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//------------------------------------------------------------------------------
// <copyright file="SmiEventSink_DeferedProcessing.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------
namespace Microsoft.SqlServer.Server {
using System.Data.Sql;
using System.Data.SqlClient;
using System.Diagnostics;
// This class exists purely to defer processing of messages until a later time.
// It is designed to allow calling common code that interacts with the SMI layers
// without throwing or otherwise processing messages in the sink until later on.
//
// Main example:
// SqlCommand.ExecuteNonQuerySmi calls EventStream.ProcessEvent with it's command event sink (CES)
// ProcessEvent calls OnParametersAvailable on the CES
// OnParametersAvailable sets up a deferedprocessing event sink (DPES) with the CES as its parent
// OnParametersAvailable calls ValueUtils to extract param values passing the DPES
// ValueUtils calls Smi passing DPES
// Smi may call MessagePosted, which will send a message up the sink parent chain and save it.
// ValueUtils calls ProcessMessagesAndThrow on DPES, which skips handling
// ... return up the stack ...
// SqlCommand.ExecuteNonQuerySmi calls CES.ProcessMessagesAndThrow, which handles the messages
// sent from the Smi value extraction code.
//
// IMPORTANT: Code that uses the DeferedProccess event sink is responsible for ensuring that
// these messages ARE processed at some point.
internal class SmiEventSink_DeferedProcessing : SmiEventSink_Default {
internal SmiEventSink_DeferedProcessing ( SmiEventSink parent ) : base(parent) {
}
protected override void DispatchMessages(bool ignoreNonFatalMessages) {
// Skip processing messages. Since messages are sent to parent and calling code will call
// ProcessMessages against parent, messages ARE NOT LOST!
}
}
}
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