Removed fixed dependencies

packages/analyzer/lib/src/source/source_resource.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.source.source_resource;
+
+import 'dart:collection';
+
+import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer/src/generated/source.dart';
+
+/**
+ * A function that can translate the contents of files on disk as they are read.
+ * This is now obsolete, but supported the ability of server to deal with
+ * clients that convert all text to an internal format.
+ */
+typedef String FileReadMode(String s);
+
+/**
+ * A source that represents a file.
+ */
+class FileSource extends Source {
+  /**
+   * A function that changes the way that files are read off of disk.
+   */
+  static FileReadMode fileReadMode = (String s) => s;
+
+  /**
+   * Map from encoded URI/filepath pair to a unique integer identifier.  This
+   * identifier is used for equality tests and hash codes.
+   *
+   * The URI and filepath are joined into a pair by separating them with an '@'
+   * character.
+   */
+  static final Map<String, int> _idTable = new HashMap<String, int>();
+
+  /**
+   * The URI from which this source was originally derived.
+   */
+  @override
+  final Uri uri;
+
+  /**
+   * The unique ID associated with this source.
+   */
+  final int id;
+
+  /**
+   * The file represented by this source.
+   */
+  final File file;
+
+  /**
+   * The cached absolute path of this source.
+   */
+  String _absolutePath;
+
+  /**
+   * The cached encoding for this source.
+   */
+  String _encoding;
+
+  /**
+   * Initialize a newly created source object to represent the given [file]. If
+   * a [uri] is given, then it will be used as the URI from which the source was
+   * derived, otherwise a `file:` URI will be created based on the [file].
+   */
+  FileSource(File file, [Uri uri])
+      : this.uri = uri ?? file.toUri(),
+        this.file = file,
+        id = _idTable.putIfAbsent(
+            '${uri ?? file.toUri()}@${file.path}', () => _idTable.length);
+
+  @override
+  TimestampedData<String> get contents {
+    return PerformanceStatistics.io.makeCurrentWhile(() {
+      return contentsFromFile;
+    });
+  }
+
+  /**
+   * Get and return the contents and timestamp of the underlying file.
+   *
+   * Clients should consider using the method [AnalysisContext.getContents]
+   * because contexts can have local overrides of the content of a source that
+   * the source is not aware of.
+   *
+   * Throws an exception if the contents of this source could not be accessed.
+   * See [contents].
+   */
+  TimestampedData<String> get contentsFromFile {
+    return new TimestampedData<String>(
+        modificationStamp, fileReadMode(file.readAsStringSync()));
+  }
+
+  @override
+  String get encoding => _encoding ??= uri.toString();
+
+  @override
+  String get fullName => _absolutePath ??= file.path;
+
+  @override
+  int get hashCode => uri.hashCode;
+
+  @override
+  bool get isInSystemLibrary => uri.scheme == DartUriResolver.DART_SCHEME;
+
+  @override
+  int get modificationStamp {
+    try {
+      return file.modificationStamp;
+    } on FileSystemException {
+      return -1;
+    }
+  }
+
+  @override
+  String get shortName => file.shortName;
+
+  @override
+  UriKind get uriKind => UriKind.fromScheme(uri.scheme);
+
+  @override
+  bool operator ==(Object object) {
+    if (object is FileSource) {
+      return id == object.id;
+    } else if (object is Source) {
+      return uri == object.uri;
+    }
+    return false;
+  }
+
+  @override
+  bool exists() => file.exists;
+
+  @override
+  String toString() {
+    if (file == null) {
+      return "<unknown source>";
+    }
+    return file.path;
+  }
+}