Re: .Net: separate methods for async operations.

[Pavel Tupitsyn]

As a .Net dev, I support this change very much.

Current design with 2 method calls is not easy to use, is error prone, and
is not familiar to .Net crowd:

var cache = ignite.GetCache<int, int>().WithAsync();
var value = cache.Get(1);   // Is it sync or async? Can't tell from code.
In async mode this always returns 0.
var future = cache.GetFuture<int>();   // User has to specify right generic
argument here. Not convenient, error prone, violates design guidelines
var actualValue = await future.ToTask();


As opposed to:
var value = await cache.GetAsync(1).ToTask();

Which is one line, obviously async, with proper generic inference.



On Fri, Oct 9, 2015 at 4:47 PM, Vladimir Ozerov <voze...@gridgain.com>
wrote:

> Igniters,
>
> Some time ago we decided to merge sync and async methods. E.g. instead of
> ...
>
> interface Cache<K, V> {
>     V get(K key);
>     Future<V> getAsync(K key);
> }
>
> ... we now have:
>
> interface Cache<K, V> extends AsyncSupport {
>     V get(K key);
>     Cache withAsync();
>
>     Future lastFuture(); // From AsyncSupport, returns future for the last
> operation.
> }
>
> This approach is questionable. Less methods is good, and all methods go
> through JCache API. But async mode became more complex and less usable.
> This is especially obvious in Java 8 with its lambdas and
> CompletableFuture.
>
> In .Net we blindly applied this approach as well. But in this world
> AsyncSupport gives even less advantages than in Java:
> 1) There is no JCache spec here;
> 2) Core .Net API very often use paired sync and async operations in the
> same class near each other - DoMethod(), DoMethodAsync() - and this is what
> users normally expect from async-enabled classes.
> 3) [AsyncSupported] attribute is not highlighted in Visual Studio. The only
> way to understand that method supports async mode is to install ReSharper
> or to look into source code.
> 4) .Net has native continuations support with async/await keywords. Our API
> doesn't support it well.
>
> Having said that I want to return paired "async" operations to .Net API:
> interface ICache<K, V> {
>     V Get(K key);
>     IFuture<V> GetAsync(K key);
> }
>
> It will add 25 new methods to ICache interface and remove 2. But API will
> become much more friendly and natural for .Net users.
>
> Any thoughts/objections?
>
> Vladimir.
>



-- 
-- 
Pavel Tupitsyn
GridGain Systems, Inc.
www.gridgain.com