aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/OpenSim/Region/Environment/Modules/Agent/TextureDownload/UserTextureDownloadService.cs
blob: 12ee27870a352ff6566614f86caeae2730658011 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/*
 * 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 OpenSim 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
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System.Collections.Generic;
using System.Reflection;
using libsecondlife;
using log4net;
using OpenSim.Framework;
using OpenSim.Framework.Communications.Limit;
using OpenSim.Region.Environment.Interfaces;
using OpenSim.Region.Environment.Scenes;

namespace OpenSim.Region.Environment.Modules.Agent.TextureDownload
{
    /// <summary>
    /// This module sets up texture senders in response to client texture requests, and places them on a
    /// processing queue once those senders have the appropriate data (i.e. a texture retrieved from the 
    /// asset cache).
    /// </summary>
    public class UserTextureDownloadService
    {
        private static readonly ILog m_log
            = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        /// <summary>
        /// We will allow the client to request the same texture n times before dropping further requests
        /// 
        /// This number includes repeated requests for the same texture at different resolutions (which we don't
        /// currently handle properly as far as I know).  However, this situation should be handled in a more
        /// sophisticated way.
        /// </summary>
        private static readonly int MAX_ALLOWED_TEXTURE_REQUESTS = 5;

        /// <summary>
        /// XXX Also going to limit requests for found textures.
        /// </summary>
        private readonly IRequestLimitStrategy<LLUUID> foundTextureLimitStrategy
            = new RepeatLimitStrategy<LLUUID>(MAX_ALLOWED_TEXTURE_REQUESTS);

        private readonly IClientAPI m_client;
        private readonly Scene m_scene;

        /// <summary>
        /// Texture Senders are placed in this queue once they have received their texture from the asset
        /// cache.  Another module actually invokes the send.
        /// </summary>
        private readonly BlockingQueue<ITextureSender> m_sharedSendersQueue;

        /// <summary>
        /// Holds texture senders before they have received the appropriate texture from the asset cache.
        /// </summary>
        private readonly Dictionary<LLUUID, TextureSender.TextureSender> m_textureSenders = new Dictionary<LLUUID, TextureSender.TextureSender>();

        /// <summary>
        /// We're going to limit requests for the same missing texture.
        /// XXX This is really a temporary solution to deal with the situation where a client continually requests
        /// the same missing textures
        /// </summary>        
        private readonly IRequestLimitStrategy<LLUUID> missingTextureLimitStrategy
            = new RepeatLimitStrategy<LLUUID>(MAX_ALLOWED_TEXTURE_REQUESTS);

        public UserTextureDownloadService(
            IClientAPI client, Scene scene, BlockingQueue<ITextureSender> sharedQueue)
        {
            m_client = client;
            m_scene = scene;
            m_sharedSendersQueue = sharedQueue;
        }

        /// <summary>
        /// Handle a texture request.  This involves creating a texture sender and placing it on the 
        /// previously passed in shared queue.
        /// </summary>
        /// <param name="e"></param>
        public void HandleTextureRequest(TextureRequestArgs e)
        {
            TextureSender.TextureSender textureSender;

            //TODO: should be working out the data size/ number of packets to be sent for each discard level
            if ((e.DiscardLevel >= 0) || (e.Priority != 0))
            {
                lock (m_textureSenders)
                {
                    if (m_textureSenders.TryGetValue(e.RequestedAssetID, out textureSender))
                    {
                        // If we've received new non UUID information for this request and it hasn't dispatched 
                        // yet, then update the request accordingly.
                        textureSender.UpdateRequest(e.DiscardLevel, e.PacketNumber);
                    }
                    else
                    {
                        if (!foundTextureLimitStrategy.AllowRequest(e.RequestedAssetID))
                        {
//                            m_log.DebugFormat(
//                                "[USER TEXTURE DOWNLOAD SERVICE]: Refusing request for {0} from client {1}", 
//                                e.RequestedAssetID, m_client.AgentId);

                            return;
                        }
                        else if (!missingTextureLimitStrategy.AllowRequest(e.RequestedAssetID))
                        {
                            if (missingTextureLimitStrategy.IsFirstRefusal(e.RequestedAssetID))
                            {
                                // Commenting out this message for now as it causes too much noise with other 
                                // debug messages.  
                                // TODO: possibly record this as a statistic in the future
                                //
//                                m_log.DebugFormat(
//                                    "[USER TEXTURE DOWNLOAD SERVICE]: Dropping requests for notified missing texture {0} for client {1} since we have received more than {2} requests",
//                                    e.RequestedAssetID, m_client.AgentId, MAX_ALLOWED_TEXTURE_REQUESTS);
                            }

                            return;
                        }

                        m_scene.AddPendingDownloads(1);

                        TextureSender.TextureSender requestHandler = new TextureSender.TextureSender(m_client, e.DiscardLevel, e.PacketNumber);
                        m_textureSenders.Add(e.RequestedAssetID, requestHandler);

                        m_scene.AssetCache.GetAsset(e.RequestedAssetID, TextureCallback, true);
                    }
                }
            }
            else
            {
                lock (m_textureSenders)
                {
                    if (m_textureSenders.TryGetValue(e.RequestedAssetID, out textureSender))
                    {
                        textureSender.Cancel = true;
                    }
                }
            }
        }

        /// <summary>
        /// The callback for the asset cache when a texture has been retrieved.  This method queues the
        /// texture sender for processing.
        /// </summary>
        /// <param name="textureID"></param>
        /// <param name="texture"></param>
        public void TextureCallback(LLUUID textureID, AssetBase texture)
        {
            //m_log.DebugFormat("[USER TEXTURE DOWNLOAD SERVICE]: Calling TextureCallback with {0}, texture == null is {1}", textureID, (texture == null ? true : false));

            lock (m_textureSenders)
            {
                TextureSender.TextureSender textureSender;

                if (m_textureSenders.TryGetValue(textureID, out textureSender))
                {
                    // XXX It may be perfectly valid for a texture to have no data...  but if we pass
                    // this on to the TextureSender it will blow up, so just discard for now.
                    // Needs investigation.
                    if (texture == null || texture.Data == null)
                    {
                        if (!missingTextureLimitStrategy.IsMonitoringRequests(textureID))
                        {
                            missingTextureLimitStrategy.MonitorRequests(textureID);

//                            m_log.DebugFormat(
//                                "[USER TEXTURE DOWNLOAD SERVICE]: Queueing first TextureNotFoundSender for {0}, client {1}",
//                                textureID, m_client.AgentId);
                        }

                        ITextureSender textureNotFoundSender = new TextureNotFoundSender(m_client, textureID);
                        EnqueueTextureSender(textureNotFoundSender);
                    }
                    else
                    {
                        if (!textureSender.ImageLoaded)
                        {
                            textureSender.TextureReceived(texture);
                            EnqueueTextureSender(textureSender);

                            foundTextureLimitStrategy.MonitorRequests(textureID);
                        }
                    }

                    //m_log.InfoFormat("[TEXTURE SENDER] Removing texture sender with uuid {0}", textureID);
                    m_textureSenders.Remove(textureID);
                    //m_log.InfoFormat("[TEXTURE SENDER] Current texture senders in dictionary: {0}", m_textureSenders.Count);
                }
                else
                {
                    m_log.WarnFormat(
                        "Got a texture uuid {0} with no sender object to handle it, this shouldn't happen",
                        textureID);
                }
            }
        }

        /// <summary>
        /// Place a ready texture sender on the processing queue.
        /// </summary>
        /// <param name="textureSender"></param>
        private void EnqueueTextureSender(ITextureSender textureSender)
        {
            textureSender.Cancel = false;
            textureSender.Sending = true;

            if (!m_sharedSendersQueue.Contains(textureSender))
            {
                m_sharedSendersQueue.Enqueue(textureSender);
            }
        }

        /// <summary>
        /// Close this module.
        /// </summary>
        internal void Close()
        {
            lock (m_textureSenders)
            {
                foreach (TextureSender.TextureSender textureSender in m_textureSenders.Values)
                {
                    textureSender.Cancel = true;
                }

                m_textureSenders.Clear();
            }
        }
    }
}