/*@Param Integer value of book id
*@return An object view model for Book and Stock
* A method which will pass back the correct stock
* for the desired book and a BookStockViewModel
*/
private BookStockViewModel GetStockCount(int bookId)
{
var Query = (from p in db.Stocks
where p.BookID == bookId
select p.StockCount).FirstOrDefault();
BookStockViewModel objReturn = new BookStockViewModel();
objReturn.stock.StockCount = Query;
return(objReturn);
}
public async Task <bool> DecrementStocks(BookStockViewModel bookStockViewModel)
{
var books = bookStockViewModel.StockViewModels.GroupBy(s => s.Sn)
.Select(g => new { Sn = g.Key, Count = g.Sum(s => s.Count) })
.ToList();
var sns = books.Select(b => b.Sn).ToList();
//var lockKey = string.Join(",", sns);
// using var distributedLock = await distributedLockProvider.Acquire(lockKey);
var stocks = await bookContext.BookStocks
.Where(s => sns.Contains(s.Sn))
.ToListAsync();
await Task.Delay(500);
var errors = new List <string>();
foreach (var book in books)
{
var stock = stocks.Find(s => s.Sn == book.Sn);
if (stock == null)
{
errors.Add($"book {book.Sn} doesn't exist in stocks");
continue;
}
if (stock.StockCount < book.Count)
{
errors.Add($"book {book.Sn} doesn't have enough stocks");
continue;
}
stock.StockCount -= book.Count;
stock.FreezeStock -= book.Count;
bookContext.OrderStocks
.Add(new OrderStock
{
OrderId = bookStockViewModel.OrderId,
Sn = book.Sn,
Count = book.Count
});
}
if (errors.Any())
{
throw new DomainException(string.Join(",", errors));
}
await bookContext.SaveChangesAsync();
return(true);
}
// GET: Books/Details/5
public ActionResult Details(int?id)
{
if (id == null)
{
return(new HttpStatusCodeResult(HttpStatusCode.BadRequest));
}
Book book = db.Books.Find(id);
BookStockViewModel books = new BookStockViewModel();
books.book = book;
if (book == null)
{
return(HttpNotFound());
}
return(View(books));
}
public async Task <bool> IncrementStocks(BookStockViewModel bookStockViewModel)
{
var books = bookStockViewModel.StockViewModels.GroupBy(s => s.Sn)
.Select(g => new { Sn = g.Key, Count = g.Sum(s => s.Count) })
.ToList();
var sns = books.Select(b => b.Sn).ToList();
var stocks = await bookContext.BookStocks
.Where(s => sns.Contains(s.Sn))
.ToListAsync();
foreach (var book in books)
{
var stock = stocks.Find(s => s.Sn == book.Sn);
if (stock == null)
{
stock = new BookStock
{
Sn = book.Sn,
StockCount = 0
};
bookContext.BookStocks.Add(stock);
}
if (stock.StockCount < 0 || stock.FreezeStock > stock.StockCount)
{
logger.LogError("detected data {Id} run into concurrent conflict state! freeze {freezeCount}, stock {stockCount}", stock.Id, stock.FreezeStock, stock.StockCount);
continue;
}
//test
//stock.StockCount += book.Count;
stock.StockCount = 30;
stock.FreezeStock = 0;
}
await bookContext.SaveChangesAsync();
return(true);
}
public PartialViewResult GetStock(int bookId)
{
BookStockViewModel objReturnStock = GetStockCount(bookId);
return(PartialView("~/Views/Shared/_StockForBooks.cshtml", objReturnStock));
}
