author | Dominic Pinkman <dominic.pinkman@nokia.com> |
Tue, 20 Jul 2010 12:00:49 +0100 | |
changeset 13 | 48780e181b38 |
parent 7 | 51a74ef9ed63 |
permissions | -rw-r--r-- |
7
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
1 |
<?xml version="1.0" encoding="utf-8"?> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
2 |
<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
3 |
<!-- This component and the accompanying materials are made available under the terms of the License |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
4 |
"Eclipse Public License v1.0" which accompanies this distribution, |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
5 |
and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
6 |
<!-- Initial Contributors: |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
7 |
Nokia Corporation - initial contribution. |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
8 |
Contributors: |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
9 |
--> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
10 |
<!DOCTYPE concept |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
11 |
PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
12 |
<concept id="GUID-442F2E69-87B5-54E7-B62A-70B742432372" xml:lang="en"><title>How |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
13 |
to Commit and Revert </title><shortdesc>Changes to a store are not made permanent until they are committed |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
14 |
and until such changes are committed, they can be rolled back (i.e. reverted)</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
15 |
<p>Transactions are supported by a commit and revert protocol.</p> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
16 |
<p>In the following code fragment, <codeph>store</codeph> is a pointer to |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
17 |
an opened permanent file store. The function <codeph>doUpdateStoreL()</codeph> adds |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
18 |
a number of streams to this store and, if successful, establishes a new commit |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
19 |
point.</p> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
20 |
<p>If a failure occurs or the call to <codeph>CommitL()</codeph> fails, then <codeph>doUpdateStoreL()</codeph> leaves; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
21 |
the leave is trapped and any changes made to the store are rolled back, so |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
22 |
that the store is in the same state as it was before the changes were started. |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
23 |
The store, therefore, remains in a consistent state in the event of failure.</p> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
24 |
<p><codeph>CItemArray</codeph> is a class that encapsulates an array of <codeph>TItem</codeph> objects; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
25 |
the relevant part of the definition is:</p> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
26 |
<codeblock id="GUID-0B5B04A7-AB4A-55CA-BCF0-9E19623F1554" xml:space="preserve">typedef TBuf<100> TItem;</codeblock> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
27 |
<codeblock id="GUID-52A3FAC2-4E23-5574-A21C-DE087ADDB911" xml:space="preserve">class CItemArray : public CBase |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
28 |
{ |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
29 |
public: |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
30 |
... |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
31 |
void AddItemL(const TItem& anItem); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
32 |
void StoreL() const; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
33 |
void ExternalizeL(RWriteStream& aStream) const; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
34 |
... |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
35 |
private: |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
36 |
CStreamStore& iStore; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
37 |
... |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
38 |
CArrayFixFlat<TStreamId>* iArray; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
39 |
}</codeblock> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
40 |
<p>The example also assumes that the store is one that allows streams to be |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
41 |
modified and replaced; for example, a permanent file store.</p> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
42 |
<codeblock id="GUID-21AFD117-3D52-55BE-BEB7-430CF08D0429" xml:space="preserve">... |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
43 |
TRAPD(error,doUpdateStoreL(*store)); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
44 |
if (error!=KErrNone) |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
45 |
{ |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
46 |
store->Revert(); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
47 |
... |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
48 |
} |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
49 |
...</codeblock> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
50 |
<codeblock id="GUID-EB07D2AA-ECAA-5014-84F0-85767A60E366" xml:space="preserve">LOCAL_C void doUpdateStoreL(CPersistentStore& aStore) |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
51 |
{ |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
52 |
_LIT(KTxtHello,"hello"); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
53 |
_LIT(KtxtWorld," world!"); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
54 |
// get the root stream into memory |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
55 |
CItemArray* array=CItemArray::NewLC(aStore,aStore.Root()); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
56 |
|
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
57 |
// Add some items |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
58 |
TItem item; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
59 |
item = KTxtHello; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
60 |
array->AddItemL(item); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
61 |
item = KTxtWorld; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
62 |
array->AddItemL(item); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
63 |
// Re-write the root stream with new data |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
64 |
array->StoreL(); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
65 |
// commit all changes |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
66 |
aStore.CommitL(); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
67 |
... |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
68 |
}</codeblock> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
69 |
<codeblock id="GUID-3E2184DA-7C74-58F0-925E-6AE1317732C9" xml:space="preserve">void CItemArray::AddItemL(const TItem& anItem) |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
70 |
{ |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
71 |
RStoreWriteStream outstream; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
72 |
TStreamId id=outstream.CreateLC(iStore); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
73 |
outstream<<anItem; |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
74 |
outstream.CommitL(); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
75 |
CleanupStack::PopAndDestroy(); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
76 |
iArray->AppendL(id); |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
77 |
} |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
78 |
</codeblock> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
79 |
</conbody><related-links> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
80 |
<link href="GUID-C9D8D913-C65F-5A69-A606-30F59BFB38E2.dita"><linktext>File Stores</linktext> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
81 |
</link> |
51a74ef9ed63
Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff
changeset
|
82 |
</related-links></concept> |