OpenSimMirror/OpenSim/Framework/IAssetCache.cs

115 lines
5.2 KiB
C#

/*
* Copyright (c) Contributors, http://opensimulator.org/
* See CONTRIBUTORS.TXT for a full list of copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the OpenSimulator Project nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
using OpenMetaverse;
using OpenMetaverse.Packets;
namespace OpenSim.Framework
{
public delegate void AssetRequestCallback(UUID assetId, AssetBase asset);
/// <summary>
/// Interface to the local asset cache. This is the mechanism through which assets can be added and requested.
/// </summary>
public interface IAssetCache : IPlugin
{
/// <value>
/// The 'server' from which assets can be requested and to which assets are persisted.
/// </value>
void Initialise(ConfigSettings cs);
/// <summary>
/// Report statistical data to the log.
/// </summary>
void ShowState();
/// <summary>
/// Clear the asset cache.
/// </summary>
void Clear();
/// <summary>
/// Get an asset only if it's already in the cache.
/// </summary>
/// <param name="assetId"></param>
/// <param name="asset"></param>
/// <returns>true if the asset was in the cache, false if it was not</returns>
bool TryGetCachedAsset(UUID assetID, out AssetBase asset);
/// <summary>
/// Asynchronously retrieve an asset.
/// </summary>
/// <param name="assetId"></param>
/// <param name="callback">
/// <param name="isTexture"></param>
/// A callback invoked when the asset has either been found or not found.
/// If the asset was found this is called with the asset UUID and the asset data
/// If the asset was not found this is still called with the asset UUID but with a null asset data reference</param>
void GetAsset(UUID assetID, AssetRequestCallback callback, bool isTexture);
/// <summary>
/// Synchronously retreive an asset. If the asset isn't in the cache, a request will be made to the persistent store to
/// load it into the cache.
/// </summary>
///
/// XXX We'll keep polling the cache until we get the asset or we exceed
/// the allowed number of polls. This isn't a very good way of doing things since a single thread
/// is processing inbound packets, so if the asset server is slow, we could block this for up to
/// the timeout period. Whereever possible we want to use the asynchronous callback GetAsset()
///
/// <param name="assetID"></param>
/// <param name="isTexture"></param>
/// <returns>null if the asset could not be retrieved</returns>
AssetBase GetAsset(UUID assetID, bool isTexture);
/// <summary>
/// Add an asset to both the persistent store and the cache.
/// </summary>
/// <param name="asset"></param>
void AddAsset(AssetBase asset);
/// <summary>
/// Expire an asset from the cache
/// </summary>
/// Allows you to clear a specific asset by uuid out
/// of the asset cache. This is needed because the osdynamic
/// texture code grows the asset cache without bounds. The
/// real solution here is a much better cache archicture, but
/// this is a stop gap measure until we have such a thing.
void ExpireAsset(UUID assetID);
/// <summary>
/// Handle an asset request from the client. The result will be sent back asynchronously.
/// </summary>
/// <param name="userInfo"></param>
/// <param name="transferRequest"></param>
void AddAssetRequest(IClientAPI userInfo, TransferRequestPacket transferRequest);
}
}