public async Task Consume(ConsumeContext <BookStock> context)
{
await EnsureBaseCreatedAsync();
var id = context.CorrelationId.GetValueOrDefault();
var quantity = context.Message.Quantity;
logger.LogInformation($"Received {nameof(BookStock)} message with Id = '{id}' and Quantity = {quantity}.");
var couldEnterSemaphore = await locker.WaitAsync(TimeSpan.FromSeconds(30));
if (!couldEnterSemaphore)
{
logger.LogError($"Technical Error : couldn't enter thread-safe area.");
await context.Publish <StockBookingFailed>(new { context.CorrelationId });
return;
}
var stock = await dbContext.Stocks.FirstOrDefaultAsync();
if (stock is null || stock.Quantity < quantity)
{
logger.LogInformation($"Not enough stock left.");
await context.Publish <StockBookingFailed>(new { context.CorrelationId });
locker.Release();
return;
}
logger.LogInformation($"'{stock.Quantity}' left in stock. Removing {quantity}.");
stock.Quantity -= quantity;
dbContext.StockBookings.Add(new StockBooking {
Quantity = quantity, Id = id
});
await dbContext.SaveChangesAsync();
await context.Publish <StockBooked>(new { context.CorrelationId });
locker.Release();
}
public async Task Consume(ConsumeContext <UnbookStock> context)
{
await EnsureBaseCreatedAsync();
var id = context.CorrelationId.GetValueOrDefault();
var quantity = context.Message.Quantity;
logger.LogInformation($"Received {nameof(UnbookStock)} message with Id = '{id}' and Quantity = {quantity}.");
var couldEnterSemaphore = await locker.WaitAsync(TimeSpan.FromSeconds(30));
if (!couldEnterSemaphore)
{
logger.LogError($"Technical Error : couldn't enter thread-safe area. Will retry.");
throw new Exception();
}
var stock = await dbContext.Stocks.FirstAsync();
var booking = await dbContext.StockBookings.FindAsync(id);
if (booking is null)
{
logger.LogInformation($"No booking find with Id = '{id}'. Skipping.");
locker.Release();
return;
}
dbContext.StockBookings.Remove(booking);
logger.LogInformation($"'{stock.Quantity}' left in stock. Adding {quantity} back.");
stock.Quantity += quantity;
await dbContext.SaveChangesAsync();
locker.Release();
}