Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/analyzer/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 memory_file_system;
+
+import 'dart:async';
+import 'dart:collection';
+
+import 'package:analyzer/src/generated/engine.dart' show TimestampedData;
+import 'package:analyzer/src/generated/source_io.dart';
+import 'package:path/path.dart';
+import 'package:watcher/watcher.dart';
+
+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 ${resource.runtimeType} found');
+    }
+  }
+
+  void _notifyWatchers(String path, ChangeType changeType) {
+    _pathToWatchers.forEach(
+        (String watcherPath, List<StreamController<WatchEvent>> streamControllers) {
+      if (posix.isWithin(watcherPath, path)) {
+        for (StreamController<WatchEvent> streamController in streamControllers)
+            {
+          streamController.add(new WatchEvent(changeType, path));
+        }
+      }
+    });
+  }
+}
+
+
+/**
+ * An in-memory implementation of [File] which acts like a symbolic link to a
+ * non-existent file.
+ */
+class _MemoryDummyLink extends _MemoryResource implements File {
+  _MemoryDummyLink(MemoryResourceProvider provider, String path) : super(
+      provider,
+      path);
+
+  @override
+  bool get exists => false;
+
+  String get _content {
+    throw new MemoryResourceException(path, "File '$path' could not be read");
+  }
+
+  int get _timestamp => _provider._pathToTimestamp[path];
+
+  @override
+  Source createSource([Uri uri]) {
+    throw new MemoryResourceException(path, "File '$path' could not be read");
+  }
+
+  @override
+  bool isOrContains(String path) {
+    return path == this.path;
+  }
+}
+
+
+/**
+ * An in-memory implementation of [File].
+ */
+class _MemoryFile extends _MemoryResource implements File {
+  _MemoryFile(MemoryResourceProvider provider, String path) : super(
+      provider,
+      path);
+
+  String get _content {
+    String content = _provider._pathToContent[path];
+    if (content == null) {
+      throw new MemoryResourceException(path, "File '$path' does not exist");
+    }
+    return content;
+  }
+
+  int get _timestamp => _provider._pathToTimestamp[path];
+
+  @override
+  Source createSource([Uri uri]) {
+    if (uri == null) {
+      uri = posix.toUri(path);
+    }
+    return new _MemoryFileSource(this, uri);
+  }
+
+  @override
+  bool isOrContains(String path) {
+    return path == this.path;
+  }
+}
+
+
+/**
+ * An in-memory implementation of [Source].
+ */
+class _MemoryFileSource implements Source {
+  final _MemoryFile _file;
+
+  final Uri uri;
+
+  _MemoryFileSource(this._file, this.uri);
+
+  @override
+  TimestampedData<String> get contents {
+    return new TimestampedData<String>(modificationStamp, _file._content);
+  }
+
+  @override
+  String get encoding {
+    return uri.toString();
+  }
+
+  @override
+  String get fullName => _file.path;
+
+  @override
+  int get hashCode => _file.hashCode;
+
+  @override
+  bool get isInSystemLibrary => uriKind == UriKind.DART_URI;
+
+  @override
+  int get modificationStamp => _file._timestamp;
+
+  @override
+  String get shortName => _file.shortName;
+
+  @override
+  UriKind get uriKind {
+    String scheme = uri.scheme;
+    if (scheme == PackageUriResolver.PACKAGE_SCHEME) {
+      return UriKind.PACKAGE_URI;
+    } else if (scheme == DartUriResolver.DART_SCHEME) {
+      return UriKind.DART_URI;
+    } else if (scheme == FileUriResolver.FILE_SCHEME) {
+      return UriKind.FILE_URI;
+    }
+    return UriKind.FILE_URI;
+  }
+
+  @override
+  bool operator ==(other) {
+    if (other is _MemoryFileSource) {
+      return other._file == _file;
+    }
+    return false;
+  }
+
+  @override
+  bool exists() => _file.exists;
+
+  @override
+  Uri resolveRelativeUri(Uri relativeUri) {
+    return uri.resolveUri(relativeUri);
+  }
+
+  @override
+  String toString() => _file.toString();
+}
+
+
+/**
+ * An in-memory implementation of [Folder].
+ */
+class _MemoryFolder extends _MemoryResource implements Folder {
+  _MemoryFolder(MemoryResourceProvider provider, String path) : super(
+      provider,
+      path);
+  @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
+  bool contains(String path) {
+    return posix.isWithin(this.path, 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
+  bool isOrContains(String path) {
+    if (path == this.path) {
+      return true;
+    }
+    return contains(path);
+  }
+}
+
+
+/**
+ * An in-memory implementation of [Resource].
+ */
+abstract class _MemoryResource implements Resource {
+  final MemoryResourceProvider _provider;
+  final String path;
+
+  _MemoryResource(this._provider, this.path);
+
+  @override
+  bool get exists => _provider._pathToResource.containsKey(path);
+
+  @override
+  get hashCode => path.hashCode;
+
+  @override
+  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 toString() => path;
+}