1 <?xml version="1.0" encoding="utf-8"?>

     2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->

     3 <!-- This component and the accompanying materials are made available under the terms of the License 

     4 "Eclipse Public License v1.0" which accompanies this distribution, 

     5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->

     6 <!-- Initial Contributors:

     7     Nokia Corporation - initial contribution.

     8 Contributors: 

     9 -->

    10 <!DOCTYPE task

    11   PUBLIC "-//OASIS//DTD DITA Task//EN" "task.dtd">

    12 <task id="GUID-B31D30BF-9D55-5215-9D34-DD619D4E4D47" xml:lang="en"><title>Unlocking

    13 a Large File </title><shortdesc>How to unlock a section of a large file. </shortdesc><prolog><metadata><keywords/></metadata></prolog><taskbody>

    14 <context id="GUID-641B66B8-24DE-48F0-BA92-85B8551D4A0C"><p> <xref href="GUID-83A415A0-F417-3CA5-BA10-5AEF119AB1F7.dita#GUID-83A415A0-F417-3CA5-BA10-5AEF119AB1F7/GUID-5955E095-D4DB-34CE-8254-D6B5C9BFC05B"><apiname>RFile64::Unlock()</apiname></xref> allows a section of data

    15 within a file to be unlocked. This function uses 64-bit <xref href="GUID-AAE85115-A8AA-3F6C-BA8C-69F5A23B0D90.dita"><apiname>TInt64</apiname></xref> variables

    16 rather than 32-bit <xref href="GUID-7A2A43EC-6125-3BFE-834B-23C37F7B40D5.dita"><apiname>TInt</apiname></xref> variables. The area to unlock within

    17 a file is specified by the starting position and length of the area. Using

    18 a 64-bit variable rather than a 32-bit variable allows the specified position

    19 and length of the section to be greater than 2GB-1. </p> </context>

    20 <steps id="GUID-217627C2-06FF-5EF2-9DFE-D145FD901B36">

    21 <step id="GUID-32016E81-8E90-5A98-A116-43FED2AAE9B4"><cmd>Use the 64-bit <xref href="GUID-83A415A0-F417-3CA5-BA10-5AEF119AB1F7.dita"><apiname>RFile64</apiname></xref> class

    22 instead of the 32-bit <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita"><apiname>RFile</apiname></xref> class. </cmd>

    23 <stepxmp><codeblock id="GUID-0201BA15-B253-52E1-9B15-C4D0F5C5024B" xml:space="preserve">//RFile file;

    24 RFile64 file;</codeblock> </stepxmp>

    25 </step>

    26 <step id="GUID-A7ADFF86-86B9-5C79-B0CD-D6DA0B502279"><cmd>Use a <xref href="GUID-AAE85115-A8AA-3F6C-BA8C-69F5A23B0D90.dita"><apiname>TInt64</apiname></xref> variable

    27 to specify the position and length of the file to unlock. </cmd>

    28 <stepxmp><codeblock id="GUID-56183384-E96D-5A02-82A4-C6AAA056ACB2" xml:space="preserve">TInt r;

    29 // TInt lockPosition, lockLength;

    30 TInt64 lockPosition, lockLength;

    31 ...

    32 r = file.UnLock(lockPosition, lockLength);</codeblock> </stepxmp>

    33 </step>

    34 </steps>

    35 <example><title>Unlock example</title><codeblock id="GUID-F1AEB6D8-12F2-5302-9DBF-60C31FABD72F" xml:space="preserve">    // Replace RFile with RFile64

    36     RFile64 file;

    37     TInt err = file.Open(TheFs, _L(“BIGFILE.BIG”), EFileWrite);

    38     if(err != KErrNone)

    39         {

    40         // handle unrelated error

    41         return err;

    42         }

    43 

    44     // Change the TInt type to TInt64

    45     TInt64 lockPosition, lockLength;

    46     err = file.UnLock(lockPosition,lockLength);

    47     if(err != KErrNone)

    48         {

    49         //could return with KErrArgument if lockPosition + lockLength > 63Bytes   

    50         return err;

    51         }</codeblock> </example>

    52 </taskbody></task>