Cache PropertyInfo lookups for JsonRpc

[benaadams]

Changes

• Cache PropertyInfo lookups for JsonRpc rather than searching with reflection each time

Before

After

Types of changes

What types of changes does your code introduce?

• Optimization

Testing

Requires testing

• No

[Copilot]

Pull Request Overview

This PR adds a cache for PropertyInfo lookups of task results in the JSON-RPC service to reduce repeated reflection calls and improve performance.

• Introduces a Dictionary<TypeAsKey, PropertyInfo?> with copy-on-write semantics for caching Result property lookups.
• Adds GetResultProperty and GetResultPropertySlow methods to centralize and cache reflection logic.
• Defines a new TypeAsKey struct to allow using Type instances as dictionary keys.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/Nethermind/Nethermind.JsonRpc/JsonRpcService.cs	Added caching infrastructure, synchronization, and helper methods.
src/Nethermind/Nethermind.Core/Collections/TypeAsKey.cs	Added TypeAsKey struct for using Type as a dictionary key.

Comments suppressed due to low confidence (4)

src/Nethermind/Nethermind.JsonRpc/JsonRpcService.cs:252

• The new caching logic in GetResultProperty/GetResultPropertySlow isn’t covered by existing unit tests. Consider adding tests to verify cache hits, misses, and thread-safety.

    private PropertyInfo? GetResultProperty(Task task)

src/Nethermind/Nethermind.Core/Collections/TypeAsKey.cs:8

• [nitpick] Add XML documentation to the public TypeAsKey struct and its members to explain its purpose as a wrapper for using Type instances as dictionary keys.

public readonly struct TypeAsKey(Type key) : IEquatable<TypeAsKey>

src/Nethermind/Nethermind.JsonRpc/JsonRpcService.cs:35

• Initializing a Dictionary<...> with [] is invalid syntax. Replace with a constructor call such as new Dictionary<TypeAsKey, PropertyInfo?>() or another supported collection expression.

    private Dictionary<TypeAsKey, PropertyInfo?> _propertyInfoCache = [];

src/Nethermind/Nethermind.JsonRpc/JsonRpcService.cs:265

• The lock statement expects an object for Monitor.Enter/Exit, but _propertyInfoModificationLock is a custom Lock type. Either use a plain object as the lock target or invoke the Lock type’s own acquisition/release methods.

        lock (_propertyInfoModificationLock)

[LukaszRozmej]

maybe do frozendictionary then?