// Copyright 2005, 2006 - Morten Nielsen (www.iter.dk)

//

// This file is part of SharpMap.

// SharpMap is free software; you can redistribute it and/or modify

// it under the terms of the GNU Lesser General Public License as published by

// the Free Software Foundation; either version 2 of the License, or

// (at your option) any later version.

//

// SharpMap is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

// GNU Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public License

// along with SharpMap; if not, write to the Free Software

// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

using System;

using System.Drawing;

using System.Drawing.Imaging;

using System.IO;

using System.Web;

using System.Web.Caching;

namespace SharpMap.Web

{

/// <summary>

/// Class for storing rendered images in the httpcache

/// </summary>

public class Caching

{

/// <summary>

/// Inserts an image into the HttpCache and returns the cache identifier.

/// </summary>

/// <remarks>

/// Image can after insertion into the cache be requested by calling getmap.aspx?ID=[identifier]<br/>

/// This requires you to add the following to web.config:

/// <code escaped="true">

/// <httpHandlers>

/// <add verb="*" path="GetMap.aspx" type="SharpMap.Web.HttpHandler,SharpMap.Web"/>

/// </httpHandlers>

/// </code>

/// <example>

/// Inserting the map into the cache and setting the ImageUrl:

/// <code>

/// string imgID = SharpMap.Web.Caching.CacheMap(5, myMap.GetMap(), Session.SessionID, Context);

/// imgMap.ImageUrl = "getmap.aspx?ID=" + HttpUtility.UrlEncode(imgID);

/// </code>

/// </example>

/// </remarks>

/// <param name="minutes">Number of minutes to cache the map</param>

/// <param name="map">Map reference</param>

/// <returns>Image identifier</returns>

public static string InsertIntoCache(int minutes, Image map)

{

var guid = Guid.NewGuid().ToString().Replace("-", "");

using (var stream = new MemoryStream())

{

map.Save(stream, ImageFormat.Png);

HttpContext.Current.Cache.Insert(guid, stream.ToArray(), null,

Cache.NoAbsoluteExpiration,

TimeSpan.FromMinutes(minutes));

}

map.Dispose();

return guid;

}

}

}