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authorRoland Reichwein <mail@reichwein.it>2022-11-27 14:58:40 +0100
committerRoland Reichwein <mail@reichwein.it>2022-11-27 14:58:40 +0100
commit0ae30508da3b8902c78b07760e51f92bf9783d31 (patch)
tree6f8c2dc09c89818c0a86b47e9920041f092faaa0 /html
parent7619dc0bef58d00c816b6628e457a85845b9edee (diff)
Dynamic reload times to limit server load
Diffstat (limited to 'html')
-rw-r--r--html/whiteboard.js68
1 files changed, 67 insertions, 1 deletions
diff --git a/html/whiteboard.js b/html/whiteboard.js
index 9018f92..d9f0904 100644
--- a/html/whiteboard.js
+++ b/html/whiteboard.js
@@ -3,6 +3,65 @@ function init() {
init_board();
}
+class AdjustingTimer {
+ constructor() {
+ this.update_counter = 0; // counting seconds since last counter reset
+ }
+
+ fast_mode() {
+ if (this.update_counter < 5*60)
+ return true;
+ return false;
+ }
+
+ // private method
+ // returns current interval in ms
+ current_update_interval()
+ {
+ if (this.fast_mode())
+ return 2000; // 2s
+ else
+ return 5 * 60000; // 5min
+ };
+
+ // private
+ count() {
+ this.update_counter += this.current_update_interval() / 1000;
+ };
+
+ // private
+ on_timeout() {
+ this.m_fn();
+ this.count();
+ var _this = this;
+ this.update_timer = setTimeout(function(){_this.on_timeout();}, this.current_update_interval());
+ };
+
+ // to be called once on startup
+ start(fn) {
+ this.m_fn = fn;
+ var _this = this;
+ this.update_timer = setTimeout(function(){_this.on_timeout();}, this.current_update_interval());
+ };
+
+ // to be called on activity:
+ // * changes from remote
+ // * changes by ourselves
+ // * local activity, e.g. mouse move, or key presses
+ reset() {
+ if (!this.fast_mode()) {
+ this.update_counter = 0;
+ clearTimeout(this.update_timer);
+ var _this = this;
+ this.update_timer = setTimeout(function(){_this.on_timeout();}, this.current_update_interval());
+ } else {
+ this.update_counter = 0;
+ }
+ };
+}
+
+var timer = new AdjustingTimer();
+
function init_board() {
var xhr = new XMLHttpRequest();
@@ -35,7 +94,10 @@ function init_board() {
// Initialization done. Now we can start modifying.
board.addEventListener("input", function() {on_modify(); });
- setInterval(function() {checkupdate();}, 2000);
+ // Initialization done. Now we can start modifying.
+ document.addEventListener("mousemove", function() {timer.reset(); });
+
+ timer.start(checkupdate);
}
reader.readAsBinaryString(file);
@@ -121,8 +183,11 @@ function redirect_to_new_page()
//set_status("Please wait while server prepares " + filename + " ...");
}
+// local change done
function on_modify()
{
+ timer.reset();
+
var xhr = new XMLHttpRequest();
// run on data received back
@@ -196,6 +261,7 @@ function checkupdate() {
// no change if response is text/plain
if (this.getResponseHeader("Content-Type") == "application/octet-stream") {
+ timer.reset();
var file = new Blob([this.response]);
reader = new FileReader();
reader.onload = function() {