Emit to StreamCodeOutput instead of CodeBuffer.

pkg/compiler/lib/src/io/source_map_builder.dart

 // Copyright (c) 2012, 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 dart2js.source_map_builder;
 
 import '../util/util.dart';
 import '../scanner/scannerlib.dart' show Token;
-import '../source_file.dart';
 import '../util/uri_extras.dart' show relativize;
+import 'line_column_provider.dart';
+import 'source_file.dart';
 
 class SourceMapBuilder {
   static const int VLQ_BASE_SHIFT = 5;
   static const int VLQ_BASE_MASK = (1 << 5) - 1;
   static const int VLQ_CONTINUATION_BIT = 1 << 5;
   static const int VLQ_CONTINUATION_MASK = 1 << 5;
   static const String BASE64_DIGITS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn'
                                       'opqrstuvwxyz0123456789+/';
 
   final Uri uri;
   final Uri fileUri;
 
-  SourceFile targetFile;
+  LineColumnProvider lineColumnProvider;
   List<SourceMapEntry> entries;
 
   Map<String, int> sourceUrlMap;
   List<String> sourceUrlList;
   Map<String, int> sourceNameMap;
   List<String> sourceNameList;
 
   int previousTargetLine;
   int previousTargetColumn;
   int previousSourceUrlIndex;
   int previousSourceLine;
   int previousSourceColumn;
   int previousSourceNameIndex;
   bool firstEntryInLine;
 
-  SourceMapBuilder(this.uri, this.fileUri, this.targetFile) {
+  SourceMapBuilder(this.uri, this.fileUri, this.lineColumnProvider) {
     entries = new List<SourceMapEntry>();
 
     sourceUrlMap = new Map<String, int>();
     sourceUrlList = new List<String>();
     sourceNameMap = new Map<String, int>();
     sourceNameList = new List<String>();
 
     previousTargetLine = 0;
     previousTargetColumn = 0;
     previousSourceUrlIndex = 0;
@@ skipping 30 matching lines @@
         indexOf(sourceUrlList, sourceLocation.getSourceUrl(), sourceUrlMap);
     return
        sourceUrlIndex == previousSourceUrlIndex &&
        sourceLocation.getLine() == previousSourceLine &&
        sourceLocation.getColumn() == previousSourceColumn;
   }
 
   void addMapping(int targetOffset, SourceFileLocation sourceLocation) {
 
     bool sameLine(int position, otherPosition) {
-      return targetFile.getLine(position) == targetFile.getLine(otherPosition);
+      return lineColumnProvider.getLine(position) ==
+                 lineColumnProvider.getLine(otherPosition);
     }
 
     if (!entries.isEmpty && sameLine(targetOffset, entries.last.targetOffset)) {
       if (sameAsPreviousLocation(sourceLocation)) {
         // The entry points to the same source location as the previous entry in
         // the same line, hence it is not needed for the source map.
         //
         // TODO(zarah): Remove this check and make sure that [addMapping] is not
         // called for this position. Instead, when consecutive lines in the
         // generated code point to the same source location, record this and use
@@ skipping 17 matching lines @@
       writeJsonEscapedCharsOn(string, buffer);
       buffer.write('"');
       first = false;
     }
     buffer.write(']');
   }
 
   String build() {
     resetPreviousSourceLocation();
     StringBuffer mappingsBuffer = new StringBuffer();
-    entries.forEach((SourceMapEntry entry) => writeEntry(entry, targetFile,
-                                                         mappingsBuffer));
+    entries.forEach((SourceMapEntry entry) {
+      writeEntry(entry, mappingsBuffer);
+    });
     StringBuffer buffer = new StringBuffer();
     buffer.write('{\n');
     buffer.write('  "version": 3,\n');
     if (uri != null && fileUri != null) {
       buffer.write('  "file": "${relativize(uri, fileUri, false)}",\n');
     }
     buffer.write('  "sourceRoot": "",\n');
     buffer.write('  "sources": ');
     if (uri != null) {
       sourceUrlList =
           sourceUrlList.map((url) => relativize(uri, Uri.parse(url), false))
               .toList();
     }
     printStringListOn(sourceUrlList, buffer);
     buffer.write(',\n');
     buffer.write('  "names": ');
     printStringListOn(sourceNameList, buffer);
     buffer.write(',\n');
     buffer.write('  "mappings": "');
     buffer.write(mappingsBuffer);
     buffer.write('"\n}\n');
     return buffer.toString();
   }
 
-  void writeEntry(SourceMapEntry entry, SourceFile targetFile, StringBuffer output) {
-    int targetLine = targetFile.getLine(entry.targetOffset);
-    int targetColumn = targetFile.getColumn(targetLine, entry.targetOffset);
+  void writeEntry(SourceMapEntry entry, StringBuffer output) {
+    int targetLine = lineColumnProvider.getLine(entry.targetOffset);
+    int targetColumn =
+        lineColumnProvider.getColumn(targetLine, entry.targetOffset);
 
     if (targetLine > previousTargetLine) {
       for (int i = previousTargetLine; i < targetLine; ++i) {
         output.write(';');
       }
       previousTargetLine = targetLine;
       previousTargetColumn = 0;
       firstEntryInLine = true;
     }
 
@@ skipping 91 matching lines @@
 
   TokenSourceFileLocation(SourceFile sourceFile, this.token, this.name)
     : super(sourceFile);
 
   int get offset => token.charOffset;
 
   String getSourceName() {
     return name;
   }
 }