dart/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/sdk/DirectoryBasedDartSdk.java - external/dart - Git at Google

 /*
  * 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.engine.sdk;

 import com.google.dart.engine.AnalysisEngine;
 import com.google.dart.engine.context.AnalysisContext;
 import com.google.dart.engine.context.ChangeSet;
 import com.google.dart.engine.internal.context.InternalAnalysisContext;
 import com.google.dart.engine.internal.context.SdkAnalysisContext;
 import com.google.dart.engine.internal.sdk.LibraryMap;
 import com.google.dart.engine.internal.sdk.SdkLibrariesReader;
 import com.google.dart.engine.source.DartUriResolver;
 import com.google.dart.engine.source.FileBasedSource;
 import com.google.dart.engine.source.Source;
 import com.google.dart.engine.source.SourceFactory;
 import com.google.dart.engine.utilities.io.FileUtilities;
 import com.google.dart.engine.utilities.os.OSUtilities;
 import com.google.dart.engine.utilities.translation.DartBlockBody;
 import com.google.dart.engine.utilities.translation.DartOmit;
 import com.google.dart.engine.utilities.translation.DartOptional;

 import java.io.File;
 import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;

 /**
  * Instances of the class {@code DirectoryBasedDartSdk} represent a Dart SDK installed in a
  * specified directory. Typical Dart SDK layout is something like...
  *
  * <pre>
  *    dart-sdk/
  *       bin/
  *          dart[.exe]  <-- VM
  *       lib/
  *          core/
  *             core.dart
  *             ... other core library files ...
  *          ... other libraries ...
  *       util/
  *          ... Dart utilities ...
  *    Chromium/   <-- Dartium typically exists in a sibling directory
  * </pre>
  *
  * @coverage dart.engine.sdk
  */
 public class DirectoryBasedDartSdk implements DartSdk {
   /**
    * The {@link AnalysisContext} which is used for all of the sources in this {@link DartSdk}.
    */
   private InternalAnalysisContext analysisContext;

   /**
    * The directory containing the SDK.
    */
   private final File sdkDirectory;

   /**
    * The revision number of this SDK, or {@code "0"} if the revision number cannot be discovered.
    */
   private String sdkVersion;

   /**
    * The file containing the dart2js executable.
    */
   private File dart2jsExecutable;

   /**
    * The file containing the dart formatter executable.
    */
   private File dartFmtExecutable;

   /**
    * The file containing the Dartium executable.
    */
   private File dartiumExecutable;

   /**
    * The file containing the pub executable.
    */
   private File pubExecutable;

   /**
    * The file containing the VM executable.
    */
   private File vmExecutable;

   /**
    * A mapping from Dart library URI's to the library represented by that URI.
    */
   private LibraryMap libraryMap;

   /**
    * The default SDK, or {@code null} if the default SDK either has not yet been created or cannot
    * be created for some reason.
    */
   private static DirectoryBasedDartSdk DEFAULT_SDK;

   /**
    * The name of the directory within the SDK directory that contains executables.
    */
   private static final String BIN_DIRECTORY_NAME = "bin"; //$NON-NLS-1$

   /**
    * The name of the directory on non-Mac that contains dartium.
    */
   private static final String DARTIUM_DIRECTORY_NAME = "chromium"; //$NON-NLS-1$

   /**
    * The name of the dart2js executable on non-windows operating systems.
    */
   private static final String DART2JS_EXECUTABLE_NAME = "dart2js"; //$NON-NLS-1$

   /**
    * The name of the file containing the dart2js executable on Windows.
    */
   private static final String DART2JS_EXECUTABLE_NAME_WIN = "dart2js.bat"; //$NON-NLS-1$

   /**
    * The name of the dart formatter executable on non-windows operating systems.
    */
   private static final String DARTFMT_EXECUTABLE_NAME = "dartfmt"; //$NON-NLS-1$

   /**
    * The name of the dart formatter executable on windows operating systems.
    */
   private static final String DARTFMT_EXECUTABLE_NAME_WIN = "dartfmt.bat"; //$NON-NLS-1$

   /**
    * The name of the file containing the Dartium executable on Linux.
    */
   private static final String DARTIUM_EXECUTABLE_NAME_LINUX = "chrome"; //$NON-NLS-1$

   /**
    * The name of the file containing the Dartium executable on Macintosh.
    */
   private static final String DARTIUM_EXECUTABLE_NAME_MAC = "Chromium.app/Contents/MacOS/Chromium"; //$NON-NLS-1$

   /**
    * The name of the file containing the Dartium executable on Windows.
    */
   private static final String DARTIUM_EXECUTABLE_NAME_WIN = "Chrome.exe"; //$NON-NLS-1$

   /**
    * The name of the {@link System} property whose value is the path to the default Dart SDK
    * directory.
    */
   private static final String DEFAULT_DIRECTORY_PROPERTY_NAME = "com.google.dart.sdk"; //$NON-NLS-1$

   /**
    * The name of the directory within the SDK directory that contains documentation for the
    * libraries.
    */
   private static final String DOCS_DIRECTORY_NAME = "docs"; //$NON-NLS-1$

   /**
    * The suffix added to the name of a library to derive the name of the file containing the
    * documentation for that library.
    */
   private static final String DOC_FILE_SUFFIX = "_api.json"; //$NON-NLS-1$

   /**
    * The name of the directory within the SDK directory that contains the libraries file.
    */
   private static final String INTERNAL_DIR = "_internal"; //$NON-NLS-1$

   /**
    * The name of the directory within the SDK directory that contains the libraries.
    */
   private static final String LIB_DIRECTORY_NAME = "lib"; //$NON-NLS-1$

   /**
    * The name of the libraries file.
    */
   private static final String LIBRARIES_FILE = "libraries.dart"; //$NON-NLS-1$

   /**
    * The name of the pub executable on windows.
    */
   private static final String PUB_EXECUTABLE_NAME_WIN = "pub.bat"; //$NON-NLS-1$

   /**
    * The name of the pub executable on non-windows operating systems.
    */
   private static final String PUB_EXECUTABLE_NAME = "pub"; //$NON-NLS-1$

   /**
    * The name of the file within the SDK directory that contains the version number of the SDK.
    */
   private static final String VERSION_FILE_NAME = "version"; //$NON-NLS-1$

   /**
    * The name of the file containing the VM executable on the Windows operating system.
    */
   private static final String VM_EXECUTABLE_NAME_WIN = "dart.exe"; //$NON-NLS-1$

   /**
    * The name of the file containing the VM executable on non-Windows operating systems.
    */
   private static final String VM_EXECUTABLE_NAME = "dart"; //$NON-NLS-1$

   /**
    * Return the default Dart SDK, or {@code null} if the directory containing the default SDK cannot
    * be determined (or does not exist).
    *
    * @return the default Dart SDK
    */
   public static DirectoryBasedDartSdk getDefaultSdk() {
     if (DEFAULT_SDK == null) {
       File sdkDirectory = getDefaultSdkDirectory();
       if (sdkDirectory == null) {
         return null;
       }
       DEFAULT_SDK = new DirectoryBasedDartSdk(sdkDirectory);
     }
     return DEFAULT_SDK;
   }

   /**
    * Return the default directory for the Dart SDK, or {@code null} if the directory cannot be
    * determined (or does not exist). The default directory is provided by a {@link System} property
    * named {@code com.google.dart.sdk}.
    *
    * @return the default directory for the Dart SDK
    */
   public static File getDefaultSdkDirectory() {
     String sdkProperty = System.getProperty(DEFAULT_DIRECTORY_PROPERTY_NAME);
     if (sdkProperty == null) {
       return null;
     }
     File sdkDirectory = new File(sdkProperty);
     if (!sdkDirectory.exists()) {
       return null;
     }
     return sdkDirectory;
   }

   /**
    * Initialize a newly created SDK to represent the Dart SDK installed in the given directory.
    *
    * @param sdkDirectory the directory containing the SDK
    */
   @DartOmit
   public DirectoryBasedDartSdk(File sdkDirectory) {
     this(sdkDirectory, false);
   }

   /**
    * Initialize a newly created SDK to represent the Dart SDK installed in the given directory.
    *
    * @param sdkDirectory the directory containing the SDK
    * @param useDart2jsPaths {@code true} if the dart2js path should be used when it is available
    */
   public DirectoryBasedDartSdk(File sdkDirectory,
       @DartOptional(defaultValue = "false") boolean useDart2jsPaths) {
     this.sdkDirectory = sdkDirectory.getAbsoluteFile();
     libraryMap = initialLibraryMap(useDart2jsPaths);
   }

   @Override
   public Source fromFileUri(URI uri) {
     File file = new File(uri);
     String filePath = file.getAbsolutePath();
     String libPath = getLibraryDirectory().getAbsolutePath();
     if (!filePath.startsWith(libPath + File.separator)) {
       return null;
     }
     filePath = filePath.substring(libPath.length() + 1);
     for (SdkLibrary library : libraryMap.getSdkLibraries()) {
       String libraryPath = library.getPath();
       if (filePath.replace('\\', '/').equals(libraryPath)) {
         String path = library.getShortName();
         try {
           return new FileBasedSource(new URI(path), file);
         } catch (URISyntaxException exception) {
           AnalysisEngine.getInstance().getLogger().logInformation(
               "Failed to create URI: " + path,
               exception);
           return null;
         }
       }
       libraryPath = new File(libraryPath).getParent();
       if (filePath.startsWith(libraryPath + File.separator)) {
         String path = library.getShortName() + "/" + filePath.substring(libraryPath.length() + 1);
         try {
           return new FileBasedSource(new URI(path), file);
         } catch (URISyntaxException exception) {
           AnalysisEngine.getInstance().getLogger().logInformation(
               "Failed to create URI: " + path,
               exception);
           return null;
         }
       }
     }
     return null;
   }

   @Override
   public AnalysisContext getContext() {
     if (analysisContext == null) {
       analysisContext = new SdkAnalysisContext();
       SourceFactory factory = new SourceFactory(new DartUriResolver(this));
       analysisContext.setSourceFactory(factory);
       String[] uris = getUris();
       ChangeSet changeSet = new ChangeSet();
       for (String uri : uris) {
         changeSet.addedSource(factory.forUri(uri));
       }
       analysisContext.applyChanges(changeSet);
     }
     return analysisContext;
   }

   /**
    * Return the file containing the dart2js executable, or {@code null} if it does not exist.
    *
    * @return the file containing the dart2js executable
    */
   public File getDart2JsExecutable() {
     synchronized (this) {
       if (dart2jsExecutable == null) {
         dart2jsExecutable = FileUtilities.verifyExecutable(new File(new File(
             sdkDirectory,
             BIN_DIRECTORY_NAME), OSUtilities.isWindows() ? DART2JS_EXECUTABLE_NAME_WIN
             : DART2JS_EXECUTABLE_NAME));
       }
     }
     return dart2jsExecutable;
   }

   /**
    * Return the file containing the dart formatter executable, or {@code null} if it does not exist.
    *
    * @return the file containing the dart formatter executable
    */
   public File getDartFmtExecutable() {
     synchronized (this) {
       if (dartFmtExecutable == null) {
         dartFmtExecutable = FileUtilities.verifyExecutable(new File(new File(
             sdkDirectory,
             BIN_DIRECTORY_NAME), OSUtilities.isWindows() ? DARTFMT_EXECUTABLE_NAME_WIN
             : DARTFMT_EXECUTABLE_NAME));
       }
     }
     return dartFmtExecutable;
   }

   /**
    * Return the file containing the Dartium executable, or {@code null} if it does not exist.
    *
    * @return the file containing the Dartium executable
    */
   public File getDartiumExecutable() {
     synchronized (this) {
       if (dartiumExecutable == null) {
         dartiumExecutable = FileUtilities.verifyExecutable(new File(
             getDartiumWorkingDirectory(),
             getDartiumBinaryName()));
       }
     }
     return dartiumExecutable;
   }

   /**
    * Return the directory where dartium can be found (the directory that will be the working
    * directory is Dartium is invoked without changing the default).
    *
    * @return the directory where dartium can be found
    */
   public File getDartiumWorkingDirectory() {
     return getDartiumWorkingDirectory(sdkDirectory.getParentFile());
   }

   /**
    * Return the directory where dartium can be found (the directory that will be the working
    * directory is Dartium is invoked without changing the default).
    *
    * @param installDir the installation directory
    * @return the directory where dartium can be found
    */
   public File getDartiumWorkingDirectory(File installDir) {
     return new File(installDir, DARTIUM_DIRECTORY_NAME);
   }

   /**
    * Return the directory containing the SDK.
    *
    * @return the directory containing the SDK
    */
   public File getDirectory() {
     return sdkDirectory;
   }

   /**
    * Return the directory containing documentation for the SDK.
    *
    * @return the SDK's documentation directory
    */
   public File getDocDirectory() {
     return new File(sdkDirectory, DOCS_DIRECTORY_NAME);
   }

   /**
    * Return the auxiliary documentation file for the given library, or {@code null} if no such file
    * exists.
    *
    * @param libraryName the name of the library associated with the documentation file to be
    *          returned
    * @return the auxiliary documentation file for the library
    */
   public File getDocFileFor(String libraryName) {
     File dir = getDocDirectory();
     if (!dir.exists()) {
       return null;
     }
     File libDir = new File(dir, libraryName);
     File docFile = new File(libDir, libraryName + DOC_FILE_SUFFIX);
     if (docFile.exists()) {
       return docFile;
     }
     return null;
   }

   /**
    * Return the directory within the SDK directory that contains the libraries.
    *
    * @return the directory that contains the libraries
    */
   public File getLibraryDirectory() {
     return new File(sdkDirectory, LIB_DIRECTORY_NAME);
   }

   /**
    * Return the file containing the Pub executable, or {@code null} if it does not exist.
    *
    * @return the file containing the Pub executable
    */
   public File getPubExecutable() {
     synchronized (this) {
       if (pubExecutable == null) {
         pubExecutable = FileUtilities.verifyExecutable(new File(new File(
             sdkDirectory,
             BIN_DIRECTORY_NAME), OSUtilities.isWindows() ? PUB_EXECUTABLE_NAME_WIN
             : PUB_EXECUTABLE_NAME));
       }
     }
     return pubExecutable;
   }

   @Override
   public SdkLibrary[] getSdkLibraries() {
     return libraryMap.getSdkLibraries();
   }

   @Override
   public SdkLibrary getSdkLibrary(String dartUri) {
     return libraryMap.getLibrary(dartUri);
   }

   /**
    * Return the revision number of this SDK, or {@code "0"} if the revision number cannot be
    * discovered.
    *
    * @return the revision number of this SDK
    */
   @Override
   public String getSdkVersion() {
     synchronized (this) {
       if (sdkVersion == null) {
         sdkVersion = DEFAULT_VERSION;
         File revisionFile = new File(sdkDirectory, VERSION_FILE_NAME);
         try {
           String revision = FileUtilities.getContents(revisionFile);
           if (revision != null) {
             sdkVersion = revision.trim();
           }
         } catch (IOException exception) {
           // Fall through to return the default.
         }
       }
     }
     return sdkVersion;
   }

   /**
    * Return an array containing the library URI's for the libraries defined in this SDK.
    *
    * @return the library URI's for the libraries defined in this SDK
    */
   @Override
   public String[] getUris() {
     return libraryMap.getUris();
   }

   /**
    * Return the file containing the VM executable, or {@code null} if it does not exist.
    *
    * @return the file containing the VM executable
    */
   public File getVmExecutable() {
     synchronized (this) {
       if (vmExecutable == null) {
         vmExecutable = FileUtilities.verifyExecutable(new File(new File(
             sdkDirectory,
             BIN_DIRECTORY_NAME), getVmBinaryName()));
       }
     }
     return vmExecutable;
   }

   /**
    * Return {@code true} if this SDK includes documentation.
    *
    * @return {@code true} if this installation of the SDK has documentation
    */
   public boolean hasDocumentation() {
     return getDocDirectory().exists();
   }

   /**
    * Return {@code true} if the Dartium binary is available.
    *
    * @return {@code true} if the Dartium binary is available
    */
   public boolean isDartiumInstalled() {
     return getDartiumExecutable() != null;
   }

   @Override
   public Source mapDartUri(String dartUri) {
     String libraryName;
     String relativePath;
     int index = dartUri.indexOf('/');
     if (index >= 0) {
       libraryName = dartUri.substring(0, index);
       relativePath = dartUri.substring(index + 1);
     } else {
       libraryName = dartUri;
       relativePath = "";
     }
     SdkLibrary library = getSdkLibrary(libraryName);
     if (library == null) {
       return null;
     }
     try {
       File file = new File(getLibraryDirectory(), library.getPath());
       if (!relativePath.isEmpty()) {
         file = file.getParentFile();
         file = new File(file, relativePath);
       }
       return new FileBasedSource(new URI(dartUri), file);
     } catch (URISyntaxException exception) {
       return null;
     }
   }

   /**
    * Read all of the configuration files to initialize the library maps.
    *
    * @param useDart2jsPaths {@code true} if the dart2js path should be used when it is available
    * @return the initialized library map
    */
   protected LibraryMap initialLibraryMap(boolean useDart2jsPaths) {
     File librariesFile = new File(new File(getLibraryDirectory(), INTERNAL_DIR), LIBRARIES_FILE);
     try {
       String contents = FileUtilities.getContents(librariesFile);
       return new SdkLibrariesReader(useDart2jsPaths).readFromFile(librariesFile, contents);
     } catch (Exception exception) {
       AnalysisEngine.getInstance().getLogger().logError(
           "Could not initialize the library map from " + librariesFile.getAbsolutePath(),
           exception);
       return new LibraryMap();
     }
   }

   /**
    * Ensure that the dart VM is executable. If it is not, make it executable and log that it was
    * necessary for us to do so.
    */
   @DartBlockBody({})
   private void ensureVmIsExecutable() {
     File dartVm = getVmExecutable();
     if (dartVm != null) {
       if (!dartVm.canExecute()) {
         FileUtilities.makeExecutable(dartVm);
         AnalysisEngine.getInstance().getLogger().logError(dartVm.getPath() + " was not executable");
       }
     }
   }

   /**
    * Return the name of the file containing the Dartium executable.
    *
    * @return the name of the file containing the Dartium executable
    */
   private String getDartiumBinaryName() {
     if (OSUtilities.isWindows()) {
       return DARTIUM_EXECUTABLE_NAME_WIN;
     } else if (OSUtilities.isMac()) {
       return DARTIUM_EXECUTABLE_NAME_MAC;
     } else {
       return DARTIUM_EXECUTABLE_NAME_LINUX;
     }
   }

   /**
    * Return the name of the file containing the VM executable.
    *
    * @return the name of the file containing the VM executable
    */
   private String getVmBinaryName() {
     if (OSUtilities.isWindows()) {
       return VM_EXECUTABLE_NAME_WIN;
     } else {
       return VM_EXECUTABLE_NAME;
     }
   }

 }
	/*
	* 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.engine.sdk;

	import com.google.dart.engine.AnalysisEngine;
	import com.google.dart.engine.context.AnalysisContext;
	import com.google.dart.engine.context.ChangeSet;
	import com.google.dart.engine.internal.context.InternalAnalysisContext;
	import com.google.dart.engine.internal.context.SdkAnalysisContext;
	import com.google.dart.engine.internal.sdk.LibraryMap;
	import com.google.dart.engine.internal.sdk.SdkLibrariesReader;
	import com.google.dart.engine.source.DartUriResolver;
	import com.google.dart.engine.source.FileBasedSource;
	import com.google.dart.engine.source.Source;
	import com.google.dart.engine.source.SourceFactory;
	import com.google.dart.engine.utilities.io.FileUtilities;
	import com.google.dart.engine.utilities.os.OSUtilities;
	import com.google.dart.engine.utilities.translation.DartBlockBody;
	import com.google.dart.engine.utilities.translation.DartOmit;
	import com.google.dart.engine.utilities.translation.DartOptional;

	import java.io.File;
	import java.io.IOException;
	import java.net.URI;
	import java.net.URISyntaxException;

	/**
	* Instances of the class {@code DirectoryBasedDartSdk} represent a Dart SDK installed in a
	* specified directory. Typical Dart SDK layout is something like...
	*
	* <pre>
	* dart-sdk/
	* bin/
	* dart[.exe] <-- VM
	* lib/
	* core/
	* core.dart
	* ... other core library files ...
	* ... other libraries ...
	* util/
	* ... Dart utilities ...
	* Chromium/ <-- Dartium typically exists in a sibling directory
	* </pre>
	*
	* @coverage dart.engine.sdk
	*/
	public class DirectoryBasedDartSdk implements DartSdk {
	/**
	* The {@link AnalysisContext} which is used for all of the sources in this {@link DartSdk}.
	*/
	private InternalAnalysisContext analysisContext;

	/**
	* The directory containing the SDK.
	*/
	private final File sdkDirectory;

	/**
	* The revision number of this SDK, or {@code "0"} if the revision number cannot be discovered.
	*/
	private String sdkVersion;

	/**
	* The file containing the dart2js executable.
	*/
	private File dart2jsExecutable;

	/**
	* The file containing the dart formatter executable.
	*/
	private File dartFmtExecutable;

	/**
	* The file containing the Dartium executable.
	*/
	private File dartiumExecutable;

	/**
	* The file containing the pub executable.
	*/
	private File pubExecutable;

	/**
	* The file containing the VM executable.
	*/
	private File vmExecutable;

	/**
	* A mapping from Dart library URI's to the library represented by that URI.
	*/
	private LibraryMap libraryMap;

	/**
	* The default SDK, or {@code null} if the default SDK either has not yet been created or cannot
	* be created for some reason.
	*/
	private static DirectoryBasedDartSdk DEFAULT_SDK;

	/**
	* The name of the directory within the SDK directory that contains executables.
	*/
	private static final String BIN_DIRECTORY_NAME = "bin"; //$NON-NLS-1$

	/**
	* The name of the directory on non-Mac that contains dartium.
	*/
	private static final String DARTIUM_DIRECTORY_NAME = "chromium"; //$NON-NLS-1$

	/**
	* The name of the dart2js executable on non-windows operating systems.
	*/
	private static final String DART2JS_EXECUTABLE_NAME = "dart2js"; //$NON-NLS-1$

	/**
	* The name of the file containing the dart2js executable on Windows.
	*/
	private static final String DART2JS_EXECUTABLE_NAME_WIN = "dart2js.bat"; //$NON-NLS-1$

	/**
	* The name of the dart formatter executable on non-windows operating systems.
	*/
	private static final String DARTFMT_EXECUTABLE_NAME = "dartfmt"; //$NON-NLS-1$

	/**
	* The name of the dart formatter executable on windows operating systems.
	*/
	private static final String DARTFMT_EXECUTABLE_NAME_WIN = "dartfmt.bat"; //$NON-NLS-1$

	/**
	* The name of the file containing the Dartium executable on Linux.
	*/
	private static final String DARTIUM_EXECUTABLE_NAME_LINUX = "chrome"; //$NON-NLS-1$

	/**
	* The name of the file containing the Dartium executable on Macintosh.
	*/
	private static final String DARTIUM_EXECUTABLE_NAME_MAC = "Chromium.app/Contents/MacOS/Chromium"; //$NON-NLS-1$

	/**
	* The name of the file containing the Dartium executable on Windows.
	*/
	private static final String DARTIUM_EXECUTABLE_NAME_WIN = "Chrome.exe"; //$NON-NLS-1$

	/**
	* The name of the {@link System} property whose value is the path to the default Dart SDK
	* directory.
	*/
	private static final String DEFAULT_DIRECTORY_PROPERTY_NAME = "com.google.dart.sdk"; //$NON-NLS-1$

	/**
	* The name of the directory within the SDK directory that contains documentation for the
	* libraries.
	*/
	private static final String DOCS_DIRECTORY_NAME = "docs"; //$NON-NLS-1$

	/**
	* The suffix added to the name of a library to derive the name of the file containing the
	* documentation for that library.
	*/
	private static final String DOC_FILE_SUFFIX = "_api.json"; //$NON-NLS-1$

	/**
	* The name of the directory within the SDK directory that contains the libraries file.
	*/
	private static final String INTERNAL_DIR = "_internal"; //$NON-NLS-1$

	/**
	* The name of the directory within the SDK directory that contains the libraries.
	*/
	private static final String LIB_DIRECTORY_NAME = "lib"; //$NON-NLS-1$

	/**
	* The name of the libraries file.
	*/
	private static final String LIBRARIES_FILE = "libraries.dart"; //$NON-NLS-1$

	/**
	* The name of the pub executable on windows.
	*/
	private static final String PUB_EXECUTABLE_NAME_WIN = "pub.bat"; //$NON-NLS-1$

	/**
	* The name of the pub executable on non-windows operating systems.
	*/
	private static final String PUB_EXECUTABLE_NAME = "pub"; //$NON-NLS-1$

	/**
	* The name of the file within the SDK directory that contains the version number of the SDK.
	*/
	private static final String VERSION_FILE_NAME = "version"; //$NON-NLS-1$

	/**
	* The name of the file containing the VM executable on the Windows operating system.
	*/
	private static final String VM_EXECUTABLE_NAME_WIN = "dart.exe"; //$NON-NLS-1$

	/**
	* The name of the file containing the VM executable on non-Windows operating systems.
	*/
	private static final String VM_EXECUTABLE_NAME = "dart"; //$NON-NLS-1$

	/**
	* Return the default Dart SDK, or {@code null} if the directory containing the default SDK cannot
	* be determined (or does not exist).
	*
	* @return the default Dart SDK
	*/
	public static DirectoryBasedDartSdk getDefaultSdk() {
	if (DEFAULT_SDK == null) {
	File sdkDirectory = getDefaultSdkDirectory();
	if (sdkDirectory == null) {
	return null;
	}
	DEFAULT_SDK = new DirectoryBasedDartSdk(sdkDirectory);
	}
	return DEFAULT_SDK;
	}

	/**
	* Return the default directory for the Dart SDK, or {@code null} if the directory cannot be
	* determined (or does not exist). The default directory is provided by a {@link System} property
	* named {@code com.google.dart.sdk}.
	*
	* @return the default directory for the Dart SDK
	*/
	public static File getDefaultSdkDirectory() {
	String sdkProperty = System.getProperty(DEFAULT_DIRECTORY_PROPERTY_NAME);
	if (sdkProperty == null) {
	return null;
	}
	File sdkDirectory = new File(sdkProperty);
	if (!sdkDirectory.exists()) {
	return null;
	}
	return sdkDirectory;
	}

	/**
	* Initialize a newly created SDK to represent the Dart SDK installed in the given directory.
	*
	* @param sdkDirectory the directory containing the SDK
	*/
	@DartOmit
	public DirectoryBasedDartSdk(File sdkDirectory) {
	this(sdkDirectory, false);
	}

	/**
	* Initialize a newly created SDK to represent the Dart SDK installed in the given directory.
	*
	* @param sdkDirectory the directory containing the SDK
	* @param useDart2jsPaths {@code true} if the dart2js path should be used when it is available
	*/
	public DirectoryBasedDartSdk(File sdkDirectory,
	@DartOptional(defaultValue = "false") boolean useDart2jsPaths) {
	this.sdkDirectory = sdkDirectory.getAbsoluteFile();
	libraryMap = initialLibraryMap(useDart2jsPaths);
	}

	@Override
	public Source fromFileUri(URI uri) {
	File file = new File(uri);
	String filePath = file.getAbsolutePath();
	String libPath = getLibraryDirectory().getAbsolutePath();
	if (!filePath.startsWith(libPath + File.separator)) {
	return null;
	}
	filePath = filePath.substring(libPath.length() + 1);
	for (SdkLibrary library : libraryMap.getSdkLibraries()) {
	String libraryPath = library.getPath();
	if (filePath.replace('\\', '/').equals(libraryPath)) {
	String path = library.getShortName();
	try {
	return new FileBasedSource(new URI(path), file);
	} catch (URISyntaxException exception) {
	AnalysisEngine.getInstance().getLogger().logInformation(
	"Failed to create URI: " + path,
	exception);
	return null;
	}
	}
	libraryPath = new File(libraryPath).getParent();
	if (filePath.startsWith(libraryPath + File.separator)) {
	String path = library.getShortName() + "/" + filePath.substring(libraryPath.length() + 1);
	try {
	return new FileBasedSource(new URI(path), file);
	} catch (URISyntaxException exception) {
	AnalysisEngine.getInstance().getLogger().logInformation(
	"Failed to create URI: " + path,
	exception);
	return null;
	}
	}
	}
	return null;
	}

	@Override
	public AnalysisContext getContext() {
	if (analysisContext == null) {
	analysisContext = new SdkAnalysisContext();
	SourceFactory factory = new SourceFactory(new DartUriResolver(this));
	analysisContext.setSourceFactory(factory);
	String[] uris = getUris();
	ChangeSet changeSet = new ChangeSet();
	for (String uri : uris) {
	changeSet.addedSource(factory.forUri(uri));
	}
	analysisContext.applyChanges(changeSet);
	}
	return analysisContext;
	}

	/**
	* Return the file containing the dart2js executable, or {@code null} if it does not exist.
	*
	* @return the file containing the dart2js executable
	*/
	public File getDart2JsExecutable() {
	synchronized (this) {
	if (dart2jsExecutable == null) {
	dart2jsExecutable = FileUtilities.verifyExecutable(new File(new File(
	sdkDirectory,
	BIN_DIRECTORY_NAME), OSUtilities.isWindows() ? DART2JS_EXECUTABLE_NAME_WIN
	: DART2JS_EXECUTABLE_NAME));
	}
	}
	return dart2jsExecutable;
	}

	/**
	* Return the file containing the dart formatter executable, or {@code null} if it does not exist.
	*
	* @return the file containing the dart formatter executable
	*/
	public File getDartFmtExecutable() {
	synchronized (this) {
	if (dartFmtExecutable == null) {
	dartFmtExecutable = FileUtilities.verifyExecutable(new File(new File(
	sdkDirectory,
	BIN_DIRECTORY_NAME), OSUtilities.isWindows() ? DARTFMT_EXECUTABLE_NAME_WIN
	: DARTFMT_EXECUTABLE_NAME));
	}
	}
	return dartFmtExecutable;
	}

	/**
	* Return the file containing the Dartium executable, or {@code null} if it does not exist.
	*
	* @return the file containing the Dartium executable
	*/
	public File getDartiumExecutable() {
	synchronized (this) {
	if (dartiumExecutable == null) {
	dartiumExecutable = FileUtilities.verifyExecutable(new File(
	getDartiumWorkingDirectory(),
	getDartiumBinaryName()));
	}
	}
	return dartiumExecutable;
	}

	/**
	* Return the directory where dartium can be found (the directory that will be the working
	* directory is Dartium is invoked without changing the default).
	*
	* @return the directory where dartium can be found
	*/
	public File getDartiumWorkingDirectory() {
	return getDartiumWorkingDirectory(sdkDirectory.getParentFile());
	}

	/**
	* Return the directory where dartium can be found (the directory that will be the working
	* directory is Dartium is invoked without changing the default).
	*
	* @param installDir the installation directory
	* @return the directory where dartium can be found
	*/
	public File getDartiumWorkingDirectory(File installDir) {
	return new File(installDir, DARTIUM_DIRECTORY_NAME);
	}

	/**
	* Return the directory containing the SDK.
	*
	* @return the directory containing the SDK
	*/
	public File getDirectory() {
	return sdkDirectory;
	}

	/**
	* Return the directory containing documentation for the SDK.
	*
	* @return the SDK's documentation directory
	*/
	public File getDocDirectory() {
	return new File(sdkDirectory, DOCS_DIRECTORY_NAME);
	}

	/**
	* Return the auxiliary documentation file for the given library, or {@code null} if no such file
	* exists.
	*
	* @param libraryName the name of the library associated with the documentation file to be
	* returned
	* @return the auxiliary documentation file for the library
	*/
	public File getDocFileFor(String libraryName) {
	File dir = getDocDirectory();
	if (!dir.exists()) {
	return null;
	}
	File libDir = new File(dir, libraryName);
	File docFile = new File(libDir, libraryName + DOC_FILE_SUFFIX);
	if (docFile.exists()) {
	return docFile;
	}
	return null;
	}

	/**
	* Return the directory within the SDK directory that contains the libraries.
	*
	* @return the directory that contains the libraries
	*/
	public File getLibraryDirectory() {
	return new File(sdkDirectory, LIB_DIRECTORY_NAME);
	}

	/**
	* Return the file containing the Pub executable, or {@code null} if it does not exist.
	*
	* @return the file containing the Pub executable
	*/
	public File getPubExecutable() {
	synchronized (this) {
	if (pubExecutable == null) {
	pubExecutable = FileUtilities.verifyExecutable(new File(new File(
	sdkDirectory,
	BIN_DIRECTORY_NAME), OSUtilities.isWindows() ? PUB_EXECUTABLE_NAME_WIN
	: PUB_EXECUTABLE_NAME));
	}
	}
	return pubExecutable;
	}

	@Override
	public SdkLibrary[] getSdkLibraries() {
	return libraryMap.getSdkLibraries();
	}

	@Override
	public SdkLibrary getSdkLibrary(String dartUri) {
	return libraryMap.getLibrary(dartUri);
	}

	/**
	* Return the revision number of this SDK, or {@code "0"} if the revision number cannot be
	* discovered.
	*
	* @return the revision number of this SDK
	*/
	@Override
	public String getSdkVersion() {
	synchronized (this) {
	if (sdkVersion == null) {
	sdkVersion = DEFAULT_VERSION;
	File revisionFile = new File(sdkDirectory, VERSION_FILE_NAME);
	try {
	String revision = FileUtilities.getContents(revisionFile);
	if (revision != null) {
	sdkVersion = revision.trim();
	}
	} catch (IOException exception) {
	// Fall through to return the default.
	}
	}
	}
	return sdkVersion;
	}

	/**
	* Return an array containing the library URI's for the libraries defined in this SDK.
	*
	* @return the library URI's for the libraries defined in this SDK
	*/
	@Override
	public String[] getUris() {
	return libraryMap.getUris();
	}

	/**
	* Return the file containing the VM executable, or {@code null} if it does not exist.
	*
	* @return the file containing the VM executable
	*/
	public File getVmExecutable() {
	synchronized (this) {
	if (vmExecutable == null) {
	vmExecutable = FileUtilities.verifyExecutable(new File(new File(
	sdkDirectory,
	BIN_DIRECTORY_NAME), getVmBinaryName()));
	}
	}
	return vmExecutable;
	}

	/**
	* Return {@code true} if this SDK includes documentation.
	*
	* @return {@code true} if this installation of the SDK has documentation
	*/
	public boolean hasDocumentation() {
	return getDocDirectory().exists();
	}

	/**
	* Return {@code true} if the Dartium binary is available.
	*
	* @return {@code true} if the Dartium binary is available
	*/
	public boolean isDartiumInstalled() {
	return getDartiumExecutable() != null;
	}

	@Override
	public Source mapDartUri(String dartUri) {
	String libraryName;
	String relativePath;
	int index = dartUri.indexOf('/');
	if (index >= 0) {
	libraryName = dartUri.substring(0, index);
	relativePath = dartUri.substring(index + 1);
	} else {
	libraryName = dartUri;
	relativePath = "";
	}
	SdkLibrary library = getSdkLibrary(libraryName);
	if (library == null) {
	return null;
	}
	try {
	File file = new File(getLibraryDirectory(), library.getPath());
	if (!relativePath.isEmpty()) {
	file = file.getParentFile();
	file = new File(file, relativePath);
	}
	return new FileBasedSource(new URI(dartUri), file);
	} catch (URISyntaxException exception) {
	return null;
	}
	}

	/**
	* Read all of the configuration files to initialize the library maps.
	*
	* @param useDart2jsPaths {@code true} if the dart2js path should be used when it is available
	* @return the initialized library map
	*/
	protected LibraryMap initialLibraryMap(boolean useDart2jsPaths) {
	File librariesFile = new File(new File(getLibraryDirectory(), INTERNAL_DIR), LIBRARIES_FILE);
	try {
	String contents = FileUtilities.getContents(librariesFile);
	return new SdkLibrariesReader(useDart2jsPaths).readFromFile(librariesFile, contents);
	} catch (Exception exception) {
	AnalysisEngine.getInstance().getLogger().logError(
	"Could not initialize the library map from " + librariesFile.getAbsolutePath(),
	exception);
	return new LibraryMap();
	}
	}

	/**
	* Ensure that the dart VM is executable. If it is not, make it executable and log that it was
	* necessary for us to do so.
	*/
	@DartBlockBody({})
	private void ensureVmIsExecutable() {
	File dartVm = getVmExecutable();
	if (dartVm != null) {
	if (!dartVm.canExecute()) {
	FileUtilities.makeExecutable(dartVm);
	AnalysisEngine.getInstance().getLogger().logError(dartVm.getPath() + " was not executable");
	}
	}
	}

	/**
	* Return the name of the file containing the Dartium executable.
	*
	* @return the name of the file containing the Dartium executable
	*/
	private String getDartiumBinaryName() {
	if (OSUtilities.isWindows()) {
	return DARTIUM_EXECUTABLE_NAME_WIN;
	} else if (OSUtilities.isMac()) {
	return DARTIUM_EXECUTABLE_NAME_MAC;
	} else {
	return DARTIUM_EXECUTABLE_NAME_LINUX;
	}
	}

	/**
	* Return the name of the file containing the VM executable.
	*
	* @return the name of the file containing the VM executable
	*/
	private String getVmBinaryName() {
	if (OSUtilities.isWindows()) {
	return VM_EXECUTABLE_NAME_WIN;
	} else {
	return VM_EXECUTABLE_NAME;
	}
	}

	}