Remove unused field, fix LruCache. (#4110)

Author: davidmorgan

build/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 3.0.1-wip
+
+- Small improvements to RAM usage.
+
 ## 3.0.0
 
 - Removed unused deps: `meta`, `pool`.

build/lib/src/library_cycle_graph/library_cycle_graph_loader.dart

@@ -73,8 +73,6 @@ class LibraryCycleGraphLoader {
   /// for its sorting, so earlier phases are processed first in [_nextIdToLoad].
   final SplayTreeMap<int, List<AssetId>> _idsToLoad = SplayTreeMap();
 
-  final List<(int, AssetId)> _loadingIds = [];
-
   /// All loaded library cycles, by asset.
   final Map<AssetId, PhasedValue<LibraryCycle>> _cycles = {};
 
@@ -136,7 +134,6 @@ class LibraryCycleGraphLoader {
     // Return the last ID from the list of IDs at this phase because it's
     // cheapest to remove in `_removeIdToLoad`.
     final result = first.value.last;
-    _loadingIds.add((first.key, result));
     return (first.key, result);
   }
 

build/lib/src/state/lru_cache.dart

@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:meta/meta.dart';
+
 /// A basic LRU Cache.
 class LruCache<K, V> {
   _Entry<K, V>? _head;
@@ -55,13 +57,15 @@ class LruCache<K, V> {
     _currentWeightTotal -= entry.weight;
     _entries.remove(key);
 
+    // Remove from linked list.
+    entry.previous?.next = entry.next;
+    entry.next?.previous = entry.previous;
+
     if (entry == _tail) {
       _tail = entry.next;
-      _tail?.previous = null;
     }
     if (entry == _head) {
       _head = entry.previous;
-      _head?.next = null;
     }
 
     return entry.value;
@@ -75,19 +79,27 @@ class LruCache<K, V> {
       _tail = link.next;
     }
 
-    if (link.previous != null) {
-      link.previous!.next = link.next;
-    }
-    if (link.next != null) {
-      link.next!.previous = link.previous;
-    }
+    // Remove from linked list.
+    link.previous?.next = link.next;
+    link.next?.previous = link.previous;
 
     _head?.next = link;
     link.previous = _head;
     _head = link;
     _tail ??= link;
     link.next = null;
   }
+
+  @visibleForTesting
+  int get linkedListLength {
+    var result = 0;
+    var current = _head;
+    while (current != null) {
+      ++result;
+      current = current.previous;
+    }
+    return result;
+  }
 }
 
 /// An entry in an [LruCache] which is also a part of a doubly linked list.

build/pubspec.yaml

@@ -1,5 +1,5 @@
 name: build
-version: 3.0.0
+version: 3.0.1-wip
 description: A package for authoring build_runner compatible code generators.
 repository: https://github.com/dart-lang/build/tree/master/build
 resolution: workspace
@@ -10,14 +10,15 @@ environment:
 dependencies:
   analyzer: '>=7.4.0 <8.0.0'
   async: ^2.5.0
-  build_runner_core: '9.2.0'
+  build_runner_core: '9.2.1-wip'
   built_collection: ^5.1.1
   built_value: ^8.9.5
   convert: ^3.0.0
   crypto: ^3.0.0
   glob: ^2.0.0
   graphs: ^2.2.0
   logging: ^1.0.0
+  meta: ^1.17.0
   package_config: ^2.1.0
   path: ^1.8.0
 

build/test/state/lru_cache_test.dart

@@ -120,4 +120,36 @@ void main() {
       expect(cache['$i'], maxIndividualWeight);
     }
   });
+
+  test('removes also remove from linked list', () {
+    cache['a'] = 1;
+    expect(cache.linkedListLength, 1);
+    cache.remove('a');
+    expect(cache.linkedListLength, 0);
+  });
+
+  test('removes also remove from middle of linked list', () {
+    cache['a'] = 1;
+    cache['b'] = 1;
+    cache['c'] = 1;
+    expect(cache.linkedListLength, 3);
+    cache.remove('b');
+    expect(cache.linkedListLength, 2);
+  });
+
+  test('updates remove old from linked list', () {
+    cache['a'] = 1;
+    expect(cache.linkedListLength, 1);
+    cache['a'] = 2;
+    expect(cache.linkedListLength, 1);
+  });
+
+  test('updates remove old from middle of linked list', () {
+    cache['a'] = 1;
+    cache['b'] = 1;
+    cache['c'] = 1;
+    expect(cache.linkedListLength, 3);
+    cache['b'] = 2;
+    expect(cache.linkedListLength, 3);
+  });
 }

build_resolvers/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 3.0.1-wip
+
+- Use `build` 3.0.1.
+
 ## 3.0.0
 
 - Remove unused deps: `graphs`, `logging`, `stream_transform`.

build_resolvers/pubspec.yaml

@@ -1,5 +1,5 @@
 name: build_resolvers
-version: 3.0.0
+version: 3.0.1-wip
 description: Resolve Dart code in a Builder
 repository: https://github.com/dart-lang/build/tree/master/build_resolvers
 resolution: workspace
@@ -10,8 +10,8 @@ environment:
 dependencies:
   analyzer: '>=7.4.0 <8.0.0'
   async: ^2.5.0
-  build: '3.0.0'
-  build_runner_core: '9.2.0'
+  build: '3.0.1-wip'
+  build_runner_core: '9.2.1-wip'
   collection: ^1.17.0
   convert: ^3.1.1
   crypto: ^3.0.0

build_runner/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.6.1-wip
+
+- Use `build` 3.0.1.
+
 ## 2.6.0
 
 - Remove unused deps: `analyzer`, `build_resolvers`, `collection`, `http`,

build_runner/pubspec.yaml

@@ -1,5 +1,5 @@
 name: build_runner
-version: 2.6.0
+version: 2.6.1-wip
 description: A build system for Dart code generation and modular compilation.
 repository: https://github.com/dart-lang/build/tree/master/build_runner
 resolution: workspace
@@ -15,10 +15,10 @@ platforms:
 dependencies:
   args: ^2.0.0
   async: ^2.5.0
-  build: '3.0.0'
+  build: '3.0.1-wip'
   build_config: ">=1.1.0 <1.2.0"
   build_daemon: ^4.0.0
-  build_runner_core: '9.2.0'
+  build_runner_core: '9.2.1-wip'
   code_builder: ^4.2.0
   crypto: ^3.0.0
   dart_style: '>=2.3.7 <4.0.0'

build_runner_core/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 9.2.1-wip
+
+- Use `build` 3.0.1.
+
 ## 9.2.0
 
 - Removed unused dev_deps: `test_process`.