/// <summary>
/// The is cancelled.
/// </summary>
/// <param name="e">
/// The e.
/// </param>
/// <returns>
/// </returns>
private static bool IsCancelled(NotifyScannerStateChangedEventArgs e)
{
lock (SyncRoot)
{
return(currentScan != e.Id);
}
}
/// <summary>
/// The fire scanner state changed.
/// </summary>
/// <param name="dispatcher">
/// The dispatcher.
/// </param>
/// <param name="e">
/// The e.
/// </param>
private static void FireScannerStateChanged(Dispatcher dispatcher, NotifyScannerStateChangedEventArgs e)
{
NotifyScannerStateChangedEventHandler scannerStateChanged;
lock (SyncRoot)
{
if (currentScan != e.Id)
{
return;
}
scannerStateChanged = ScannerStateChanged;
}
if (scannerStateChanged != null)
{
if (dispatcher.CheckAccess())
{
scannerStateChanged(null, e);
}
else
{
dispatcher.Invoke(new Action <Dispatcher, NotifyScannerStateChangedEventArgs>(FireScannerStateChanged), DispatcherPriority.Send, dispatcher, e);
}
}
}
/// <summary>
/// The begin scan.
/// </summary>
/// <param name="client">
/// The client.
/// </param>
/// <param name="namespaceName">
/// The namespace name.
/// </param>
/// <param name="tableName">
/// The table name.
/// </param>
/// <param name="action">
/// The action.
/// </param>
public static void BeginScan(IClient client, string namespaceName, string tableName, Action <IList <Cell> > action)
{
lock (SyncRoot)
{
tasks = tasks.Where(t => !t.IsCompleted).ToList();
}
var dispatcher = Dispatcher.CurrentDispatcher;
var beginScan = Task.Factory.StartNew(
() =>
{
using (var ns = client.OpenNamespace(namespaceName))
using (var table = ns.OpenTable(tableName))
{
var notify = new NotifyScannerStateChangedEventArgs();
lock (SyncRoot)
{
currentScan = notify.Id;
}
FireScannerStateChanged(dispatcher, notify);
if (client.Context.HasFeature(ContextFeature.AsyncTableScanner))
{
using (var asyncResult = new AsyncResult(
(asyncScannerContext, cells) =>
{
if (!IsCancelled(notify))
{
FireScannerStateChanged(dispatcher, notify.Executing(cells));
action(cells);
return(AsyncCallbackResult.Continue);
}
return(AsyncCallbackResult.Abort);
}))
{
table.BeginScan(asyncResult);
asyncResult.Join();
}
}
else
{
using (var scanner = table.CreateScanner())
using (var bc = new BlockingCollection <List <Cell> >())
{
var task = Task.Factory.StartNew(
() =>
{
try
{
while (!IsCancelled(notify))
{
var cells = bc.Take();
FireScannerStateChanged(dispatcher, notify.Executing(cells));
action(cells);
}
}
catch (InvalidOperationException)
{
}
});
const int ChunkSize = 2500;
var chunk = new List <Cell>(ChunkSize);
Cell cell;
for (var c = 1; !IsCancelled(notify) && scanner.Next(out cell); ++c)
{
chunk.Add(cell);
if ((c % chunk.Capacity) == 0)
{
bc.Add(chunk);
chunk = new List <Cell>(ChunkSize);
}
}
if (!IsCancelled(notify) && chunk.Count > 0)
{
bc.Add(chunk);
}
bc.CompleteAdding();
task.Wait();
}
}
FireScannerStateChanged(dispatcher, notify.Completed());
}
});
lock (SyncRoot)
{
tasks.Add(beginScan);
}
}
/// <summary>
/// The is cancelled.
/// </summary>
/// <param name="e">
/// The e.
/// </param>
/// <returns>
/// </returns>
private static bool IsCancelled(NotifyScannerStateChangedEventArgs e)
{
lock (SyncRoot)
{
return currentScan != e.Id;
}
}
/// <summary>
/// The fire scanner state changed.
/// </summary>
/// <param name="dispatcher">
/// The dispatcher.
/// </param>
/// <param name="e">
/// The e.
/// </param>
private static void FireScannerStateChanged(Dispatcher dispatcher, NotifyScannerStateChangedEventArgs e)
{
NotifyScannerStateChangedEventHandler scannerStateChanged;
lock (SyncRoot)
{
if (currentScan != e.Id)
{
return;
}
scannerStateChanged = ScannerStateChanged;
}
if (scannerStateChanged != null)
{
if (dispatcher.CheckAccess())
{
scannerStateChanged(null, e);
}
else
{
dispatcher.Invoke(new Action<Dispatcher, NotifyScannerStateChangedEventArgs>(FireScannerStateChanged), DispatcherPriority.Send, dispatcher, e);
}
}
}
/// <summary>
/// The begin scan.
/// </summary>
/// <param name="client">
/// The client.
/// </param>
/// <param name="namespaceName">
/// The namespace name.
/// </param>
/// <param name="tableName">
/// The table name.
/// </param>
/// <param name="action">
/// The action.
/// </param>
public static void BeginScan(IClient client, string namespaceName, string tableName, Action<IList<Cell>> action)
{
lock (SyncRoot)
{
tasks = tasks.Where(t => !t.IsCompleted).ToList();
}
var dispatcher = Dispatcher.CurrentDispatcher;
var beginScan = Task.Factory.StartNew(
() =>
{
using (var ns = client.OpenNamespace(namespaceName))
using (var table = ns.OpenTable(tableName))
{
var notify = new NotifyScannerStateChangedEventArgs();
lock (SyncRoot)
{
currentScan = notify.Id;
}
FireScannerStateChanged(dispatcher, notify);
if (client.Context.HasFeature(ContextFeature.AsyncTableScanner))
{
using (var asyncResult = new AsyncResult(
(asyncScannerContext, cells) =>
{
if (!IsCancelled(notify))
{
FireScannerStateChanged(dispatcher, notify.Executing(cells));
action(cells);
return AsyncCallbackResult.Continue;
}
return AsyncCallbackResult.Abort;
}))
{
table.BeginScan(asyncResult);
asyncResult.Join();
}
}
else
{
using (var scanner = table.CreateScanner())
using (var bc = new BlockingCollection<List<Cell>>())
{
var task = Task.Factory.StartNew(
() =>
{
try
{
while (!IsCancelled(notify))
{
var cells = bc.Take();
FireScannerStateChanged(dispatcher, notify.Executing(cells));
action(cells);
}
}
catch (InvalidOperationException)
{
}
});
const int ChunkSize = 2500;
var chunk = new List<Cell>(ChunkSize);
Cell cell;
for (var c = 1; !IsCancelled(notify) && scanner.Next(out cell); ++c)
{
chunk.Add(cell);
if ((c % chunk.Capacity) == 0)
{
bc.Add(chunk);
chunk = new List<Cell>(ChunkSize);
}
}
if (!IsCancelled(notify) && chunk.Count > 0)
{
bc.Add(chunk);
}
bc.CompleteAdding();
task.Wait();
}
}
FireScannerStateChanged(dispatcher, notify.Completed());
}
});
lock (SyncRoot)
{
tasks.Add(beginScan);
}
}
