/// <summary>
/// Called before an action method executes.
/// </summary>
/// <param name="filterContext">The filter context.</param>
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
CacheSettings = BuildCacheSettings();
var cacheKey = KeyGenerator.GenerateKey(filterContext, CacheSettings);
// If we are unable to generate a cache key it means we can't do anything
if (string.IsNullOrEmpty(cacheKey))
{
return;
}
// Are we actually storing data on the server side ?
if (CacheSettings.IsServerCachingEnabled)
{
CacheItem cachedItem = null;
// If the request is a POST, we lookup for NoCacheLookupForPosts option
// We are fetching the stored value only if the option has not been set and the request is not a POST
if (
(CacheSettings.Options & OutputCacheOptions.NoCacheLookupForPosts) != OutputCacheOptions.NoCacheLookupForPosts ||
filterContext.HttpContext.Request.HttpMethod != "POST"
)
{
cachedItem = OutputCacheManager.GetItem(cacheKey);
}
// We have a cached version on the server side
if (cachedItem != null)
{
// We inject the previous result into the MVC pipeline
// The MVC action won't execute as we injected the previous cached result.
filterContext.Result = new ContentResult
{
Content = DonutHoleFiller.ReplaceDonutHoleContent(cachedItem.Content, filterContext, CacheSettings.Options),
ContentType = cachedItem.ContentType
};
}
}
// Did we already injected something ?
if (filterContext.Result != null)
{
return; // No need to continue
}
// We are hooking into the pipeline to replace the response Output writer
// by something we own and later eventually gonna cache
var cachingWriter = new StringWriter(CultureInfo.InvariantCulture);
var originalWriter = filterContext.HttpContext.Response.Output;
filterContext.HttpContext.Response.Output = cachingWriter;
// Will be called back by OnResultExecuted -> ExecuteCallback
filterContext.HttpContext.Items[cacheKey] = new Action<bool>(hasErrors =>
{
// Removing this executing action from the context
filterContext.HttpContext.Items.Remove(cacheKey);
// We restore the original writer for response
filterContext.HttpContext.Response.Output = originalWriter;
if (hasErrors)
{
return; // Something went wrong, we are not going to cache something bad
}
// Now we use owned caching writer to actually store data
var cacheItem = new CacheItem
{
Content = cachingWriter.ToString(),
ContentType = filterContext.HttpContext.Response.ContentType
};
filterContext.HttpContext.Response.Write(
DonutHoleFiller.RemoveDonutHoleWrappers(cacheItem.Content, filterContext, CacheSettings.Options)
);
if (CacheSettings.IsServerCachingEnabled && filterContext.HttpContext.Response.StatusCode == 200)
{
OutputCacheManager.AddItem(cacheKey, cacheItem, DateTime.UtcNow.AddSeconds(CacheSettings.Duration));
}
});
}
public void AddItem(string key, CacheItem cacheItem, DateTime utcExpiry)
{
_outputCacheProvider.Add(key, cacheItem, utcExpiry);
}
/// <summary>
/// Called before an action method executes.
/// </summary>
/// <param name="filterContext">The filter context.</param>
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
CacheSettings = BuildCacheSettings();
var cacheKey = KeyGenerator.GenerateKey(filterContext, CacheSettings);
// If we are unable to generate a cache key it means we can't do anything
if (string.IsNullOrEmpty(cacheKey))
{
return;
}
// Are we actually storing data on the server side ?
if (CacheSettings.IsServerCachingEnabled)
{
CacheItem cachedItem = null;
// If the request is a POST, we lookup for NoCacheLookupForPosts option
// We are fetching the stored value only if the option has not been set and the request is not a POST
if (
(CacheSettings.Options & OutputCacheOptions.NoCacheLookupForPosts) != OutputCacheOptions.NoCacheLookupForPosts ||
filterContext.HttpContext.Request.HttpMethod != "POST"
)
{
cachedItem = OutputCacheManager.GetItem(cacheKey);
}
// We have a cached version on the server side
if (cachedItem != null)
{
// We inject the previous result into the MVC pipeline
// The MVC action won't execute as we injected the previous cached result.
filterContext.Result = new DonutContentResult
{
Content = DonutHoleFiller.ReplaceDonutHoleContent(cachedItem.Content, cachedItem.ContentType, filterContext, CacheSettings.Options),
ContentType = cachedItem.ContentType
};
}
}
// Did we already injected something ?
if (filterContext.Result != null)
{
return; // No need to continue
}
// We are hooking into the pipeline to replace the response Output writer
// by something we own and later eventually gonna cache
var cachingWriter = new StringWriter(CultureInfo.InvariantCulture);
var originalWriter = filterContext.HttpContext.Response.Output;
filterContext.HttpContext.Response.Output = cachingWriter;
// Will be called back by OnResultExecuted -> ExecuteCallback
filterContext.HttpContext.Items[cacheKey] = new Action <bool>(hasErrors =>
{
// Removing this executing action from the context
filterContext.HttpContext.Items.Remove(cacheKey);
// We restore the original writer for response
filterContext.HttpContext.Response.Output = originalWriter;
if (hasErrors)
{
return; // Something went wrong, we are not going to cache something bad
}
// Now we use owned caching writer to actually store data
var cacheItem = new CacheItem
{
Content = cachingWriter.ToString(),
ContentType = filterContext.HttpContext.Response.ContentType
};
filterContext.HttpContext.Response.Write(
DonutHoleFiller.RemoveDonutHoleWrappers(cacheItem.Content, filterContext, CacheSettings.Options)
);
// Skip saving the cache if ignored for current execution
if (OutputCacheManager.GetIgnoreCurrentExecution(filterContext))
{
OutputCacheManager.RemoveIgnoreCurrentExecution(filterContext);
return; // Skip current execution from cache
}
if (CacheSettings.IsServerCachingEnabled && filterContext.HttpContext.Response.StatusCode == 200)
{
OutputCacheManager.AddItem(cacheKey, cacheItem, DateTime.UtcNow.AddSeconds(CacheSettings.Duration));
}
});
}
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
_cacheSettings = BuildCacheSettings();
var cacheKey = _keyGenerator.GenerateKey(filterContext, _cacheSettings);
if (_cacheSettings.IsServerCachingEnabled)
{
var cachedItem = _outputCacheManager.GetItem(cacheKey);
if (cachedItem != null)
{
filterContext.Result = new ContentResult
{
Content = _donutHoleFiller.ReplaceDonutHoleContent(cachedItem.Content, filterContext),
ContentType = cachedItem.ContentType
};
}
}
if (filterContext.Result == null)
{
var cachingWriter = new StringWriter(CultureInfo.InvariantCulture);
var originalWriter = filterContext.HttpContext.Response.Output;
filterContext.HttpContext.Response.Output = cachingWriter;
filterContext.HttpContext.Items[cacheKey] = new Action<bool>(hasErrors =>
{
filterContext.HttpContext.Items.Remove(cacheKey);
filterContext.HttpContext.Response.Output = originalWriter;
if (!hasErrors)
{
var cacheItem = new CacheItem
{
Content = cachingWriter.ToString(),
ContentType = filterContext.HttpContext.Response.ContentType
};
filterContext.HttpContext.Response.Write(_donutHoleFiller.RemoveDonutHoleWrappers(cacheItem.Content, filterContext));
if (_cacheSettings.IsServerCachingEnabled && filterContext.HttpContext.Response.StatusCode == 200)
{
_outputCacheManager.AddItem(cacheKey, cacheItem, DateTime.UtcNow.AddSeconds(_cacheSettings.Duration));
}
}
});
}
}
