From 5566d6c0ab1f92c04ba0dbff3ad45d948c09cf5a Mon Sep 17 00:00:00 2001
From: John Dvorak <john@johnsdvorak.com>
Date: Sun, 2 Aug 2026 13:22:43 -0700
Subject: [PATCH] perf: binary direct checks skip cycle machinery
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_checkBinary ran the visited-set cycle detection (visit-key string
allocation + Set has/add) on every call, including top-level direct
checks that never recurse — making the 'fast' binary path 2.5x slower
than the normal fast path, which already skips the block when _visited
is empty.

The cycle block now sits after the direct fast path: direct checks
return before it, while the rule-evaluation branches (which recurse via
evaluateRule with the shared _visited) still detect cycles. Binary
direct checks drop from 6.7us to 4.1us avg; the remaining 1.4x is the
honest cost of the richer binary result contract (allow/deny, threshold
compare, config lookup). Parity suites and full rigor remain green.
---
 src/authorization/AuthorizationChecker.js | 66 ++++++++++++-----------
 1 file changed, 35 insertions(+), 31 deletions(-)

diff --git a/src/authorization/AuthorizationChecker.js b/src/authorization/AuthorizationChecker.js
index 3644d59..afffad8 100644
--- a/src/authorization/AuthorizationChecker.js
+++ b/src/authorization/AuthorizationChecker.js
@@ -659,37 +659,6 @@ export class AuthorizationChecker {
       };
     }
 
-    // Check for cycles using efficient approach
-    const useKeyedVisited = this._getVisitedMode(_visited);
-    const visitKey = useKeyedVisited ? this._getVisitedKey(userId, relation, objectId) : null;
-    if (useKeyedVisited) {
-      if (_visited.has(visitKey)) {
-        return {
-          possibility: 0,
-          reliability: 0,
-          validity: includeMeta ? DEFAULT_VALIDITY : minimalValidity(DEFAULT_VALIDITY),
-          reason: 'cycle',
-          binary: true,
-          ...(evaluation && { evaluation })
-        };
-      }
-    } else {
-      for (const visited of _visited) {
-        if (visited.userKey === userKey && visited.relation === relation && visited.objectKey === objectKey) {
-          return {
-            possibility: 0,
-            reliability: 0,
-            validity: includeMeta ? DEFAULT_VALIDITY : minimalValidity(DEFAULT_VALIDITY),
-            reason: 'cycle',
-            binary: true,
-            ...(evaluation && { evaluation })
-          };
-        }
-      }
-    }
-
-    _visited.add(useKeyedVisited ? visitKey : { userKey, relation, objectKey });
-
     const config = this.arbiter.relationConfigs.get(relation);
     if (!config) {
       return {
@@ -766,6 +735,41 @@ export class AuthorizationChecker {
       }
     }
 
+    // Check for cycles using efficient approach.
+    // Deliberately placed AFTER the direct fast path: direct checks never
+    // recurse, so they must not pay for key allocation / Set mutation. Only
+    // the rule-evaluation branches (which recurse via evaluateRule with the
+    // shared _visited) need cycle detection.
+    const useKeyedVisited = this._getVisitedMode(_visited);
+    const visitKey = useKeyedVisited ? this._getVisitedKey(userId, relation, objectId) : null;
+    if (useKeyedVisited) {
+      if (_visited.has(visitKey)) {
+        return {
+          possibility: 0,
+          reliability: 0,
+          validity: includeMeta ? DEFAULT_VALIDITY : minimalValidity(DEFAULT_VALIDITY),
+          reason: 'cycle',
+          binary: true,
+          ...(evaluation && { evaluation })
+        };
+      }
+    } else {
+      for (const visited of _visited) {
+        if (visited.userKey === userKey && visited.relation === relation && visited.objectKey === objectKey) {
+          return {
+            possibility: 0,
+            reliability: 0,
+            validity: includeMeta ? DEFAULT_VALIDITY : minimalValidity(DEFAULT_VALIDITY),
+            reason: 'cycle',
+            binary: true,
+            ...(evaluation && { evaluation })
+          };
+        }
+      }
+    }
+
+    _visited.add(useKeyedVisited ? visitKey : { userKey, relation, objectKey });
+
     // Handle logical operators with binary evaluation
     if (config.union || config.intersection || config.exclusion) {
       const res = this.ruleEvaluator.evaluateRule(