Files
sdk/utils/pub/system_cache.dart
T
nweiz@google.com 3085912d01 Add support for pub install.
This CL does several things:

* Adds explicit infrastructure for package sources.
* Adds the Dart SDK as such a source.
* Adds an explicit class for managing the packages/ directory (AppCache, as
  opposed to SystemCache).
* Adds an "install" command that installs to packages/, backed up by the system
  cache.

Review URL: https://chromiumcodereview.appspot.com//10340005

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@7398 260f80e4-7a28-3924-810f-c04153c831b5
2012-05-07 19:58:32 +00:00

79 lines
2.4 KiB
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.
/**
* The system-wide cache of installed packages.
*
* This cache contains all packages that are downloaded from the internet.
* Packages that are available locally (e.g. from the SDK) don't use this cache.
*/
class SystemCache {
/**
* The root directory where this package cache is located.
*/
final String rootDir;
/**
* Packages which are currently being asynchronously installed to the cache.
*/
final Map<PackageId, Future<Package>> _pendingInstalls;
/**
* Creates a new package cache which is backed by the given directory on the
* user's file system.
*/
SystemCache(this.rootDir)
: _pendingInstalls = new Map<PackageId, Future<Package>>();
/**
* Loads all of the package ids in the cache and returns them.
*/
Future<List<PackageId>> listAll() {
return listDir(rootDir).chain((paths) {
final sources = paths.map((path) {
final source = Source.fromName(basename(path));
return listDir(path).transform((subpaths) {
return subpaths.map((subpath) =>
new PackageId(basename(subpath), source));
});
});
return Futures.wait(sources).transform(flatten);
});
}
/**
* Ensures that the package identified by [id] is installed to the cache,
* loads it, and returns it.
*
* It is an error to try installing a package from a source with `shouldCache
* == false` to the system cache.
*/
Future<Package> install(PackageId id) {
if (!id.source.shouldCache) {
throw new IllegalArgumentException("Package $id is not cacheable.");
}
var pending = _pendingInstalls[id];
if (pending != null) return pending;
var path = join(rootDir, id.source.name, id.source.packageName(id));
var future = exists(path).chain((exists) {
// TODO(nweiz): better error handling
if (exists) throw 'Package $id is already installed.';
return ensureDir(dirname(path));
}).chain((_) {
return id.source.install(id, path);
}).chain((found) {
if (!found) {
throw 'Package ${id.fullName} not found in source "${id.source.name}".';
}
return Package.load(path);
});
always(future, () => _pendingInstalls.remove(id));
_pendingInstalls[id] = future;
return future;
}
}