simplify EmbedderUrlResolver

pkg/analyzer/lib/source/embedder.dart

 // Copyright (c) 2015, 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.source.embedder;
 
 import 'dart:collection' show HashMap;
 import 'dart:core' hide Resource;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/context/context.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_core.dart';
 import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:analyzer/src/generated/java_io.dart' show JavaFile;
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart' show FileBasedSource;
-import 'package:path/path.dart' as pathos;
 import 'package:yaml/yaml.dart';
 
 const String _DART_COLON_PREFIX = 'dart:';
 
 /// Given a packageMap, check in each package's lib directory for the
 /// existence of an `_embedder.yaml` file. If the file contains a top level
 /// YamlMap, it will be added to the [embedderYamls] map.
 class EmbedderYamlLocator {
   static const String EMBEDDER_FILE_NAME = '_embedder.yaml';
 
@@ skipping 79 matching lines @@
 ///   'dart:io': '../../sdk/io/io.dart'
 ///
 /// If a key doesn't begin with `dart:` it is ignored.
 ///
 class EmbedderUriResolver extends DartUriResolver {
   final Map<String, String> _urlMappings = <String, String>{};
 
   /// Construct a [EmbedderUriResolver] from a package map
   /// (see [PackageMapProvider]).
   EmbedderUriResolver(Map<Folder, YamlMap> embedderYamls)
-      : super(new _EmbedderSdk()) {
-    (dartSdk as _EmbedderSdk)._resolver = this;
+      : super(new EmbedderSdk()) {
+    (dartSdk as EmbedderSdk)._resolver = this;
     if (embedderYamls == null) {
       return;
     }
     embedderYamls.forEach(_processEmbedderYaml);
   }
 
   void _processEmbedderYaml(Folder libDir, YamlMap map) {
     YamlNode embedder_libs = map['embedder_libs'];
     if (embedder_libs == null) {
       return;
     }
     if (embedder_libs is! YamlMap) {
       return;
     }
     (embedder_libs as YamlMap)
         .forEach((k, v) => _processEmbedderLibs(k, v, libDir));
   }
 
   /// Install the mapping from [name] to [libDir]/[file].
   void _processEmbedderLibs(String name, String file, Folder libDir) {
     if (!name.startsWith(_DART_COLON_PREFIX)) {
       // SDK libraries must begin with 'dart:'.
       // TODO(pquitslund): Notify developer that something is wrong with the
       // _embedder.yaml file in libDir.
       return;
     }
-    String key = name;
-    String value = libDir.canonicalizePath(file);
-    _urlMappings[key] = value;
+    String libPath = libDir.canonicalizePath(file);
+    _urlMappings[name] = libPath;
     String shortName = name.substring(_DART_COLON_PREFIX.length);
     SdkLibraryImpl library = new SdkLibraryImpl(shortName);
-    library.path = value;
-    (dartSdk as _EmbedderSdk)._librariesMap.setLibrary(name, library);
+    library.path = libPath;
+    (dartSdk as EmbedderSdk)._librariesMap.setLibrary(name, library);
   }
 
   /// Number of embedder libraries.
   int get length => _urlMappings.length;
 
-  /// Return the path mapping for [libName] or null if there is none.
-  String operator [](String libName) => _urlMappings[libName];
-
-  @override
-  Source resolveAbsolute(Uri importUri, [Uri actualUri]) {
-    String libraryName = _libraryName(importUri);
-    String partPath = _partPath(importUri);
-    // Lookup library name in mappings.
-    String mapping = _urlMappings[libraryName];
-    if (mapping == null) {
-      // Not found.
-      return null;
-    }
-    // This mapping points to the main entry file of the dart: library.
-    Uri libraryEntry = new Uri.file(mapping);
-    if (!libraryEntry.isAbsolute) {
-      // We expect an absolute path.
-      return null;
-    }
-
-    if (partPath != null) {
-      return _resolvePart(libraryEntry, partPath, importUri);
-    } else {
-      return _resolveEntry(libraryEntry, importUri);
-    }
-  }
-
   @override
   Uri restoreAbsolute(Source source) {
-    String extensionName = _findExtensionNameFor(source.fullName);
-    if (extensionName != null) {
-      return Uri.parse(extensionName);
-    }
-    // TODO(johnmccutchan): Handle restoring parts.
-    return null;
-  }
-
-  /// Return the extension name for [fullName] or `null`.
-  String _findExtensionNameFor(String fullName) {
-    String result;
-    _urlMappings.forEach((extensionName, pathMapping) {
-      if (pathMapping == fullName) {
-        result = extensionName;
-      }
-    });
-    return result;
-  }
-
-  /// Return the library name of [importUri].
-  String _libraryName(Uri importUri) {
-    String uri = importUri.toString();
-    int index = uri.indexOf('/');
-    if (index >= 0) {
-      return uri.substring(0, index);
-    }
-    return uri;
-  }
-
-  /// Return the part path of [importUri].
-  String _partPath(Uri importUri) {
-    String uri = importUri.toString();
-    int index = uri.indexOf('/');
-    if (index >= 0) {
-      return uri.substring(index + 1);
-    }
-    return null;
-  }
-
-  /// Resolve an import of an sdk extension.
-  Source _resolveEntry(Uri libraryEntry, Uri importUri) {
-    // Library entry.
-    JavaFile javaFile = new JavaFile.fromUri(libraryEntry);
-    return new FileBasedSource(javaFile, importUri);
-  }
-
-  /// Resolve a 'part' statement inside an sdk extension.
-  Source _resolvePart(Uri libraryEntry, String partPath, Uri importUri) {
-    // Library part.
-    String directory = pathos.dirname(libraryEntry.path);
-    Uri partUri = new Uri.file(pathos.join(directory, partPath));
-    assert(partUri.isAbsolute);
-    JavaFile javaFile = new JavaFile.fromUri(partUri);
-    return new FileBasedSource(javaFile, importUri);
+    Source sdkSource = dartSdk.fromFileUri(Uri.parse(source.fullName));
+    return sdkSource?.uri;
   }
 }
 
-class _EmbedderSdk implements DartSdk {
+class EmbedderSdk implements DartSdk {
   // TODO(danrubel) Refactor this with DirectoryBasedDartSdk
 
   /// The resolver associated with this embedder sdk.
   EmbedderUriResolver _resolver;
 
   /// The [AnalysisContext] which is used for all of the sources in this sdk.
   InternalAnalysisContext _analysisContext;
 
   /// The library map that is populated by visiting the AST structure parsed from
   /// the contents of the libraries file.
@@ skipping 22 matching lines @@
   @override
   String get sdkVersion => '0';
 
   @override
   List<String> get uris => _librariesMap.uris;
 
   @override
   Source fromFileUri(Uri uri) {
     JavaFile file = new JavaFile.fromUri(uri);
     String filePath = file.getAbsolutePath();
-    String srcPath = filePath.replaceAll('\\', '/');
 
     String path;
     for (SdkLibrary library in _librariesMap.sdkLibraries) {
       String libraryPath = library.path;
-      if (srcPath == libraryPath) {
+      if (filePath == libraryPath) {
         path = '$_DART_COLON_PREFIX${library.shortName}';
         break;
       }
     }
     if (path == null) {
       for (SdkLibrary library in _librariesMap.sdkLibraries) {
         String libraryPath = library.path;
         int index = libraryPath.lastIndexOf('/');
         if (index == -1) {
           continue;
         }
         String prefix = libraryPath.substring(0, index + 1);
-        if (!srcPath.startsWith(prefix)) {
+        if (!filePath.startsWith(prefix)) {
           continue;
         }
-        var relPath = srcPath.substring(prefix.length);
+        var relPath = filePath.substring(prefix.length);
         path = '$_DART_COLON_PREFIX${library.shortName}/$relPath';
         break;
       }
     }
 
     if (path != null) {
       try {
         return new FileBasedSource(file, parseUriWithException(path));
       } on URISyntaxException catch (exception, stackTrace) {
         AnalysisEngine.instance.logger.logInformation(
@@ skipping 38 matching lines @@
     }
     String filePath = srcPath.replaceAll('/', JavaFile.separator);
     try {
       JavaFile file = new JavaFile(filePath);
       return new FileBasedSource(file, parseUriWithException(dartUri));
     } on URISyntaxException {
       return null;
     }
   }
 }