12 <concept xml:lang="en" id="GUID-34E19A27-F61D-5190-8709-151523CB0BE1"><title>Reclamation and compaction, incrementally</title><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> <section><title>See also</title> <p><xref href="GUID-6EE0CB66-A759-5E0C-884D-90895F35F267.dita">Transactions</xref> </p> <p><xref href="GUID-C2608BF5-CDA7-530A-B67A-0414C7FA585D.dita">High level asynchronous service handling</xref> </p> </section> </conbody></concept>

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

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

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

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

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

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

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

    19 call:</p>

    20 <ul>

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

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

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

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

    25 </ul>

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

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

    28 The class provides both synchronous and asynchronous variants of these two

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

    30 and compaction.</p>

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

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

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

    34 <ul>

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

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

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

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

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

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

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

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

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

    44 </ul>

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

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

    47 the use of active objects. </p>

    48 </conbody></concept>