namespace GMap.NET.Internals{
using System.Collections.Generic;
using System.IO;
using System;
/// <summary>
/// kiber speed memory cache for tiles with history support ;}
/// </summary>
internal class KiberTileCache : Dictionary<RawTile, MemoryStream>
{
readonly Queue<RawTile> Queue = new Queue<RawTile>();
/// <summary>
/// the amount of tiles in MB to keep in memmory, default: 22MB, if each ~100Kb it's ~222 tiles
/// </summary>
#if !PocketPC
public int MemoryCacheCapacity = 22;
#else
public int MemoryCacheCapacity = 3;
#endif
long memoryCacheSize = 0;
/// <summary>
/// current memmory cache size in MB
/// </summary>
public double MemoryCacheSize
{
get
{
return memoryCacheSize/1048576.0;
}
}
public new void Add(RawTile key, MemoryStream value)
{
Queue.Enqueue(key);
base.Add(key, value);
memoryCacheSize += value.Length;
}
// do not allow directly removal of elements
private new void Remove(RawTile key)
{
}
internal void RemoveMemoryOverload()
{
while(MemoryCacheSize > MemoryCacheCapacity)
{
if(Keys.Count > 0 && Queue.Count > 0)
{
RawTile first = Queue.Dequeue();
try
{
using(MemoryStream m = base[first])
{
base.Remove(first);
memoryCacheSize -= m.Length;
}
}
catch
{
}
}
else
{
break;
}
}
}
}
}
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