theodorzoulias

using System;
using System.Threading.Tasks;
using System.Windows.Threading;

namespace App;

static partial class Extensions
{
    // https://stackoverflow.com/questions/79806454/task-delay-versus-custom-dispatchertimer-based-delay-in-wpf
    public static Task Delay(this DispatcherObject source, int millisecondsDelay)

theodorzoulias

// https://stackoverflow.com/questions/60695167/concurrentdictionary-with-multiple-values-per-key-removing-empty-entries
// Alternative implementation
using System.Collections;
using System.Collections.Generic;
using System.Collections.Concurrent;
using System.Collections.Immutable;
using System.Linq;

public class ConcurrentMultiDictionary<TKey, TValue>
    : IEnumerable<KeyValuePair<TKey, TValue[]>>

theodorzoulias

// Related: https://github.com/dotnet/runtime/issues/101003 -- [API Proposal]: New method HashSet<T>.Add that replaces an existing element if found
abstract class JsonKeyedCollectionBase<TKey, TItem> : ICollection<TItem>, IEqualityComparer<TItem>
{
    private readonly HashSet<TItem> _set;

    protected abstract TKey GetKeyForItem(TItem item);
    protected abstract TItem GetItemForKey(TKey key);

    protected virtual IEqualityComparer<TKey> KeyComparer => EqualityComparer<TKey>.Default;
    protected virtual IComparer<TItem> EnumerationComparer => null;

theodorzoulias

/// <summary>
/// Returns an existing task from the concurrent dictionary, or adds a new task
/// using the specified asynchronous factory method. Concurrent invocations for
/// the same key are prevented, unless the task is removed before the completion
/// of the delegate. Failed tasks are evicted from the concurrent dictionary.
/// </summary>
public static ValueTask<TValue> GetOrAddAsync<TKey, TValue>(
    this ConcurrentDictionary<TKey, ValueTask<TValue>> source, TKey key,
    Func<TKey, Task<TValue>> valueFactory)
{

theodorzoulias

/// <summary>
/// Represents the result of an asynchronous operation that is invoked lazily on demand,
/// it is retried as many times as needed until it succeeds, while enforcing a non-overlapping execution policy.
/// </summary>
public class AsyncLazyRetryOnFailure<TResult>
{
    private volatile State _state;
    private TResult _result; // The _result is assigned only once, along with the _state becoming null.

    private record class State(Func<Task<TResult>> TaskFactory, Task<TResult> Task);

theodorzoulias

/// <summary>
/// Invokes a delegate for a node and all its descendants in parallel.
/// Children are invoked after the completion of their parent.
/// </summary>
public static ParallelLoopResult ParallelTraverseHierarchical<TNode>(
    TNode root,
    ParallelOptions parallelOptions,
    Action<TNode, ParallelLoopState> body,
    Func<TNode, IEnumerable<TNode>> childrenSelector)
{

theodorzoulias

// https://stackoverflow.com/questions/73056639/how-to-chunkify-an-ienumerablet-without-losing-discarding-items-in-case-of-fa
private async static IAsyncEnumerable<TOutput> DeferErrorUntilCompletion<TInput, TOutput>(
    IAsyncEnumerable<TInput> input,
    Func<IAsyncEnumerable<TInput>, IAsyncEnumerable<TOutput>> conversion,
    [EnumeratorCancellation] CancellationToken cancellationToken = default)
{
    Task errorContainer = null;

    async IAsyncEnumerable<TInput> InputIterator(
        [EnumeratorCancellation] CancellationToken innerToken = default)

theodorzoulias

/// <summary>
/// Represents an asynchronous operation that is invoked lazily on demand, can be
/// invoked multiple times, and is subject to a non-concurrent execution policy.
/// Concurrent observers receive the result of the same operation.
/// </summary>
public class AsyncCollapseConcurrent<TResult>
{
    private readonly Func<Task<TResult>> _taskFactory;
    private volatile Task<TResult> _task;

theodorzoulias

using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;

public static class ConcurrentDictionaryExtensions
{
    /// <summary>
    /// Uses the specified function to update a key/collection pair in the dictionary,
    /// if the key already exists. In case the function returns a null or empty

theodorzoulias

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;

/// <summary>
/// Represents a read-only collection of key/value pairs that are sorted on the key.
/// </summary>
/// <remarks>