how to save list of data in memory? - asp.net-mvc

Question

I have an ajax function which is called by the jquery-datatable and ve two responsibility.
To get data from the database.
To serve the search, sort, pagination like functional work.
Now all I need is I just wanna get data once and save it in memory so that when user type something in the search box it performs the search from stored data directly.
Here the code.
public ActionResult AjaxOil(JQueryDataTableParamModel param)
{
//To get data and should be run only once.
IEnumerable<Oil> allOils = _context.Oils.ToList();
//All others function.
IEnumerable<Oil> filteredOils;
if (!string.IsNullOrEmpty(param.sSearch))
{
filteredOils = allOils
.Where(c => c.CommonName.Contains(param.sSearch)
||
c.BotanicalName.Contains(param.sSearch)
||
c.PlantParts.Contains(param.sSearch)
||
c.Distillation.Contains(param.sSearch));
}
else
{
filteredOils = allOils;
}
var sortColumnIndex = Convert.ToInt32(Request["iSortCol_0"]);
Func<Oil, string> orderingFunction = (c => sortColumnIndex == 1 ? c.CommonName :
sortColumnIndex == 2 ? c.BotanicalName :
c.PlantParts);
var distillationFilter = Convert.ToString(Request["sSearch_4"]);
var commonFilter = Convert.ToString(Request["sSearch_1"]);
var botanicalFilter = Convert.ToString(Request["sSearch_2"]);
var plantFilter = Convert.ToString(Request["sSearch_3"]);
if (!string.IsNullOrEmpty(commonFilter))
{
filteredOils = filteredOils.Where(c => c.CommonName.Contains(commonFilter));
}
if (!string.IsNullOrEmpty(botanicalFilter))
{
filteredOils = filteredOils.Where(c => c.BotanicalName.Contains(botanicalFilter));
}
if (!string.IsNullOrEmpty(plantFilter))
{
filteredOils = filteredOils.Where(c => c.PlantParts.Contains(plantFilter));
}
if (!string.IsNullOrEmpty(distillationFilter))
{
filteredOils = filteredOils.Where(c => c.Distillation.Contains(distillationFilter));
}
var sortDirection = Request["sSortDir_0"];
if (sortDirection == "asc")
filteredOils = filteredOils.OrderBy(orderingFunction);
else
filteredOils = filteredOils.OrderByDescending(orderingFunction);
var displayedOils = filteredOils
.Skip(param.iDisplayStart)
.Take(param.iDisplayLength);
var result = from c in displayedOils
select new[] { Convert.ToString(c.OilId), c.CommonName, c.BotanicalName, c.PlantParts, c.Distillation };
return Json(new
{
sEcho = param.sEcho,
iTotalRecords = allOils.Count(),
iTotalDisplayRecords = filteredOils.Count(),
aaData = result
},
JsonRequestBehavior.AllowGet);

Answer 1

On first load save the data in cache/session/static field. On next search check if the cache/session/static field is not null and read from there, not from db, else take again from db..
Example:
private static ObjectCache _cache = new MemoryCache("MemoryCache");
public List<Oils> GetDataFromCache(string keyName)
{
//private static ObjectCache _cache = new MemoryCache("keyName");
var data = _cache.Get(keyName);
if (data != null) return data as List<Oils>;
data = _context.Oils.ToList();
//keep the cache for 2h
_cache.Add(keyName, data, DateTimeOffset.Now.AddHours(2));
return data;
}
(didn't test the code, but that's the logic) or you can use Session if you prefer
Session example:
if(Session["Data_Oils"] != null) { return Session["Data_Oils"] as List<Oils; } else { var temp = _context.Oils.ToList(); Session["Data_Oils"] = temp; return temp; }