Multithreading for Node Reductions

src/utility.jl

@@ -7,3 +7,56 @@ function bytes_to_human_readable(bytes::Int64)
     end
     return string(round(bytes, sigdigits=4), " ", units[unit_index])
 end
+
+# Trie data structure for node reduction, inserts nodes by children
+# Assumes that given nodes have ordered sets of children (see sort_node)
+mutable struct NodeTrie
+    value::Set{Node}
+    children::Dict{UUID, NodeTrie}
+end
+
+NodeTrie() = NodeTrie(Set{Node}(), Dict{UUID, NodeTrie}())
+
+function insert_helper!(trie::NodeTrie, node::Node, depth::Int)
+    if (length(node.children) == depth)
+        push!(trie.value, node)
+        return nothing
+    end
+    
+    depth = depth + 1
+    id = node.children[depth].id
+    if (!haskey(trie.children, id))
+        trie.children[id] = NodeTrie()
+    end
+    insert_helper!(trie.children[id], node, depth)
+end
+
+function insert!(trie::NodeTrie, node::Node)
+    insert_helper!(trie, node, 0)
+end
+
+function collect_helper(trie::NodeTrie, acc::Set{Set{Node}})
+    if (length(trie.value) >= 2)
+        push!(acc, trie.value)
+    end
+
+    for (id,child) in trie.children
+        collect_helper(child, acc)
+    end
+    return nothing
+end
+
+# returns all sets of multiple nodes that have accumulated in leaves
+function collect(trie::NodeTrie)
+    acc = Set{Set{Node}}()
+    collect_helper(trie, acc)
+    return acc
+end
+
+function lt_nodes(n1::Node, n2::Node)
+    return n1.id < n2.id
+end
+
+function sort_node!(node::Node)
+    sort!(node.children, lt=lt_nodes)
+end