C# ConcurrentBag.Skip方法代码示例

        static void Main(string[] args)
        {
            var sw = new Stopwatch();
            sw.Start();

            var from = DatabaseFactory.CreateMongoDatabase();
            var to = DatabaseFactory.CreateMongoDatabase("light-1.com");

            if (false) {
                var categoryCollection = to.GetCollection<Category>("categories");
                categoryCollection.Drop();
                categoryCollection.EnsureIndex(IndexKeys.Ascending("Source", "Number"), IndexOptions.SetUnique(true));

                var categories = from.GetCollection<Category>("categories").FindAll();
                categoryCollection.InsertBatch(categories);
            }

            var productCollection = to.GetCollection<Product>("products");
            productCollection.Drop();

            var products = from.GetCollection<Product>("products").FindAll().ToList();

            var productsCollection = new List<List<Product>>();
            const int BATCH_SIZE = 200;
            for (var offset = 0; offset < products.Count; offset += BATCH_SIZE) {
                Console.Write(".");
                var productsInBatch = products.Skip(offset).Take(BATCH_SIZE).ToList();
                productsCollection.Add(productsInBatch);
            }

            var failedProducts = new ConcurrentBag<Product>();

            Parallel.ForEach(productsCollection,
                //new ParallelOptions { MaxDegreeOfParallelism = 4 },
                productsInBatch => {
                    try {
                        Console.Write("+");
                        productCollection.InsertBatch(productsInBatch);
                    }
                    catch {
                        Console.Write("x");
                        foreach (var p in productsInBatch)
                            failedProducts.Add(p);
                    }
                });

            for (var offset = 0; offset < failedProducts.Count; offset += BATCH_SIZE) {
                Console.Write("=");
                var productsInBatch = failedProducts.Skip(offset).Take(BATCH_SIZE).ToList();
                productCollection.InsertBatch(productsInBatch);
            }

            productCollection.EnsureIndex(IndexKeys.Ascending("Source", "Number"), IndexOptions.SetUnique(true));
        }

//.........这里部分代码省略.........
                            pObj.Brand = brand;
                            pObj.Name = name;
                            pObj.Price = strPrice;
                            pObj.OldPrice = strOldPrice;
                            pObj.Sku = sku;
                            pObj.Sizes.AddRange(sizeList);
                            photoStorage.Add(pObj);
                            Interlocked.Increment(ref totalCount);
                        }
                    }
                    catch (Exception ex)
                    {
                        // an error happened
                        Console.WriteLine(ex.Message);
                        throw new Exception(ex.Message);
                    }
                }

                Interlocked.Increment(ref processedCount);
                progressValue = (int)(100.0f / totalCount * processedCount);
                self.ReportProgress(progressValue, "Reading products");

            });

            // in case when folder separation is needed, we create those folders
            if (cfg.DirectoryLimit > 0)
            {
                int numberOfDirectories = (int)Math.Ceiling((double)((float)photoStorage.Count / cfg.DirectoryLimit));
                for (int dn = 0; dn < numberOfDirectories; dn++)
                {
                    string subdir = (dn + 1).ToString("D4");
                    string dirPath = Path.Combine(cfg.Folder, subdir);
                    if (!Directory.Exists(dirPath)) Directory.CreateDirectory(dirPath);
                    var part = photoStorage.Skip(cfg.DirectoryLimit * dn).Take(cfg.DirectoryLimit);
                    foreach (Photo p in part)
                        p.SubDirectory = subdir;
                }
            }

            // download and update photos
            var unprocessedPhotos = photoStorage.Where(p => p.Status == PhotoStatus.New || p.Status == PhotoStatus.Downloaded).ToArray();
            while (unprocessedPhotos.Length > 0)
            {
                Parallel.ForEach(unprocessedPhotos, photo =>
                {
                    // download or convert
                    string folder = cfg.Folder;
                    if (!String.IsNullOrEmpty(photo.SubDirectory))
                        folder = Path.Combine(cfg.Folder, photo.SubDirectory);
                    string orgname = Path.Combine(folder, "org." + photo.FileName);
                    string destname = Path.Combine(folder, photo.FileName);

                    if (photo.Status == PhotoStatus.New)
                    {
                        // try download
                        DownloadResult result = Web.GetFile(photo.Uri, orgname);
                        switch (result)
                        {
                            case DownloadResult.NotFound:
                                // just skip the picture
                                photo.Status = PhotoStatus.Rejected;
                                break;
                            case DownloadResult.Error:
                                // try again
                                self.ReportProgress(progressValue, CONNECTION_ERROR);
                                Console.WriteLine("Failed {0}", photo.Uri);