Virtual filesystem support for dart_analyzer.

compiler/java/com/google/dart/compiler/FileBasedSystemLibraryProvider.java

Index: compiler/java/com/google/dart/compiler/FileBasedSystemLibraryProvider.java
===================================================================
--- compiler/java/com/google/dart/compiler/FileBasedSystemLibraryProvider.java	(revision 0)
+++ compiler/java/com/google/dart/compiler/FileBasedSystemLibraryProvider.java	(revision 0)
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2012, the Dart project authors.
+ * 
+ * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ * 
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.google.dart.compiler;
+
+import com.google.dart.compiler.SystemLibrariesReader.DartLibrary;
+
+import java.io.File;
+import java.net.URI;
+import java.util.Map;
+
+/**
+ * A file-based {@link SystemLibraryProvider} that reads dart-sdk/lib/_internal/libraries.dart for
+ * system library information.
+ */
+public class FileBasedSystemLibraryProvider implements SystemLibraryProvider {
+
+  private File sdkLibPath;
+  private URI sdkLibPathUri;
+
+  /**
+   * Create a {@link FileBasedSystemLibraryProvider} with the given path to the dart SDK.
+   */
+  public FileBasedSystemLibraryProvider(File sdkPath) {
+    sdkLibPath = new File(sdkPath, "lib").getAbsoluteFile();
+    sdkLibPathUri = sdkLibPath.toURI();
+  }
+
+
+  @Override
+  public URI getSdkLibPathUri() {
+    return sdkLibPathUri;
+  }
+
+  @Override
+  public Map<String, DartLibrary> getLibraryMap() {
+    SystemLibrariesReader reader = new SystemLibrariesReader(sdkLibPath);
+    return reader.getLibrariesMap();
+  }
+
+  @Override
+  public URI resolveHost(String host, URI uri) {
+    return new File(sdkLibPath, host).toURI().resolve("." + uri.getPath());
+  }
+
+  @Override
+  public boolean exists(URI uri) {
+    return new File(uri).exists();
+  }
+  
+  
+  @Override
+  public SystemLibrary createSystemLibrary(String name, String host, String pathToLib,
+      String category, boolean documented, boolean implementation) {
+    
+    
+    File dir = new File(sdkLibPath, host);
+    
+    File libFile = new File(dir, pathToLib);
+    if (!libFile.isFile()) {
+      throw new InternalCompilerException("Error mapping dart:" + host + ", path "
+          + libFile.getAbsolutePath() + " is not a file.");
+    }
+    
+    return new SystemLibrary(
+        name, host, pathToLib, dir, category, documented, implementation);
+  }
+  
+}