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<concept id="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC" xml:lang="en"><title>Changes

to File Server Behaviour</title><shortdesc>Describes the behaviour changes of APIs that have been made 64-bit

aware. The signature of these APIs has not changed but the change in their

behaviour may impact existing applications. </shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>If you wish to use large files with your application and you are using

any of the following functions, check that the changes in behaviour described

here do not cause your application to fail. </p>

<ul>

<li id="GUID-E9044715-E60B-5D82-BB90-3284C0E8498F"><p> <xref href="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC.dita#GUID-19E4573B-3561-5BD0-862C-DC6392A968EC/GUID-7F63E81E-3E56-5F5A-980C-3843913D3F67">RFile::Read()</xref>  </p> </li>

<li id="GUID-80A44708-BE6C-5B95-A4B1-EC56553FB381"><p> <xref href="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC.dita#GUID-19E4573B-3561-5BD0-862C-DC6392A968EC/GUID-AD981741-0472-5A90-92DA-CF81A62B9D90">RFile::Seek()</xref>  </p> </li>

<li id="GUID-0A42DC9A-1C42-5665-9892-2D943689C614"><p> <xref href="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC.dita#GUID-19E4573B-3561-5BD0-862C-DC6392A968EC/GUID-0000F940-1831-57C0-8A9E-29EB20B11A0C">RFile::Size()</xref>  </p> </li>

<li id="GUID-4162E24B-DE1F-5D22-8278-A2160D8DCFD6"><p> <xref href="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC.dita#GUID-19E4573B-3561-5BD0-862C-DC6392A968EC/GUID-8EEB2085-351D-5DB0-9B3D-B0E0AF416646">CDir::Sort()</xref>  </p> </li>

<li id="GUID-5CB1C0F7-0676-5B99-8DE8-068B99B2E717"><p> <xref href="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC.dita#GUID-19E4573B-3561-5BD0-862C-DC6392A968EC/GUID-C67F312D-8C85-537F-826C-162CF757A1CC">RDir::GetDir()</xref>  </p> </li>

<li id="GUID-E47766BC-111A-59DB-8A77-7BA227B6B850"><p> <xref href="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC.dita#GUID-19E4573B-3561-5BD0-862C-DC6392A968EC/GUID-86B6B023-586A-5B56-8971-DB9EB1A6A876">CFileMan::Copy()</xref>  </p> </li>

<li id="GUID-84FEA1E1-0C95-56EE-BCA1-57849B68FA51"><p> <xref href="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC.dita#GUID-19E4573B-3561-5BD0-862C-DC6392A968EC/GUID-66AA8177-3E90-5A10-89DB-401E58F74A36">CFileMan::Move()</xref>. </p> </li>

</ul>

<note>If your legacy application opens a file in shared write mode, another

application can make it large using the 64-bit APIs. If your application is

affected, you should:<ul>

<li id="GUID-B55E4B74-812C-50FA-8584-4259BE3BA093"><p>enable 64-bit file support

to allow access to files beyond the 2GB boundary </p> </li>

<li id="GUID-1F159C18-0B52-55B1-B3F9-658561BD537F"><p>migrate to <codeph>TInt64</codeph> offsets </p> </li>

<li id="GUID-536D46FB-BAB2-577F-B80C-D8278DE1838B"><p>migrate to the <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-218CA816-A257-3B6E-94C7-9722FD5D147C"><apiname>RFile::Seek64()</apiname></xref> and <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-61BEEB4F-4771-30F5-9B20-F8AC44655640"><apiname>RFile::Size64()</apiname></xref> APIs. </p> </li>

</ul> </note>

<p>Clients that do not migrate need to ensure t hey handle the error <codeph>KErrTooBig</codeph>: </p>

<ul>

<li id="GUID-0AA448C1-4E0B-58E1-B251-A6BA6A1B3099"><p> <xref href="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC.dita#GUID-19E4573B-3561-5BD0-862C-DC6392A968EC/GUID-7F63E81E-3E56-5F5A-980C-3843913D3F67">RFile::Read()</xref> returns <codeph>KErrTooBig</codeph> if the read position

goes beyond 2GB-1. </p> </li>

<li id="GUID-2D7F696E-3024-5EF1-AFFE-5BE0DA8BC768"><p> <xref href="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC.dita#GUID-19E4573B-3561-5BD0-862C-DC6392A968EC/GUID-AD981741-0472-5A90-92DA-CF81A62B9D90">RFile::Seek()</xref> returns <codeph>KErrTooBig</codeph> if the 64-bit <codeph>Seek()</codeph> function

seeks to a location greater than 2GB-1. </p> </li>

<li id="GUID-A0110A50-BDB9-59AB-A264-D4DC97D19F56"><p> <xref href="GUID-19E4573B-3561-5BD0-862C-DC6392A968EC.dita#GUID-19E4573B-3561-5BD0-862C-DC6392A968EC/GUID-0000F940-1831-57C0-8A9E-29EB20B11A0C">RFile::Size()</xref> returns the lower 32-bits of the file size and <codeph>KErrTooBig</codeph>. </p> </li>

</ul>

<section id="GUID-7F63E81E-3E56-5F5A-980C-3843913D3F67"><title>RFile::Read()</title> <p>There

are four <codeph>RFile::Read()</codeph> overloaded functions that can perform

a read from the current file position. These functions can read from a position

beyond 2GB–1: </p><ul>

<li id="GUID-52DB7776-C28D-58D1-8BF8-B1EFEC1DF044"><p> <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-5CB6C63F-A6E3-3835-95C4-DE5F0AA5A74E"><apiname>RFile::Read(TDes8&amp;

aDes)</apiname></xref>  </p> </li>

<li id="GUID-DAE68DDF-C1F2-5062-B071-C8D13DD756F3"><p> <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-F845B529-7E5C-3702-8473-DCBBE154FBEE"><apiname>RFile::Read(TDes8&amp;

aDes, TRequestStatus&amp; aStatus)</apiname></xref>  </p> </li>

<li id="GUID-F01ABF44-48EE-5D46-BC28-9E0DBBE4A64F"><p> <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-5D58841A-90A6-30AE-8DC1-6940F7FC8D7D"><apiname>RFile::Read(TDes8&amp;

aDes, TInt aLength)</apiname></xref>  </p> </li>

<li id="GUID-B2B6BD4B-5CAF-5812-A1DF-9A10BCC79FA4"><p> <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-7E05F49C-77C1-3537-B437-31DE35982E40"><apiname>RFile::Read(TDes8&amp;

aDes, TInt aLength, TRequestStatus&amp; aStatus)</apiname></xref>. </p> </li>

</ul> <p>Verify that your application can handle reads greater than 2GB. The

following example shows a counter variable accumulating the number of bytes.

As this can be more than 2GB, the counter should be of type <xref href="GUID-AAE85115-A8AA-3F6C-BA8C-69F5A23B0D90.dita"><apiname>TInt64</apiname></xref>. </p><codeblock id="GUID-E187355B-9800-5C30-9671-3971A85C3275" xml:space="preserve">    TInt r;

    RFile file;

    // Replace TInt variable with TInt64 variable

    // TInt bytesRead = 0;

    TInt64 bytesRead = 0;

    TBuf8<4096> readBuf;

    ...

    // Read loop

    FOREVER

        {

        // Read a block

        r = file.Read(readBuf);

        if(KErrNone != r)

            {

            // Error handling

            break;

            }

        bytesRead += readBuf.Length();</codeblock> </section>

<section id="GUID-AD981741-0472-5A90-92DA-CF81A62B9D90"><title>RFile::Seek()</title> <p> <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-07136402-8D95-3256-9591-EE4141748E15"><apiname>RFile::Seek()</apiname></xref> has

not been altered to handle large files. The table below describes the behaviour

for the different seek modes as defined in <xref href="GUID-5AFEBCA5-00CE-3D2F-A4F9-5E1EABDD7F3C.dita"><apiname>TMode</apiname></xref>. </p><table id="GUID-300EBDEA-F417-5D37-9C0C-6340B9983C00">

<tgroup cols="2"><colspec colname="col0"/><colspec colname="col1"/>

<tbody>

<row>

<entry><p> <b>Seek mode</b>  </p> </entry>

<entry><p> <b>New behaviour</b>  </p> </entry>

</row>

<row>

<entry><p> <xref href="GUID-575221DD-F696-313A-90B4-D3ED6D96E8C7.dita"><apiname>ESeekAddress</apiname></xref>  </p></entry>

<entry><p>No change in behaviour.</p></entry>

</row>

<row>

<entry><p> <xref href="GUID-458B652E-537A-3FC0-9DF7-396907A13522.dita"><apiname>ESeekStart</apiname></xref>  </p></entry>

<entry><p>Can seek up to 2GB–1.</p></entry>

</row>

<row>

<entry><p> <xref href="GUID-054ECFC9-C8C2-32B6-81DE-0526B3B17FF1.dita"><apiname>ESeekCurrent</apiname></xref>  </p> </entry>

<entry><p>If the current position is less than 2GB–1 and the expected position

is less than 2GB–1, then the current file pointer is moved, the output parameter

is updated with the new file position and <codeph>KErrNone</codeph> is returned. </p><p>If

either the current position or the expected position is more than 2GB–1, seek

fails with the error code <codeph>KErrTooBig</codeph> and the output parameter

is not modified. </p></entry>

</row>

<row>

<entry><p> <xref href="GUID-08B70CC6-3EFE-3355-9E96-9C99FCA6D911.dita"><apiname>ESeekEnd</apiname></xref>  </p> </entry>

<entry><p>If the current position is less than 2GB–1 and the expected position

is less than 2GB–1, then the current file pointer is moved and the output

parameter is updated with the new file position and <codeph>KErrNone</codeph> is

returned. </p><p>If either the current position or the expected position is

more than 2GB–1, seek fails with the error code <codeph>KErrTooBig</codeph> and

the output parameter is not modified. </p></entry>

</row>

</tbody>

</tgroup>

</table> <p>To handle large files use <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-218CA816-A257-3B6E-94C7-9722FD5D147C"><apiname>RFile::Seek64()</apiname></xref> instead

of <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-07136402-8D95-3256-9591-EE4141748E15"><apiname>RFile::Seek()</apiname></xref>. See <xref href="GUID-A7C26FE4-54B2-58D6-9FDF-4B0A565D00DE.dita">Seeking

a Position in a Large File</xref>. </p> </section>

<section id="GUID-0000F940-1831-57C0-8A9E-29EB20B11A0C"><title>RFile::Size()</title> <p>If

the file is less than 2GB-1 <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-01ACE541-916F-3811-A596-E25F1EF1C409"><apiname>RFile::Size()</apiname></xref> behaves as usual

and returns <codeph>KErrNone</codeph> with the size of the file. If the file

is larger than 2GB–1 the function returns <codeph>KErrTooBig</codeph> and

the lower 32 bits of the file size is returned. </p> <p>To handle files larger

than 2GB-1 use the function <xref href="GUID-BE0804F6-4375-3C8A-8C83-968F510466E0.dita#GUID-BE0804F6-4375-3C8A-8C83-968F510466E0/GUID-61BEEB4F-4771-30F5-9B20-F8AC44655640"><apiname>RFile::Size64()</apiname></xref>. See <xref href="GUID-B6F35F05-8EFB-5E88-B14B-C1B2F83E6015.dita">Getting the Size of a Large

File using RFile</xref> and <xref href="GUID-B97C3C1D-7F35-4B0A-9420-180CE70EF6DE.dita">Getting

the Size of a Large File using TEntry</xref>. </p> </section>

<section id="GUID-8EEB2085-351D-5DB0-9B3D-B0E0AF416646"><title>CRir::Sort()</title> <p> <xref href="GUID-DB05F06E-4770-3255-BED9-6D3ACC845652.dita#GUID-DB05F06E-4770-3255-BED9-6D3ACC845652/GUID-C46316DF-79F1-32D9-9545-7F5D448C3873"><apiname>CRir::Sort()</apiname></xref> has

been enhanced so that it can handle the sorting by size of large directory

entries. No change is required to applications currently using this function. </p> <note>Sort

by size is limited to 4GB-1.</note> </section>

<section id="GUID-C67F312D-8C85-537F-826C-162CF757A1CC"><title>RDir::GetDir()</title> <p>The

implementation of the three overloaded functions for <xref href="GUID-12AE154F-7741-38C0-ADFE-9784FCF5E516.dita#GUID-12AE154F-7741-38C0-ADFE-9784FCF5E516/GUID-766549C6-AC07-3958-9100-59A238BD8367"><apiname>RDir::GetDir()</apiname></xref> has

been updated so that these functions can correctly sort directory entries

by size. No change is required to applications currently using this function. </p> <note>Sort

by size is limited to 4GB-1.</note></section>

<section id="GUID-86B6B023-586A-5B56-8971-DB9EB1A6A876"><title>CFileMan::Copy()</title> <p> <xref href="GUID-82CEC14F-1479-3922-846A-9FCDB6465EF7.dita#GUID-82CEC14F-1479-3922-846A-9FCDB6465EF7/GUID-633C2FF5-4077-346D-B7B6-4CC04F887D7B"><apiname>CFileMan::Copy()</apiname></xref> copies

a large file to any location on either the same drive or a different drive.

If the target drive does not support large files, the function returns the

error <codeph>KErrTooBig</codeph>. </p> <p>No change is required to applications

currently using this function. </p> </section>

<section id="GUID-66AA8177-3E90-5A10-89DB-401E58F74A36"><title>CFileMan::Move()</title> <p> <xref href="GUID-82CEC14F-1479-3922-846A-9FCDB6465EF7.dita#GUID-82CEC14F-1479-3922-846A-9FCDB6465EF7/GUID-9456C8B9-C975-356C-B3A4-755928DE2AC3"><apiname>CFileMan::Move()</apiname></xref> moves

a file to any location on either the same drive or a different drive. If the

target drive does not support large files, the function returns the error <codeph>KErrTooBig</codeph>. </p> <p>No

change is required to applications currently using this function. </p> </section>

</conbody></concept>