Ejemplo n.º 1
0
        /// <summary>
        /// Finds the next file to download
        /// </summary>
        protected virtual DownloadRequest GetNextDownloadRequest()
        {
            DownloadRequest bestRequest  = null;
            float           highestScore = float.MinValue;

            lock (m_requests.SyncRoot)
            {
                for (int i = m_requests.Count - 1; i >= 0; i--)
                {
                    DownloadRequest request = (DownloadRequest)m_requests[i];
                    if (request.IsDownloading)
                    {
                        continue;
                    }

                    float score = request.CalculateScore();
                    if (float.IsNegativeInfinity(score))
                    {
                        // Request is of no interest anymore, remove it
                        m_requests.RemoveAt(i);
                        request.Dispose();
                        continue;
                    }

                    if (score > highestScore)
                    {
                        highestScore = score;
                        bestRequest  = request;
                    }
                }
            }

            return(bestRequest);
        }
Ejemplo n.º 2
0
        /// <summary>
        /// Starts downloads when there are threads available
        /// </summary>
        protected virtual void ServiceDownloadQueue()
        {
            lock (m_requests.SyncRoot)
            {
                // Remove finished downloads
                for (int i = m_activeDownloads.Count - 1; i >= 0; i--)
                {
                    DownloadRequest request = (DownloadRequest)m_activeDownloads[i];
                    if (!request.IsDownloading)
                    {
                        m_activeDownloads.RemoveAt(i);
                    }
                }

                // Start new downloads
                while (m_activeDownloads.Count < MaxConcurrentDownloads)
                {
                    DownloadRequest request = GetNextDownloadRequest();
                    if (request == null)
                    {
                        break;
                    }

                    m_activeDownloads.Add(request);
                    request.Start();
                }
            }
        }
Ejemplo n.º 3
0
        /// <summary>
        /// Callback when download is complete.
        /// </summary>
        internal void OnComplete(DownloadRequest request)
        {
            lock (m_requests.SyncRoot)
            {
                // Remove the finished item from queue
                m_requests.Remove(request);
                request.Dispose();
            }

            // Start next download
            ServiceDownloadQueue();
        }
Ejemplo n.º 4
0
 /// <summary>
 /// Remove all requests with a certain owner.
 /// </summary>
 /// <param name="owner"></param>
 public virtual void Clear(object owner)
 {
     lock (m_requests.SyncRoot)
     {
         for (int i = m_requests.Count - 1; i >= 0; i--)
         {
             DownloadRequest request = (DownloadRequest)m_requests[i];
             if (request.Owner == owner)
             {
                 m_requests.RemoveAt(i);
                 request.Dispose();
             }
         }
     }
     ServiceDownloadQueue();
 }
Ejemplo n.º 5
0
        /// <summary>
        /// Removes a request from the download queue.
        /// </summary>
        public virtual void Remove(DownloadRequest request)
        {
            lock (m_requests.SyncRoot)
            {
                for (int i = m_activeDownloads.Count - 1; i >= 0; i--)
                {
                    if (request == m_activeDownloads[i])
                    {
                        // Already downloading, let it finish
                        return;
                    }
                }

                m_requests.Remove(request);
            }
            request.Dispose();

            ServiceDownloadQueue();
        }
Ejemplo n.º 6
0
        /// <summary>
        /// Add a download request to the queue.
        /// </summary>
        public virtual void Add(DownloadRequest newRequest)
        {
            if (newRequest == null)
            {
                throw new NullReferenceException();
            }

            lock (m_requests.SyncRoot)
            {
                foreach (DownloadRequest request in m_requests)
                {
                    if (request.Key == newRequest.Key)
                    {
                        newRequest.Dispose();
                        return;
                    }
                }

                // don't forget to also check the currently active downloads!
                foreach (DownloadRequest request in m_activeDownloads)
                {
                    if (request.Key == newRequest.Key)
                    {
                        newRequest.Dispose();
                        return;
                    }
                }

                m_requests.Add(newRequest);

                if (m_requests.Count > MaxQueueLength)
                {
                    // Remove lowest scoring queued request
                    DownloadRequest leastImportantRequest = null;
                    float           lowestScore           = float.MinValue;

                    for (int i = m_requests.Count - 1; i >= 0; i--)
                    {
                        DownloadRequest request = (DownloadRequest)m_requests[i];
                        if (request.IsDownloading)
                        {
                            continue;
                        }

                        float score = request.CalculateScore();
                        if (score == float.MinValue)
                        {
                            // Request is of no interest anymore, remove it
                            m_requests.Remove(request);
                            request.Dispose();
                            return;
                        }

                        if (score < lowestScore)
                        {
                            lowestScore           = score;
                            leastImportantRequest = request;
                        }
                    }

                    if (leastImportantRequest != null)
                    {
                        m_requests.Remove(leastImportantRequest);
                        leastImportantRequest.Dispose();
                    }
                }
            }

            ServiceDownloadQueue();
        }