FilePageManager - disk based PageManager.

pkg/analysis_server/lib/src/index/page_node_manager.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 index.page_node_manager;
 
 import 'dart:collection';
 import 'dart:typed_data';
 
 import 'b_plus_tree.dart';
@@ skipping 151 matching lines @@
 
   final Set<int> indexPages = new HashSet<int>();
   Codec<K> keyCodec;
   final Set<int> leafPages = new HashSet<int>();
   PageManager pageManager;
   Codec<V> valueCodec;
 
   PageNodeManager(this.pageManager, this.keyCodec, this.valueCodec);
 
   @override
+  int get maxIndexKeys {
+    int keySize = keyCodec.sizeInBytes;
+    int childSize = 4;
+    int dataSize = pageManager.pageSizeInBytes - INDEX_OFFSET_DATA;
+    return (dataSize - childSize) ~/ (keySize + childSize);
+  }
+
+  @override
+  int get maxLeafKeys {
+    int keySize = keyCodec.sizeInBytes;
+    int valueSize = valueCodec.sizeInBytes;
+    int dataSize = pageManager.pageSizeInBytes - INDEX_OFFSET_DATA;
+    return dataSize ~/ (keySize + valueSize);
+  }
+
+  @override
   int createIndex() {
     int id = pageManager.alloc();
     indexPages.add(id);
     return id;
   }
 
   @override
   int createLeaf() {
     int id = pageManager.alloc();
     leafPages.add(id);
@@ skipping 169 matching lines @@
   @override
   int decode(ByteData buffer) {
     return buffer.getUint32(0);
   }
 
   @override
   void encode(ByteData buffer, int element) {
     buffer.setUint32(0, element);
   }
 }