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pkg/analyzer/lib/src/generated/utilities_general.dart

 // Copyright (c) 2014, 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.
 
 library engine.utilities.general;
 
+import 'dart:collection';
 import 'dart:developer' show UserTag;
 
 /**
  * Jenkins hash function, optimized for small integers.
  * Borrowed from sdk/lib/math/jenkins_smi_hash.dart.
  */
 class JenkinsSmiHash {
   static int combine(int hash, int value) {
     hash = 0x1fffffff & (hash + value);
     hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
     return hash ^ (hash >> 6);
   }
 
   static int finish(int hash) {
     hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
     hash = hash ^ (hash >> 11);
     return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
   }
 
   static int hash2(a, b) => finish(combine(combine(0, a), b));
 
   static int hash3(a, b, c) => finish(combine(combine(combine(0, a), b), c));
 
   static int hash4(a, b, c, d) =>
       finish(combine(combine(combine(combine(0, a), b), c), d));
 }
 
 /**
+ * A simple limited queue.
+ */
+class LimitedQueue<E> extends ListQueue<E> {
+  final int limit;
+
+  /**
+   * Create a queue with [limit] items.
+   */
+  LimitedQueue(this.limit);
+
+  @override
+  void add(E o) {
+    super.add(o);
+    while (length > limit) {
+      remove(first);
+    }
+  }
+}
+
+/**
  * Helper class for gathering performance statistics.  This class is modeled on
  * the UserTag class in dart:developer so that it can interoperate easily with
  * it.
  */
 abstract class PerformanceTag {
   /**
    * Return a list of all [PerformanceTag]s which have been created.
    */
   static List<PerformanceTag> get all => _PerformanceTagImpl.all.toList();
 
@@ skipping 100 matching lines @@
 
   makeCurrentWhile(f()) {
     PerformanceTag prevTag = makeCurrent();
     try {
       return f();
     } finally {
       prevTag.makeCurrent();
     }
   }
 }