perf: reuse configuration alias traversal results

CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.2.32] - 2026-07-24
+
+### Changed
+- Reused replacement-closure results while cloning repeated acyclic configuration aliases, reducing traversal work from quadratic to linear without changing merge identity or isolation semantics.
+
 ## [0.2.31] - 2026-07-23
 
 ### Fixed
@@ -263,7 +268,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Code quality tools including Ruff and mypy
   - Documentation and browser extension setup guides
 
-[Unreleased]: https://github.com/Enablement-Engineering/gobbler/compare/v0.2.31...HEAD
+[Unreleased]: https://github.com/Enablement-Engineering/gobbler/compare/v0.2.32...HEAD
+[0.2.32]: https://github.com/Enablement-Engineering/gobbler/compare/v0.2.31...v0.2.32
 [0.2.31]: https://github.com/Enablement-Engineering/gobbler/compare/v0.2.30...v0.2.31
 [0.2.30]: https://github.com/Enablement-Engineering/gobbler/compare/v0.2.29...v0.2.30
 [0.2.29]: https://github.com/Enablement-Engineering/gobbler/compare/v0.2.28...v0.2.29

browser-extension/background.js

@@ -564,7 +564,7 @@ function connectWebSocket() {
     // Send registration message
     ws.send(JSON.stringify({
       type: 'register',
-      extension_version: '0.2.31',
+      extension_version: '0.2.32',
     }));
 
     // Clear reconnect interval if it exists

browser-extension/manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "Gobbler",
-  "version": "0.2.31",
+  "version": "0.2.32",
   "description": "Extract, navigate, and automate tabs in Gobbler's managed browser group",
   "permissions": [
     "activeTab",

docs/changelog.md

@@ -6,6 +6,12 @@ icon: material/history
 
 All notable changes to this project are tracked in the root [CHANGELOG.md](https://github.com/Enablement-Engineering/gobbler/blob/main/CHANGELOG.md).
 
+## [0.2.32] - 2026-07-24
+
+### Changed
+
+- Reused replacement-closure results while cloning repeated acyclic configuration aliases, reducing traversal work from quadratic to linear without changing merge identity or isolation semantics.
+
 ## [0.2.31] - 2026-07-23
 
 ### Fixed

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "gobbler"
-version = "0.2.31"
+version = "0.2.32"
 description = "Universal content conversion fabric - convert YouTube, web, documents, audio/video to markdown via CLI and skills"
 authors = [
     {name = "Dylan Isaac", email = "dylan@enablement.engineering"}

src/gobbler_cli/__init__.py

@@ -12,6 +12,6 @@
     $ gobbler relay start
 """
 
-__version__ = "0.2.31"
+__version__ = "0.2.32"
 
 __all__ = ["__version__"]

src/gobbler_core/__init__.py

@@ -20,7 +20,7 @@
 Converters live in this package and are used by the CLI.
 """
 
-__version__ = "0.2.31"
+__version__ = "0.2.32"
 
 # Convenience imports for common use cases
 from gobbler_core.providers.youtube import (

src/gobbler_core/config.py

@@ -589,9 +589,14 @@ def _clone_projected_override(
         active: dict[int, dict[str, Any]],
         shared: dict[int, Any],
         projection: dict[int, Any],
+        replacement_cache: dict[int, set[int]],
     ) -> Any:
         """Clone a value, isolating only paths that reference an active merge projection."""
-        marked = _ConfigLoader._replacement_closure(value, active)
+        value_id = id(value)
+        marked = replacement_cache.get(value_id)
+        if marked is None:
+            marked = _ConfigLoader._replacement_closure(value, active)
+            replacement_cache[value_id] = marked
         if id(value) not in marked:
             return Config._clone_override_value(value, active, shared)
 
@@ -689,11 +694,19 @@ def _deep_merge(
                 int,
                 dict[str, Any],
                 dict[int, Any],
+                dict[int, set[int]],
                 tuple[int, int] | None,
             ]
-        ] = [(iter(override.items()), override_id, result, {}, None)]
+        ] = [(iter(override.items()), override_id, result, {}, {}, None)]
         while stack:
-            iterator, current_override_id, target, projection, completed_key = stack[-1]
+            (
+                iterator,
+                current_override_id,
+                target,
+                projection,
+                replacement_cache,
+                completed_key,
+            ) = stack[-1]
             try:
                 key, value = next(iterator)
             except StopIteration:
@@ -727,6 +740,7 @@ def _deep_merge(
                         value_id,
                         child,
                         {},
+                        {},
                         pair if cacheable else None,
                     )
                 )
@@ -737,6 +751,7 @@ def _deep_merge(
                 active,
                 cloned,
                 projection,
+                replacement_cache,
             )
         return result
 

src/gobbler_queue/__init__.py

@@ -29,7 +29,7 @@
 from .models import Job, JobStatus, JobSummary, JobType
 from .worker import Worker
 
-__version__ = "0.2.31"
+__version__ = "0.2.32"
 
 __all__ = [
     "Database",

tests/unit/test_browser_extension_static.py

@@ -138,7 +138,7 @@ def test_background_command_contract_matches_relay_client_helpers() -> None:
     assert "command_id: command_id" in background
     assert "result: result" in background
     assert "type: 'register'" in background
-    assert "extension_version: '0.2.31'" in background
+    assert "extension_version: '0.2.32'" in background
     assert "type: 'ping'" in background
     assert "message.type === 'pong'" in background
 

tests/unit/test_config.py

@@ -1058,6 +1058,55 @@ def test_cycle_detection_memoizes_matching_cycle_members(self) -> None:
         assert Config._has_container_cycle(nodes[0], cache)
         assert all(cache[id(node)] for node in nodes)
 
+    def test_deep_merge_clones_shared_acyclic_payload_once(self) -> None:
+        """Test repeated aliases do not retraverse an already cloned payload."""
+
+        class CountingList(list[object]):
+            yielded = 0
+
+            def __iter__(self):
+                for item in super().__iter__():
+                    type(self).yielded += 1
+                    yield item
+
+        alias_count = 80
+        payload = CountingList([[] for _index in range(alias_count)])
+
+        merged = Config._deep_merge(
+            {},
+            {str(index): payload for index in range(alias_count)},
+        )
+
+        assert all(merged[str(index)] is merged["0"] for index in range(alias_count))
+        assert merged["0"] is not payload
+        assert CountingList.yielded <= alias_count * 5
+
+    def test_deep_merge_reuses_alias_scan_after_sibling_mapping_merges(self) -> None:
+        """Test sibling merge frames do not evict an outer frame's alias scan."""
+
+        class CountingList(list[object]):
+            yielded = 0
+
+            def __iter__(self):
+                for item in super().__iter__():
+                    type(self).yielded += 1
+                    yield item
+
+        alias_count = 80
+        payload = CountingList([[] for _index in range(alias_count)])
+        base: dict[str, object] = {}
+        override: dict[str, object] = {}
+        for index in range(alias_count):
+            override[f"alias_{index}"] = payload
+            base[f"merge_{index}"] = {"base": index}
+            override[f"merge_{index}"] = {"override": index}
+
+        merged = Config._deep_merge(base, override)
+
+        assert all(merged[f"alias_{index}"] is merged["alias_0"] for index in range(alias_count))
+        assert merged["alias_0"] is not payload
+        assert CountingList.yielded <= alias_count * 5
+
     def test_deep_merge_clones_shared_empty_mutable_overrides(self) -> None:
         """Test empty mutable override containers are cloned once without mutating input."""
         shared_list: list[object] = []