/// <summary>
/// Throw if requests are greater than maximum allowed
/// </summary>
private void ThrowIfExceeded()
{
if (AdoPersistenceService.GetConfiguration().MaxRequests == 0 ||
Interlocked.Read(ref m_currentRequests) < AdoPersistenceService.GetConfiguration().MaxRequests)
{
Interlocked.Increment(ref m_currentRequests);
}
else
{
throw new LimitExceededException("Data layer restricted maximum system requests");
}
}
/// <summary>
/// Instructs the service
/// </summary>
protected virtual IEnumerable <TData> QueryInternal(Expression <Func <TData, bool> > query, Guid queryId, int offset, int?count, IPrincipal authContext, out int totalCount, bool fastQuery)
{
if (query == null)
{
throw new ArgumentNullException(nameof(query));
}
#if DEBUG
Stopwatch sw = new Stopwatch();
sw.Start();
#endif
PreQueryEventArgs <TData> preArgs = new PreQueryEventArgs <TData>(query, authContext);
this.Querying?.Invoke(this, preArgs);
if (preArgs.Cancel)
{
this.m_tracer.TraceEvent(TraceEventType.Warning, 0, "Pre-Event handler indicates abort query {0}", query);
totalCount = 0;
return(null);
}
// Query object
using (var connection = m_configuration.Provider.GetReadonlyConnection())
try
{
this.ThrowIfExceeded();
connection.Open();
this.m_tracer.TraceEvent(TraceEventType.Verbose, 0, "QUERY {0}", query);
// Is there an obsoletion item already specified?
if ((count ?? 1000) > 25 && AdoPersistenceService.GetConfiguration().PrepareStatements)
{
connection.PrepareStatements = true;
}
if (fastQuery)
{
connection.AddData("loadFast", true);
connection.LoadState = LoadState.PartialLoad;
}
else
{
connection.LoadState = LoadState.FullLoad;
}
var results = this.Query(connection, query, queryId, offset, count ?? 1000, out totalCount, true, authContext);
var postData = new PostQueryEventArgs <TData>(query, results.AsQueryable(), authContext);
this.Queried?.Invoke(this, postData);
var retVal = postData.Results.ToList();
// Add to cache
foreach (var i in retVal.AsParallel().Where(i => i != null))
{
connection.AddCacheCommit(i);
}
ApplicationContext.Current.GetService <IThreadPoolService>()?.QueueUserWorkItem(o =>
{
foreach (var itm in (o as IEnumerable <IdentifiedData>))
{
ApplicationContext.Current.GetService <IDataCachingService>()?.Add(itm);
}
}, connection.CacheOnCommit.ToList());
this.m_tracer.TraceEvent(TraceEventType.Verbose, 0, "Returning {0}..{1} or {2} results", offset, offset + (count ?? 1000), totalCount);
return(retVal);
}
catch (NotSupportedException e)
{
throw new DataPersistenceException("Cannot perform LINQ query", e);
}
catch (Exception e)
{
this.m_tracer.TraceEvent(TraceEventType.Error, 0, "Error : {0}", e);
throw;
}
finally
{
#if DEBUG
sw.Stop();
this.m_tracer.TraceEvent(TraceEventType.Verbose, 0, "Query {0} took {1} ms", query, sw.ElapsedMilliseconds);
#endif
Interlocked.Decrement(ref m_currentRequests);
}
}