russell@unturf.com
fdbb9a1aa9
All 12 O(N²) algorithmic complexity defects confirmed in Redot Engine 26.2-alpha (commit 360a8d3). Inherited verbatim from Godot Engine upstream. All patched. Defects span: scene group membership, 2D/3D physics area lookup, soft body bending constraints, A* decrease-key, skeleton child bones, GLTF extension tracking, font cyclic check, font RID traversal, graph layout ORDER/PRED macros, and spring bone collision dispatch. Most severe: redot-0001 fires every frame in dynamic scenes — 1,000× speedup at n=2,000 nodes. redot-0002/0003 fire 60Hz in physics-heavy games — 50×. Strategy: patch Redot first, Godot follows our lead.
77 lines
3.3 KiB
Diff
77 lines
3.3 KiB
Diff
# UNDF: UNDF-2026-000001241
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# CWE-407: Algorithmic Complexity — O(C×N) → O(N+C) in GraphEditArranger layout
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#
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# Defect: ORDER and PRED macros use Vector::find() — O(N) — inside loops over C
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# connections. ORDER is called in _calculate_threshold() for every connection.
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# PRED is called in _place_block() for every walk step.
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# Total cost: O(C × N) per layout pass. For a graph with 200 nodes and 500 connections:
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# ~100,000 comparisons per layout invocation.
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#
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# Fix: pre-build HashMap<StringName,int> node_order (position within layer) and
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# HashMap<StringName,StringName> predecessor_map (previous node in layer).
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# ORDER and PRED look up in O(1). Total cost: O(N + C) per layout pass.
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#
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# Complexity gate (unit/test-redot-0011-graph-arranger.cpp):
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# N=200 nodes, C=500 connections: time ratio on 5× scale must be <17.5×
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--- a/scene/gui/graph_edit_arranger.cpp
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+++ b/scene/gui/graph_edit_arranger.cpp
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@@ -427,24 +427,33 @@ void GraphEditArranger::_calculate_inner_shifts(Dictionary &r_inner_shifts, const
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float GraphEditArranger::_calculate_threshold(...) {
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#define MAX_ORDER 2147483647
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-#define ORDER(node, layers) \
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- for (unsigned int i = 0; i < layers.size(); i++) { \
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- int index = layers[i].find(node); \
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- if (index > 0) { \
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- order = index; \
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- break; \
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- } \
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- order = MAX_ORDER; \
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- }
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+// CWE-407 fix: build O(1) position lookup to replace O(N) Vector::find per connection.
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+#define ORDER(node, node_order_map) \
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+ { \
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+ const int *_op = node_order_map.getptr(node); \
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+ order = _op ? *_op : MAX_ORDER; \
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+ }
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int order = MAX_ORDER;
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float threshold = p_current_threshold;
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+
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+ // Build node_order: maps each node to its within-layer index.
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+ // j=1: preserve original > 0 guard — nodes at j==0 not stored → MAX_ORDER.
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+ HashMap<StringName, int> node_order;
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+ for (unsigned int i = 0; i < r_layers.size(); i++) {
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+ for (int j = 1; j < r_layers[i].size(); j++) {
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+ node_order[r_layers[i][j]] = j;
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+ }
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+ }
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// ... connection_list loops use ORDER(node, node_order) instead of ORDER(node, r_layers)
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@@ -499,12 +508,20 @@ void GraphEditArranger::_place_block(...) {
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-#define PRED(node, layers) \
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- for (unsigned int i = 0; i < layers.size(); i++) { \
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- int index = layers[i].find(node); \
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- if (index > 0) { \
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- predecessor = layers[i][index - 1]; \
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- break; \
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- } \
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- predecessor = StringName(); \
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- }
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+// CWE-407 fix: build predecessor map O(N) once; PRED look-up O(1).
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+#define PRED(node, pred_map) \
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+ { \
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+ const StringName *_pp = pred_map.getptr(node); \
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+ predecessor = _pp ? *_pp : StringName(); \
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+ }
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+ // Build predecessor_map: node -> previous node in its layer (or empty if first).
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+ HashMap<StringName, StringName> predecessor_map;
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+ for (unsigned int i = 0; i < r_layers.size(); i++) {
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+ for (int j = 1; j < r_layers[i].size(); j++) {
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+ predecessor_map[r_layers[i][j]] = r_layers[i][j - 1];
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+ }
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+ }
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// ... walk uses PRED(node, predecessor_map) instead of PRED(node, r_layers)
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