FlickrNet.Flickr.DownloadPicture C# (CSharp) Method

        public System.IO.Stream DownloadPicture(string url)
        {
            const int BUFFER_SIZE = 1024 * 10;

            PictureCacheItem cacheItem = (PictureCacheItem) Cache.Downloads[url];
            if (cacheItem != null)
            {
                return  new FileStream(cacheItem.filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
            }

            PictureCacheItem picCache = new PictureCacheItem();
            picCache.filename = Path.Combine(Cache.CacheLocation,Guid.NewGuid().ToString());
            Stream read = DoDownloadPicture(url);
            Stream write = new FileStream(picCache.filename, FileMode.Create, FileAccess.Write, FileShare.None);

            byte[] buffer = new byte[BUFFER_SIZE];
            int bytes = 0;
            long fileSize = 0;

            while( (bytes = read.Read(buffer, 0, BUFFER_SIZE)) > 0 )
            {
                fileSize += bytes;
                write.Write(buffer, 0, bytes);
            }

            read.Close();
            write.Close();

            picCache.url = url;
            picCache.creationTime = DateTime.UtcNow;
            picCache.fileSize = fileSize;

            Cache.Downloads.Shrink(Math.Max(0, Cache.CacheSizeLimit - fileSize));
            Cache.Downloads[url] = picCache;

            return new FileStream(picCache.filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
        }