Parallelise the history JSON loads for faster initial load times.

As a by-product, for my test server using http/2 this halved the load time against the same code using http/1.1.
This commit is contained in:
Steven Davies 2017-07-29 17:52:24 +01:00
parent fbb87b909f
commit 74c9cb564c

View file

@ -328,24 +328,20 @@ function initialize() {
var CurrentHistoryFetch = null;
var PositionHistoryBuffer = []
var HistoryItemsReturned = 0;
function start_load_history() {
if (PositionHistorySize > 0 && window.location.hash != '#nohistory') {
$("#loader_progress").attr('max',PositionHistorySize);
console.log("Starting to load history (" + PositionHistorySize + " items)");
load_history_item(0);
} else {
end_load_history();
//Load history items in parallel
for (var i = 0; i < PositionHistorySize; i++) {
load_history_item(i);
}
}
}
function load_history_item(i) {
if (i >= PositionHistorySize) {
end_load_history();
return;
}
console.log("Loading history #" + i);
$("#loader_progress").attr('value',i);
$.ajax({ url: 'data/history_' + i + '.json',
timeout: 5000,
@ -354,12 +350,19 @@ function load_history_item(i) {
.done(function(data) {
PositionHistoryBuffer.push(data);
load_history_item(i+1);
HistoryItemsReturned++;
$("#loader_progress").attr('value',HistoryItemsReturned);
if (HistoryItemsReturned == PositionHistorySize) {
end_load_history();
}
})
.fail(function(jqxhr, status, error) {
// No more history
end_load_history();
//Doesn't matter if it failed, we'll just be missing a data point
HistoryItemsReturned++;
if (HistoryItemsReturned == PositionHistorySize) {
end_load_history();
}
});
}
@ -378,7 +381,7 @@ function end_load_history() {
// Process history
for (var h = 0; h < PositionHistoryBuffer.length; ++h) {
now = PositionHistoryBuffer[h].now;
console.log("Applying history " + h + "/" + PositionHistoryBuffer.length + " at: " + now);
console.log("Applying history " + h + 1 + "/" + PositionHistoryBuffer.length + " at: " + now);
processReceiverUpdate(PositionHistoryBuffer[h]);
// update track