--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Symbian3/PDK/Source/GUID-2B902EA0-F954-5474-9A79-7C1AB208A3D4.dita	Fri Jul 16 17:23:46 2010 +0100
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+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
+<!-- This component and the accompanying materials are made available under the terms of the License 
+"Eclipse Public License v1.0" which accompanies this distribution, 
+and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
+<!-- Initial Contributors:
+    Nokia Corporation - initial contribution.
+Contributors: 
+-->
+<!DOCTYPE concept
+  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="GUID-2B902EA0-F954-5474-9A79-7C1AB208A3D4" xml:lang="en"><title>STS Overview</title><prolog><metadata><keywords/></metadata></prolog><conbody>
+<section id="GUID-39064646-3244-42E9-962C-D5F98F61BF95"><title>Purpose</title> <p>STS provides transactional support for the Symbian platform file
+system. It helps clients (such as Software Installation Framework
+plug-ins) to maintain file system integrity during installation, uninstallation
+and upgrading of software packages. If the file system operation is
+interrupted or fails for reasons such as battery drain or a server
+crash, the STS rolls back the uncommitted file system operations performed
+as part of the transaction. </p> </section>
+<section id="GUID-9B55BDF8-9CE6-4F34-BAC7-54C215A0CD93"><title>Key
+concepts</title> <p> <b>SIF Plug-in</b>: Installs and manages a particular type of software package such as native SIS files
+or Python.</p> <p> <b>Symbian client-server framework</b>: For details,
+see <xref href="GUID-6047DB3F-DC92-51DF-9EEB-00E79E890B54.dita">Using Client/Server</xref>. </p> </section>
+<section id="GUID-992C35A4-D792-41C6-8499-E9E152916537"><title>Architectural
+relationships</title> <p>STS follows client-server architecture. The
+STS (server) has TCB capability. A STS client ( implemented by device
+creators) uses STS instead of using the file server directly. STS
+provides APIs to start a file system transaction, record various file
+system operation as part of a transaction, and commit or roll back
+the transaction. The STS client instructs the STS to commit a transaction
+atomically once all the operations have been performed.  </p><p>The
+STS client is implemented in <filepath>stsclient.dll</filepath> file. </p><p>An STS client application can access the services provided by
+the STS by linking against <filepath>stsclient.lib</filepath>. </p> <p>The figure below shows interaction between the STS, STS clients
+and the file system. </p><fig id="GUID-DC02F027-800F-4A54-864D-D746447C2EEE">
+<title>STS Architecture</title>
+<image href="GUID-9B2E8332-380E-4C7C-80BE-A858A8EE62C2_d0e42446_href.jpg" placement="inline"/>
+</fig> </section>
+<section id="GUID-78CB2DC4-5D5B-4207-838B-9D378CBF7A67"><title>APIs</title> <table id="GUID-A86AFA4C-6AAD-5DAF-923E-7750370349B5">
+<tgroup cols="2"><colspec colname="col0"/><colspec colname="col1"/>
+<thead>
+<row>
+<entry>API</entry>
+<entry>Description</entry>
+</row>
+</thead>
+<tbody>
+<row>
+<entry><p> <xref href="GUID-8ACAC5C6-1EDD-3EEB-995B-53833BEACF25.dita"><apiname>RStsSession</apiname></xref>  </p> </entry>
+<entry><p>Provides APIs for STS client applications to use the STS. </p> </entry>
+</row>
+</tbody>
+</tgroup>
+</table> </section>
+<section id="GUID-753B9DB3-5487-4B39-8515-E975218E3C0B"><title>Typical
+uses</title> <p>Software installers use the STS to provide a secure
+environment for updating the file system.</p> </section>
+</conbody></concept>
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