Make SDK summary writing available to analyzer clients.

pkg/analyzer/lib/src/summary/summary_file_builder.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.
 
 library analyzer.src.summary.summary_file_builder;
 
 import 'dart:collection';
 import 'dart:io';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_io.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/sdk_io.dart';
 import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/src/summary/flat_buffers.dart' as fb;
 import 'package:analyzer/src/summary/index_unit.dart';
 import 'package:analyzer/src/summary/summarize_elements.dart';
 import 'package:path/path.dart';
 
+const int FIELD_SPEC_INDEX = 1;
+const int FIELD_SPEC_SUM = 0;
+const int FIELD_STRONG_INDEX = 3;
+const int FIELD_STRONG_SUM = 2;
+
 class BuilderOutput {
   final List<int> sum;
   final List<int> index;
 
   BuilderOutput(this.sum, this.index);
 
   void writeMultiple(String outputDirectoryPath, String modeName) {
     // Write summary.
     {
       String outputPath = join(outputDirectoryPath, '$modeName.sum');
@@ skipping 38 matching lines @@
     for (String uri in uriSet) {
       librarySources.add(sdk.mapDartUri(uri));
     }
 
     return new SummaryBuilder(librarySources, sdk.context);
   }
 
   BuilderOutput build() => new _Builder(_context, _librarySources).build();
 }
 
+/**
+ * Intermediary summary output result.
+ */
+class SummaryOutput {
+  final BuilderOutput spec;
+  final BuilderOutput strong;
+  SummaryOutput(this.spec, this.strong);
+
+  /**
+   * Write this summary output to the given [outputPath] and return the
+   * created file.
+   */
+  File write(String outputPath) {
+    fb.Builder builder = new fb.Builder();
+    fb.Offset specSumOffset = builder.writeListUint8(spec.sum);
+    fb.Offset specIndexOffset = builder.writeListUint8(spec.index);
+    fb.Offset strongSumOffset = builder.writeListUint8(strong.sum);
+    fb.Offset strongIndexOffset = builder.writeListUint8(strong.index);
+    builder.startTable();
+    builder.addOffset(FIELD_SPEC_SUM, specSumOffset);
+    builder.addOffset(FIELD_SPEC_INDEX, specIndexOffset);
+    builder.addOffset(FIELD_STRONG_SUM, strongSumOffset);
+    builder.addOffset(FIELD_STRONG_INDEX, strongIndexOffset);
+    fb.Offset offset = builder.endTable();
+    return new File(outputPath)
+      ..writeAsBytesSync(builder.finish(offset), mode: FileMode.WRITE_ONLY);
+  }
+}
+
 class _Builder {
   final Set<Source> processedSources = new Set<Source>();
 
   final PackageBundleAssembler bundleAssembler = new PackageBundleAssembler();
   final PackageIndexAssembler indexAssembler = new PackageIndexAssembler();
 
   final AnalysisContext context;
   final Iterable<Source> librarySources;
 
   _Builder(this.context, this.librarySources);
@@ skipping 30 matching lines @@
     element.exportedLibraries.forEach((e) => _serializeLibrary(e.source));
     // Index every unit of the library.
     for (CompilationUnitElement unitElement in element.units) {
       Source unitSource = unitElement.source;
       CompilationUnit unit =
           context.resolveCompilationUnit2(unitSource, source);
       indexAssembler.indexUnit(unit);
     }
   }
 }