/**
* <summary>
* Creates a sub-projection for current projection.</summary>
*
* <param name="nodes">Collection of nodes that sub-projection will be restricted to. If <c>null</c>,</param>
* created projection is dynamic and will take nodes from topology.
* <param name="filter">Filter to be applied to nodes in projection.</param>
* <param name="balancer">Balancer to use in projection.</param>
* <returns>Created projection.</returns>
* <exception cref="GridClientException">
* If resulting projection is empty. Note that this exception may only be thrown on
* case of static projections, i.e. where collection of nodes is not null.</exception>
*/
protected T CreateProjection(ICollection <N> nodes, Predicate <N> filter, IGridClientLoadBalancer balancer)
{
if (nodes != null && nodes.Count == 0)
{
throw new GridClientException("Failed to create projection: given nodes collection is empty.");
}
if (filter != null && this._filter != null)
{
filter = U.And <N>(this._filter, filter);
}
else if (filter == null)
{
filter = this._filter;
}
ICollection <N> subset = Intersection(this._nodes, nodes);
if (subset != null && subset.Count == 0)
{
throw new GridClientException("Failed to create projection (given node set does not overlap with " +
"existing node set) [prjNodes=" + this._nodes + ", nodes=" + nodes);
}
if (filter != null && subset != null)
{
subset = U.ApplyFilter(subset, filter);
if (subset != null && subset.Count == 0)
{
throw new GridClientException("Failed to create projection (none of the nodes in projection node " +
"set passed the filter) [prjNodes=" + subset + ", filter=" + filter + ']');
}
}
if (balancer == null)
{
balancer = this._balancer;
}
return(CreateProjectionImpl(nodes, filter, balancer));
}