Query Async

[Jaben]

First of all, thanks for this library.

Quick question: is there support for async querying?

[ttu]

Hi,

There is no async support for querying. AsQueryable and Find-methods may be slow as those convert collection of JObjects to correct classes, but after conversion is done all objects are in the memory so querying is fast.

Data is in Lazy-object:
https://github.com/ttu/json-flatfile-datastore/blob/master/JsonFlatFileDataStore/DataStore.cs#L325

AsQueryable and Find-methods use data in Lazy-obejct:
https://github.com/ttu/json-flatfile-datastore/blob/master/JsonFlatFileDataStore/DocumentCollection.cs#L32

We can implement async versions for Find-methods and for AsQueryable if you think those would be useful?

[Jaben]

For concurrency it would be preferable -- that lock could be async which would help with thread resources. But I don't personally need it for my usage at this time.

Was just curious if I missing something :)

Again, thanks for this useful library!

[ttu]

Thanks for the feedback!

Have to think how async query-operations would be best to implement. Will write more specifications here when I come up with something.

[ttu]

Maybe this should be implemented with async streams? Syntax might be a little nicer than with Task<IEnumerable>.

Internally both would function in a same way, as first whole JObject would be converted to correct classes. So in the end this is only about syntax.

IDocumentCollection.cs:

Task<IEnumerable<T>> AsQueryableAsync();
Task<IEnumerable<T>> FindAsync(Predicate<T> query);

var itemDynamic = (await store.GetCollection("user")
                            .AsQueryableAsync())
                            .Single(p => p.name == "Phil");

var itemDynamic2 = (await store.GetCollection("user")
		             .FindAsync(p => p.name == "Phil"))
                             .First();
					 
foreach(var item in await store.GetCollection("user").AsQueryableAsync())
{
  // TODO
}

This seems much better option

IDocumentCollection.cs:

IAsyncEnumerable<T> AsQueryableAsync();
IAsyncEnumerable<T> FindAsync(Predicate<T> query);

var itemDynamic = await store.GetCollection("user")
                            .AsQueryableAsync()
                            .Single(p => p.name == "Phil");

await foreach(var item in store.GetCollection("user").AsQueryableAsync())
{
  // TODO
}