/// <summary>
/// Verifies that the specified node exists.
/// </summary>
protected override NodeState ValidateNode(
ServerSystemContext context,
NodeHandle handle,
IDictionary <NodeId, NodeState> cache)
{
// not valid if no root.
if (handle == null)
{
return(null);
}
// check if previously validated.
if (handle.Validated)
{
return(handle.Node);
}
NodeState target = null;
// check if already in the cache.
if (cache != null)
{
if (cache.TryGetValue(handle.NodeId, out target))
{
// nulls mean a NodeId which was previously found to be invalid has been referenced again.
if (target == null)
{
return(null);
}
handle.Node = target;
handle.Validated = true;
return(handle.Node);
}
target = null;
}
try
{
// check if the node id has been parsed.
if (handle.ParsedNodeId == null)
{
return(null);
}
NodeState root = null;
// validate a segment.
if (handle.ParsedNodeId.RootType == ModelUtils.Segment)
{
UnderlyingSystemSegment segment = m_system.FindSegment(handle.ParsedNodeId.RootId);
// segment does not exist.
if (segment == null)
{
return(null);
}
NodeId rootId = ModelUtils.ConstructIdForSegment(segment.Id, NamespaceIndex);
// create a temporary object to use for the operation.
root = new SegmentState(context, rootId, segment);
}
// validate segment.
else if (handle.ParsedNodeId.RootType == ModelUtils.Block)
{
// validate the block.
UnderlyingSystemBlock block = m_system.FindBlock(handle.ParsedNodeId.RootId);
// block does not exist.
if (block == null)
{
return(null);
}
NodeId rootId = ModelUtils.ConstructIdForBlock(block.Id, NamespaceIndex);
// check for check for blocks that are being currently monitored.
BlockState node = null;
if (m_blocks.TryGetValue(rootId, out node))
{
root = node;
}
// create a temporary object to use for the operation.
else
{
root = new BlockState(this, rootId, block);
}
}
// unknown root type.
else
{
return(null);
}
// all done if no components to validate.
if (String.IsNullOrEmpty(handle.ParsedNodeId.ComponentPath))
{
handle.Validated = true;
handle.Node = target = root;
return(handle.Node);
}
// validate component.
NodeState component = root.FindChildBySymbolicName(context, handle.ParsedNodeId.ComponentPath);
// component does not exist.
if (component == null)
{
return(null);
}
// found a valid component.
handle.Validated = true;
handle.Node = target = component;
return(handle.Node);
}
finally
{
// store the node in the cache to optimize subsequent lookups.
if (cache != null)
{
cache.Add(handle.NodeId, target);
}
}
}
/// <summary>
/// Verifies that the specified node exists.
/// </summary>
protected override NodeState ValidateNode(
ServerSystemContext context,
NodeHandle handle,
IDictionary<NodeId, NodeState> cache)
{
// not valid if no root.
if (handle == null)
{
return null;
}
// check if previously validated.
if (handle.Validated)
{
return handle.Node;
}
NodeState target = null;
// check if already in the cache.
if (cache != null)
{
if (cache.TryGetValue(handle.NodeId, out target))
{
// nulls mean a NodeId which was previously found to be invalid has been referenced again.
if (target == null)
{
return null;
}
handle.Node = target;
handle.Validated = true;
return handle.Node;
}
target = null;
}
try
{
// check if the node id has been parsed.
if (handle.ParsedNodeId == null)
{
return null;
}
NodeState root = null;
// validate a segment.
if (handle.ParsedNodeId.RootType == ModelUtils.Segment)
{
UnderlyingSystemSegment segment = m_system.FindSegment(handle.ParsedNodeId.RootId);
// segment does not exist.
if (segment == null)
{
return null;
}
NodeId rootId = ModelUtils.ConstructIdForSegment(segment.Id, NamespaceIndex);
// create a temporary object to use for the operation.
root = new SegmentState(context, rootId, segment);
}
// validate segment.
else if (handle.ParsedNodeId.RootType == ModelUtils.Block)
{
// validate the block.
UnderlyingSystemBlock block = m_system.FindBlock(handle.ParsedNodeId.RootId);
// block does not exist.
if (block == null)
{
return null;
}
NodeId rootId = ModelUtils.ConstructIdForBlock(block.Id, NamespaceIndex);
// check for check for blocks that are being currently monitored.
BlockState node = null;
if (m_blocks.TryGetValue(rootId, out node))
{
root = node;
}
// create a temporary object to use for the operation.
else
{
root = new BlockState(this, rootId, block);
}
}
// unknown root type.
else
{
return null;
}
// all done if no components to validate.
if (String.IsNullOrEmpty(handle.ParsedNodeId.ComponentPath))
{
handle.Validated = true;
handle.Node = target = root;
return handle.Node;
}
// validate component.
NodeState component = root.FindChildBySymbolicName(context, handle.ParsedNodeId.ComponentPath);
// component does not exist.
if (component == null)
{
return null;
}
// found a valid component.
handle.Validated = true;
handle.Node = target = component;
return handle.Node;
}
finally
{
// store the node in the cache to optimize subsequent lookups.
if (cache != null)
{
cache.Add(handle.NodeId, target);
}
}
}