/// <summary>
/// Try to get the cache from url and httpmethod and build the response if cache is available
/// </summary>
/// <param name="cacheControl"></param>
/// <param name="request"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public async Task <HttpResponseMessage> HandleAsync(CacheControlHeaderValue cacheControl, HttpRequestMessage request, CancellationToken cancellationToken)
{
if (ShouldIgnoreCache(cacheControl, request))
{
return(null);
}
var cacheKey = request.GetUrlBaseCacheKey();
foreach (var cacheStore in Global.CacheStoreProvider.AllAsyncCacheStores)
{
var originalKey = await cacheStore.GetAsync(cacheKey).ConfigureAwait(false) as string;
if (originalKey == null)
{
continue;
}
var cacheItem = await cacheStore.GetAsync(originalKey).ConfigureAwait(false) as WebApiCacheItem;
if (cacheItem != null)
{
return(_builder.GetResponse(cacheControl, cacheItem, request));
}
}
return(null);
}
/// <summary>
/// Try to get the cache from etag and build the response if cache is available
/// </summary>
/// <param name="cacheControl"></param>
/// <param name="request"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public async Task <HttpResponseMessage> HandleAsync(CacheControlHeaderValue cacheControl, HttpRequestMessage request, CancellationToken cancellationToken)
{
if (request.Headers.IfNoneMatch != null)
{
// Etag format: fw-StoreId-HashedKey-Checksum
var requestEtags = request.Headers.IfNoneMatch.Where(t => t.Tag != null && t.Tag.StartsWith("\"fw-")).ToList();
if (requestEtags.Count > 0)
{
foreach (var etag in requestEtags)
{
var etagString = etag.Tag.Trim('"');
var index = etagString.IndexOf("-", 4, StringComparison.Ordinal);
var storeIdString = index > 0 ? etagString.Substring(3, index - 3) : "0";
index = etagString.LastIndexOf("-", StringComparison.Ordinal);
int storeId;
IAsyncCacheStore cacheStore = null;
if (int.TryParse(storeIdString, out storeId))
{
cacheStore = Global.CacheStoreProvider.GetAsyncCacheStore(storeId) ?? Global.CacheStoreProvider.GetAsyncCacheStore();
}
if (cacheStore != null && index > 0)
{
var hashedKey = etagString.Substring(0, index);
var checkSum = etagString.Substring(index + 1);
var cacheItem = (await cacheStore.GetAsync(hashedKey)) as WebApiCacheItem;
if (cacheItem != null && cacheItem.Checksum == checkSum)
{
request.Properties[WebApiExtensions.__webApi_etag_matched] = true;
}
return(_builder.GetResponse(cacheControl, cacheItem, request));
}
}
}
}
return(null);
}