll.isActive = true;
-
     if (data.event === JOB_START) {
+        vm.scroll.isActive = true;
         vm.stream.isActive = true;
         vm.scroll.isLocked = true;
     } else if (data.event === JOB_END) {
         vm.stream.isActive = false;
     }
 
-    if (!vm.scroll.isLocked) {
-        vm.scroll.isActive = false;
-
-        return;
-    }
+    // TODO: Determine how to manage buffered events (store in page cache vs. separate)
+    //    Leaning towards keeping separate (same as they come in over WS). On resume of scroll,
+    // Clear/reset cache, append buffered events, then back to normal render cycle
 
     if (vm.stream.count % resource.page.size === 0) {
-        cache.push({
-            page: vm.stream.page
-        });
+        cache.push({ page: vm.stream.page });
 
         vm.stream.page++;
+
+        if (buffer.length > (resource.page.resultLimit - resource.page.size)) {
+            buffer.splice(0, (buffer.length - resource.page.resultLimit) + resource.page.size);
+        }
     }
 
     vm.stream.count++;
     buffer.push(data);
 
-    if (vm.stream.isRendering) {
+    if (vm.stream.isRendering || !vm.scroll.isLocked) {
         return;
     }
 
@@ -280,7 +279,7 @@ function prepend (events) {
 function pop () {
     // console.log('[3] popping old page');
     return $q(resolve => {
-        if (cache.length <= resource.page.limit) {
+        if (cache.length <= resource.page.pageLimit) {
             // console.log('[3.1] nothing to pop');
             return resolve();
         }
@@ -299,16 +298,16 @@ function pop () {
 }
 
 function shift () {
-    // console.log('[3] shifting old page');
+    console.log('[3] shifting old page', cache.length);
     return $q(resolve => {
-        if (cache.length <= resource.page.limit) {
+        if (cache.length <= resource.page.pageLimit) {
             // console.log('[3.1] nothing to shift');
             return resolve();
         }
 
         window.requestAnimationFrame(() => {
             const ejected = cache.shift();
-            // console.log('[3.1] shifting', ejected);
+            console.log('[3.1] shifting', ejected);
             const rows = $(ELEMENT_TBODY).children().slice(0, ejected.lines);
 
             rows.empty();
@@ -639,8 +638,16 @@ function scrollHome () {
 function scrollEnd () {
     if (vm.scroll.isLocked) {
         vm.scroll.isLocked = false;
+        vm.scroll.isActive = false;
 
         return;
+    } else if (!vm.scroll.isLocked && vm.stream.isActive) {
+        vm.scroll.isActive = true;
+
+        return clear()
+            .then(() => {
+                vm.scroll.isLocked = true;
+            });
     }
 
     const config = {
diff --git a/awx/ui/client/features/output/index.js b/awx/ui/client/features/output/index.js
index a23e8cbbc0..7467c0b079 100644
--- a/awx/ui/client/features/output/index.js
+++ b/awx/ui/client/features/output/index.js
@@ -59,8 +59,9 @@ function resolveResource (Job, ProjectUpdate, AdHocCommand, SystemJob, WorkflowJ
                 ws: getWebSocketResource(type),
                 page: {
                     cache: PAGE_CACHE,
-                    limit: PAGE_LIMIT,
-                    size: PAGE_SIZE
+                    size: PAGE_SIZE,
+                    pageLimit: PAGE_LIMIT,
+                    resultLimit: PAGE_SIZE * PAGE_LIMIT
                 }
             };
         });