Symbian3/Examples/guid-6013a680-57f9-415b-8851-c4fa63356636/_t_any_r_objects1_8cpp_source.html
Week 32 contribution of PDK documentation content. See release notes for details. Fixes bug Bug 3582
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<h1>examples/Base/MemMan/Cleanup/TAnyRObjects1/TAnyRObjects1.cpp</h1><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">// Copyright (c) 2000-2009 Nokia Corporation and/or its subsidiary(-ies).</span>
<a name="l00002"></a>00002 <span class="comment">// All rights reserved.</span>
<a name="l00003"></a>00003 <span class="comment">// This component and the accompanying materials are made available</span>
<a name="l00004"></a>00004 <span class="comment">// under the terms of "Eclipse Public License v1.0"</span>
<a name="l00005"></a>00005 <span class="comment">// which accompanies this distribution, and is available</span>
<a name="l00006"></a>00006 <span class="comment">// at the URL "http://www.eclipse.org/legal/epl-v10.html".</span>
<a name="l00007"></a>00007 <span class="comment">//</span>
<a name="l00008"></a>00008 <span class="comment">// Initial Contributors:</span>
<a name="l00009"></a>00009 <span class="comment">// Nokia Corporation - initial contribution.</span>
<a name="l00010"></a>00010 <span class="comment">//</span>
<a name="l00011"></a>00011 <span class="comment">// Contributors:</span>
<a name="l00012"></a>00012 <span class="comment">//</span>
<a name="l00013"></a>00013 <span class="comment">// Description:</span>
<a name="l00014"></a>00014 <span class="comment">// AIM: To provide examples for the documentation of exceptions & traps</span>
<a name="l00015"></a>00015 <span class="comment">// Situation3 - examples of cleanup-stack support for TAny* and RItems</span>
<a name="l00016"></a>00016 <span class="comment">//</span>
<a name="l00017"></a>00017
<a name="l00018"></a>00018
<a name="l00019"></a>00019 <span class="preprocessor">#include "CommonFramework.h"</span>
<a name="l00020"></a>00020
<a name="l00021"></a>00021 <span class="comment">// Name of file to be used</span>
<a name="l00022"></a>00022 <a class="code" href="secureclientandserver_8h.html#a5eadd4429627d82193b37536d4faa03a">_LIT</a>(KFileName,<span class="stringliteral">"TAnyandRObjects1.dat"</span>);
<a name="l00023"></a>00023
<a name="l00024"></a>00024 <span class="comment">// Test data to be put into the file.</span>
<a name="l00025"></a>00025 <a class="code" href="secureclientandserver_8h.html#a5eadd4429627d82193b37536d4faa03a">_LIT</a>(KTestData,<span class="stringliteral">"Test data for TAnyandRObjects1\n"</span>);
<a name="l00026"></a>00026
<a name="l00027"></a>00027 <span class="comment">// #include specific files</span>
<a name="l00028"></a>00028 <span class="preprocessor">#include <f32file.h></span>
<a name="l00029"></a>00029 <span class="preprocessor">#include "EUHEXDMP.H"</span>
<a name="l00030"></a>00030
<a name="l00031"></a>00031
<a name="l00033"></a>00033 <span class="comment">//</span>
<a name="l00034"></a>00034 <span class="comment">// -----> RFileWithCleanup(definition)</span>
<a name="l00035"></a>00035 <span class="comment">//</span>
<a name="l00036"></a>00036 <span class="comment">// Function Cleanup() and operator TCleanupItem() needed to provide </span>
<a name="l00037"></a>00037 <span class="comment">// Cleanup Stack for RFile</span>
<a name="l00038"></a>00038 <span class="comment">//</span>
<a name="l00040"></a>00040 <span class="comment"></span><span class="keyword">class </span>RFileWithCleanup : <span class="keyword">public</span> RFile
<a name="l00041"></a>00041 {
<a name="l00042"></a>00042 <span class="keyword">private</span>:
<a name="l00043"></a>00043 <span class="keyword">static</span> <span class="keywordtype">void</span> Cleanup(TAny *aPtr);
<a name="l00044"></a>00044 <span class="keyword">public</span>:
<a name="l00045"></a>00045 operator TCleanupItem();
<a name="l00046"></a>00046 };
<a name="l00047"></a>00047
<a name="l00048"></a>00048
<a name="l00050"></a>00050 <span class="comment">//</span>
<a name="l00051"></a>00051 <span class="comment">// -----> RFileWithCleanup(implementation)</span>
<a name="l00052"></a>00052 <span class="comment">//</span>
<a name="l00054"></a>00054 <span class="comment"></span><span class="keywordtype">void</span> RFileWithCleanup::Cleanup(TAny *aPtr)
<a name="l00055"></a>00055 {
<a name="l00056"></a>00056 <a class="code" href="secureclientandserver_8h.html#a5eadd4429627d82193b37536d4faa03a">_LIT</a>(KMsgDoingCleanup,<span class="stringliteral">"Doing cleanup of file.\n"</span>);
<a name="l00057"></a>00057 console->Printf(KMsgDoingCleanup);
<a name="l00058"></a>00058 <span class="comment">// Invoke the Close member on the RItem at aPtr</span>
<a name="l00059"></a>00059 ((RFileWithCleanup *)aPtr)->Close();
<a name="l00060"></a>00060 }
<a name="l00061"></a>00061
<a name="l00062"></a>00062 RFileWithCleanup::operator TCleanupItem()
<a name="l00063"></a>00063 {
<a name="l00064"></a>00064 <span class="keywordflow">return</span> TCleanupItem(Cleanup,<span class="keyword">this</span>);
<a name="l00065"></a>00065 }
<a name="l00066"></a>00066
<a name="l00067"></a>00067 LOCAL_C <span class="keywordtype">void</span> createDataFileL()
<a name="l00068"></a>00068 {
<a name="l00069"></a>00069 <span class="comment">// utility function to create some data which we can later read</span>
<a name="l00070"></a>00070 RFs createFileSession;
<a name="l00071"></a>00071 RFileWithCleanup createFile;
<a name="l00072"></a>00072
<a name="l00073"></a>00073 <span class="comment">// connect to filserver session </span>
<a name="l00074"></a>00074 User::LeaveIfError(createFileSession.Connect());
<a name="l00075"></a>00075
<a name="l00076"></a>00076 <span class="comment">// create the private directory</span>
<a name="l00077"></a>00077 <span class="comment">// on the writable drive</span>
<a name="l00078"></a>00078 <span class="comment">// i.e. "\private\0FFFFF01\"</span>
<a name="l00079"></a>00079 <span class="comment">// Note that the number 0FFFFF01 is the </span>
<a name="l00080"></a>00080 <span class="comment">// process security id taken from the 2nd UID</span>
<a name="l00081"></a>00081 <span class="comment">// specified in the mmp file.</span>
<a name="l00082"></a>00082 createFileSession.CreatePrivatePath(RFs::GetSystemDrive());
<a name="l00083"></a>00083
<a name="l00084"></a>00084 <span class="comment">// Set the session path to</span>
<a name="l00085"></a>00085 <span class="comment">// this private directory on writable drive</span>
<a name="l00086"></a>00086 createFileSession.SetSessionToPrivate(RFs::GetSystemDrive());
<a name="l00087"></a>00087
<a name="l00088"></a>00088 <span class="comment">// create TAnyandRObjects1.dat and open for writing</span>
<a name="l00089"></a>00089 User::LeaveIfError(createFile.Replace(createFileSession,
<a name="l00090"></a>00090 KFileName,
<a name="l00091"></a>00091 EFileWrite|EFileStreamText));
<a name="l00092"></a>00092
<a name="l00093"></a>00093 <span class="comment">// Note that Write() requires a TDesC8</span>
<a name="l00094"></a>00094 <span class="comment">// type so we need to construct an explicit</span>
<a name="l00095"></a>00095 <span class="comment">// TDesC8 type to represent the data contained</span>
<a name="l00096"></a>00096 <span class="comment">// in the standard (16-bit) descriptor.</span>
<a name="l00097"></a>00097 TPtrC8 representation((TUint8*)(&KTestData)->Ptr(), (&KTestData)->Size());
<a name="l00098"></a>00098
<a name="l00099"></a>00099
<a name="l00100"></a>00100 <span class="comment">// write and commit text</span>
<a name="l00101"></a>00101 User::LeaveIfError(createFile.Write(representation));
<a name="l00102"></a>00102 User::LeaveIfError(createFile.Flush());
<a name="l00103"></a>00103 <a class="code" href="secureclientandserver_8h.html#a5eadd4429627d82193b37536d4faa03a">_LIT</a>(KMsgDataWritten,<span class="stringliteral">"Data written to file\n"</span>);
<a name="l00104"></a>00104 console->Printf(KMsgDataWritten);
<a name="l00105"></a>00105
<a name="l00106"></a>00106 <span class="comment">// close file and session</span>
<a name="l00107"></a>00107 <span class="comment">// (NB. no LeaveIfError due to RFile.close and </span>
<a name="l00108"></a>00108 <span class="comment">// RFs.close guaranteed to complete)</span>
<a name="l00109"></a>00109 createFile.Close(); <span class="comment">// close file</span>
<a name="l00110"></a>00110 createFileSession.Close(); <span class="comment">// close file server session</span>
<a name="l00111"></a>00111 }
<a name="l00112"></a>00112
<a name="l00113"></a>00113 <span class="keywordtype">void</span> useBufferL(TPtr8& bufferPtr)
<a name="l00114"></a>00114 {
<a name="l00115"></a>00115 printBuffer(0,bufferPtr);
<a name="l00116"></a>00116 <span class="comment">// Remove following comment to force a leave</span>
<a name="l00117"></a>00117 <span class="comment">// while using the buffer</span>
<a name="l00118"></a>00118 <span class="comment">//User::Leave(KErrGeneral);</span>
<a name="l00119"></a>00119 }
<a name="l00120"></a>00120
<a name="l00121"></a>00121
<a name="l00122"></a>00122 LOCAL_C <span class="keywordtype">void</span> doExampleL()
<a name="l00123"></a>00123 {
<a name="l00124"></a>00124 <span class="comment">// create the datafile for the example</span>
<a name="l00125"></a>00125 createDataFileL();
<a name="l00126"></a>00126
<a name="l00127"></a>00127 <span class="comment">// create a simple buffer. In real code, you</span>
<a name="l00128"></a>00128 <span class="comment">// would probably use an HBufC*, or an RBuf.</span>
<a name="l00129"></a>00129 <span class="comment">// You could also use a TBuf on the stack if it's small.</span>
<a name="l00130"></a>00130 TText8* buffer=(TText8*) User::Alloc(100*<span class="keyword">sizeof</span>(TText8));
<a name="l00131"></a>00131
<a name="l00132"></a>00132 <span class="comment">// push it to the cleanup stack: treated as TAny*</span>
<a name="l00133"></a>00133 CleanupStack::PushL(buffer);
<a name="l00134"></a>00134
<a name="l00135"></a>00135 <span class="comment">// create a pointer to the buffer</span>
<a name="l00136"></a>00136 TPtr8 bufferPtr(buffer,100);
<a name="l00137"></a>00137
<a name="l00138"></a>00138 <span class="comment">// the file session to be used</span>
<a name="l00139"></a>00139 RFs fsSession;
<a name="l00140"></a>00140 <a class="code" href="secureclientandserver_8h.html#a5eadd4429627d82193b37536d4faa03a">_LIT</a>(KMsgOpeningSession,<span class="stringliteral">"Opening session\n"</span>);
<a name="l00141"></a>00141 console->Printf(KMsgOpeningSession);
<a name="l00142"></a>00142
<a name="l00143"></a>00143 <span class="comment">// open the file-server session</span>
<a name="l00144"></a>00144 User::LeaveIfError(fsSession.Connect());
<a name="l00145"></a>00145
<a name="l00146"></a>00146 <span class="comment">// the file instance myFile</span>
<a name="l00147"></a>00147 RFileWithCleanup myFile;
<a name="l00148"></a>00148 <a class="code" href="secureclientandserver_8h.html#a5eadd4429627d82193b37536d4faa03a">_LIT</a>(KMsgOpeningFile,<span class="stringliteral">"Opening file\n"</span>);
<a name="l00149"></a>00149 console->Printf(KMsgOpeningFile);
<a name="l00150"></a>00150
<a name="l00151"></a>00151 <span class="comment">// open the file</span>
<a name="l00152"></a>00152 User::LeaveIfError(myFile.Open(fsSession,KFileName,EFileStreamText|EFileRead));
<a name="l00153"></a>00153
<a name="l00154"></a>00154 <span class="comment">// push the file instance to the cleanup stack</span>
<a name="l00155"></a>00155 CleanupStack::PushL(myFile);
<a name="l00156"></a>00156
<a name="l00157"></a>00157 <span class="comment">// read stuff from the file to the buffer (may leave)</span>
<a name="l00158"></a>00158 <a class="code" href="secureclientandserver_8h.html#a5eadd4429627d82193b37536d4faa03a">_LIT</a>(KMsgReadingFile,<span class="stringliteral">"Reading file into buffer.\n"</span>);
<a name="l00159"></a>00159 console->Printf(KMsgReadingFile);
<a name="l00160"></a>00160 User::LeaveIfError(myFile.Read(bufferPtr));
<a name="l00161"></a>00161
<a name="l00162"></a>00162 <span class="comment">// Remove following comment to force a leave</span>
<a name="l00163"></a>00163 <span class="comment">// while using the file</span>
<a name="l00164"></a>00164 <span class="comment">//User::Leave(KErrGeneral);</span>
<a name="l00165"></a>00165
<a name="l00166"></a>00166 <span class="comment">// destroy the file on the cleanup stack</span>
<a name="l00167"></a>00167 CleanupStack::PopAndDestroy();
<a name="l00168"></a>00168
<a name="l00169"></a>00169 fsSession.Close();
<a name="l00170"></a>00170
<a name="l00171"></a>00171 <span class="comment">// use the buffer</span>
<a name="l00172"></a>00172 useBufferL(bufferPtr);
<a name="l00173"></a>00173
<a name="l00174"></a>00174 <span class="comment">// destroy the buffer on the cleanup stack</span>
<a name="l00175"></a>00175 CleanupStack::PopAndDestroy();
<a name="l00176"></a>00176 }
<a name="l00177"></a>00177
</pre></div></div>
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