c# - Performance issuses with nested foreach loops -

i don't know if issue i'm facing due nested loops or due else (bad code, large data). let me explain, hope can helps me figure out:-

i'm working on windows phone 8 app. on launch app makes 3 httpclient calls 3 different pages, converts each response (which html) xml json data(obs!!! works fine , no problems this). @ stage want extract data 3 json , combine extracted data new json saved isolatedstorage later. extraction used multiple foreach loops , linq (here think problem). each foreach loop might between 50 , >500 iterations. extraction process takes 2 mins, think much. below can see code snippet code:-

public async task loaddata()     {          //baseuri definition....          await cookiehandler.getcookies(baseuri);          _reqplist=new requestresponse();          await _reqplist.getresponse(baseuri, plist);  // first page request         xmlconvertor.converttoxml(_reqplist.response);  //first page convert xml         var phonelistresponse = xmlconvertor.xmlstring;          //second , third page request , convert xml          var handler = new datahandler();         await handler.phonelisthandler(phonelistresponse);  //first page convert json         //second , third page convert json          var jobject = jobject.parse(handler.phonelistjson);         var jcollection = jobject["tbody"]["tr"].children();          //the start of extracting data          using (var stream = new memorystream())         using (var streamwriter=new streamwriter(stream))         using (_jsonw = new jsontextwriter(streamwriter))         {                 var watch = stopwatch.startnew();             _jsonw.writestartarray();             foreach (var item in jcollection)  //first foreach loop (100 iteration) using first page             {                 var arr = item.value<jarray>("td");                 if (arr == null) continue;                 _jsonw.formatting = formatting.indented;                 _jsonw.writestartobject();                 _jsonw.writepropertyname("name");                 _jsonw.writevalue(arr[0].value<string>());                 #region info array                 _jsonw.writepropertyname("info");                 _jsonw.writestartarray();                  // extraction                  _jsonw.writeendarray();                 #endregion                 #region schedule array                 await schedulearrayasync(item, handler.schedulejson, handler); // method extract data 2nd page                 #endregion                 #region current activity                 curractivityasync(item, handler.curractivitiesjson); // method extract data 3rd page                 #endregion                 _jsonw.writeendobject();             }             _jsonw.writeendarray();                 watch.stop();                 var j = watch.elapsedmilliseconds;              await streamwriter.flushasync();             stream.position = 0;             using (var streamreader=new streamreader(stream))             {                 var json = await streamreader.readtoendasync();             }         }         this.isdataloaded = true;     }      private void curractivityasync(jtoken token, string jstring) method called 1 time     {         var arr = token.value<jarray>("td");         var personnamearray = arr[0].value<string>().split(',');         if (!_owner.contains(personnamearray[0])) return;         var jobject = jobject.parse(jstring);         var jcollection = jobject["tbody"]["tr"].children();          _jsonw.writepropertyname("current activity");         _jsonw.writestartarray();          foreach (var array in item in jcollection   // second foreach loop (almost 60 iteration)             let array = item.value<jobject>().value<jarray>("td")             array != null && item.children().count() > 1             select array)         {             _jsonw.writestartobject();              // extraction               _jsonw.writeendobject();         }         _jsonw.writeendarray();     }      private async task schedulearrayasync(jtoken token, string jstring, datahandler handler)  // method called 100 times.     {         var arr = token.value<jarray>("td");         var personnamearray = arr[0].value<string>().split(',');         var jobject = jobject.parse(jstring);         var trlist = jobject["tbody"]["tr"];         var selectedarray = default(jarray);         var weeknumber = trlist.selectmany(tr => tr.selecttokens("td[1].table.tbody.tr", false))             .selectmany(lk => lk.selecttokens("td", false))             .where(j => (!j.hasvalues) && (j.value<string>().contains("v")))             .select(lo => lo.value<string>())             .toarray();          var pstypeone = trlist.selectmany(tr => tr.selecttokens("td[0].a.#text", false))             .where(hashtext => (hashtext.value<string>().contains(personnamearray[0])) &&                          (hashtext.value<string>().contains(personnamearray[1])))             .select(td => td.parent.parent.parent.parent.parent)             .toarray();           if (pstypeone != null)         {             _jsonw.writepropertyname("schedule");             _jsonw.writestartarray();             _jsonw.writestartobject();             _jsonw.writepropertyname("week number");             _jsonw.writevalue(weeknumber[0].remove(0, 2));             _jsonw.writepropertyname("week days");             _jsonw.writestartarray();              foreach (var day in selectedarray) // 7 itereation             {                 if (day.selecttoken("table", false) == null) continue;                 _jsonw.writestartobject();                 _jsonw.writepropertyname("day name");                 var dayname = convert.todatetime(day.value<string>("@id").remove(0, 8));                 _jsonw.writevalue(dayname.dayofweek.tostring());                 _jsonw.writepropertyname("date");                 _jsonw.writevalue(day.value<string>("@id").remove(0, 8));                 var assignments = day.selecttoken("table.tbody.tr", false);                 _jsonw.writepropertyname("assignments");                 _jsonw.writestartarray();                  //foreach loop 2 start or foreach                 foreach (var assignment in assignments) // between 1 , 5 iterations                 {                     //some extractions                          if (info[0].contains("slotinfo")) //here new webrequests , extractions                         {                             await _reqplist.getslotinfopost(info[1]);                             xmlconvertor.converttoxml(_reqplist.response);                             addedinfo = xmlconvertor.xmlstring;                             await handler.infohandler(addedinfo);                             var jo = jobject.parse(handler.infojson);                             addedjtoken = jo.selecttoken("td");                              // extractions                          }                     }                     else                     {                         // code                     }                 }                 //foreach loop 2 end                 //some code close array             }             //foreach loop 1 end             //some code close array         }     } 

now considering iterations , method calls, can optimize code processing faster less 2 mins?

edit:-

let me give more info pages parsed in begining of code. first of pages belong online schedule site use @ work. don't have api work with. why need parse httpclient htmlresponse , convert xml json.

second each of pages have complex structure combind bad naming. please @ below:-

<tr class="odd"> <td class="user" onmouseover="userinfo('469');" onmouseout="userinfo(0);" onmousemove="moveslotinfo();"> user one</td> // user 1 needed <td id="day-469-2014-03-31" style="vertical-align: top;">   <table class="ss" cellspacing="1">     <tbody>       <tr>         <td class="as"> </td>       </tr>     </tbody>   </table> </td> <td id="day-469-2014-04-01" style="vertical-align: top;">   // date needed   <table class="ss" cellspacing="1">     <tbody>       <tr>         <td class="as" style="color: #ffffff; background-color: #4040ff;" onmouseover="this.classname=(document.week_vs_doctor.activityid.value==-1?'sd':'sp');slotinfo('177738',false);" onmouseout="this.classname='as';slotinfo(0,false);" onmousemove="moveslotinfo();">kavaul</td>  // kavaul needed       </tr>     </tbody>   </table> </td> 

obs!!! demo code make point (i know not functional).

even when convert json still in need adjuctment why decided rewrite json according needs. take @ code snippet shows how need it.

[ { "name": "user name", "info": [   {     "signature": "un"   },   {     "group": "group1"   },   {     "e-mail": "user.name@group1.com"   } ], "schedule": [   {     "week number": "14",     "week days": [       {         "day name": "monday",         "date": "2014-03-31",         "assignments": [           {             "assignment name": "aaa",             "assignment time": "07:30 - 16:00",             "assignment provider": "bbb, 2014-03-07 16:42"           } 

obs!!! know json data needs closing, make point.

i think more simple using htmlagility pack traverse html httprequest response.

a custom class represent you're final object serializable attribute , when class has been filled call javascript serializer serialize json object(you may use json converter online convert json in custom class can deserialize json custom object without issues , viceversa).

also there's importan thing: data dimension. if you're working few data more faster if work large data require more time have response , more time processed.

may tell page involded , final json object???