Layomi Akinrinade layomia

Approach A

/// <summary>
/// Prevents a property from being serialized or deserialized.
/// </summary>
[AttributeUsage(AttributeTargets.Property, AllowMultiple = false)]
public sealed class JsonIgnoreAttribute : JsonAttribute
{
    /// <summary>

Deserializing objects using parameterless constructors with `JsonSerializer`

Motivation

JsonSerializer deserializes instances of objects (classes and structs) using public parameterless constructors. If none is present, and deserialization is attempted, the serializer throws a NotSupportedException with a message stating that objects without public parameterless constructors, including interfaces and abstract types, are not supported for deserialization. There is no way to deserialize an instance of an object using a parameterized constructor.

Deserialize LoginViewModel

Method	Mean	Error	StdDev	Median	Min	Max	Gen 0	Gen 1	Gen 2	Allocated
Jil	492.3 ns	11.13 ns	11.43 ns	488.6 ns	479.8 ns	522.1 ns	0.0629	-	-	264 B
JSON.NET	1,288.4 ns	26.17 ns	67.55 ns	1,263.9 ns	1,209.4 ns	1,493.6 ns	0.6618	-	-	2776 B
Utf8Json	360.5 ns	3.07 ns	2.56 ns	360.4 ns	355.4 ns	365.5 ns	0.0668	-	-	280 B
Default	517.7 ns	3.63 ns	3.03 ns	517.3 ns	512.5 ns	522.3 ns	0.0391	-	-	168 B
AOT_LoadConverters	471.8 ns	9.14 ns	11.22 ns	469.3 ns	452.2 ns	494.5 ns	0.0401	-	-	168 B
AOT_Raw	402.2 ns	10.17 ns	9.51 ns

Converters

JsonDefaultArrayConverter<>
- Single-dimentional arrays
JsonListOfTConverter<>
- List
- Types deriving from List
JsonDictionaryOfStringTValueConverter<,>
- Dictionary<string, TValue>
Types deriving from Dictionary

Some performance notes.

TLDR

There's no significant performance impact on hot path (de)serialization i.e. primitives, objects, and enumerables.
There's a little (~4.6% avg.) regression for deserializing Dictionary, IDictionary, and IReadOnlyDictionary. This is due to some necessary if-checks introduced in shared code-paths between non-immutable dicts and immutable dicts. Splitting their code-paths entirely might mitigate this, but is beyond the scope for preview 6. This will be targeted in preview 7.
We might be able to improve the performance of (de)serializing ImmutableDicitonary, IImmutableDictionary, and ImmutableSortedDictionay by using IL emit to generate high performance CreateRange methods.

Hot-path deserialization and serialization use cases (Primitives, enumerables, objects)

These benchmarks live in the perf repo.

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

Stores data elements based on an sequential, most commonly 0 based, index.
Based on tuples from set theory.

	sudo ./build.sh -subsetCategory coreclr -configuration Release
	__DistroRid: linux-x64
	__RuntimeId: linux-x64
	Downloading 'https://dot.net/v1/dotnet-install.sh'
	Trying to run 'curl https://dot.net/v1/dotnet-install.sh -sSL --retry 10 --create-dirs -o /home/layomia/repos/dotnet_runtime/.dotnet/dotnet-install.sh' for maximum of 5 attempts.
	Ran 'curl https://dot.net/v1/dotnet-install.sh -sSL --retry 10 --create-dirs -o /home/layomia/repos/dotnet_runtime/.dotnet/dotnet-install.sh' successfully.
	dotnet_install: Warning: Unable to locate zlib. Probable prerequisite missing; install zlib.
	dotnet-install: Downloading link: https://dotnetcli.azureedge.net/dotnet/Sdk/5.0.100-preview.3.20168.11/dotnet-sdk-5.0.100-preview.3.20168.11-linux-x64.tar.gz
	dotnet-install: Extracting zip from https://dotnetcli.azureedge.net/dotnet/Sdk/5.0.100-preview.3.20168.11/dotnet-sdk-5.0.100-preview.3.20168.11-linux-x64.tar.gz
	dotnet-install: Adding to current process PATH: `/home/layomia/repos/dotnet_runtime/.dotnet`. Note: This change will

	private static void HandleStartObject(JsonSerializerOptions options, ref ReadStack state)
	{
	Debug.Assert(!state.Current.IsProcessingDictionary());

	if (state.Current.IsProcessingEnumerable())
	{
	// A nested object within an enumerable.
	Type objType = state.Current.GetElementType();
	state.Push();
	state.Current.Initialize(objType, options);

	private static void HandleStartDictionary(JsonSerializerOptions options, ref ReadStack state)
	{
	Debug.Assert(!state.Current.IsProcessingEnumerable());

	JsonPropertyInfo jsonPropertyInfo = state.Current.JsonPropertyInfo;
	if (jsonPropertyInfo == null)
	{
	jsonPropertyInfo = state.Current.JsonClassInfo.CreateRootProperty(options);
	}