| // 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 analyzer.source.package_map_resolver; |
| |
| import 'dart:core'; |
| |
| import 'package:analyzer/file_system/file_system.dart'; |
| import 'package:analyzer/src/generated/source.dart'; |
| import 'package:analyzer/src/util/asserts.dart' as asserts; |
| import 'package:path/path.dart' as pathos; |
| |
| /** |
| * A [UriResolver] implementation for the `package:` scheme that uses a map of |
| * package names to their directories. |
| */ |
| class PackageMapUriResolver extends UriResolver { |
| /** |
| * The name of the `package` scheme. |
| */ |
| static const String PACKAGE_SCHEME = "package"; |
| |
| /** |
| * A table mapping package names to the path of the directories containing |
| * the package. |
| */ |
| final Map<String, List<Folder>> packageMap; |
| |
| /** |
| * The [ResourceProvider] for this resolver. |
| */ |
| final ResourceProvider resourceProvider; |
| |
| /** |
| * Create a new [PackageMapUriResolver]. |
| * |
| * [packageMap] is a table mapping package names to the paths of the |
| * directories containing the package |
| */ |
| PackageMapUriResolver(this.resourceProvider, this.packageMap) { |
| asserts.notNull(resourceProvider); |
| asserts.notNull(packageMap); |
| } |
| |
| @override |
| Source resolveAbsolute(Uri uri, [Uri actualUri]) { |
| if (!isPackageUri(uri)) { |
| return null; |
| } |
| // Prepare path. |
| String path = uri.path; |
| // Prepare path components. |
| int index = path.indexOf('/'); |
| if (index == -1 || index == 0) { |
| return null; |
| } |
| // <pkgName>/<relPath> |
| String pkgName = path.substring(0, index); |
| String relPath = path.substring(index + 1); |
| // Try to find an existing file. |
| List<Folder> packageDirs = packageMap[pkgName]; |
| if (packageDirs != null) { |
| for (Folder packageDir in packageDirs) { |
| if (packageDir.exists) { |
| Resource result = packageDir.getChild(relPath); |
| if (result is File && result.exists) { |
| return result.createSource(uri); |
| } |
| } |
| } |
| } |
| // Return a NonExistingSource instance. |
| // This helps provide more meaningful error messages to users |
| // (a missing file error, as opposed to an invalid URI error). |
| String fullPath = packageDirs != null && packageDirs.isNotEmpty |
| ? packageDirs.first.canonicalizePath(relPath) |
| : relPath; |
| return new NonExistingSource(fullPath, uri, UriKind.PACKAGE_URI); |
| } |
| |
| @override |
| Uri restoreAbsolute(Source source) { |
| String sourcePath = source.fullName; |
| Uri bestMatch; |
| int bestMatchLength = -1; |
| pathos.Context pathContext = resourceProvider.pathContext; |
| for (String pkgName in packageMap.keys) { |
| List<Folder> pkgFolders = packageMap[pkgName]; |
| for (int i = 0; i < pkgFolders.length; i++) { |
| Folder pkgFolder = pkgFolders[i]; |
| String pkgFolderPath = pkgFolder.path; |
| if (pkgFolderPath.length > bestMatchLength && |
| sourcePath.startsWith(pkgFolderPath + pathContext.separator)) { |
| String relPath = sourcePath.substring(pkgFolderPath.length + 1); |
| if (_isReversibleTranslation(pkgFolders, i, relPath)) { |
| List<String> relPathComponents = pathContext.split(relPath); |
| String relUriPath = pathos.posix.joinAll(relPathComponents); |
| bestMatch = Uri.parse('$PACKAGE_SCHEME:$pkgName/$relUriPath'); |
| bestMatchLength = pkgFolderPath.length; |
| } |
| } |
| } |
| } |
| return bestMatch; |
| } |
| |
| /** |
| * A translation from file path to package URI has just been found for |
| * using the [packageDirIndex]th element of [packageDirs], and appending the |
| * relative path [relPath]. Determine whether the translation is reversible; |
| * that is, whether translating the package URI pack to a file path will |
| * produce the file path we started with. |
| */ |
| bool _isReversibleTranslation( |
| List<Folder> packageDirs, int packageDirIndex, String relPath) { |
| // The translation is reversible provided there is no prior element of |
| // [packageDirs] containing a file matching [relPath]. |
| for (int i = 0; i < packageDirIndex; i++) { |
| Folder packageDir = packageDirs[i]; |
| if (packageDir.exists) { |
| Resource result = packageDir.getChild(relPath); |
| if (result is File && result.exists) { |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Returns `true` if [uri] is a `package` URI. |
| */ |
| static bool isPackageUri(Uri uri) { |
| return uri.scheme == PACKAGE_SCHEME; |
| } |
| } |