Improve precision of JS printer callbacks (2nd try)

pkg/compiler/lib/src/dump_info.dart

 // Copyright (c) 2013, 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 dump_info;
 
 import 'dart:convert' show
     HtmlEscape,
     JsonEncoder,
     StringConversionSink,
@@ skipping 392 matching lines @@
   // A set of javascript AST nodes that we care about the size of.
   // This set is automatically populated when registerElementAst()
   // is called.
   final Set<jsAst.Node> _tracking = new Set<jsAst.Node>();
   // A mapping from Dart Elements to Javascript AST Nodes.
   final Map<Element, List<jsAst.Node>> _elementToNodes =
     <Element, List<jsAst.Node>>{};
   // A mapping from Javascript AST Nodes to the size of their
   // pretty-printed contents.
   final Map<jsAst.Node, int> _nodeToSize = <jsAst.Node, int>{};
-  final Map<jsAst.Node, int> _nodeBeforeSize = <jsAst.Node, int>{};
   final Map<Element, int> _fieldNameToSize = <Element, int>{};
 
   final Map<Element, Set<Selector>> selectorsFromElement = {};
   final Map<Element, int> inlineCount = <Element, int>{};
   // A mapping from an element to a list of elements that are
   // inlined inside of it.
   final Map<Element, List<Element>> inlineMap = <Element, List<Element>>{};
 
   /// Register the size of the generated output.
   void reportSize(int programSize) {
@@ skipping 30 matching lines @@
     } else {
       return selectorsFromElement[element].expand(
         (selector) {
           return compiler.world.allFunctions.filter(selector).map((element) {
             return new Selection(element, selector);
           });
         });
     }
   }
 
-  /**
-   * A callback that can be called before a jsAst [node] is
-   * pretty-printed. The size of the code buffer ([aftersize])
-   * is also passed.
-   */
-  void enteringAst(jsAst.Node node, int beforeSize) {
-    if (isTracking(node)) {
-      _nodeBeforeSize[node] = beforeSize;
-    }
-  }
-
-  /**
-   * A callback that can be called after a jsAst [node] is
-   * pretty-printed. The size of the code buffer ([aftersize])
-   * is also passed.
-   */
-  void exitingAst(jsAst.Node node, int afterSize) {
-    if (isTracking(node)) {
-      int diff = afterSize - _nodeBeforeSize[node];
-      recordAstSize(node, diff);
-    }
-  }
-
   // Returns true if we care about tracking the size of
   // this node.
   bool isTracking(jsAst.Node code) {
     if (compiler.dumpInfo) {
       return _tracking.contains(code);
     } else {
       return false;
     }
   }
 
   // Registers that a javascript AST node `code` was produced by the
   // dart Element `element`.
   void registerElementAst(Element element, jsAst.Node code) {
     if (compiler.dumpInfo) {
       _elementToNodes
         .putIfAbsent(element, () => new List<jsAst.Node>())
         .add(code);
       _tracking.add(code);
     }
   }
 
   // Records the size of a dart AST node after it has been
   // pretty-printed into the output buffer.
   void recordAstSize(jsAst.Node code, int size) {

[floitsch, 2015/04/14 15:09:31]

I would rename the variable to "node" since it reads better: if
(isTracking(node)) { ...

[Johnni Winther, 2015/04/15 11:15:28]

Done.

-    if (compiler.dumpInfo) {
+    if (isTracking(code)) {
       //TODO: should I be incrementing here instead?
       _nodeToSize[code] = size;
     }
   }
 
   // Field names are treated differently by the dart compiler
   // so they must be recorded seperately.
   void recordFieldNameSize(Element element, int size) {
     _fieldNameToSize[element] = size;
   }
@@ skipping 140 matching lines @@
     ChunkedConversionSink<Object> sink =
       encoder.startChunkedConversion(
           new StringConversionSink.fromStringSink(buffer));
     sink.add(outJson);
     compiler.reportInfo(NO_LOCATION_SPANNABLE,
         const MessageKind(
             "View the dumped .info.json file at "
             "https://dart-lang.github.io/dump-info-visualizer"));
   }
 }