You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
67 lines
2.6 KiB
67 lines
2.6 KiB
4 years ago
|
using System;
|
||
|
|
using System.Threading.Tasks;
|
||
|
|
|
||
|
|
namespace Discord
|
||
|
|
{
|
||
|
|
/// <summary>
|
||
|
|
/// Represents a cached entity.
|
||
|
|
/// </summary>
|
||
|
|
/// <typeparam name="TEntity">The type of entity that is cached.</typeparam>
|
||
|
|
/// <typeparam name="TId">The type of this entity's ID.</typeparam>
|
||
|
|
public struct Cacheable<TEntity, TId>
|
||
|
|
where TEntity : IEntity<TId>
|
||
|
|
where TId : IEquatable<TId>
|
||
|
|
{
|
||
|
|
/// <summary>
|
||
|
|
/// Gets whether this entity is cached.
|
||
|
|
/// </summary>
|
||
|
|
public bool HasValue { get; }
|
||
|
|
/// <summary>
|
||
|
|
/// Gets the ID of this entity.
|
||
|
|
/// </summary>
|
||
|
|
public TId Id { get; }
|
||
|
|
/// <summary>
|
||
|
|
/// Gets the entity if it could be pulled from cache.
|
||
|
|
/// </summary>
|
||
|
|
/// <remarks>
|
||
|
|
/// This value is not guaranteed to be set; in cases where the entity cannot be pulled from cache, it is
|
||
|
|
/// <c>null</c>.
|
||
|
|
/// </remarks>
|
||
|
|
public TEntity Value { get; }
|
||
|
|
private Func<Task<TEntity>> DownloadFunc { get; }
|
||
|
|
|
||
|
|
internal Cacheable(TEntity value, TId id, bool hasValue , Func<Task<TEntity>> downloadFunc)
|
||
|
|
{
|
||
|
|
Value = value;
|
||
|
|
Id = id;
|
||
|
|
HasValue = hasValue;
|
||
|
|
DownloadFunc = downloadFunc;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Downloads this entity to cache.
|
||
|
|
/// </summary>
|
||
|
|
/// <exception cref="Discord.Net.HttpException">Thrown when used from a user account.</exception>
|
||
|
|
/// <exception cref="NullReferenceException">Thrown when the message is deleted.</exception>
|
||
|
|
/// <returns>
|
||
|
|
/// A task that represents the asynchronous download operation. The task result contains the downloaded
|
||
|
|
/// entity.
|
||
|
|
/// </returns>
|
||
|
|
public async Task<TEntity> DownloadAsync()
|
||
|
|
{
|
||
|
|
return await DownloadFunc().ConfigureAwait(false);
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Returns the cached entity if it exists; otherwise downloads it.
|
||
|
|
/// </summary>
|
||
|
|
/// <exception cref="Discord.Net.HttpException">Thrown when used from a user account.</exception>
|
||
|
|
/// <exception cref="NullReferenceException">Thrown when the message is deleted and is not in cache.</exception>
|
||
|
|
/// <returns>
|
||
|
|
/// A task that represents the asynchronous operation that attempts to get the message via cache or to
|
||
|
|
/// download the message. The task result contains the downloaded entity.
|
||
|
|
/// </returns>
|
||
|
|
public async Task<TEntity> GetOrDownloadAsync() => HasValue ? Value : await DownloadAsync().ConfigureAwait(false);
|
||
|
|
}
|
||
|
|
}
|