Add batch retrieval for IdentityLinkUser entities

[maliming]

No description provided.

[duncansultan]

@maliming
Your solution worked great for pagination.

I also have to make these changes to get login to work.

LinkLogin.cshtml.cs

using (CurrentTenant.Change(SourceLinkTenantId))
{
    var sourceUser = await UserManager.GetByIdAsync(SourceLinkUserId);
    using (CurrentPrincipalAccessor.Change(await SignInManager.CreateUserPrincipalAsync(sourceUser)))
    {
        // OPTIMIZATION: Use GetAllListAsync instead of IsLinkedAsync to avoid timeout with indirect links
        // GetAllListAsync uses batch retrieval (fixed in ABP PR #23929), while IsLinkedAsync uses slow iterative queries
        // This is the key performance improvement that prevents timeout issues
        var linkedUsers = await IdentityLinkUserAppService.GetAllListAsync();
        var isLinked = linkedUsers.Items.Any(x =>
            x.TargetUserId == TargetLinkUserId && x.TargetTenantId == TargetLinkTenantId);

        if (isLinked)
        {
        }
    }
}

CustomLinkLoginExtensionGrant.cs

/// <summary>
/// Custom link login extension grant for OpenIddict OAuth flows.
/// Extends ABP's default link login grant with optimized performance for linked account verification.
/// This override fixes timeout issues that occur with indirect linked accounts by using batch retrieval
/// instead of slow iterative database queries when validating account links.
/// </summary>
public class CustomLinkLoginExtensionGrant : LinkLoginExtensionGrant
{
   
      // ========== KEY OPTIMIZATION: Use batch retrieval instead of IsLinkedAsync ==========
      // ORIGINAL (slow): var isLinked = await identityLinkUserManager.IsLinkedAsync(...)
      // OPTIMIZED (fast): Use GetListAsync which uses batch retrieval from ABP PR #23929
      var linkedUsers = await identityLinkUserManager.GetListAsync(
          new IdentityLinkUserInfo(currentUser.GetId(), currentTenant.Id),
          includeIndirect: true);
      var isLinked = linkedUsers.Any(x =>
          (x.SourceUserId == linkUserId.Value && x.SourceTenantId == linkTenantId) ||
          (x.TargetUserId == linkUserId.Value && x.TargetTenantId == linkTenantId));
      // ================================================================================      
}

[maliming]

Thanks duncansultan

I will check your code. 👍

[maliming]

hi @duncansultan

After this PR, you will no longer need to change the LinkLogin and LinkLoginExtensionGrant values.

You can consider overriding the IdentityLinkUserManager based on this PR.

Thanks.