/// <summary>
/// Load an image from the blob cache.
/// </summary>
/// <param name="key">The key to look up in the cache.</param>
/// <returns>A Future result representing the bitmap image. This
/// Observable is guaranteed to be returned on the UI thread.</returns>
public static IObservable <IBitmap> LoadImage(this IBlobCache This, string key, float?desiredWidth = null, float?desiredHeight = null)
{
return(This.GetAsync(key)
.SelectMany(ThrowOnBadImageBuffer)
.SelectMany(x => bytesToImage(x, desiredWidth, desiredHeight))
.ObserveOn(RxApp.MainThreadScheduler));
}
/// <summary>
/// Load a XAML image from the blob cache.
/// </summary>
/// <param name="key">The key to look up in the cache.</param>
/// <returns>A Future result representing the bitmap image. This
/// Observable is guaranteed to be returned on the UI thread.</returns>
public static IObservable <BitmapImage> LoadImage(this IBlobCache This, string key)
{
return(This.GetAsync(key)
.SelectMany(ThrowOnBadImageBuffer)
.SelectMany(BytesToImage)
.ObserveOn(RxApp.DeferredScheduler));
}
/// <summary>
/// Get an object from the cache and deserialize it via the JSON
/// serializer.
/// </summary>
/// <param name="key">The key to look up in the cache.</param>
/// <param name="noTypePrefix">Use the exact key name instead of a
/// modified key name. If this is true, GetAllObjects will not find this object.</param>
/// <returns>A Future result representing the object in the cache.</returns>
public static IObservable <T> GetObjectAsync <T>(this IBlobCache This, string key, bool noTypePrefix = false)
{
var objCache = This as IObjectBlobCache;
if (objCache != null)
{
return(objCache.GetObjectAsync <T>(key, noTypePrefix));
}
return(This.GetAsync(key).SelectMany(DeserializeObject <T>));
}
/// <summary>
/// Download data from an HTTP URL and insert the result into the
/// cache. If the data is already in the cache, this returns
/// a cached value. The URL itself is used as the key.
/// </summary>
/// <param name="url">The URL to download.</param>
/// <param name="headers">An optional Dictionary containing the HTTP
/// request headers.</param>
/// <param name="fetchAlways">Force a web request to always be issued, skipping the cache.</param>
/// <param name="absoluteExpiration">An optional expiration date.</param>
/// <returns>The data downloaded from the URL.</returns>
public IObservable<byte[]> DownloadUrl(IBlobCache This, string url, IDictionary<string, string> headers = null, bool fetchAlways = false, DateTimeOffset? absoluteExpiration = null)
{
var doFetch = new Func<KeyNotFoundException, IObservable<byte[]>>(_ => inflightWebRequests.GetOrAdd(url, __ => Observable.Defer(() =>
{
return MakeWebRequest(new Uri(url), headers)
.SelectMany(x => ProcessAndCacheWebResponse(x, url, This, absoluteExpiration));
}).Multicast(new AsyncSubject<byte[]>()).RefCount()));
IObservable<byte[]> dontcare;
var ret = fetchAlways ? doFetch(null) : This.GetAsync(url).Catch(doFetch);
return ret.Finally(() => inflightWebRequests.TryRemove(url, out dontcare));
}
/// <summary>
/// Download data from an HTTP URL and insert the result into the
/// cache. If the data is already in the cache, this returns
/// a cached value. The URL itself is used as the key.
/// </summary>
/// <param name="url">The URL to download.</param>
/// <param name="headers">An optional Dictionary containing the HTTP
/// request headers.</param>
/// <param name="fetchAlways">Force a web request to always be issued, skipping the cache.</param>
/// <param name="absoluteExpiration">An optional expiration date.</param>
/// <returns>The data downloaded from the URL.</returns>
public static IObservable <byte[]> DownloadUrl(this IBlobCache This, string url, Dictionary <string, string> headers = null, bool fetchAlways = false, DateTimeOffset?absoluteExpiration = null)
{
var doFetch = new Func <KeyNotFoundException, IObservable <byte[]> >(_ => inflightWebRequests.GetOrAdd(url, __ => Observable.Defer(() =>
{
return(MakeWebRequest(new Uri(url), headers)
.SelectMany(x => ProcessAndCacheWebResponse(x, url, This, absoluteExpiration)));
}).Multicast(new AsyncSubject <byte[]>()).RefCount()));
IObservable <byte[]> dontcare;
var ret = fetchAlways ? doFetch(null) : This.GetAsync(url).Catch(doFetch);
return(ret.Finally(() => inflightWebRequests.TryRemove(url, out dontcare)));
}
public static IObservable <IDictionary <string, byte[]> > GetAsync(this IBlobCache This, IEnumerable <string> keys)
{
var bulkCache = This as IBulkBlobCache;
if (bulkCache != null)
{
return(bulkCache.GetAsync(keys));
}
return(keys.ToObservable()
.SelectMany(x =>
{
return This.GetAsync(x)
.Select(y => new KeyValuePair <string, byte[]>(x, y))
.Catch <KeyValuePair <string, byte[]>, KeyNotFoundException>(_ => Observable.Empty <KeyValuePair <string, byte[]> >());
})
.ToDictionary(k => k.Key, v => v.Value));
}
public IObservable <byte[]> GetAsync(string key)
{
return(_inner.GetAsync(key));
}
/// <summary>
/// Get an object from the cache and deserialize it via the JSON
/// serializer.
/// </summary>
/// <param name="key">The key to look up in the cache.</param>
/// <param name="noTypePrefix">Use the exact key name instead of a
/// modified key name. If this is true, GetAllObjects will not find this object.</param>
/// <returns>A Future result representing the object in the cache.</returns>
public static IObservable <T> GetObjectAsync <T>(this IBlobCache This, string key, bool noTypePrefix = false)
{
return(This.GetAsync(noTypePrefix ? key : GetTypePrefixedKey(key, typeof(T)))
.SelectMany(DeserializeObject <T>));
}
