
<section id='WCCACHExWCF_ApplicationOptions_CacheOptions_id'>
    <title>
        Cache Options
    </title>
    <para>
        The cache is a portion of your computer's memory and hard disk
        that is used to store data for reuse. Typically, this data is
        either the result of a time-consuming calculation, or else is
        downloaded over a (relatively) slow internet connection. The cache
        is a performance optimization &emdash; if the data is needed again in
        the future, it can be quickly retrieved from the cache.
    </para>
    <note type='tip'>
        <para>
            The files in the disk cache can be deleted at any time, with no
            effect on the application other than the performance penalty of
            having to recalculate or redownload the data when it is needed
            in the future.
        </para>
    </note>
    <para>
        Use the Cache Options page of the <link
        target='#WCF_ApplicationOptionsDialogBox_id'>&app_name; Application
        Options dialog box</link> to manage the cache.
    </para>
    <exhibit>
        <img
        src='WCCACHExWCF_ApplicationOptions_CacheOptions_ScreenCap.png'/>
    </exhibit>
    <para>
        <italic>Maximum memory cache size:</italic> Enter the maximum
        amount of your computer's memory, in megabytes, that the cache
        will use. Increasing the memory cache size can result in greater
        performance. But it also decreases the amount of memory available
        for data that does not reside in the cache. If you are experiencing
        out-of-memory errors from &app_name;, try decreasing the memory
        cache size.
    </para>
    <para>
        <italic>Disk cache root directory:</italic> Enter the directory
        where disk cache files will be stored. As the disk cache can grow
        quite large, you may want to place the cache root on a drive with
        plenty of free space.
    </para>
    <para>
        <italic>Show Cache Information:</italic> Pressing this button
        will display the number of items and the total summed size of
        both the memory and disk caches.
    </para>
    <para>
        <italic>Empty Disk Cache:</italic> Pressing this button will delete
        all files in the disk cache. Normally, you would not need to do
        this. Each disk cache file has an expiration date, after which
        the file is automatically deleted, so the cache will not grow
        without limit. But it is possible for it to grow quite large.
        If disk space is low, you may need to manually empty the cache.
    </para>
</section>
