/// <summary>
/// marks cacheable element as unused
/// </summary>
/// <param name="baseName"></param>
public void MarkUnused(string baseName)
{
//LibSys.StatusBar.Trace("OK: MyCache:MarkUnused() - tile '" + baseName + "'");
if (this.Contains(baseName))
{
MyCacheable mc = (MyCacheable)this[baseName];
if (mc != null)
{
mc.MarkUnused();
}
else
{
// non-existent object behind the name, just remove the name:
this.Remove(baseName);
}
}
}
/// <summary>
/// remove old unused elements from cache
/// </summary>
/// <param name="cacheMinCount"></param>
public void purge(int cacheMinCount)
{
//LibSys.StatusBar.Trace("IP: MyCache:purge()");
SortedList list = new SortedList(); // will contain ticks-based string keys, oldest first:
int cnt = countUnused();
if (cnt <= cacheMinCount)
{
//LibSys.StatusBar.Trace(" too few unused yet: " + cnt);
}
else
{
int toTrim = cnt - cacheMinCount;
foreach (MyCacheable mc in this.Values)
{
if (mc != null && !mc.IsUsed)
{
long lKey = mc.LastUsed;
while (list.Contains(lKey)) // SortedList doesn't tolerate repeated keys
{
lKey--;
}
list.Add(lKey, mc.BaseName);
if (--toTrim <= 0)
{
break;
}
}
}
for (int i = 0; i < list.Count; i++)
{
string key = (string)list.GetByIndex(i);
//LibSys.StatusBar.Trace(" OK: removing " + this[key]);
// all bitmaps and features need to be disposed before they are removed from cache.
// disposing of bitmaps releases files from which they were loaded.
MyCacheable mc = (MyCacheable)this[key];
mc.Dispose();
this.Remove(key);
}
}
}