Sitecore.Security.AccessControl.cs

/// <summary>
    /// Gets the access control type for an item from its ancestors.
    /// </summary>
    /// <param name="item">The item.</param>
    /// <param name="account">The account.</param>
    /// <param name="accessRight">The desired access right.</param>
    /// <param name="propagationType">Type of propagation.</param>
    /// <returns></returns>
    protected virtual AccessResult GetAncestorAccess(
      Item item,
      Account account,
      AccessRight accessRight,
      PropagationType propagationType)
    {
      Assert.ArgumentNotNull((object) item, nameof (item));
      Assert.ArgumentNotNull((object) account, nameof (account));
      Assert.ArgumentNotNull((object) accessRight, nameof (accessRight));
      if (propagationType == PropagationType.Entity && propagationType != PropagationType.Descendants)
        propagationType = PropagationType.Descendants;
      if (propagationType != PropagationType.Descendants)
        return AccessResult.NotSet;
      Item parent = ItemManager.GetParent(item, SecurityCheck.Disable);
      if (parent == null)
        return AccessResult.NotSet;
      AccessResultCache accessResultCache = CacheManager.GetAccessResultCache();
      AccessResultCacheRecord record = accessResultCache.GetRecord((ISecurable) item, account, accessRight, propagationType);
      if (record != null)
        return record.Value;
      AccessResult itemAccess = this.GetItemAccess(parent, account, accessRight, propagationType);
      accessResultCache.AddRecord((ISecurable) item, account, accessRight, propagationType, itemAccess);
      return itemAccess;
    }