private static void CategorizeNodesByLabels(
TreeComparer <TNode> comparer,
TNode root,
int labelCount,
out List <TNode>[] nodes,
out int totalCount)
{
nodes = new List <TNode> [labelCount];
int count = 0;
// It is important that we add the nodes in depth-first prefix order.
// This order ensures that a node of a certain kind can have a parent of the same kind
// and we can still use tied-to-parent for that kind. That's because the parent will always
// be processed earlier than the child due to depth-first prefix ordering.
foreach (TNode node in comparer.GetDescendants(root))
{
int label = comparer.GetLabel(node);
if (label < 0 || label >= labelCount)
{
throw new InvalidOperationException(string.Format(WorkspacesResources.Label_for_node_0_is_invalid_it_must_be_within_bracket_0_1, node, labelCount));
}
var list = nodes[label];
if (list == null)
{
nodes[label] = list = new List <TNode>();
}
list.Add(node);
count++;
}
totalCount = count;
}
internal Match(TNode root1, TNode root2, TreeComparer <TNode> comparer, IEnumerable <KeyValuePair <TNode, TNode> > knownMatches)
{
_root1 = root1;
_root2 = root2;
_comparer = comparer;
int labelCount = comparer.LabelCount;
CategorizeNodesByLabels(comparer, root1, labelCount, out var nodes1, out var count1);
CategorizeNodesByLabels(comparer, root2, labelCount, out var nodes2, out var count2);
_oneToTwo = new Dictionary <TNode, TNode>();
_twoToOne = new Dictionary <TNode, TNode>();
// Root nodes always match. Add them before adding known matches to make sure we always have root mapping.
TryAdd(root1, root2);
if (knownMatches != null)
{
foreach (var knownMatch in knownMatches)
{
if (comparer.GetLabel(knownMatch.Key) != comparer.GetLabel(knownMatch.Value))
{
throw new ArgumentException(string.Format(WorkspacesResources.Matching_nodes_0_and_1_must_have_the_same_label, knownMatch.Key, knownMatch.Value), nameof(knownMatches));
}
if (!comparer.TreesEqual(knownMatch.Key, root1))
{
throw new ArgumentException(string.Format(WorkspacesResources.Node_0_must_be_contained_in_the_old_tree, knownMatch.Key), nameof(knownMatches));
}
if (!comparer.TreesEqual(knownMatch.Value, root2))
{
throw new ArgumentException(string.Format(WorkspacesResources.Node_0_must_be_contained_in_the_new_tree, knownMatch.Value), nameof(knownMatches));
}
// skip pairs whose key or value is already mapped:
TryAdd(knownMatch.Key, knownMatch.Value);
}
}
ComputeMatch(nodes1, nodes2);
}
internal Edit(EditKind kind, TreeComparer <TNode> comparer, TNode oldNode, TNode newNode)
{
Debug.Assert((oldNode == null || oldNode.Equals(default)) == (kind == EditKind.Insert));
