// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env, IPolicyRegistry <string> policyRegistry, IAsyncCacheProvider memoryCache)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
Func <Context, HttpResponseMessage, Ttl> ttlFilter = (context, result) =>
new Ttl(result.IsSuccessStatusCode ? TimeSpan.FromSeconds(30) : TimeSpan.Zero);
AsyncCachePolicy <HttpResponseMessage> policy =
Policy.CacheAsync(memoryCache.AsyncFor <HttpResponseMessage>(),
new ResultTtl <HttpResponseMessage>(ttlFilter));
policyRegistry.Add("cache", policy);
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
public CacheManagement(ILogger logger, IPolicyRegistry <string> registry, IAsyncCacheProvider cacheProvider, IMemoryCacheExtended cache)
{
this.logger = logger;
this.registry = registry;
this.cacheProvider = cacheProvider.AsyncFor <CacheFormat>();
this.cache = cache;
}
/// <summary>
/// <para>Builds a <see cref="Policy" /> that will function like a result cache for delegate executions returning a <typeparamref name="TResult"/>.</para>
/// <para>Before executing a delegate, checks whether the <paramref name="cacheProvider" /> holds a value for the cache key determined by applying the <paramref name="cacheKeyStrategy"/> to the execution <see cref="Context"/>.
/// If the <paramref name="cacheProvider" /> provides a value, returns that value and does not execute the governed delegate. If the <paramref name="cacheProvider" /> does not provide a value, executes the governed delegate, stores the value with the <paramref name="cacheProvider" />, then returns the value.
/// </para>
/// </summary>
/// <param name="cacheProvider">The cache provider.</param>
/// <param name="ttl">Duration (ttl) for which to cache values.</param>
/// <param name="cacheKeyStrategy">The cache key strategy.</param>
/// <param name="onCacheError">Delegate to call if an exception is thrown when attempting to get a value from or put a value into the cache, passing the execution context, the cache key, and the exception.</param>
/// <returns>The policy instance.</returns>
/// <exception cref="ArgumentNullException">cacheKeyStrategy</exception>
/// <exception cref="ArgumentNullException">cacheProvider</exception>
public static CachePolicy <TResult> CacheAsync <TResult>(IAsyncCacheProvider cacheProvider, TimeSpan ttl, Func <Context, string> cacheKeyStrategy, Action <Context, string, Exception> onCacheError = null)
{
if (cacheProvider == null)
{
throw new ArgumentNullException(nameof(cacheProvider));
}
return(CacheAsync <TResult>(cacheProvider.AsyncFor <TResult>(), new RelativeTtl(ttl), cacheKeyStrategy, onCacheError));
}
/// <summary>
/// <para>Builds a <see cref="Policy"/> that will function like a result cache for delegate executions returning a <typeparamref name="TResult"/>.</para>
/// <para>Before executing a delegate, checks whether the <paramref name="cacheProvider"/> holds a value for the cache key specified by <see cref="M:Context.ExecutionKey"/>.
/// If the <paramref name="cacheProvider"/> provides a value, returns that value and does not execute the governed delegate. If the <paramref name="cacheProvider"/> does not provide a value, executes the governed delegate, stores the value with the <paramref name="cacheProvider"/>, then returns the value.
/// </para>
/// </summary>
/// <param name="cacheProvider">The cache provider.</param>
/// <param name="ttlStrategy">A strategy for specifying ttl for values to be cached.</param>
/// <param name="onCacheError">Delegate to call if an exception is thrown when attempting to get a value from or put a value into the cache, passing the execution context, the cache key, and the exception.</param>
/// <returns>The policy instance.</returns>
/// <exception cref="ArgumentNullException">cacheProvider</exception>
/// <exception cref="ArgumentNullException">ttlStrategy</exception>
public static CachePolicy <TResult> CacheAsync <TResult>(IAsyncCacheProvider cacheProvider, ITtlStrategy ttlStrategy, Action <Context, string, Exception> onCacheError = null)
{
if (cacheProvider == null)
{
throw new ArgumentNullException(nameof(cacheProvider));
}
return(CacheAsync <TResult>(cacheProvider.AsyncFor <TResult>(), ttlStrategy, DefaultCacheKeyStrategy.Instance.GetCacheKey, onCacheError));
}
/// <summary>
/// Executes the specified action asynchronously within the cache policy and returns the result.
/// </summary>
/// <typeparam name="TResult">The type of the result.</typeparam>
/// <param name="action">The action to perform.</param>
/// <param name="context">Execution context that is passed to the exception policy; defines the cache key to use in cache lookup.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <param name="continueOnCapturedContext">Whether to continue on a captured synchronization context.</param>
/// <returns>The value returned by the action, or the cache.</returns>
public override Task <TResult> ExecuteAsync <TResult>(Func <Context, CancellationToken, Task <TResult> > action, Context context, CancellationToken cancellationToken, bool continueOnCapturedContext)
{
return(CacheEngine.ImplementationAsync <TResult>(
_asyncCacheProvider.AsyncFor <TResult>(),
_ttlStrategy,
_cacheKeyStrategy,
action,
context,
cancellationToken,
continueOnCapturedContext,
_onCacheGet,
_onCacheMiss,
_onCachePut,
_onCacheGetError,
_onCachePutError));
}
internal override Task <TResult> ExecuteAsyncInternal <TResult>(Func <Context, CancellationToken, Task <TResult> > action, Context context, CancellationToken cancellationToken, bool continueOnCapturedContext)
{
if (_asyncCacheProvider == null)
{
throw new InvalidOperationException("Please use asynchronous-defined policies when calling asynchronous ExecuteAsync (and similar) methods.");
}
return(CacheEngine.ImplementationAsync <TResult>(
_asyncCacheProvider.AsyncFor <TResult>(),
_ttlStrategy.For <TResult>(),
_cacheKeyStrategy,
action,
context,
cancellationToken,
continueOnCapturedContext,
_onCacheGet,
_onCacheMiss,
_onCachePut,
_onCacheGetError,
_onCachePutError));
}
