ASP.NET Core使用filter和redis实现接口防重 - ToB企服应用市场:ToB评测及商务社交产业平台

public class PreventDuplicateRequestsActionFilter : IAsyncActionFilter
{
public string[] FactorNames { get; set; }
public TimeSpan? AbsoluteExpirationRelativeToNow { get; set; }
private readonly IDistributedCache _cache;
private readonly ILogger<PreventDuplicateRequestsActionFilter> _logger;
public PreventDuplicateRequestsActionFilter(IDistributedCache cache, ILogger<PreventDuplicateRequestsActionFilter> logger)
{
_cache = cache;
_logger = logger;
}
public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
{
var factorValues = new string?[FactorNames.Length];
var isFromBody =
context.ActionDescriptor.Parameters.Any(r => r.BindingInfo?.BindingSource == BindingSource.Body);
if (isFromBody)
{
var parameterValue = context.ActionArguments.FirstOrDefault().Value;
factorValues = FactorNames.Select(name =>
parameterValue?.GetType().GetProperty(name)?.GetValue(parameterValue)?.ToString()).ToArray();
}
else
{
for (var index = 0; index < FactorNames.Length; index++)
{
if (context.ActionArguments.TryGetValue(FactorNames[index], out var factorValue))
{
factorValues[index] = factorValue?.ToString();
}
}
}
if (factorValues.All(string.IsNullOrEmpty))
{
_logger.LogWarning("Please config FactorNames.");
await next();
return;
}
var idempotentKey = $"{context.HttpContext.Request.Path.Value}:{string.Join("-", factorValues)}";
var idempotentValue = await _cache.GetStringAsync(idempotentKey);
if (idempotentValue != null)
{
_logger.LogWarning("Received duplicate request({},{}), short-circuiting...", idempotentKey, idempotentValue);
context.Result = new AcceptedResult();
}
else
{
await _cache.SetStringAsync(idempotentKey, DateTimeOffset.UtcNow.ToString(),
new DistributedCacheEntryOptions {AbsoluteExpirationRelativeToNow = AbsoluteExpirationRelativeToNow});
await next();
}
}
}

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[AttributeUsage(AttributeTargets.Method)]
public class PreventDuplicateRequestsAttribute : Attribute, IFilterFactory
{
private readonly string[] _factorNames;
private readonly int _expiredMinutes;
public PreventDuplicateRequestsAttribute(int expiredMinutes, params string[] factorNames)
{
_expiredMinutes = expiredMinutes;
_factorNames = factorNames;
}
public IFilterMetadata CreateInstance(IServiceProvider serviceProvider)
{
var filter = serviceProvider.GetService<PreventDuplicateRequestsActionFilter>();
filter.FactorNames = _factorNames;
filter.AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(_expiredMinutes);
return filter;
}
public bool IsReusable => false;
}

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builder.Services.AddStackExchangeRedisCache(options =>
{
options.Configuration = "127.0.0.1:6379,DefaultDatabase=1";
});
builder.Services.AddScoped<PreventDuplicateRequestsActionFilter>();

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namespace PreventDuplicateRequestDemo.Controllers
{
[Route("api/[controller]")]
[ApiController]
public class OrderController : ControllerBase
{
[HttpPost(nameof(CancelOrder))]
[PreventDuplicateRequests(5, "OrderId", "Reason")]
public async Task<IActionResult> CancelOrder([FromBody] CancelOrderRequest request)
{
await Task.Delay(1000);
return new OkResult();
}
}
public class CancelOrderRequest
{
public Guid OrderId { get; set; }
public string Reason { get; set; }
}
}

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