public void TestPagingTechniques()
{
const bool debugRequests = true;
// loads/saves a very large number of objects
const int maxLoopCount = 5;
const int itemsPerLoop = 400;
const int itemsPerPage = 154;
const int totalItems = maxLoopCount * itemsPerLoop;
using (Reference <ILogger> loggerRef = Reference <ILogger> .Create(new TraceLogger(true)))
{
NamedValueSet serverSettings = new NamedValueSet();
serverSettings.Set(CfgPropName.NodeType, (int)NodeType.Router);
serverSettings.Set(CfgPropName.EnvName, "UTT");
using (CoreServer server = new CoreServer(loggerRef, serverSettings))
{
server.Start();
// save
using (ICoreClient client1 = new CoreClientFactory(loggerRef).SetEnv("UTT").Create())
{
for (int loop = 0; loop < maxLoopCount; loop++)
{
ICoreItem[] items = new ICoreItem[itemsPerLoop];
for (int i = 0; i < itemsPerLoop; i++)
{
client1.DebugRequests = i == 0;
int n = loop * itemsPerLoop + i;
TestData data = new TestData(n.ToString(), n);
NamedValueSet props = new NamedValueSet(new NamedValue("n", n));
items[i] = client1.MakeObject(data, "Test." + n, props);
}
client1.SaveItems(items);
}
}
// load (using original paging technique)
loggerRef.Target.LogDebug("---------- multi page load");
// - slow because it scans and sort the entire data set for each page
using (ICoreClient client3 = new CoreClientFactory(loggerRef).SetEnv("UTT").Create())
{
// count the items
int itemCount1 = client3.CountObjects <TestData>(null);
// now get the items in pages
IExpression orderExpr = Expr.Prop("n");
client3.DebugRequests = debugRequests;
int itemCount2 = 0;
int startRow = 0;
List <ICoreItem> page;
do
{
page = client3.LoadItems <TestData>(null, orderExpr, startRow, itemsPerPage);
itemCount2 += page.Count;
startRow += page.Count;
}while (page.Count == itemsPerPage);
Assert.AreEqual(totalItems, itemCount1);
Assert.AreEqual(totalItems, itemCount2);
}
// paged load (using pre-load of item header info)
loggerRef.Target.LogDebug("---------- header pre-load");
// - faster because it only scans sorts the entire data set once and sorting
// can use local compiled methods instead of server-side expression evaluation.
using (ICoreClient client4 = new CoreClientFactory(loggerRef).SetEnv("UTT").Create())
{
// get all the items (without data)
List <ICoreItemInfo> itemInfoList = client4.LoadItemInfos <TestData>(null);
int itemCount1 = itemInfoList.Count;
// optionally sort the list here
//IExpression orderExpr = Expr.Prop("n");
// now get the items in pages
client4.DebugRequests = debugRequests;
int itemCount2 = 0;
int maxPages = ((itemCount1 / itemsPerPage) + 1);
for (int pageNum = 0; pageNum < maxPages; pageNum++)
{
// get the item names/ids for the current page
int startRow = itemsPerPage * pageNum;
List <string> itemNames = new List <string>();
for (int i = 0; i < itemsPerPage; i++)
{
int n = startRow + i;
if (n < itemCount1)
{
itemNames.Add(itemInfoList[n].Name);
}
}
// now get the objects (with data)
var page = client4.LoadItems <TestData>(itemNames);
itemCount2 += page.Count;
}
Assert.AreEqual(totalItems, itemCount1);
Assert.AreEqual(totalItems, itemCount2);
}
}
}
}
