ASP.NET Core 中的响应缓存中间件
内容导读
互联网集市收集整理的这篇技术教程文章主要介绍了ASP.NET Core 中的响应缓存中间件，小编现在分享给大家，供广大互联网技能从业者学习和参考。文章包含4891字，纯文字阅读大概需要7分钟。
内容图文
客户端(浏览器)缓存
通过设置HTTP的响应头来完成
1、直接用Response对象去设置
[HttpGet]
public IEnumerable<WeatherForecast> Get()
{
Console.WriteLine("服务响应");
//直接一，简单粗暴，不要拼写错了就好~~
Response.Headers[Microsoft.Net.Http.Headers.HeaderNames.CacheControl] = "public, max-age=600";
var rng = new Random();
return Enumerable.Range(1, 5).Select(index => new WeatherForecast
{
Date = DateTime.Now.AddDays(index),
TemperatureC = rng.Next(-20, 55),
Summary = Summaries[rng.Next(Summaries.Length)]
})
.ToArray();
}
View Code
查看http响应头
上面的示例设置客户端缓存600秒，如果直接刷新浏览器或者按F5进行刷新，缓存会失效（cache-control对刷新无效）
2、用ResponseCacheAttribute类设置缓存
[HttpGet]
[ResponseCache(Duration = 100)]
public IEnumerable<WeatherForecast> Get()
{
Console.WriteLine("服务响应");
////直接一，简单粗暴，不要拼写错了就好~~
//Response.Headers[Microsoft.Net.Http.Headers.HeaderNames.CacheControl] = "public, max-age=600";
var rng = new Random();
return Enumerable.Range(1, 5).Select(index => new WeatherForecast
{
Date = DateTime.Now.AddDays(index),
TemperatureC = rng.Next(-20, 55),
Summary = Summaries[rng.Next(Summaries.Length)]
})
.ToArray();
}
View Code
效果和上面是一致的，通过源码分析发现ResponseCacheAttribute也是通过设置http头来实现的。
/// <summary>
/// Specifies the parameters necessary for setting appropriate headers in response caching.
/// </summary>
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
public class ResponseCacheAttribute : Attribute, IFilterFactory, IOrderedFilter
{
/// <inheritdoc />
public IFilterMetadata CreateInstance(IServiceProvider serviceProvider)
{
if (serviceProvider == null)
{
throw new ArgumentNullException(nameof(serviceProvider));
}
var loggerFactory = serviceProvider.GetRequiredService<ILoggerFactory>();
var optionsAccessor = serviceProvider.GetRequiredService<IOptions<MvcOptions>>();
var cacheProfile = GetCacheProfile(optionsAccessor.Value);
// ResponseCacheFilter cannot take any null values. Hence, if there are any null values,
// the properties convert them to their defaults and are passed on.
return new ResponseCacheFilter(cacheProfile, loggerFactory);
}
}
View Code
ResponseCacheFilter部分代码如下
/// <summary>
/// An <see cref="IActionFilter"/> which sets the appropriate headers related to response caching.
/// </summary>
internal class ResponseCacheFilter : IActionFilter, IResponseCacheFilter
{
/// <inheritdoc />
public void OnActionExecuting(ActionExecutingContext context)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
// If there are more filters which can override the values written by this filter,
// then skip execution of this filter.
var effectivePolicy = context.FindEffectivePolicy<IResponseCacheFilter>();
if (effectivePolicy != null && effectivePolicy != this)
{
_logger.NotMostEffectiveFilter(GetType(), effectivePolicy.GetType(), typeof(IResponseCacheFilter));
return;
}
_executor.Execute(context);
}
}
View Code
具体的实现是在ResponseCacheFilterExecutor类中，代码如下
internal class ResponseCacheFilterExecutor
{
public void Execute(FilterContext context)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
if (!NoStore)
{
// Duration MUST be set (either in the cache profile or in this filter) unless NoStore is true.
if (_cacheProfile.Duration == null && _cacheDuration == null)
{
throw new InvalidOperationException(
Resources.FormatResponseCache_SpecifyDuration(nameof(NoStore), nameof(Duration)));
}
}
var headers = context.HttpContext.Response.Headers;
// Clear all headers
headers.Remove(HeaderNames.Vary);
headers.Remove(HeaderNames.CacheControl);
headers.Remove(HeaderNames.Pragma);
if (!string.IsNullOrEmpty(VaryByHeader))
{
headers[HeaderNames.Vary] = VaryByHeader;
}
if (VaryByQueryKeys != null)
{
var responseCachingFeature = context.HttpContext.Features.Get<IResponseCachingFeature>();
if (responseCachingFeature == null)
{
throw new InvalidOperationException(
Resources.FormatVaryByQueryKeys_Requires_ResponseCachingMiddleware(nameof(VaryByQueryKeys)));
}
responseCachingFeature.VaryByQueryKeys = VaryByQueryKeys;
}
if (NoStore)
{
headers[HeaderNames.CacheControl] = "no-store";
// Cache-control: no-store, no-cache is valid.
if (Location == ResponseCacheLocation.None)
{
headers.AppendCommaSeparatedValues(HeaderNames.CacheControl, "no-cache");
headers[HeaderNames.Pragma] = "no-cache";
}
}
else
{
string cacheControlValue;
switch (Location)
{
case ResponseCacheLocation.Any:
cacheControlValue = "public,";
break;
case ResponseCacheLocation.Client:
cacheControlValue = "private,";
break;
case ResponseCacheLocation.None:
cacheControlValue = "no-cache,";
headers[HeaderNames.Pragma] = "no-cache";
break;
default:
cacheControlValue = null;
break;
}
cacheControlValue = $"{cacheControlValue}max-age={Duration}";
headers[HeaderNames.CacheControl] = cacheControlValue;
}
}
}
View Code
通过源码分析已经知道了ResponseCacheAttribute运作的基本原理，下面再来看看如何配置出其他不同的效果。
内容总结
以上是互联网集市为您收集整理的ASP.NET Core 中的响应缓存中间件全部内容，希望文章能够帮你解决ASP.NET Core 中的响应缓存中间件所遇到的程序开发问题。 如果觉得互联网集市技术教程内容还不错，欢迎将互联网集市网站推荐给程序员好友。
内容备注
版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 gblab@vip.qq.com 举报，一经查实，本站将立刻删除。
内容手机端
扫描二维码推送至手机访问。
来源：【匿名】