Add support for pub install.

utils/pub/pub.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 main entrypoint for the pub command line application.
  */
 #library('pub');
 
 #import('../yaml/yaml.dart');
 
 #import('io.dart');
 #import('utils.dart');
 
-#source('cache.dart');
+#source('system_cache.dart');
+#source('app_cache.dart');
 #source('command_list.dart');
+#source('command_install.dart');
 #source('command_update.dart');
 #source('command_version.dart');
 #source('package.dart');
+#source('source.dart');
+#source('sdk_source.dart');
 
 main() {
   final args = new Options().arguments;
 
   // TODO(rnystrom): In addition to explicit "help" and "version" commands,
   // should also add special-case support for --help and --version arguments to
   // be consistent with other Unix apps.
   final commands = {
     'list': new ListCommand(),
+    'install': new InstallCommand(),
     'update': new UpdateCommand(),
     'version': new VersionCommand()
   };
 
   if (args.length == 0) {
     printUsage(commands);
     return;
   }
 
   // For consistency with expected unix idioms, support --help, -h, and
   // --version in addition to the regular commands.
   if (args.length == 1) {
     if (args[0] == '--help' || args[0] == '-h') {
       printUsage(commands);
       return;
     }
 
     if (args[0] == '--version') {
       printVersion();
       return;
     }
   }
 
   // TODO(rnystrom): Hack. This is temporary code to allow the pub tests to
   // pass in relevant paths. Eventually these should be either environment
   // variables or at least a cleaner arg parser.
-  var cacheDir;
+  var cacheDir, sdkDir;
   for (var i = 0; i < args.length; i++) {
     if (args[i].startsWith('--cachedir=')) {
       cacheDir = args[i].substring('--cachedir='.length);
       args.removeRange(i, 1);
-      break;
+      i--;
+    } else if (args[i].startsWith('--sdkdir=')) {
+      sdkDir = args[i].substring('--sdkdir='.length);
+      args.removeRange(i, 1);
+      i--;
     }
   }
 
   // TODO(rnystrom): Do we want this to be global?
-  final cache = new PackageCache(cacheDir);
+  final systemCache = new SystemCache(cacheDir);
+
+  Source.defaultSource = new SdkSource(sdkDir);
 
   // Select the command.
   final command = commands[args[0]];
   if (command == null) {
     print('Unknown command "${args[0]}".');
     print('Run "pub help" to see available commands.');
     exit(64); // See http://www.freebsd.org/cgi/man.cgi?query=sysexits.
     return;
   }
 
   args.removeRange(0, 1);
-  command.run(cache, args);
+  command.run(systemCache, args);
 }
 
 /** Displays usage information for the app. */
 void printUsage(Map<String, PubCommand> commands) {
   print('Pub is a package manager for Dart.');
   print('');
   print('Usage:');
   print('');
   print('  pub command [arguments]');
   print('');
@@ skipping 28 matching lines @@
  * finds the package that the user is currently "in".
  */
 Future<Package> getWorkingPackage() {
   // TODO(rnystrom): Will eventually need better logic to walk up
   // subdirectories until we hit one that looks package-like. For now, just
   // assume the cwd is it.
   return Package.load(workingDir);
 }
 
 class PubCommand {
-  PackageCache cache;
+  SystemCache systemCache;
+  AppCache appCache;
 
   abstract String get description();
 
-  void run(PackageCache cache_, List<String> args) {
-    cache = cache_;
+  void run(SystemCache systemCache_, List<String> args) {
+    systemCache = systemCache_;
+    appCache = new AppCache(workingDir, systemCache);
 
     // TODO(rnystrom): Each command should define the arguments it expects and
     // we can handle them generically here.
 
     onRun();
   }
 
   abstract void onRun();
 }