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<concept id="GUID-34E19A27-F61D-5190-8709-151523CB0BE1" xml:lang="en"><title>Reclamation

And Compaction, Incrementally</title><shortdesc>Explains how to reclaim and compact incrementally by using smaller

steps.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>Both space reclamation and compaction can be done incrementally, i.e. broken

down into smaller steps. This allows an application to alternate reclamation

and compaction with other processing and remain responsive to other events.</p>

<p>To do this, construct an object of type <codeph>RStoreReclaim</codeph> and

call:</p>

<ul>

<li id="GUID-4C8737BC-BCEA-5D06-9F31-5E823EE39C46"><p><codeph>RStoreReclaim::OpenL()</codeph> or <codeph>RStoreReclaim::OpenLC()</codeph> to

prepare the <codeph>RStoreReclaim</codeph> object to perform space reclamation.</p> </li>

<li id="GUID-49C343FC-1C3F-5D92-A846-FC65EBEBDFA8"><p><codeph>RStoreReclaim::CompactL()</codeph> or <codeph>RStoreReclaim::CompactLC()</codeph> to

prepare the <codeph>RStoreReclaim</codeph> object to perform compaction.</p> </li>

</ul>

<p>Each stage of space reclamation and compaction is performed or initiated

by calling the appropriate variant of <codeph>RStoreReclaim::Next()</codeph> or <codeph>RStoreReclaim::NextL()</codeph>.

The class provides both synchronous and asynchronous variants of these two

functions. The asynchronous versions initiate the next stage of space reclamation

and compaction.</p>

<p>At any time during space reclamation or compaction, the <codeph>RStoreReclaim::Available()</codeph> returns

a running total of free space discovered so far.</p>

<p>Compaction and normal access to the store interact in the following ways:</p>

<ul>

<li id="GUID-CE0ADA7E-0790-55A6-B9E3-4A237DACEE1E"><p>if a compaction step

is in progress, committing the store causes the compaction step to be abandoned

and to complete or leave with <codeph>KErrNotReady</codeph>. All subsequent

attempts to initiate a compaction step, complete or leave with <codeph>KErrNotReady</codeph>.

Compaction can be restarted by first doing a reset, i.e. by calling <codeph>ResetL()</codeph>.</p> </li>

<li id="GUID-86F776A3-D1C0-55DB-A365-C085BFEFA28F"><p>a compaction step which

needs to physically move a stream, completes or leaves with <codeph>KErrInUse</codeph>,

if any stream within the store is open. The stream must be closed before initiating

another compaction step.</p> </li>

</ul>

<p>Once compaction is complete, the store must be committed.</p>

<p>Doing an incremental space reclamation or compaction asynchronously requires

the use of active objects. </p>

</conbody></concept>