Abstraction around EF Core 3 DbContextPool

_Instructions.md

// In your Startup.cs
.AddSingleton<IDbContextPool<MyCompanyDbContext>, OurDbContextPool<MyCompanyDbContext>>()

// In consumer code:
await using var db = _dbContextPool.Rent();
try
{
    await db.FindAsync(1);
}
finally
{
    _dbContextPool.Return(db);
}

IDbContextPool.cs

#nullable enable
using Microsoft.EntityFrameworkCore;

namespace MyCompany
{
    /// <summary>
    /// An abstraction around EF Core's DbContextPool (as it's an internal API that becomes public in .NET 5)
    /// for renting a DbContext.
    /// </summary>
    public interface IDbContextPool<TDbContext>
        where TDbContext : DbContext
    {
        /// <summary>
        /// Rents a DbContext from the pool.
        /// When finished using, consumer should call <see cref="Return(TDbContext)"/>.
        /// </summary>
        /// <returns>Context.</returns>
        TDbContext Rent();

        /// <summary>
        /// Returns a DbContext to the pool.
        /// </summary>
        /// <param name="context">Context to return.</param>
        /// <returns></returns>
        bool Return(TDbContext context);
    }
}

OurDbContextPool.cs

#nullable enable
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Internal;

namespace MyCompany
{
#pragma warning disable EF1001 // Internal EF Core API usage.
    
    /// <inheritdoc/>
    public class OurDbContextPool<TDbContext> : IDbContextPool<TDbContext>
        where TDbContext : DbContext
    {
        private readonly DbContextPool<TDbContext> _dbContextPool;
        public OurDbContextPool(DbContextPool<TDbContext> dbContextPool) => _dbContextPool = dbContextPool;

        /// <inheritdoc/>
        public TDbContext Rent() => _dbContextPool.Rent();

        /// <inheritdoc/>
        public bool Return(TDbContext context) => _dbContextPool.Return(context);
    }
}