Add a Pub source for pub.dartlang.org.

utils/pub/repo_source.dart

+// Copyright (c) 2012, 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('dartlang_source');
+
+#import('dart:io');
+#import('dart:uri');
+#import('io.dart');
+#import('package.dart');
+#import('source.dart');
+#import('utils.dart');
+
+/**
+ * A package source that installs packages from a package repository that uses
+ * the same API as pub.dartlang.org.
+ */
+class RepoSource extends Source {
+  final String name = "repo";
+
+  final bool shouldCache = true;
+
+  /**
+   * The URL of the default package repository.
+   *
+   * At time of writing, pub.dartlang.org is not yet online, but it should be

[Bob Nystrom, 2012/06/22 22:35:44]

I'd leave a TODO here to update this comment when it changes.

[nweiz, 2012/06/25 22:25:17]

Done.

+   * soon.
+   */
+  static final String defaultUrl = "http://pub.dartlang.org";
+
+  RepoSource();
+
+  /**
+   * Downloads a package from a package repository and unpacks it.
+   */
+  Future<bool> install(PackageId id, String destPath) {
+    var parsedDescription = _parseDescription(id.description);
+    var name = parsedDescription.first;
+    var url = parsedDescription.last;
+
+    return ensureDir(destPath).chain((_) {
+      var fullUrl = "$url/packages/$name/versions/${id.version}.tar.gz";
+      var httpStream = httpGet(fullUrl);
+      var process = Process.start("tar",
+          ["--extract", "--gunzip", "--directory", destPath]);

[Bob Nystrom, 2012/06/22 22:35:44]

How do you feel about wrapping this in a function in pub_io? It's going to need
some Windows-specific support at some point, and I'd like to keep the
platform-specific code in one place. I think other stuff that needs Windows love
(like symlink) is there now.

[nweiz, 2012/06/25 22:25:17]

Done.

+      var completer = new Completer<int>();
+
+      httpStream.pipe(process.stdin);
+      process.stdout.pipe(stdout, close: false);
+      process.stderr.pipe(stderr, close: false);
+
+      process.onExit = completer.complete;
+      process.onError = completer.completeException;
+      return completer.future;
+    }).transform((exitCode) => exitCode == 0);
+  }
+
+  /**
+   * The system cache directory for the repo source contains subdirectories for
+   * each separate repository URL that's used on the system. Each of these
+   * subdirectories then contains a subdirectory for each package installed from
+   * that repository.
+   */
+  String systemCacheDirectory(PackageId id, String parent) {
+    var parsed = _parseDescription(id.description);
+    var url = parsed.last.replaceAll(new RegExp(@"^https?://"), "");
+    var urlDir = replace(url, new RegExp(@'[<>:"\\/|?*%]'), (match) {
+      return '%${match[0].charCodeAt(0)}';
+    });
+    return join(parent, urlDir, "${parsed.first}-${id.version}");
+  }
+
+  String packageName(PackageId id) => _parseDescription(id.description).first;
+
+  /**
+   * Ensures that [description] is a valid repo description.
+   *
+   * There are two valid formats. A plain string refers to a package with the
+   * given name from the default repository, while a map with keys "name" and
+   * "url" refers to a package with the given name from the repo at the given
+   * URL.
+   */
+  void validateDescription(description) {
+    _parseDescription(description);
+  }
+
+  /**
+   * Parses the description blob for a package.
+   *
+   * If the package parses correctly, this returns a (name, url) pair. If not,
+   * this throws a descriptive FormatException.
+   */
+  Pair<String, String> _parseDescription(description) {
+    if (description is String) {
+      return new Pair<String, String>(description, defaultUrl);
+    }
+
+    if (description is! Map) {
+      throw new FormatException(
+          "The description must be a package name or map.");
+    }
+
+    if (!description.containsKey("name")) {
+      throw new FormatException(
+          "The description map must contain a 'name' key.");
+    }
+
+    var name = description["name"];
+    if (name is! String) {
+      throw new FormatException("The 'name' key must have a string value.");
+    }
+
+    var url = description.containsKey("url") ? description["url"] : defaultUrl;
+    return new Pair<String, String>(name, url);
+  }
+}