Index: utils/pub/cache.dart |
diff --git a/utils/pub/cache.dart b/utils/pub/cache.dart |
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+// 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. |
+ |
+/** |
+ * The local cache of previously installed packages. |
+ */ |
+class PackageCache { |
+ /** |
+ * The root directory where this package cache is located. |
+ */ |
+ final String rootDir; |
+ |
+ // TODO(rnystrom): When packages are versioned, String here and elsewhere will |
+ // become a name/version/(source?) tuple. |
+ final Map<String, Package> _loadedPackages; |
+ |
+ /** |
+ * Packages which are currently being asynchronously loaded. |
+ */ |
+ final Map<String, Future<Package>> _pendingPackages; |
+ |
+ /** |
+ * Creates a new package cache which is backed by the given directory on the |
+ * user's file system. |
+ */ |
+ PackageCache(this.rootDir) |
+ : _loadedPackages = <Package>{}, |
+ _pendingPackages = <Future<Package>>{}; |
+ |
+ /** |
+ * Loads all of the packages in the cache and returns them. |
+ */ |
+ Future<List<Package>> listAll() { |
+ return listDir(rootDir).chain((paths) { |
+ final packages = paths.map((path) => find(basename(path))); |
+ return Futures.wait(packages); |
+ }); |
+ } |
+ |
+ /** |
+ * Loads the package named [name] from this cache, if present. |
+ */ |
+ // TODO(rnystrom): What happens if the package isn't cached? |
+ Future<Package> find(String name) { |
+ // Use the previously loaded one. |
+ final package = _loadedPackages[name]; |
+ if (package != null) { |
+ return new Future.immediate(package); |
+ } |
+ |
+ // If we are already in-progress loading it, re-use that one. |
+ final pending = _pendingPackages[name]; |
+ if (pending != null) { |
+ return pending; |
+ } |
+ |
+ return _loadPackage(name); |
+ } |
+ |
+ /** |
+ * Start loading the package. |
+ */ |
+ Future<Package> _loadPackage(String name) { |
+ final completer = new Completer<Package>(); |
+ final pubspecPath = join(rootDir, name, 'pubspec'); |
nweiz
2012/04/17 20:08:46
Unused variable
Bob Nystrom
2012/04/18 18:09:18
Done.
|
+ |
+ _pendingPackages[name] = completer.future; |
+ _parsePubspec(name).then((dependencies) { |
nweiz
2012/04/17 20:08:46
I think using transform here rather than manually
Bob Nystrom
2012/04/18 18:09:18
Great idea. Still learning my way around transform
|
+ final package = new Package._(this, name, dependencies); |
+ |
+ _pendingPackages.remove(name); |
+ _loadedPackages[name] = package; |
+ completer.complete(package); |
+ }); |
+ |
+ return completer.future; |
+ } |
+ |
+ Future<List<String>> _parsePubspec(String name) { |
+ final completer = new Completer<List<String>>(); |
+ final pubspecPath = join(rootDir, name, 'pubspec'); |
+ |
+ // TODO(rnystrom): Handle the directory not existing. |
+ // TODO(rnystrom): Error-handling. |
+ final readFuture = readTextFile(pubspecPath); |
+ readFuture.handleException((error) { |
+ // If there is no pubspec, we implicitly treat that as a package with no |
+ // dependencies. |
+ // TODO(rnystrom): Distinguish file not found from other real errors. |
+ completer.complete(<String>[]); |
+ return true; |
+ }); |
+ |
+ readFuture.then((pubspec) { |
nweiz
2012/04/17 20:08:46
I feel like it's a flaw in our Future API that you
Bob Nystrom
2012/04/18 18:09:18
Done.
|
+ // TODO(rnystrom): Use YAML parser when ready. For now, it's just a flat |
+ // list of newline-separated strings. |
+ final dependencyNames = pubspec.split('\n') |
+ .map((name) => name.trim()) |
nweiz
2012/04/17 20:08:46
I thought the style was putting the . on the previ
Bob Nystrom
2012/04/18 18:09:18
Done.
|
+ .filter((name) => (name != null) && (name != '')); |
+ |
+ completer.complete(dependencyNames); |
+ }); |
+ |
+ return completer.future; |
+ } |
+} |