/// <summary>
/// <para>Builds a <see cref="Policy"/> that will function like a result cache for delegate executions returning a result.</para>
/// <para>Before executing a delegate returning a result, 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 from cache, 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="onCacheGet">Delegate to call on a cache hit, when value is returned from cache.</param>
/// <param name="onCacheMiss">Delegate to call on a cache miss.</param>
/// <param name="onCachePut">Delegate to call on cache put.</param>
/// <param name="onCacheGetError">Delegate to call if an exception is thrown when attempting to get a value from the cache, passing the execution context, the cache key, and the exception.</param>
/// <param name="onCachePutError">Delegate to call if an exception is thrown when attempting to put a value in the cache, passing the execution context, the cache key, and the exception.</param>
/// <returns>The policy instance.</returns>
/// <exception cref="System.ArgumentNullException">
/// </exception>
/// <exception cref="ArgumentNullException">cacheProvider</exception>
/// <exception cref="ArgumentNullException">cacheKeyStrategy</exception>
/// <exception cref="ArgumentNullException">onCacheGet</exception>
/// <exception cref="ArgumentNullException">onCacheMiss</exception>
/// <exception cref="ArgumentNullException">onCachePut</exception>
/// <exception cref="ArgumentNullException">onCacheGetError</exception>
/// <exception cref="ArgumentNullException">onCachePutError</exception>
public static CachePolicy Cache(
ISyncCacheProvider cacheProvider,
TimeSpan ttl,
ICacheKeyStrategy cacheKeyStrategy,
Action <Context, string> onCacheGet,
Action <Context, string> onCacheMiss,
Action <Context, string> onCachePut,
Action <Context, string, Exception> onCacheGetError,
Action <Context, string, Exception> onCachePutError)
{
return(Cache(cacheProvider, new RelativeTtl(ttl), cacheKeyStrategy.GetCacheKey, onCacheGet, onCacheMiss, onCachePut, onCacheGetError, onCachePutError));
}
/// <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" /> contains 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="cacheKeyStrategy">The cache key strategy.</param>
/// <param name="onCacheGet">Delegate to call on a cache hit, when value is returned from cache.</param>
/// <param name="onCacheMiss">Delegate to call on a cache miss.</param>
/// <param name="onCachePut">Delegate to call on cache put.</param>
/// <param name="onCacheGetError">Delegate to call if an exception is thrown when attempting to get a value from the cache, passing the execution context, the cache key, and the exception.</param>
/// <param name="onCachePutError">Delegate to call if an exception is thrown when attempting to put a value in 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>
/// <exception cref="ArgumentNullException">cacheKeyStrategy</exception>
/// <exception cref="ArgumentNullException">onCacheGet</exception>
/// <exception cref="ArgumentNullException">onCacheMiss</exception>
/// <exception cref="ArgumentNullException">onCachePut</exception>
/// <exception cref="ArgumentNullException">onCacheGetError</exception>
/// <exception cref="ArgumentNullException">onCachePutError</exception>
public static CachePolicy <TResult> Cache <TResult>(
ISyncCacheProvider <TResult> cacheProvider,
ITtlStrategy ttlStrategy,
ICacheKeyStrategy cacheKeyStrategy,
Action <Context, string> onCacheGet,
Action <Context, string> onCacheMiss,
Action <Context, string> onCachePut,
Action <Context, string, Exception> onCacheGetError,
Action <Context, string, Exception> onCachePutError)
{
return(Cache <TResult>(cacheProvider, ttlStrategy, cacheKeyStrategy.GetCacheKey, onCacheGet, onCacheMiss, onCachePut, onCacheGetError, onCachePutError));
}
/// <summary>
/// <para>Builds an <see cref="AsyncPolicy" /> that will function like a result cache for delegate executions returning a result.</para>
/// <para>Before executing a delegate returning a result, 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="ttlStrategy">A strategy for specifying ttl for values to be cached.</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">cacheProvider</exception>
/// <exception cref="ArgumentNullException">ttlStrategy</exception>
/// <exception cref="ArgumentNullException">cacheKeyStrategy</exception>
public static AsyncCachePolicy CacheAsync(IAsyncCacheProvider cacheProvider, ITtlStrategy ttlStrategy, ICacheKeyStrategy cacheKeyStrategy, Action <Context, string, Exception> onCacheError = null)
{
if (cacheProvider == null)
{
throw new ArgumentNullException(nameof(cacheProvider));
}
if (ttlStrategy == null)
{
throw new ArgumentNullException(nameof(ttlStrategy));
}
if (cacheKeyStrategy == null)
{
throw new ArgumentNullException(nameof(cacheKeyStrategy));
}
onCacheError = onCacheError ?? ((_, __, ___) => { });
Action <Context, string> emptyDelegate = (_, __) => { };
return(new AsyncCachePolicy(cacheProvider, ttlStrategy, cacheKeyStrategy.GetCacheKey, emptyDelegate, emptyDelegate, emptyDelegate, onCacheError, onCacheError));
}
/// <summary> /// <para>Builds an <see cref="AsyncPolicy"/> that will function like a result cache for delegate executions returning a result.</para> /// <para>Before executing a delegate returning a result, 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">cacheProvider</exception> /// <exception cref="ArgumentNullException">cacheKeyStrategy</exception> public static AsyncCachePolicy CacheAsync(IAsyncCacheProvider cacheProvider, TimeSpan ttl, ICacheKeyStrategy cacheKeyStrategy, Action <Context, string, Exception> onCacheError = null) => CacheAsync(cacheProvider, new RelativeTtl(ttl), cacheKeyStrategy.GetCacheKey, onCacheError);
/// <summary>
/// Initialises a new instance of the <see cref="HttpCachingHandler"/> class.
/// </summary>
/// <param name="cache">The <see cref="IHttpCache"/> that will be used to store HTTP responses.</param>
/// <param name="keyStrategy">The <see cref="ICacheKeyStrategy"/> that will be used to create cache keys.</param>
public HttpCachingHandler(IHttpCache cache, ICacheKeyStrategy keyStrategy)
{
_cache = cache ?? throw new ArgumentNullException(nameof(cache));
_keyStrategy = keyStrategy ?? throw new ArgumentNullException(nameof(keyStrategy));
InnerHandler = new HttpClientHandler();
}
/// <summary>
/// Initialises a new instance of the <see cref="HttpCachingHandler"/> class with the given <see cref="HttpMessageHandler"/>
/// </summary>
/// <param name="cache">The <see cref="IHttpCache"/>; that will be used to store HTTP responses.</param>
/// <param name="keyStrategy">The <see cref="ICacheKeyStrategy"/> that will be used to create cache keys.</param>
/// <param name="innerHandler">The <see cref="HttpMessageHandler"/> that will be used to send the HTTP request.</param>
public HttpCachingHandler(IHttpCache cache, ICacheKeyStrategy keyStrategy, HttpMessageHandler innerHandler)
{
_cache = cache ?? throw new ArgumentNullException(nameof(cache));
_keyStrategy = keyStrategy ?? throw new ArgumentNullException(nameof(keyStrategy));
InnerHandler = innerHandler;
}
/// <summary>
/// Initialises a new instance of the <see cref="HttpCachingHandler"/> class with the default message handler.
/// </summary>
/// <param name="cache">The <see cref="IHttpCache"/> that will be used to store HTTP responses.</param>
/// <param name="keyStrategy">The <see cref="ICacheKeyStrategy"/> that will be used to create cache keys.</param>
public HttpCachingHandler(IHttpCache cache, ICacheKeyStrategy keyStrategy) : this(cache, keyStrategy, new HttpClientHandler())
{
}
