IDeserializationDriver.cs

using System;
using System.Collections.Generic;
using System.Text;

namespace CK.BinarySerialization;

/// <summary>
/// Deserialization driver that knows how to instantiate an instance of a <see cref="ResolvedType"/> 
/// and initializes it from a <see cref="IBinaryDeserializer"/> or handles null thanks to its 2 drivers.
/// </summary>
public interface IDeserializationDriver
{
    /// <summary>
    /// Gets the type that this drivers is able to resolve.
    /// </summary>
    Type ResolvedType { get; }

    /// <summary>
    /// Gets a <see cref="TypedReader{T}"/> for this type and nullability.
    /// </summary>
    Delegate TypedReader { get; }

    /// <summary>
    /// Gets whether this driver is cached and reused.
    /// <para>
    /// Note that this caching is not done at the <see cref="BinaryDeserializerContext"/> level nor at
    /// the <see cref="SharedBinaryDeserializerContext"/>: this can only be done by resolvers. (Ultimately,
    /// the deserializer is always cached in the <see cref="ITypeReadInfo"/> per deserialization session instance).
    /// </para>
    /// <para>
    /// A driver that relies on other drivers can only be cached and reused if 
    /// all the drivers it relies on are cached (this is a necessary and but not a sufficient condition
    /// to actually be cached).
    /// </para>
    /// <para>
    /// Resolvers should use <see cref="SharedBinaryDeserializerContext.PureLocalTypeDependentDrivers"/> concurrent
    /// dictionary to cache drivers that can be cached and when the deserializer depends only on the local type to
    /// deserialize. For more complex cache condition (typically when the deserialization uses the <see cref="BinaryDeserializerContext.Services"/>),
    /// it is up to the resolver to handle its caching if it can.
    /// </para>
    /// </summary>
    bool IsCached { get; }

    /// <summary>
    /// Gets the nullable driver.
    /// </summary>
    IDeserializationDriver ToNullable { get; }

    /// <summary>
    /// Gets the non nullable driver.
    /// </summary>
    IDeserializationDriver ToNonNullable { get; }
}