Evict from FileByteStore by the total cache size in bytes.

pkg/analyzer/test/src/dart/analysis/file_byte_store_test.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// 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:analyzer/file_system/file_system.dart';
+import 'package:analyzer/file_system/memory_file_system.dart';
+import 'package:analyzer/src/dart/analysis/file_byte_store.dart';
+import 'package:test/test.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(FileByteStoreTest);
+  });
+}
+
+@reflectiveTest
+class FileByteStoreTest {
+  final MemoryResourceProvider provider = new MemoryResourceProvider();
+  Folder folder;
+  FileByteStore store;
+
+  void setUp() {
+    folder = provider.newFolder('/my/cache');
+  }
+
+  test_evict_afterGet() {
+    store = new FileByteStore(folder, '__temp', 100);
+
+    store.put('1', _b(40));
+    store.put('2', _b(50));
+    store.get('1');
+
+    store.put('3', _b(30));
+    _assertExists('1', 40);
+    _assertNotExists('2');
+    _assertExists('3', 30);
+  }
+
+  test_evict_first() {
+    store = new FileByteStore(folder, '__temp', 100);
+
+    store.put('1', _b(40));
+    store.put('2', _b(50));
+    _assertExists('1', 40);
+    _assertExists('2', 50);
+
+    store.put('3', _b(30));
+    _assertNotExists('1');
+    _assertExists('2', 50);
+    _assertExists('3', 30);
+  }
+
+  test_evict_firstAndSecond() {
+    store = new FileByteStore(folder, '__temp', 100);
+
+    store.put('1', _b(10));
+    store.put('2', _b(80));
+    _assertExists('1', 10);
+    _assertExists('2', 80);
+
+    store.put('3', _b(30));
+    _assertNotExists('1');
+    _assertNotExists('2');
+    _assertExists('3', 30);
+  }
+
+  test_evict_preExisting() {
+    folder.getChildAssumingFile('1').writeAsBytesSync(_b(40));
+    folder.getChildAssumingFile('2').writeAsBytesSync(_b(50));
+    store = new FileByteStore(folder, '__temp', 100);
+
+    // Access '1', so now the queue looks [2, 1].
+    store.get('1');
+
+    // 40 + 50 + 30 > 100
+    // So, '2' is removed.
+    store.put('3', _b(30));
+    _assertExists('1', 40);
+    _assertNotExists('2');
+    _assertExists('3', 30);
+  }
+
+  test_get_null() {
+    store = new FileByteStore(folder, '__temp', 1 << 10);
+    List<int> bytes = store.get('foo');
+    expect(bytes, isNull);
+  }
+
+  test_put_get() {
+    store = new FileByteStore(folder, '__temp', 1 << 10);
+    List<int> bytes = [0, 1, 2, 3, 4];
+    store.put('foo', bytes);
+    expect(store.get('foo'), bytes);
+  }
+
+  void _assertExists(String key, int length) {
+    expect(folder.getChildAssumingFile(key).exists, isTrue);
+    expect(store.get(key), hasLength(length));
+  }
+
+  void _assertNotExists(String key) {
+    expect(folder.getChildAssumingFile(key).exists, isFalse);
+    expect(store.get(key), isNull);
+  }
+
+  static List<int> _b(int length) {

[Brian Wilkerson, 2016/11/10 22:12:04]

Really ?!? If we can't just write "new List<int>", could we at least have a name
with some meaning, such as "_bytes"?

+    return new List<int>(length);
+  }
+}