added option to set request size limit

content/js/streamdownload.js

@@ -4,6 +4,8 @@
 var towerMet;
 var buoyMet;
 var multilevel_streams = new Object();
+var MAX_DATA = 15000;
+
 var show_multistream_panel = function(streams){
     var curr_selected = $('#multi_streams').val();
     $('#multi_streams').empty();
@@ -152,16 +154,22 @@ var getTimeRange = function(){
     //Check that both a time is selected and that it matches a valid date
     var time_query = false;
     var error = false;
+    var time_span = 0;
     if($("#last_x_days").is(":checked")){
-        if(/^[0-9]+$/.test(val_or_place('#x_days')))
+        if(/^[0-9]+$/.test(val_or_place('#x_days'))){
             time_query = '&begin=-'+24*Number(val_or_place('#x_days'))+':00:00';
+            time_span =60*60*24*Number(val_or_place('#x_days')); 
+        }
     }else if ($("#date_range").is(":checked")){
         time_query = make_date_range_query();
+        if(time_query){
+            time_span = -(moment($('#Start-date-picker').val())-moment($('#End-date-picker').val()))/1000;
+        }
     } 
     if(!time_query)
         error = "#time_err";
 
-    return {error:error,query:time_query};
+    return {error:error,query:time_query,time_span:time_span};
 
 };
 
@@ -175,7 +183,7 @@ var buildRequestUrl = function(format,interval,epoch,sep,order,time,streams){
     request_url+='&symbols='+streams;
     return request_url;
 }
-function findFormErrors(){
+function findFormErrors(checkNPoints){
     $(".err_msg").hide();
     $("select").removeClass("alert-danger");
     var errors = [];
@@ -204,6 +212,21 @@ function findFormErrors(){
 
     if(timeRangeInfo.error)
         errors.push(timeRangeInfo.error);
+    else if(checkNPoints){
+        var span = timeRangeInfo.time_span;
+        var nStreams = getSelectedStreams().split(':').length;
+        var interval = $('#interval').val();
+        interval = {'m':60,'h':60*60,'d':60*60*24}[_.last(interval)]*
+            Number(_.initial(interval).join(''));
+        var npoints = span*nStreams/interval;
+        console.log(span,nStreams,interval,npoints);
+        if(npoints>MAX_DATA){
+            errors.push('#interval_err');
+            $('#max_points').html(MAX_DATA);
+            $('#too_many_points').html(npoints);
+        }
+
+    }
     
     if(errors.length >0){
         _.each(errors,function(error){
@@ -220,7 +243,7 @@ function findFormErrors(){
  * Read the values of the various inputs on the page and formulate an API request
  */
 var submitForm = function(){
-    if(!findFormErrors()){
+    if(!findFormErrors(true)){
         var format = $('#format').val().toLowerCase();
         var time_query = getTimeRange().query;
         var streams=getSelectedStreams();

content/pages/streamdownload.html

@@ -59,11 +59,14 @@
             <div class="col-sm-4">
                 <h4>Interval</h4>
             </div>
-            <div id="interval_err" class="col-xs-8 text-right err_msg" style="margin-top:10px;display: none;">
-                <span class="alert alert-danger" style="padding:0 1em">&#9888; Too many data points requested. Use a larger interval.
+            <div class="col-xs-8">
+                <div id="interval_err" class="text-right err_msg" style="margin-top:10px;display: none;">
+                    <span class="alert alert-danger" style="padding:0 1em">&#9888; Too many data points requested. 
+                        (Max:<span id='max_points'></span>, Requested: <span id='too_many_points'></span>)
                     </span>
                 </div>
             </div>
+        </div>
         <div class="row" style='padding: 0 1em;'>
             <div class="col-xs-12">
                 <div class="form-group">