protected override async Task <HttpResponseMessage> SendAsync(
HttpRequestMessage request,
CancellationToken cancellationToken)
{
var resourceKey = GetResourceKey(request.RequestUri, _varyHeaders, request);
CacheableEntity cacheableEntity = null;
var cacheControlHeader = new CacheControlHeaderValue {
Private = true,
MustRevalidate = true,
MaxAge = TimeSpan.FromSeconds(0)
};
if (request.Method == HttpMethod.Get)
{
var eTags = request.Headers.IfNoneMatch;
var modifiedSince = request.Headers.IfModifiedSince;
var anyEtagsFromTheClientExist = eTags.Any();
var doWeHaveAnyCacheableEntityForTheRequest =
_eTagCacheDictionary.TryGetValue(resourceKey, out cacheableEntity);
if (anyEtagsFromTheClientExist)
{
if (doWeHaveAnyCacheableEntityForTheRequest)
{
if (eTags.Any(x => x.Tag == cacheableEntity.EntityTag.Tag))
{
var tempResp = new HttpResponseMessage(HttpStatusCode.NotModified);
tempResp.Headers.CacheControl = cacheControlHeader;
return(tempResp);
}
}
}
else if (modifiedSince.HasValue)
{
if (doWeHaveAnyCacheableEntityForTheRequest)
{
if (cacheableEntity.IsValid(modifiedSince.Value))
{
var tempResp = new HttpResponseMessage(HttpStatusCode.NotModified);
tempResp.Headers.CacheControl = cacheControlHeader;
return(tempResp);
}
}
}
}
HttpResponseMessage response;
try {
response = await base.SendAsync(request, cancellationToken);
}
catch (Exception ex) {
response = request.CreateErrorResponse(
HttpStatusCode.InternalServerError, ex);
}
if (response.IsSuccessStatusCode)
{
if (request.Method == HttpMethod.Get &&
!_eTagCacheDictionary.TryGetValue(resourceKey, out cacheableEntity))
{
cacheableEntity = new CacheableEntity(resourceKey);
cacheableEntity.EntityTag = GenerateETag();
cacheableEntity.LastModified = DateTimeOffset.Now;
_eTagCacheDictionary.AddOrUpdate(
resourceKey, cacheableEntity, (k, e) => cacheableEntity);
}
if (request.Method == HttpMethod.Put ||
request.Method == HttpMethod.Post ||
request.Method == HttpMethod.Delete)
{
HashSet <string> invalidCaches = new HashSet <string>();
invalidCaches.Add(GetRequestUri(request.RequestUri));
CacheInvalidationStore.ForEach(
func => func(GetRequestUri(request.RequestUri))
.ForEach(uri => invalidCaches.Add(uri)));
invalidCaches.ForEach(invalidCacheUri => {
var cacheEntityKeys = _eTagCacheDictionary.Keys.Where(
x => x.StartsWith(
string.Format("{0}:", invalidCacheUri),
StringComparison.InvariantCultureIgnoreCase));
cacheEntityKeys.ForEach(key => {
if (!string.IsNullOrEmpty(key))
{
CacheableEntity outVal = null;
_eTagCacheDictionary.TryRemove(key, out outVal);
}
});
});
}
else
{
response.Headers.CacheControl = cacheControlHeader;
response.Headers.ETag = cacheableEntity.EntityTag;
response.Content.Headers.LastModified = cacheableEntity.LastModified;
_varyHeaders.ForEach(
varyHeader => response.Headers.Vary.Add(varyHeader));
}
}
return(response);
}
protected override async Task<HttpResponseMessage> SendAsync(
HttpRequestMessage request,
CancellationToken cancellationToken) {
var resourceKey = GetResourceKey(request.RequestUri, _varyHeaders, request);
CacheableEntity cacheableEntity = null;
var cacheControlHeader = new CacheControlHeaderValue {
Private = true,
MustRevalidate = true,
MaxAge = TimeSpan.FromSeconds(0)
};
if (request.Method == HttpMethod.Get) {
var eTags = request.Headers.IfNoneMatch;
var modifiedSince = request.Headers.IfModifiedSince;
var anyEtagsFromTheClientExist = eTags.Any();
var doWeHaveAnyCacheableEntityForTheRequest =
_eTagCacheDictionary.TryGetValue(resourceKey, out cacheableEntity);
if (anyEtagsFromTheClientExist) {
if (doWeHaveAnyCacheableEntityForTheRequest) {
if (eTags.Any(x => x.Tag == cacheableEntity.EntityTag.Tag)) {
var tempResp = new HttpResponseMessage(HttpStatusCode.NotModified);
tempResp.Headers.CacheControl = cacheControlHeader;
return tempResp;
}
}
}
else if (modifiedSince.HasValue) {
if (doWeHaveAnyCacheableEntityForTheRequest) {
if (cacheableEntity.IsValid(modifiedSince.Value)) {
var tempResp = new HttpResponseMessage(HttpStatusCode.NotModified);
tempResp.Headers.CacheControl = cacheControlHeader;
return tempResp;
}
}
}
}
HttpResponseMessage response;
try {
response = await base.SendAsync(request, cancellationToken);
}
catch (Exception ex) {
response = request.CreateErrorResponse(
HttpStatusCode.InternalServerError, ex);
}
if (response.IsSuccessStatusCode) {
if (request.Method == HttpMethod.Get &&
!_eTagCacheDictionary.TryGetValue(resourceKey, out cacheableEntity)) {
cacheableEntity = new CacheableEntity(resourceKey);
cacheableEntity.EntityTag = GenerateETag();
cacheableEntity.LastModified = DateTimeOffset.Now;
_eTagCacheDictionary.AddOrUpdate(
resourceKey, cacheableEntity, (k, e) => cacheableEntity);
}
if (request.Method == HttpMethod.Put ||
request.Method == HttpMethod.Post ||
request.Method == HttpMethod.Delete) {
HashSet<string> invalidCaches = new HashSet<string>();
invalidCaches.Add(GetRequestUri(request.RequestUri));
CacheInvalidationStore.ForEach(
func => func(GetRequestUri(request.RequestUri))
.ForEach(uri => invalidCaches.Add(uri)));
invalidCaches.ForEach(invalidCacheUri => {
var cacheEntityKeys = _eTagCacheDictionary.Keys.Where(
x => x.StartsWith(
string.Format("{0}:", invalidCacheUri),
StringComparison.InvariantCultureIgnoreCase));
cacheEntityKeys.ForEach(key => {
if (!string.IsNullOrEmpty(key)) {
CacheableEntity outVal = null;
_eTagCacheDictionary.TryRemove(key, out outVal);
}
});
});
}
else {
response.Headers.CacheControl = cacheControlHeader;
response.Headers.ETag = cacheableEntity.EntityTag;
response.Content.Headers.LastModified = cacheableEntity.LastModified;
_varyHeaders.ForEach(
varyHeader => response.Headers.Vary.Add(varyHeader));
}
}
return response;
}
