This service helps to reduce server load for repetitive OpenSRF
calls by dividing a large array of promises into batches. It
maintains the original order of the array when returning results.
Within each batch, calls are sent simultaneously. The batches
themselves are run sequentially.
This represents a middle ground between running a ton of OpenSRF
calls sequentially -- which leads to a long wait for the user --
and running them simultaneously, which can result in some serious
wait times.
One use case is when you need to get several rows from pcrud,
but the order of results is important and can't be just passed
using orderBy.
To use, you can just replace $q.all with egBatchPromises.all
This also changes the item status refresh code to use
egBatchPromises.all instead of $q.all, in response to some
pcrud-monopolizing noted in
https://bugs.launchpad.net/evergreen/+bug/
1821094/comments/14
Signed-off-by: Jane Sandberg <sandbej@linnbenton.edu>
<script src="[% ctx.media_prefix %]/js/ui/default/staff/services/ui.js"></script>
<script src="[% ctx.media_prefix %]/js/ui/default/staff/services/file.js"></script>
<script src="[% ctx.media_prefix %]/js/ui/default/staff/services/eframe.js"></script>
+<script src="[% ctx.media_prefix %]/js/ui/default/staff/services/batch_promises.js"></script>
<script src="[% ctx.media_prefix %]/js/ui/default/staff/cat/item/app.js"></script>
<script src="[% ctx.media_prefix %]/js/ui/default/staff/cat/services/record.js"></script>
<script src="[% ctx.media_prefix %]/js/ui/default/staff/circ/services/billing.js"></script>
*/
angular.module('egItemStatus',
- ['ngRoute', 'ui.bootstrap', 'egCoreMod', 'egUiMod', 'egGridMod', 'egUserMod'])
+ ['ngRoute', 'ui.bootstrap', 'egCoreMod', 'egUiMod', 'egGridMod', 'egUserMod', 'egBatchPromisesMod'])
.filter('boolText', function(){
return function (v) {
.controller('ListCtrl',
['$scope','$q','$routeParams','$location','$timeout','$window','egCore',
'egGridDataProvider','egItem','egUser','$uibModal','egCirc','egConfirmDialog',
- 'egProgressDialog', 'ngToast',
+ 'egProgressDialog', 'ngToast', 'egBatchPromises',
// function($scope , $q , $routeParams , $location , $timeout , $window , egCore ,
// egGridDataProvider , itemSvc , egUser , $uibModal , egCirc , egConfirmDialog,
// egProgressDialog, ngToast) {
function($scope , $q , $routeParams , $location , $timeout , $window , egCore , egGridDataProvider , itemSvc , egUser , $uibModal , egCirc , egConfirmDialog,
- egProgressDialog, ngToast) {
+ egProgressDialog, ngToast, egBatchPromises) {
var copyId = [];
var cp_list = $routeParams.idList;
if (cp_list) {
progress_bar = $timeout(egProgressDialog.open, 5000, true, {value: 0, max: fetch_list.length});
- $q.all(fetch_list)
+ egBatchPromises.all(fetch_list)
.then( function() {
copyGrid.refresh();
if (progress_bar) $timeout.cancel(progress_bar);
--- /dev/null
+/**
+ * Module for batching promises
+ *
+ * This service helps to reduce server load for repetitive OpenSRF
+ * calls by dividing a large array of promises into batches. It
+ * maintains the original order of the array when returning results.
+ *
+ * Within each batch, calls are sent simultaneously. The batches
+ * themselves are run sequentially.
+ *
+ * This represents a middle ground between running a ton of OpenSRF
+ * calls sequentially -- which leads to a long wait for the user --
+ * and running them simultaneously, which can result in some serious
+ * wait times.
+ *
+ * One use case is when you need to get several rows from pcrud,
+ * but the order of results is important and can't be just passed
+ * using orderBy.
+ *
+ * You can just replace $q.all with egBatchPromises.all
+ */
+
+angular.module('egBatchPromisesMod', [])
+
+.factory('egBatchPromises', ['$q', function($q) {
+
+ var service = {};
+
+ // Helper method to break an array into chunks of a specified size
+ service.createChunks = function(array_to_be_chunked, chunk_size = 10) {
+ var results = [];
+
+ while (array_to_be_chunked.length) {
+ results.push(array_to_be_chunked.splice(0, chunk_size));
+ }
+
+ return results;
+ };
+
+ // Helper method that adds a batch of simultaneous promises to a sequential
+ // chain
+ service.addBatchToChain = function(chain, batch) {
+ return chain.then(() => $q.all(batch));
+ }
+
+ // Returns a chain of chunked promises
+ service.all = function(array_of_promises, chunk_size = 10) {
+ var chunked_array = this.createChunks(array_of_promises, chunk_size);
+ return chunked_array.reduce(this.addBatchToChain, $q.when());
+ };
+
+ return service;
+}]);
+
'services/grid.js',
'services/patron_search.js',
'services/user-bucket.js',
+ 'services/batch_promises.js',
// load app scripts
'app.js',
--- /dev/null
+'use strict';
+
+describe('egBatchPromises', function(){
+ beforeEach(module('egBatchPromisesMod'));
+
+ it('should chunk an array properly', inject(function(egBatchPromises) {
+ var original_array = [1, 2, 3, 4, 5, 6, 7, 8];
+ var expected_array = [[1, 2, 3], [4, 5, 6], [7, 8]];
+ expect(egBatchPromises.createChunks(original_array, 3)).toEqual(expected_array);
+ }));
+
+ it('should add a batch to a promise chain properly', inject(function(egBatchPromises, $q, $rootScope, $timeout) {
+ var resolved_value;
+ var promise_that_shares_its_value = function (value) {
+ return $q.when(value)
+ .then((val) => {resolved_value = val});
+ };
+
+ var promise = promise_that_shares_its_value(1);
+ var batch_to_add = [
+ promise_that_shares_its_value(2),
+ promise_that_shares_its_value(3),
+ promise_that_shares_its_value(4),
+ ];
+
+ var chain = egBatchPromises.addBatchToChain(promise, batch_to_add);
+
+ chain.then();
+ $rootScope.$apply();
+ expect(resolved_value).toEqual(4);
+ }));
+
+});
projects / working / Evergreen.git / commitdiff