private ProfileElement getWebApiCacheProfile()
{
var webApiCacheConfig = WebApiCacheConfigSection.GetConfig();
ProfileElement webApiProfileElement = null;
if (webApiCacheConfig != null && webApiCacheConfig.Profiles != null && webApiCacheConfig.Profiles.Count > 0)
{
webApiProfileElement = webApiCacheConfig.Profiles[CacheProfile];
}
return(webApiProfileElement);
}
public async override Task OnActionExecutingAsync(HttpActionContext actionContext, CancellationToken cancellationToken)
{
if (actionContext == null)
{
throw new ArgumentNullException("actionContext");
}
ProfileElement webApiProfileElement = null;
webApiProfileElement = getWebApiCacheProfile();
if (webApiProfileElement != null && webApiProfileElement.Enable)
{
this.ClientTimeSpan = webApiProfileElement.ClientTimeSpan;
this.ServerTimeSpan = webApiProfileElement.ServerTimeSpan;
this.MustRevalidate = webApiProfileElement.MustRevalidate;
this.ExcludeQueryStringFromCacheKey = webApiProfileElement.ExcludeQueryStringFromCacheKey;
this.AnonymousOnly = webApiProfileElement.AnonymousOnly;
}
//是否允许缓存
if (!IsCachingAllowed(actionContext, AnonymousOnly))
{
return;
}
var config = actionContext.Request.GetConfiguration();
EnsureCacheTimeQuery();
EnsureCache(config, actionContext.Request);
//Key
var cacheKeyGenerator = config.CacheOutputConfiguration().GetCacheKeyGenerator(actionContext.Request, CacheKeyGenerator);
//返回值类型
var responseMediaType = GetExpectedMediaType(config, actionContext);
actionContext.Request.Properties[CurrentRequestMediaType] = responseMediaType;
//生成Key
var cachekey = cacheKeyGenerator.MakeCacheKey(actionContext, responseMediaType, ExcludeQueryStringFromCacheKey);
if (!_webApiCache.Contains(cachekey))
{
return;
}
//ETag判断
if (actionContext.Request.Headers.IfNoneMatch != null)
{
var etag = _webApiCache.Get <string>(cachekey + Constants.EtagKey);
if (etag != null)
{
if (actionContext.Request.Headers.IfNoneMatch.Any(x => x.Tag == etag))
{
var time = CacheTimeQuery.Execute(DateTime.Now);
var quickResponse = actionContext.Request.CreateResponse(HttpStatusCode.NotModified);
ApplyCacheHeaders(quickResponse, time);
//输出
actionContext.Response = quickResponse;
return;
}
}
}
//直接从缓存返回
var val = _webApiCache.Get <byte[]>(cachekey);
if (val == null)
{
return;
}
var contenttype = _webApiCache.Get <MediaTypeHeaderValue>(cachekey + Constants.ContentTypeKey) ?? new MediaTypeHeaderValue(cachekey.Split(new[] { ':' }, 2)[1].Split(';')[0]);
actionContext.Response = actionContext.Request.CreateResponse();
actionContext.Response.Content = new ByteArrayContent(val);
actionContext.Response.Content.Headers.ContentType = contenttype;
var responseEtag = _webApiCache.Get <string>(cachekey + Constants.EtagKey);
if (responseEtag != null)
{
SetEtag(actionContext.Response, responseEtag);
}
var cacheTime = CacheTimeQuery.Execute(DateTime.Now);
ApplyCacheHeaders(actionContext.Response, cacheTime);
//判断是否需要预读
if (PreloadAllowed(actionContext))
{
await PreloadNextPageByHttpClient(actionContext);
}
}