Symbian3/SDK/Source/GUID-2FAB8281-569A-52BE-8BC8-A2D378068706.dita
author Dominic Pinkman <dominic.pinkman@nokia.com>
Fri, 11 Jun 2010 12:39:03 +0100
changeset 8 ae94777fff8f
parent 7 51a74ef9ed63
child 13 48780e181b38
permissions -rw-r--r--
Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
8
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
     1
<?xml version="1.0" encoding="utf-8"?>
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
     2
<!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. -->
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
     3
<!-- This component and the accompanying materials are made available under the terms of the License 
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
     4
"Eclipse Public License v1.0" which accompanies this distribution, 
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
     5
and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". -->
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
     6
<!-- Initial Contributors:
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
     7
    Nokia Corporation - initial contribution.
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
     8
Contributors: 
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
     9
-->
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    10
<!DOCTYPE concept
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    11
  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    12
<concept id="GUID-2FAB8281-569A-52BE-8BC8-A2D378068706" xml:lang="en"><title>Caching</title><prolog><metadata><keywords/></metadata></prolog><conbody>
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    13
<p>In Symbian OS v9.3 and earlier, index entries were stored in a single index
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    14
file in a permanent file store and the entire file was loaded into RAM on
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    15
start up. In Symbian^3 index entries are stored in an SQL database and only
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    16
the most recently used index entries are cached in RAM. </p>
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    17
<p>The following figure shows how a client request is completed using the
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    18
cache functionality in the Message Server. </p>
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    19
<fig id="GUID-43D2AE30-9221-500A-B934-5D3636168273">
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    20
<title>           Caching architecture          </title>
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    21
<image href="GUID-53A2CA11-2ABF-5ED7-A26C-7BE9FD9A1D22_d0e281197_href.png" placement="inline"/>
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    22
</fig>
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    23
<section id="GUID-D3F3D019-736E-4527-8099-9BE8883CF37C"><title>Creating and
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    24
maintaining free space in memory</title> <p>Memory allocation to the cache
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    25
is done incrementally, to reduce the Message Server start up time. When the
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    26
Message Server starts, only a percentage of the maximum cache size (<codeph>MsvMaximumCacheSize</codeph>)
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    27
is allocated to cache. The percentage is specified by the <codeph>MsvInitialCacheCreation</codeph> parameter.
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    28
The next iteration of memory allocation is not initiated until the memory
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    29
threshold (set using the <codeph>MsvCacheThreshold</codeph> parameter) is
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    30
reached. The subsequent memory allocation is always done by a low priority
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    31
active object. </p> <p><b>Example</b> </p> <p>The memory allocation strategy
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    32
is illustrated in the following figures, based on the default values (shown
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    33
in the preceding table). </p> <p>When Message Server starts, the cache is
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    34
created with an initial size of 410KB (40 percent of 1024KB). If 70 percent
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    35
of the free space in the cache gets used the server allocates an additional
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    36
205KB (20 percent of 1024). </p> <fig id="GUID-CA4A08C8-C4E8-575F-8F03-F3D1F6579E5F">
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    37
<image href="GUID-B459E37A-BECE-5087-9827-C93310890674_d0e281229_href.png" placement="inline"/>
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    38
</fig> <p>Message Server can make two further 205KB allocations which it does
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    39
as use reaches 70 percent of the memory already allocated. </p> <fig id="GUID-21A40614-046B-56DD-9DDD-34B2F9681B5C">
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    40
<image href="GUID-107F7BC4-F776-512D-AD6F-1674B7ED19B5_d0e281237_href.png" placement="inline"/>
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    41
</fig> <p>If more than 70 percent of the first two allocated memory chunks
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    42
is used, an additional 20 percent of memory is added to the free space. </p> <fig id="GUID-EBF4FF85-D6D6-518C-9391-C3AFF8821F83">
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    43
<image href="GUID-5E380880-9DBB-51D7-8942-829C6FD788C2_d0e281245_href.png" placement="inline"/>
ae94777fff8f Week 23 contribution of SDK documentation content. See release notes for details. Fixes bugs Bug 2714, Bug 462.
Dominic Pinkman <dominic.pinkman@nokia.com>
parents: 7
diff changeset
    44
</fig> </section>
7
51a74ef9ed63 Week 12 contribution of API Specs and fix SDK submission
Dominic Pinkman <Dominic.Pinkman@Nokia.com>
parents:
diff changeset
    45
</conbody></concept>