Move file_system libraries into 'analyzer'.

pkg/analyzer/lib/file_system/memory_file_system.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 resource;
+library memory_file_system;
 
 import 'dart:async';
 import 'dart:collection';
-import 'dart:io' as io;
 
 import 'package:analyzer/src/generated/engine.dart' show TimestampedData;
-import 'package:analyzer/src/generated/java_io.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:path/path.dart';
 import 'package:watcher/watcher.dart';
 
-
-/**
- * [File]s are leaf [Resource]s which contain data.
- */
-abstract class File extends Resource {
-  /**
-   * Create a new [Source] instance that serves this file.
-   */
-  Source createSource(UriKind uriKind);
-}
-
-
-/**
- * [Folder]s are [Resource]s which may contain files and/or other folders.
- */
-abstract class Folder extends Resource {
-  /**
-   * Return an existing child [Resource] with the given [relPath].
-   * Return a not existing [File] if no such child exist.
-   */
-  Resource getChild(String relPath);
-
-  /**
-   * Return a list of existing direct children [Resource]s (folders and files)
-   * in this folder, in no particular order.
-   */
-  List<Resource> getChildren();
-
-  /**
-   * Watch for changes to the files inside this folder (and in any nested
-   * folders, including folders reachable via links).
-   */
-  Stream<WatchEvent> get changes;
-
-  /**
-   * If the path [path] is a relative path, convert it to an absolute path
-   * by interpreting it relative to this folder.  If it is already an aboslute
-   * path, then don't change it.
-   *
-   * However, regardless of whether [path] is relative or absolute, normalize
-   * it by removing path components of the form '.' or '..'.
-   */
-  String canonicalizePath(String path);
-}
-
-
-/**
- * The abstract class [Resource] is an abstraction of file or folder.
- */
-abstract class Resource {
-  /**
-   * Return `true` if this resource exists.
-   */
-  bool get exists;
-
-  /**
-   * Return the full path to this resource.
-   */
-  String get path;
-
-  /**
-   * Return a short version of the name that can be displayed to the user to
-   * denote this resource.
-   */
-  String get shortName;
-
-  /**
-   * Return the [Folder] that contains this resource, or `null` if this resource
-   * is a root folder.
-   */
-  Folder get parent;
-}
-
-
-/**
- * Instances of the class [ResourceProvider] convert [String] paths into
- * [Resource]s.
- */
-abstract class ResourceProvider {
-  /**
-   * Return the [Resource] that corresponds to the given [path].
-   */
-  Resource getResource(String path);
-
-  /**
-   * Get the path context used by this resource provider.
-   */
-  Context get pathContext;
-}
-
-
-/**
- * An in-memory implementation of [Resource].
- */
-abstract class _MemoryResource implements Resource {
-  final MemoryResourceProvider _provider;
-  final String path;
-
-  _MemoryResource(this._provider, this.path);
-
-  @override
-  bool operator ==(other) {
-    if (runtimeType != other.runtimeType) {
-      return false;
-    }
-    return path == other.path;
-  }
-
-  @override
-  bool get exists => _provider._pathToResource.containsKey(path);
-
-  @override
-  get hashCode => path.hashCode;
-
-  @override
-  String get shortName => posix.basename(path);
-
-  @override
-  String toString() => path;
-
-  @override
-  Folder get parent {
-    String parentPath = posix.dirname(path);
-    if (parentPath == path) {
-      return null;
-    }
-    return _provider.getResource(parentPath);
-  }
-}
-
-
-/**
- * An in-memory implementation of [File].
- */
-class _MemoryFile extends _MemoryResource implements File {
-  _MemoryFile(MemoryResourceProvider provider, String path) :
-      super(provider, path);
-
-  @override
-  Source createSource(UriKind uriKind) {
-    return new _MemoryFileSource(this, uriKind);
-  }
-
-  String get _content {
-    String content = _provider._pathToContent[path];
-    if (content == null) {
-      throw new MemoryResourceException(path, "File '$path' does not exist");
-    }
-    return content;
-  }
-
-  int get _timestamp => _provider._pathToTimestamp[path];
-}
+import 'file_system.dart';
 
 
 /**
  * Exception thrown when a memory [Resource] file operation fails.
  */
 class MemoryResourceException {
   final path;
   final message;
 
   MemoryResourceException(this.path, this.message);
 
   @override
   String toString() {
     return "MemoryResourceException(path=$path; message=$message)";
   }
 }
 
 
 /**
+ * An in-memory implementation of [ResourceProvider].
+ * Use `/` as a path separator.
+ */
+class MemoryResourceProvider implements ResourceProvider {
+  final Map<String, _MemoryResource> _pathToResource =
+      new HashMap<String, _MemoryResource>();
+  final Map<String, String> _pathToContent = new HashMap<String, String>();
+  final Map<String, int> _pathToTimestamp = new HashMap<String, int>();
+  final Map<String, List<StreamController<WatchEvent>>> _pathToWatchers =
+      new HashMap<String, List<StreamController<WatchEvent>>>();
+  int nextStamp = 0;
+
+  @override
+  Context get pathContext => posix;
+
+  void deleteFile(String path) {
+    _checkFileAtPath(path);
+    _pathToResource.remove(path);
+    _pathToContent.remove(path);
+    _pathToTimestamp.remove(path);
+    _notifyWatchers(path, ChangeType.REMOVE);
+  }
+
+  @override
+  Resource getResource(String path) {
+    path = posix.normalize(path);
+    Resource resource = _pathToResource[path];
+    if (resource == null) {
+      resource = new _MemoryFile(this, path);
+    }
+    return resource;
+  }
+
+  void modifyFile(String path, String content) {
+    _checkFileAtPath(path);
+    _pathToContent[path] = content;
+    _pathToTimestamp[path] = nextStamp++;
+    _notifyWatchers(path, ChangeType.MODIFY);
+  }
+
+  /**
+   * Create a resource representing a dummy link (that is, a File object which
+   * appears in its parent directory, but whose `exists` property is false)
+   */
+  File newDummyLink(String path) {
+    path = posix.normalize(path);
+    newFolder(posix.dirname(path));
+    _MemoryDummyLink link = new _MemoryDummyLink(this, path);
+    _pathToResource[path] = link;
+    _pathToTimestamp[path] = nextStamp++;
+    _notifyWatchers(path, ChangeType.ADD);
+    return link;
+  }
+
+  File newFile(String path, String content) {
+    path = posix.normalize(path);
+    newFolder(posix.dirname(path));
+    _MemoryFile file = new _MemoryFile(this, path);
+    _pathToResource[path] = file;
+    _pathToContent[path] = content;
+    _pathToTimestamp[path] = nextStamp++;
+    _notifyWatchers(path, ChangeType.ADD);
+    return file;
+  }
+
+  Folder newFolder(String path) {
+    path = posix.normalize(path);
+    if (!path.startsWith('/')) {
+      throw new ArgumentError("Path must start with '/'");
+    }
+    _MemoryResource resource = _pathToResource[path];
+    if (resource == null) {
+      String parentPath = posix.dirname(path);
+      if (parentPath != path) {
+        newFolder(parentPath);
+      }
+      _MemoryFolder folder = new _MemoryFolder(this, path);
+      _pathToResource[path] = folder;
+      _pathToTimestamp[path] = nextStamp++;
+      return folder;
+    } else if (resource is _MemoryFolder) {
+      return resource;
+    } else {
+      String message = 'Folder expected at '
+                       "'$path'"
+                       'but ${resource.runtimeType} found';
+      throw new ArgumentError(message);
+    }
+  }
+
+  void _checkFileAtPath(String path) {
+    _MemoryResource resource = _pathToResource[path];
+    if (resource is! _MemoryFile) {
+      throw new ArgumentError(
+          'File expected at "$path" but ${resource.runtimeType} found');
+    }
+  }
+
+  void _notifyWatchers(String path, ChangeType changeType) {
+    _pathToWatchers.forEach((String watcherPath, List<StreamController<WatchEvent>> streamControllers) {
+      if (posix.isWithin(watcherPath, path)) {
+        for (StreamController<WatchEvent> streamController in streamControllers) {
+          streamController.add(new WatchEvent(changeType, path));
+        }
+      }
+    });
+  }
+}
+
+
+/**
  * An in-memory implementation of [File] which acts like a symbolic link to a
  * non-existent file.
  */
 class _MemoryDummyLink extends _MemoryResource implements File {
   _MemoryDummyLink(MemoryResourceProvider provider, String path) :
       super(provider, path);
 
   @override
-  Source createSource(UriKind uriKind) {
-    throw new MemoryResourceException(path, "File '$path' could not be read");
-  }
+  bool get exists => false;
 
   String get _content {
     throw new MemoryResourceException(path, "File '$path' could not be read");
   }
 
   int get _timestamp => _provider._pathToTimestamp[path];
 
   @override
-  bool get exists => false;
+  Source createSource(UriKind uriKind) {
+    throw new MemoryResourceException(path, "File '$path' could not be read");
+  }
 }
 
 
+/**
+ * An in-memory implementation of [File].
+ */
+class _MemoryFile extends _MemoryResource implements File {
+  _MemoryFile(MemoryResourceProvider provider, String path) :
+      super(provider, path);
+
+  String get _content {
+    String content = _provider._pathToContent[path];
+    if (content == null) {
+      throw new MemoryResourceException(path, "File '$path' does not exist");
+    }
+    return content;
+  }
+
+  int get _timestamp => _provider._pathToTimestamp[path];
+
+  @override
+  Source createSource(UriKind uriKind) {
+    return new _MemoryFileSource(this, uriKind);
+  }
+}
+
+
 /**
  * An in-memory implementation of [Source].
  */
 class _MemoryFileSource implements Source {
   final _MemoryFile _file;
 
   final UriKind uriKind;
 
   _MemoryFileSource(this._file, this.uriKind);
 
   @override
-  bool operator ==(other) {
-    if (other is _MemoryFileSource) {
-      return other._file == _file;
-    }
-    return false;
-  }
-
-  @override
   TimestampedData<String> get contents {
     return new TimestampedData<String>(modificationStamp, _file._content);
   }
 
   @override
   String get encoding {
     return '${new String.fromCharCode(uriKind.encoding)}${_file.path}';
   }
 
   @override
-  bool exists() => _file.exists;
-
-  @override
   String get fullName => _file.path;
 
   @override
   int get hashCode => _file.hashCode;
 
   @override
   bool get isInSystemLibrary => false;
 
   @override
   int get modificationStamp => _file._timestamp;
 
   @override
+  String get shortName => _file.shortName;
+
+  @override
+  bool operator ==(other) {
+    if (other is _MemoryFileSource) {
+      return other._file == _file;
+    }
+    return false;
+  }
+
+  @override
+  bool exists() => _file.exists;
+
+  @override
   Source resolveRelative(Uri relativeUri) {
     String relativePath = posix.fromUri(relativeUri);
     String folderPath = posix.dirname(_file.path);
     String path = posix.join(folderPath, relativePath);
     path = posix.normalize(path);
     _MemoryFile file = new _MemoryFile(_file._provider, path);
     return new _MemoryFileSource(file, uriKind);
   }
-
-  @override
-  String get shortName => _file.shortName;
 }
 
 
 /**
  * An in-memory implementation of [Folder].
  */
 class _MemoryFolder extends _MemoryResource implements Folder {
   _MemoryFolder(MemoryResourceProvider provider, String path) :
       super(provider, path);
   @override
-  Resource getChild(String relPath) {
-    String childPath = canonicalizePath(relPath);
-    _MemoryResource resource = _provider._pathToResource[childPath];
-    if (resource == null) {
-      resource = new _MemoryFile(_provider, childPath);
-    }
-    return resource;
-  }
-
-  @override
-  List<Resource> getChildren() {
-    List<Resource> children = <Resource>[];
-    _provider._pathToResource.forEach((resourcePath, resource) {
-      if (posix.dirname(resourcePath) == path) {
-        children.add(resource);
-      }
-    });
-    return children;
-  }
-
-  @override
   Stream<WatchEvent> get changes {
     StreamController<WatchEvent> streamController = new StreamController<WatchEvent>();
     if (!_provider._pathToWatchers.containsKey(path)) {
       _provider._pathToWatchers[path] = <StreamController<WatchEvent>>[];
     }
     _provider._pathToWatchers[path].add(streamController);
     streamController.done.then((_) {
       _provider._pathToWatchers[path].remove(streamController);
       if (_provider._pathToWatchers[path].isEmpty) {
         _provider._pathToWatchers.remove(path);
       }
     });
     return streamController.stream;
   }
 
   @override
   String canonicalizePath(String relPath) {
     relPath = posix.normalize(relPath);
     String childPath = posix.join(path, relPath);
     childPath = posix.normalize(childPath);
     return childPath;
   }
+
+  @override
+  Resource getChild(String relPath) {
+    String childPath = canonicalizePath(relPath);
+    _MemoryResource resource = _provider._pathToResource[childPath];
+    if (resource == null) {
+      resource = new _MemoryFile(_provider, childPath);
+    }
+    return resource;
+  }
+
+  @override
+  List<Resource> getChildren() {
+    List<Resource> children = <Resource>[];
+    _provider._pathToResource.forEach((resourcePath, resource) {
+      if (posix.dirname(resourcePath) == path) {
+        children.add(resource);
+      }
+    });
+    return children;
+  }
 }
 
 
 /**
- * An in-memory implementation of [ResourceProvider].
- * Use `/` as a path separator.
+ * An in-memory implementation of [Resource].
  */
-class MemoryResourceProvider implements ResourceProvider {
-  final Map<String, _MemoryResource> _pathToResource =
-      new HashMap<String, _MemoryResource>();
-  final Map<String, String> _pathToContent = new HashMap<String, String>();
-  final Map<String, int> _pathToTimestamp = new HashMap<String, int>();
-  final Map<String, List<StreamController<WatchEvent>>> _pathToWatchers =
-      new HashMap<String, List<StreamController<WatchEvent>>>();
-  int nextStamp = 0;
+abstract class _MemoryResource implements Resource {
+  final MemoryResourceProvider _provider;
+  final String path;
+
+  _MemoryResource(this._provider, this.path);
 
   @override
-  Resource getResource(String path) {
-    path = posix.normalize(path);
-    Resource resource = _pathToResource[path];
-    if (resource == null) {
-      resource = new _MemoryFile(this, path);
-    }
-    return resource;
-  }
-
-  Folder newFolder(String path) {
-    path = posix.normalize(path);
-    if (!path.startsWith('/')) {
-      throw new ArgumentError("Path must start with '/'");
-    }
-    _MemoryResource resource = _pathToResource[path];
-    if (resource == null) {
-      String parentPath = posix.dirname(path);
-      if (parentPath != path) {
-        newFolder(parentPath);
-      }
-      _MemoryFolder folder = new _MemoryFolder(this, path);
-      _pathToResource[path] = folder;
-      _pathToTimestamp[path] = nextStamp++;
-      return folder;
-    } else if (resource is _MemoryFolder) {
-      return resource;
-    } else {
-      String message = 'Folder expected at '
-                       "'$path'"
-                       'but ${resource.runtimeType} found';
-      throw new ArgumentError(message);
-    }
-  }
-
-  File newFile(String path, String content) {
-    path = posix.normalize(path);
-    newFolder(posix.dirname(path));
-    _MemoryFile file = new _MemoryFile(this, path);
-    _pathToResource[path] = file;
-    _pathToContent[path] = content;
-    _pathToTimestamp[path] = nextStamp++;
-    _notifyWatchers(path, ChangeType.ADD);
-    return file;
-  }
-
-  /**
-   * Create a resource representing a dummy link (that is, a File object which
-   * appears in its parent directory, but whose `exists` property is false)
-   */
-  File newDummyLink(String path) {
-    path = posix.normalize(path);
-    newFolder(posix.dirname(path));
-    _MemoryDummyLink link = new _MemoryDummyLink(this, path);
-    _pathToResource[path] = link;
-    _pathToTimestamp[path] = nextStamp++;
-    _notifyWatchers(path, ChangeType.ADD);
-    return link;
-  }
-
-  void _notifyWatchers(String path, ChangeType changeType) {
-    _pathToWatchers.forEach((String watcherPath, List<StreamController<WatchEvent>> streamControllers) {
-      if (posix.isWithin(watcherPath, path)) {
-        for (StreamController<WatchEvent> streamController in streamControllers) {
-          streamController.add(new WatchEvent(changeType, path));
-        }
-      }
-    });
-  }
-
-  void modifyFile(String path, String content) {
-    _checkFileAtPath(path);
-    _pathToContent[path] = content;
-    _pathToTimestamp[path] = nextStamp++;
-    _notifyWatchers(path, ChangeType.MODIFY);
-  }
-
-  void _checkFileAtPath(String path) {
-    _MemoryResource resource = _pathToResource[path];
-    if (resource is! _MemoryFile) {
-      throw new ArgumentError(
-          'File expected at "$path" but ${resource.runtimeType} found');
-    }
-  }
-
-  void deleteFile(String path) {
-    _checkFileAtPath(path);
-    _pathToResource.remove(path);
-    _pathToContent.remove(path);
-    _pathToTimestamp.remove(path);
-    _notifyWatchers(path, ChangeType.REMOVE);
-  }
-
-  @override
-  Context get pathContext => posix;
-}
-
-
-/**
- * A `dart:io` based implementation of [File].
- */
-class _PhysicalFile extends _PhysicalResource implements File {
-  _PhysicalFile(io.File file) : super(file);
-
-  @override
-  Source createSource(UriKind uriKind) {
-    io.File file = _entry as io.File;
-    JavaFile javaFile = new JavaFile(file.absolute.path);
-    return new FileBasedSource.con2(javaFile, uriKind);
-  }
-}
-
-
-/**
- * A `dart:io` based implementation of [Folder].
- */
-class _PhysicalFolder extends _PhysicalResource implements Folder {
-  _PhysicalFolder(io.Directory directory) : super(directory);
-
-  @override
-  Resource getChild(String relPath) {
-    return PhysicalResourceProvider.INSTANCE.getResource(canonicalizePath(relPath));
-  }
-
-  @override
-  List<Resource> getChildren() {
-    List<Resource> children = <Resource>[];
-    io.Directory directory = _entry as io.Directory;
-    List<io.FileSystemEntity> entries = directory.listSync(recursive: false);
-    int numEntries = entries.length;
-    for (int i = 0; i < numEntries; i++) {
-      io.FileSystemEntity entity = entries[i];
-      if (entity is io.Directory) {
-        children.add(new _PhysicalFolder(entity));
-      } else if (entity is io.File) {
-        children.add(new _PhysicalFile(entity));
-      }
-    }
-    return children;
-  }
-
-  @override
-  Stream<WatchEvent> get changes => new DirectoryWatcher(_entry.path).events;
-
-  @override
-  String canonicalizePath(String relPath) {
-    return normalize(join(_entry.absolute.path, relPath));
-  }
-}
-
-
-/**
- * A `dart:io` based implementation of [Resource].
- */
-abstract class _PhysicalResource implements Resource {
-  final io.FileSystemEntity _entry;
-
-  _PhysicalResource(this._entry);
-
-  @override
-  bool get exists => _entry.existsSync();
-
-  @override
-  String get path => _entry.absolute.path;
+  bool get exists => _provider._pathToResource.containsKey(path);
 
   @override
   get hashCode => path.hashCode;
 
   @override
-  bool operator==(other) {
+  Folder get parent {
+    String parentPath = posix.dirname(path);
+    if (parentPath == path) {
+      return null;
+    }
+    return _provider.getResource(parentPath);
+  }
+
+  @override
+  String get shortName => posix.basename(path);
+
+  @override
+  bool operator ==(other) {
     if (runtimeType != other.runtimeType) {
       return false;
     }
     return path == other.path;
   }
 
   @override
-  String get shortName => basename(path);
-
-  @override
   String toString() => path;
-
-  @override
-  Folder get parent {
-    String parentPath = dirname(path);
-    if (parentPath == path) {
-      return null;
-    }
-    return new _PhysicalFolder(new io.Directory(parentPath));
-  }
 }
-
-
-/**
- * A `dart:io` based implementation of [ResourceProvider].
- */
-class PhysicalResourceProvider implements ResourceProvider {
-  static final PhysicalResourceProvider INSTANCE = new PhysicalResourceProvider._();
-
-  PhysicalResourceProvider._();
-
-  @override
-  Resource getResource(String path) {
-    if (io.FileSystemEntity.isDirectorySync(path)) {
-      io.Directory directory = new io.Directory(path);
-      return new _PhysicalFolder(directory);
-    } else {
-      io.File file = new io.File(path);
-      return new _PhysicalFile(file);
-    }
-  }
-
-  @override
-  Context get pathContext => io.Platform.isWindows ? windows : posix;
-}
-
-
-/**
- * A [UriResolver] for [Resource]s.
- */
-class ResourceUriResolver extends UriResolver {
-  /**
-   * The name of the `file` scheme.
-   */
-  static String _FILE_SCHEME = "file";
-
-  final ResourceProvider _provider;
-
-  ResourceUriResolver(this._provider);
-
-  @override
-  Source fromEncoding(UriKind kind, Uri uri) {
-    if (kind == UriKind.FILE_URI) {
-      Resource resource = _provider.getResource(uri.path);
-      if (resource is File) {
-        return resource.createSource(kind);
-      }
-    }
-    return null;
-  }
-
-  @override
-  Source resolveAbsolute(Uri uri) {
-    if (!_isFileUri(uri)) {
-      return null;
-    }
-    Resource resource = _provider.getResource(uri.path);
-    if (resource is File) {
-      return resource.createSource(UriKind.FILE_URI);
-    }
-    return null;
-  }
-
-  /**
-   * Return `true` if the given URI is a `file` URI.
-   *
-   * @param uri the URI being tested
-   * @return `true` if the given URI is a `file` URI
-   */
-  static bool _isFileUri(Uri uri) => uri.scheme == _FILE_SCHEME;
-}