MongoDB.Driver.Linq.AsyncEnumerable

Unofficial IAsyncEnumerable support for MongoDB C# Driver.

Provides ToAsyncEnumerable() extensions for MongoDB IAsyncCursor and IAsyncCursorSource.

Asynchronous enumeration is implemeted so that the iterator fetches documents from database to memory one batch at time.

The size of the batch can be controller by BatchSize property of e.g. AggregateOptions or FindOptions.

Usage

• Include types in MongoDB.Driver.Linq namespace by using MongoDB.Driver.Linq
• Call the ToAsyncEnumerable() extension for either IAsyncCursor or IAsyncCursorSource
• Asynchronously iterate through elements returned by ToAsyncEnumerable()

Enumerating results of Find()

using MongoDB.Bson;
using MongoDB.Driver;
using MongoDB.Driver.Linq;

var client = new MongoClient();
var database = client.GetDatabase("ExampleDatabase");
var collection = database.GetCollection<BsonDocument>("ExampleCollection");

await foreach (var document in collection.Find(_ => true).ToAsyncEnumerable())
{
    Console.WriteLine(document.ToString());
}

Enumerating results of Aggregate() by fetching documents in batches of 1000 documents

using MongoDB.Bson;
using MongoDB.Driver;
using MongoDB.Driver.Linq;

var client = new MongoClient();
var database = client.GetDatabase("ExampleDatabase");
var collection = database.GetCollection<BsonDocument>("ExampleCollection");
var options = new AggregateOptions { BatchSize = 1000 };

await foreach (var document in collection.Aggregate(options).ToAsyncEnumerable())
{
    Console.WriteLine(document.ToString());
}