Use native async/await support in pub.

sdk/lib/_internal/pub_generated/lib/src/io.dart

Index: sdk/lib/_internal/pub_generated/lib/src/io.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/io.dart b/sdk/lib/_internal/pub_generated/lib/src/io.dart
deleted file mode 100644
index 35df8d1d8232bce4a40cbbdf65e5bc38f52617ee..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/lib/src/io.dart
+++ /dev/null
@@ -1,1028 +0,0 @@
-// Copyright (c) 2013, 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.
-
-/// Helper functionality to make working with IO easier.
-library pub.io;
-
-import 'dart:async';
-import 'dart:collection';
-import 'dart:convert';
-import 'dart:io';
-
-import 'package:path/path.dart' as path;
-import 'package:pool/pool.dart';
-import 'package:http/http.dart' show ByteStream;
-import 'package:http_multi_server/http_multi_server.dart';
-import 'package:stack_trace/stack_trace.dart';
-
-import 'exit_codes.dart' as exit_codes;
-import 'exceptions.dart';
-import 'error_group.dart';
-import 'log.dart' as log;
-import 'sdk.dart' as sdk;
-import 'utils.dart';
-
-export 'package:http/http.dart' show ByteStream;
-
-/// The pool used for restricting access to asynchronous operations that consume
-/// file descriptors.
-///
-/// The maximum number of allocated descriptors is based on empirical tests that
-/// indicate that beyond 32, additional file reads don't provide substantial
-/// additional throughput.
-final _descriptorPool = new Pool(32);
-
-/// Determines if a file or directory exists at [path].
-bool entryExists(String path) =>
-    dirExists(path) || fileExists(path) || linkExists(path);
-
-/// Returns whether [link] exists on the file system.
-///
-/// This returns `true` for any symlink, regardless of what it points at or
-/// whether it's broken.
-bool linkExists(String link) => new Link(link).existsSync();
-
-/// Returns whether [file] exists on the file system.
-///
-/// This returns `true` for a symlink only if that symlink is unbroken and
-/// points to a file.
-bool fileExists(String file) => new File(file).existsSync();
-
-/// Returns the canonical path for [pathString].
-///
-/// This is the normalized, absolute path, with symlinks resolved. As in
-/// [transitiveTarget], broken or recursive symlinks will not be fully resolved.
-///
-/// This doesn't require [pathString] to point to a path that exists on the
-/// filesystem; nonexistent or unreadable path entries are treated as normal
-/// directories.
-String canonicalize(String pathString) {
-  var seen = new Set<String>();
-  var components =
-      new Queue<String>.from(path.split(path.normalize(path.absolute(pathString))));
-
-  // The canonical path, built incrementally as we iterate through [components].
-  var newPath = components.removeFirst();
-
-  // Move through the components of the path, resolving each one's symlinks as
-  // necessary. A resolved component may also add new components that need to be
-  // resolved in turn.
-  while (!components.isEmpty) {
-    seen.add(path.join(newPath, path.joinAll(components)));
-    var resolvedPath =
-        resolveLink(path.join(newPath, components.removeFirst()));
-    var relative = path.relative(resolvedPath, from: newPath);
-
-    // If the resolved path of the component relative to `newPath` is just ".",
-    // that means component was a symlink pointing to its parent directory. We
-    // can safely ignore such components.
-    if (relative == '.') continue;
-
-    var relativeComponents = new Queue<String>.from(path.split(relative));
-
-    // If the resolved path is absolute relative to `newPath`, that means it's
-    // on a different drive. We need to canonicalize the entire target of that
-    // symlink again.
-    if (path.isAbsolute(relative)) {
-      // If we've already tried to canonicalize the new path, we've encountered
-      // a symlink loop. Avoid going infinite by treating the recursive symlink
-      // as the canonical path.
-      if (seen.contains(relative)) {
-        newPath = relative;
-      } else {
-        newPath = relativeComponents.removeFirst();
-        relativeComponents.addAll(components);
-        components = relativeComponents;
-      }
-      continue;
-    }
-
-    // Pop directories off `newPath` if the component links upwards in the
-    // directory hierarchy.
-    while (relativeComponents.first == '..') {
-      newPath = path.dirname(newPath);
-      relativeComponents.removeFirst();
-    }
-
-    // If there's only one component left, [resolveLink] guarantees that it's
-    // not a link (or is a broken link). We can just add it to `newPath` and
-    // continue resolving the remaining components.
-    if (relativeComponents.length == 1) {
-      newPath = path.join(newPath, relativeComponents.single);
-      continue;
-    }
-
-    // If we've already tried to canonicalize the new path, we've encountered a
-    // symlink loop. Avoid going infinite by treating the recursive symlink as
-    // the canonical path.
-    var newSubPath = path.join(newPath, path.joinAll(relativeComponents));
-    if (seen.contains(newSubPath)) {
-      newPath = newSubPath;
-      continue;
-    }
-
-    // If there are multiple new components to resolve, add them to the
-    // beginning of the queue.
-    relativeComponents.addAll(components);
-    components = relativeComponents;
-  }
-  return newPath;
-}
-
-/// Returns the transitive target of [link] (if A links to B which links to C,
-/// this will return C).
-///
-/// If [link] is part of a symlink loop (e.g. A links to B which links back to
-/// A), this returns the path to the first repeated link (so
-/// `transitiveTarget("A")` would return `"A"` and `transitiveTarget("A")` would
-/// return `"B"`).
-///
-/// This accepts paths to non-links or broken links, and returns them as-is.
-String resolveLink(String link) {
-  var seen = new Set<String>();
-  while (linkExists(link) && !seen.contains(link)) {
-    seen.add(link);
-    link =
-        path.normalize(path.join(path.dirname(link), new Link(link).targetSync()));
-  }
-  return link;
-}
-
-/// Reads the contents of the text file [file].
-String readTextFile(String file) =>
-    new File(file).readAsStringSync(encoding: UTF8);
-
-/// Reads the contents of the binary file [file].
-List<int> readBinaryFile(String file) {
-  log.io("Reading binary file $file.");
-  var contents = new File(file).readAsBytesSync();
-  log.io("Read ${contents.length} bytes from $file.");
-  return contents;
-}
-
-/// Creates [file] and writes [contents] to it.
-///
-/// If [dontLogContents] is true, the contents of the file will never be logged.
-String writeTextFile(String file, String contents, {bool dontLogContents:
-    false}) {
-  // Sanity check: don't spew a huge file.
-  log.io("Writing ${contents.length} characters to text file $file.");
-  if (!dontLogContents && contents.length < 1024 * 1024) {
-    log.fine("Contents:\n$contents");
-  }
-
-  new File(file).writeAsStringSync(contents);
-  return file;
-}
-
-/// Creates [file] and writes [contents] to it.
-String writeBinaryFile(String file, List<int> contents) {
-  log.io("Writing ${contents.length} bytes to binary file $file.");
-  new File(file).openSync(mode: FileMode.WRITE)
-      ..writeFromSync(contents)
-      ..closeSync();
-  log.fine("Wrote text file $file.");
-  return file;
-}
-
-/// Writes [stream] to a new file at path [file].
-///
-/// Replaces any file already at that path. Completes when the file is done
-/// being written.
-Future<String> createFileFromStream(Stream<List<int>> stream, String file) {
-  // TODO(nweiz): remove extra logging when we figure out the windows bot issue.
-  log.io("Creating $file from stream.");
-
-  return _descriptorPool.withResource(() {
-    return stream.pipe(new File(file).openWrite()).then((_) {
-      log.fine("Created $file from stream.");
-      return file;
-    });
-  });
-}
-
-/// Copies all files in [files] to the directory [destination].
-///
-/// Their locations in [destination] will be determined by their relative
-/// location to [baseDir]. Any existing files at those paths will be
-/// overwritten.
-void copyFiles(Iterable<String> files, String baseDir, String destination) {
-  for (var file in files) {
-    var newPath = path.join(destination, path.relative(file, from: baseDir));
-    ensureDir(path.dirname(newPath));
-    copyFile(file, newPath);
-  }
-}
-
-/// Copies a file from [source] to [destination].
-void copyFile(String source, String destination) {
-  writeBinaryFile(destination, readBinaryFile(source));
-}
-
-/// Creates a directory [dir].
-String createDir(String dir) {
-  new Directory(dir).createSync();
-  return dir;
-}
-
-/// Ensures that [dir] and all its parent directories exist.
-///
-/// If they don't exist, creates them.
-String ensureDir(String dir) {
-  new Directory(dir).createSync(recursive: true);
-  return dir;
-}
-
-/// Creates a temp directory in [dir], whose name will be [prefix] with
-/// characters appended to it to make a unique name.
-///
-/// Returns the path of the created directory.
-String createTempDir(String base, String prefix) {
-  var tempDir = new Directory(base).createTempSync(prefix);
-  log.io("Created temp directory ${tempDir.path}");
-  return tempDir.path;
-}
-
-/// Creates a temp directory in the system temp directory, whose name will be
-/// 'pub_' with characters appended to it to make a unique name.
-///
-/// Returns the path of the created directory.
-String createSystemTempDir() {
-  var tempDir = Directory.systemTemp.createTempSync('pub_');
-  log.io("Created temp directory ${tempDir.path}");
-  return tempDir.path;
-}
-
-/// Lists the contents of [dir].
-///
-/// If [recursive] is `true`, lists subdirectory contents (defaults to `false`).
-/// If [includeHidden] is `true`, includes files and directories beginning with
-/// `.` (defaults to `false`). If [includeDirs] is `true`, includes directories
-/// as well as files (defaults to `true`).
-///
-/// [whiteList] is a list of hidden filenames to include even when
-/// [includeHidden] is `false`.
-///
-/// Note that dart:io handles recursive symlinks in an unfortunate way. You
-/// end up with two copies of every entity that is within the recursive loop.
-/// We originally had our own directory list code that addressed that, but it
-/// had a noticeable performance impact. In the interest of speed, we'll just
-/// live with that annoying behavior.
-///
-/// The returned paths are guaranteed to begin with [dir]. Broken symlinks won't
-/// be returned.
-List<String> listDir(String dir, {bool recursive: false, bool includeHidden:
-    false, bool includeDirs: true, Iterable<String> whitelist}) {
-  if (whitelist == null) whitelist = [];
-  var whitelistFilter = createFileFilter(whitelist);
-
-  // This is used in some performance-sensitive paths and can list many, many
-  // files. As such, it leans more havily towards optimization as opposed to
-  // readability than most code in pub. In particular, it avoids using the path
-  // package, since re-parsing a path is very expensive relative to string
-  // operations.
-  return new Directory(
-      dir).listSync(recursive: recursive, followLinks: true).where((entity) {
-    if (!includeDirs && entity is Directory) return false;
-    if (entity is Link) return false;
-    if (includeHidden) return true;
-
-    // Using substring here is generally problematic in cases where dir has one
-    // or more trailing slashes. If you do listDir("foo"), you'll get back
-    // paths like "foo/bar". If you do listDir("foo/"), you'll get "foo/bar"
-    // (note the trailing slash was dropped. If you do listDir("foo//"), you'll
-    // get "foo//bar".
-    //
-    // This means if you strip off the prefix, the resulting string may have a
-    // leading separator (if the prefix did not have a trailing one) or it may
-    // not. However, since we are only using the results of that to call
-    // contains() on, the leading separator is harmless.
-    assert(entity.path.startsWith(dir));
-    var pathInDir = entity.path.substring(dir.length);
-
-    // If the basename is whitelisted, don't count its "/." as making the file
-    // hidden.
-    var whitelistedBasename =
-        whitelistFilter.firstWhere(pathInDir.contains, orElse: () => null);
-    if (whitelistedBasename != null) {
-      pathInDir =
-          pathInDir.substring(0, pathInDir.length - whitelistedBasename.length);
-    }
-
-    if (pathInDir.contains("/.")) return false;
-    if (Platform.operatingSystem != "windows") return true;
-    return !pathInDir.contains("\\.");
-  }).map((entity) => entity.path).toList();
-}
-
-/// Returns whether [dir] exists on the file system.
-///
-/// This returns `true` for a symlink only if that symlink is unbroken and
-/// points to a directory.
-bool dirExists(String dir) => new Directory(dir).existsSync();
-
-/// Tries to resiliently perform [operation].
-///
-/// Some file system operations can intermittently fail on Windows because
-/// other processes are locking a file. We've seen this with virus scanners
-/// when we try to delete or move something while it's being scanned. To
-/// mitigate that, on Windows, this will retry the operation a few times if it
-/// fails.
-void _attempt(String description, void operation()) {
-  if (Platform.operatingSystem != 'windows') {
-    operation();
-    return;
-  }
-
-  getErrorReason(error) {
-    if (error.osError.errorCode == 5) {
-      return "access was denied";
-    }
-
-    if (error.osError.errorCode == 32) {
-      return "it was in use by another process";
-    }
-
-    return null;
-  }
-
-  for (var i = 0; i < 2; i++) {
-    try {
-      operation();
-      return;
-    } on FileSystemException catch (error) {
-      var reason = getErrorReason(error);
-      if (reason == null) rethrow;
-
-      log.io("Failed to $description because $reason. " "Retrying in 50ms.");
-      sleep(new Duration(milliseconds: 50));
-    }
-  }
-
-  try {
-    operation();
-  } on FileSystemException catch (error) {
-    var reason = getErrorReason(error);
-    if (reason == null) rethrow;
-
-    fail(
-        "Failed to $description because $reason.\n"
-            "This may be caused by a virus scanner or having a file\n"
-            "in the directory open in another application.");
-  }
-}
-
-/// Deletes whatever's at [path], whether it's a file, directory, or symlink.
-///
-/// If it's a directory, it will be deleted recursively.
-void deleteEntry(String path) {
-  _attempt("delete entry", () {
-    if (linkExists(path)) {
-      log.io("Deleting link $path.");
-      new Link(path).deleteSync();
-    } else if (dirExists(path)) {
-      log.io("Deleting directory $path.");
-      new Directory(path).deleteSync(recursive: true);
-    } else if (fileExists(path)) {
-      log.io("Deleting file $path.");
-      new File(path).deleteSync();
-    }
-  });
-}
-
-/// Attempts to delete whatever's at [path], but doesn't throw an exception if
-/// the deletion fails.
-void tryDeleteEntry(String path) {
-  try {
-    deleteEntry(path);
-  } catch (error, stackTrace) {
-    log.fine(
-        "Failed to delete $path: $error\n" "${new Chain.forTrace(stackTrace)}");
-  }
-}
-
-/// "Cleans" [dir].
-///
-/// If that directory already exists, it is deleted. Then a new empty directory
-/// is created.
-void cleanDir(String dir) {
-  if (entryExists(dir)) deleteEntry(dir);
-  ensureDir(dir);
-}
-
-/// Renames (i.e. moves) the directory [from] to [to].
-void renameDir(String from, String to) {
-  _attempt("rename directory", () {
-    log.io("Renaming directory $from to $to.");
-    try {
-      new Directory(from).renameSync(to);
-    } on IOException catch (error) {
-      // Ensure that [to] isn't left in an inconsistent state. See issue 12436.
-      if (entryExists(to)) deleteEntry(to);
-      rethrow;
-    }
-  });
-}
-
-/// Creates a new symlink at path [symlink] that points to [target].
-///
-/// Returns a [Future] which completes to the path to the symlink file.
-///
-/// If [relative] is true, creates a symlink with a relative path from the
-/// symlink to the target. Otherwise, uses the [target] path unmodified.
-///
-/// Note that on Windows, only directories may be symlinked to.
-void createSymlink(String target, String symlink, {bool relative: false}) {
-  if (relative) {
-    // Relative junction points are not supported on Windows. Instead, just
-    // make sure we have a clean absolute path because it will interpret a
-    // relative path to be relative to the cwd, not the symlink, and will be
-    // confused by forward slashes.
-    if (Platform.operatingSystem == 'windows') {
-      target = path.normalize(path.absolute(target));
-    } else {
-      // If the directory where we're creating the symlink was itself reached
-      // by traversing a symlink, we want the relative path to be relative to
-      // it's actual location, not the one we went through to get to it.
-      var symlinkDir = canonicalize(path.dirname(symlink));
-      target = path.normalize(path.relative(target, from: symlinkDir));
-    }
-  }
-
-  log.fine("Creating $symlink pointing to $target");
-  new Link(symlink).createSync(target);
-}
-
-/// Creates a new symlink that creates an alias at [symlink] that points to the
-/// `lib` directory of package [target].
-///
-/// If [target] does not have a `lib` directory, this shows a warning if
-/// appropriate and then does nothing.
-///
-/// If [relative] is true, creates a symlink with a relative path from the
-/// symlink to the target. Otherwise, uses the [target] path unmodified.
-void createPackageSymlink(String name, String target, String symlink,
-    {bool isSelfLink: false, bool relative: false}) {
-  // See if the package has a "lib" directory. If not, there's nothing to
-  // symlink to.
-  target = path.join(target, 'lib');
-  if (!dirExists(target)) return;
-
-  log.fine("Creating ${isSelfLink ? "self" : ""}link for package '$name'.");
-  createSymlink(target, symlink, relative: relative);
-}
-
-/// Whether pub is running from within the Dart SDK, as opposed to from the Dart
-/// source repository.
-final bool runningFromSdk = Platform.script.path.endsWith('.snapshot');
-
-/// Resolves [target] relative to the path to pub's `asset` directory.
-String assetPath(String target) {
-  if (runningFromSdk) {
-    return path.join(
-        sdk.rootDirectory,
-        'lib',
-        '_internal',
-        'pub',
-        'asset',
-        target);
-  } else {
-    return path.join(pubRoot, 'asset', target);
-  }
-}
-
-/// Returns the path to the root of pub's sources in the Dart repo.
-String get pubRoot => path.join(repoRoot, 'sdk', 'lib', '_internal', 'pub');
-
-/// Returns the path to the root of the Dart repository.
-///
-/// This throws a [StateError] if it's called when running pub from the SDK.
-String get repoRoot {
-  if (runningFromSdk) {
-    throw new StateError("Can't get the repo root from the SDK.");
-  }
-
-  // Get the path to the directory containing this very file.
-  var libDir = path.dirname(libraryPath('pub.io'));
-
-  // TODO(rnystrom): Remove this when #104 is fixed.
-  // If we are running from the async/await compiled build directory, walk out
-  // out of that. It will be something like:
-  //
-  //     <repo>/<build>/<config>/pub_async/lib/src
-  if (libDir.contains('pub_async')) {
-    return path.normalize(path.join(libDir, '..', '..', '..', '..', '..'));
-  }
-
-  // Otherwise, assume we're running directly from the source location in the
-  // repo:
-  //
-  //      <repo>/sdk/lib/_internal/pub/lib/src
-  return path.normalize(path.join(libDir, '..', '..', '..', '..', '..', '..'));
-}
-
-/// A line-by-line stream of standard input.
-final Stream<String> stdinLines =
-    streamToLines(new ByteStream(stdin).toStringStream());
-
-/// Displays a message and reads a yes/no confirmation from the user.
-///
-/// Returns a [Future] that completes to `true` if the user confirms or `false`
-/// if they do not.
-///
-/// This will automatically append " (y/n)?" to the message, so [message]
-/// should just be a fragment like, "Are you sure you want to proceed".
-Future<bool> confirm(String message) {
-  log.fine('Showing confirm message: $message');
-  if (runningAsTest) {
-    log.message("$message (y/n)?");
-  } else {
-    stdout.write(log.format("$message (y/n)? "));
-  }
-  return streamFirst(
-      stdinLines).then((line) => new RegExp(r"^[yY]").hasMatch(line));
-}
-
-/// Reads and discards all output from [stream].
-///
-/// Returns a [Future] that completes when the stream is closed.
-Future drainStream(Stream stream) {
-  return stream.fold(null, (x, y) {});
-}
-
-/// Flushes the stdout and stderr streams, then exits the program with the given
-/// status code.
-///
-/// This returns a Future that will never complete, since the program will have
-/// exited already. This is useful to prevent Future chains from proceeding
-/// after you've decided to exit.
-Future flushThenExit(int status) {
-  return Future.wait(
-      [stdout.close(), stderr.close()]).then((_) => exit(status));
-}
-
-/// Returns a [EventSink] that pipes all data to [consumer] and a [Future] that
-/// will succeed when [EventSink] is closed or fail with any errors that occur
-/// while writing.
-Pair<EventSink, Future> consumerToSink(StreamConsumer consumer) {
-  var controller = new StreamController(sync: true);
-  var done = controller.stream.pipe(consumer);
-  return new Pair<EventSink, Future>(controller.sink, done);
-}
-
-// TODO(nweiz): remove this when issue 7786 is fixed.
-/// Pipes all data and errors from [stream] into [sink].
-///
-/// When [stream] is done, the returned [Future] is completed and [sink] is
-/// closed if [closeSink] is true.
-///
-/// When an error occurs on [stream], that error is passed to [sink]. If
-/// [cancelOnError] is true, [Future] will be completed successfully and no
-/// more data or errors will be piped from [stream] to [sink]. If
-/// [cancelOnError] and [closeSink] are both true, [sink] will then be
-/// closed.
-Future store(Stream stream, EventSink sink, {bool cancelOnError: true,
-    bool closeSink: true}) {
-  var completer = new Completer();
-  stream.listen(sink.add, onError: (e, stackTrace) {
-    sink.addError(e, stackTrace);
-    if (cancelOnError) {
-      completer.complete();
-      if (closeSink) sink.close();
-    }
-  }, onDone: () {
-    if (closeSink) sink.close();
-    completer.complete();
-  }, cancelOnError: cancelOnError);
-  return completer.future;
-}
-
-/// Spawns and runs the process located at [executable], passing in [args].
-///
-/// Returns a [Future] that will complete with the results of the process after
-/// it has ended.
-///
-/// The spawned process will inherit its parent's environment variables. If
-/// [environment] is provided, that will be used to augment (not replace) the
-/// the inherited variables.
-Future<PubProcessResult> runProcess(String executable, List<String> args,
-    {workingDir, Map<String, String> environment}) {
-  return _descriptorPool.withResource(() {
-    return _doProcess(
-        Process.run,
-        executable,
-        args,
-        workingDir,
-        environment).then((result) {
-      var pubResult =
-          new PubProcessResult(result.stdout, result.stderr, result.exitCode);
-      log.processResult(executable, pubResult);
-      return pubResult;
-    });
-  });
-}
-
-/// Spawns the process located at [executable], passing in [args].
-///
-/// Returns a [Future] that will complete with the [Process] once it's been
-/// started.
-///
-/// The spawned process will inherit its parent's environment variables. If
-/// [environment] is provided, that will be used to augment (not replace) the
-/// the inherited variables.
-Future<PubProcess> startProcess(String executable, List<String> args,
-    {workingDir, Map<String, String> environment}) {
-  return _descriptorPool.request().then((resource) {
-    return _doProcess(
-        Process.start,
-        executable,
-        args,
-        workingDir,
-        environment).then((ioProcess) {
-      var process = new PubProcess(ioProcess);
-      process.exitCode.whenComplete(resource.release);
-      return process;
-    });
-  });
-}
-
-/// Like [runProcess], but synchronous.
-PubProcessResult runProcessSync(String executable, List<String> args,
-    {String workingDir, Map<String, String> environment}) {
-  var result =
-      _doProcess(Process.runSync, executable, args, workingDir, environment);
-  var pubResult =
-      new PubProcessResult(result.stdout, result.stderr, result.exitCode);
-  log.processResult(executable, pubResult);
-  return pubResult;
-}
-
-/// A wrapper around [Process] that exposes `dart:async`-style APIs.
-class PubProcess {
-  /// The underlying `dart:io` [Process].
-  final Process _process;
-
-  /// The mutable field for [stdin].
-  EventSink<List<int>> _stdin;
-
-  /// The mutable field for [stdinClosed].
-  Future _stdinClosed;
-
-  /// The mutable field for [stdout].
-  ByteStream _stdout;
-
-  /// The mutable field for [stderr].
-  ByteStream _stderr;
-
-  /// The mutable field for [exitCode].
-  Future<int> _exitCode;
-
-  /// The sink used for passing data to the process's standard input stream.
-  ///
-  /// Errors on this stream are surfaced through [stdinClosed], [stdout],
-  /// [stderr], and [exitCode], which are all members of an [ErrorGroup].
-  EventSink<List<int>> get stdin => _stdin;
-
-  // TODO(nweiz): write some more sophisticated Future machinery so that this
-  // doesn't surface errors from the other streams/futures, but still passes its
-  // unhandled errors to them. Right now it's impossible to recover from a stdin
-  // error and continue interacting with the process.
-  /// A [Future] that completes when [stdin] is closed, either by the user or by
-  /// the process itself.
-  ///
-  /// This is in an [ErrorGroup] with [stdout], [stderr], and [exitCode], so any
-  /// error in process will be passed to it, but won't reach the top-level error
-  /// handler unless nothing has handled it.
-  Future get stdinClosed => _stdinClosed;
-
-  /// The process's standard output stream.
-  ///
-  /// This is in an [ErrorGroup] with [stdinClosed], [stderr], and [exitCode],
-  /// so any error in process will be passed to it, but won't reach the
-  /// top-level error handler unless nothing has handled it.
-  ByteStream get stdout => _stdout;
-
-  /// The process's standard error stream.
-  ///
-  /// This is in an [ErrorGroup] with [stdinClosed], [stdout], and [exitCode],
-  /// so any error in process will be passed to it, but won't reach the
-  /// top-level error handler unless nothing has handled it.
-  ByteStream get stderr => _stderr;
-
-  /// A [Future] that will complete to the process's exit code once the process
-  /// has finished running.
-  ///
-  /// This is in an [ErrorGroup] with [stdinClosed], [stdout], and [stderr], so
-  /// any error in process will be passed to it, but won't reach the top-level
-  /// error handler unless nothing has handled it.
-  Future<int> get exitCode => _exitCode;
-
-  /// Creates a new [PubProcess] wrapping [process].
-  PubProcess(Process process)
-      : _process = process {
-    var errorGroup = new ErrorGroup();
-
-    var pair = consumerToSink(process.stdin);
-    _stdin = pair.first;
-    _stdinClosed = errorGroup.registerFuture(pair.last);
-
-    _stdout = new ByteStream(errorGroup.registerStream(process.stdout));
-    _stderr = new ByteStream(errorGroup.registerStream(process.stderr));
-
-    var exitCodeCompleter = new Completer();
-    _exitCode = errorGroup.registerFuture(exitCodeCompleter.future);
-    _process.exitCode.then((code) => exitCodeCompleter.complete(code));
-  }
-
-  /// Sends [signal] to the underlying process.
-  bool kill([ProcessSignal signal = ProcessSignal.SIGTERM]) =>
-      _process.kill(signal);
-}
-
-/// Calls [fn] with appropriately modified arguments.
-///
-/// [fn] should have the same signature as [Process.start], except that the
-/// returned value may have any return type.
-_doProcess(Function fn, String executable, List<String> args, String workingDir,
-    Map<String, String> environment) {
-  // TODO(rnystrom): Should dart:io just handle this?
-  // Spawning a process on Windows will not look for the executable in the
-  // system path. So, if executable looks like it needs that (i.e. it doesn't
-  // have any path separators in it), then spawn it through a shell.
-  if ((Platform.operatingSystem == "windows") &&
-      (executable.indexOf('\\') == -1)) {
-    args = flatten(["/c", executable, args]);
-    executable = "cmd";
-  }
-
-  log.process(executable, args, workingDir == null ? '.' : workingDir);
-
-  return fn(
-      executable,
-      args,
-      workingDirectory: workingDir,
-      environment: environment);
-}
-
-/// Wraps [input], an asynchronous network operation to provide a timeout.
-///
-/// If [input] completes before [milliseconds] have passed, then the return
-/// value completes in the same way. However, if [milliseconds] pass before
-/// [input] has completed, it completes with a [TimeoutException] with
-/// [description] (which should be a fragment describing the action that timed
-/// out).
-///
-/// [url] is the URL being accessed asynchronously.
-///
-/// Note that timing out will not cancel the asynchronous operation behind
-/// [input].
-Future timeout(Future input, int milliseconds, Uri url, String description) {
-  // TODO(nwiez): Replace this with [Future.timeout].
-  var completer = new Completer();
-  var duration = new Duration(milliseconds: milliseconds);
-  var timer = new Timer(duration, () {
-    // Include the duration ourselves in the message instead of passing it to
-    // TimeoutException since we show nicer output.
-    var message =
-        'Timed out after ${niceDuration(duration)} while ' '$description.';
-
-    if (url.host == "pub.dartlang.org" ||
-        url.host == "storage.googleapis.com") {
-      message += "\nThis is likely a transient error. Please try again later.";
-    }
-
-    completer.completeError(new TimeoutException(message), new Chain.current());
-  });
-  input.then((value) {
-    if (completer.isCompleted) return;
-    timer.cancel();
-    completer.complete(value);
-  }).catchError((e, stackTrace) {
-    if (completer.isCompleted) return;
-    timer.cancel();
-    completer.completeError(e, stackTrace);
-  });
-  return completer.future;
-}
-
-/// Creates a temporary directory and passes its path to [fn].
-///
-/// Once the [Future] returned by [fn] completes, the temporary directory and
-/// all its contents are deleted. [fn] can also return `null`, in which case
-/// the temporary directory is deleted immediately afterwards.
-///
-/// Returns a future that completes to the value that the future returned from
-/// [fn] completes to.
-Future withTempDir(Future fn(String path)) {
-  return new Future.sync(() {
-    var tempDir = createSystemTempDir();
-    return new Future.sync(
-        () => fn(tempDir)).whenComplete(() => deleteEntry(tempDir));
-  });
-}
-
-/// Binds an [HttpServer] to [host] and [port].
-///
-/// If [host] is "localhost", this will automatically listen on both the IPv4
-/// and IPv6 loopback addresses.
-Future<HttpServer> bindServer(String host, int port) {
-  if (host == 'localhost') return HttpMultiServer.loopback(port);
-  return HttpServer.bind(host, port);
-}
-
-/// Extracts a `.tar.gz` file from [stream] to [destination].
-///
-/// Returns whether or not the extraction was successful.
-Future<bool> extractTarGz(Stream<List<int>> stream, String destination) {
-  log.fine("Extracting .tar.gz stream to $destination.");
-
-  if (Platform.operatingSystem == "windows") {
-    return _extractTarGzWindows(stream, destination);
-  }
-
-  var args = ["--extract", "--gunzip", "--directory", destination];
-  if (_noUnknownKeyword) {
-    // BSD tar (the default on OS X) can insert strange headers to a tarfile
-    // that GNU tar (the default on Linux) is unable to understand. This will
-    // cause GNU tar to emit a number of harmless but scary-looking warnings
-    // which are silenced by this flag.
-    args.insert(0, "--warning=no-unknown-keyword");
-  }
-
-  return startProcess("tar", args).then((process) {
-    // Ignore errors on process.std{out,err}. They'll be passed to
-    // process.exitCode, and we don't want them being top-levelled by
-    // std{out,err}Sink.
-    store(process.stdout.handleError((_) {}), stdout, closeSink: false);
-    store(process.stderr.handleError((_) {}), stderr, closeSink: false);
-    return Future.wait([store(stream, process.stdin), process.exitCode]);
-  }).then((results) {
-    var exitCode = results[1];
-    if (exitCode != exit_codes.SUCCESS) {
-      throw new Exception(
-          "Failed to extract .tar.gz stream to $destination " "(exit code $exitCode).");
-    }
-    log.fine("Extracted .tar.gz stream to $destination. Exit code $exitCode.");
-  });
-}
-
-/// Whether to include "--warning=no-unknown-keyword" when invoking tar.
-///
-/// This flag quiets warnings that come from opening OS X-generated tarballs on
-/// Linux, but only GNU tar >= 1.26 supports it.
-final bool _noUnknownKeyword = _computeNoUnknownKeyword();
-bool _computeNoUnknownKeyword() {
-  if (!Platform.isLinux) return false;
-  var result = Process.runSync("tar", ["--version"]);
-  if (result.exitCode != 0) {
-    throw new ApplicationException(
-        "Failed to run tar (exit code ${result.exitCode}):\n${result.stderr}");
-  }
-
-  var match =
-      new RegExp(r"^tar \(GNU tar\) (\d+).(\d+)\n").firstMatch(result.stdout);
-  if (match == null) return false;
-
-  var major = int.parse(match[1]);
-  var minor = int.parse(match[2]);
-  return major >= 2 || (major == 1 && minor >= 23);
-}
-
-String get pathTo7zip {
-  if (runningFromSdk) return assetPath(path.join('7zip', '7za.exe'));
-  return path.join(repoRoot, 'third_party', '7zip', '7za.exe');
-}
-
-Future<bool> _extractTarGzWindows(Stream<List<int>> stream, String destination)
-    {
-  // TODO(rnystrom): In the repo's history, there is an older implementation of
-  // this that does everything in memory by piping streams directly together
-  // instead of writing out temp files. The code is simpler, but unfortunately,
-  // 7zip seems to periodically fail when we invoke it from Dart and tell it to
-  // read from stdin instead of a file. Consider resurrecting that version if
-  // we can figure out why it fails.
-
-  return withTempDir((tempDir) {
-    // Write the archive to a temp file.
-    var dataFile = path.join(tempDir, 'data.tar.gz');
-    return createFileFromStream(stream, dataFile).then((_) {
-      // 7zip can't unarchive from gzip -> tar -> destination all in one step
-      // first we un-gzip it to a tar file.
-      // Note: Setting the working directory instead of passing in a full file
-      // path because 7zip says "A full path is not allowed here."
-      return runProcess(pathTo7zip, ['e', 'data.tar.gz'], workingDir: tempDir);
-    }).then((result) {
-      if (result.exitCode != exit_codes.SUCCESS) {
-        throw new Exception(
-            'Could not un-gzip (exit code ${result.exitCode}). ' 'Error:\n'
-                '${result.stdout.join("\n")}\n' '${result.stderr.join("\n")}');
-      }
-
-      // Find the tar file we just created since we don't know its name.
-      var tarFile = listDir(
-          tempDir).firstWhere((file) => path.extension(file) == '.tar', orElse: () {
-        throw new FormatException('The gzip file did not contain a tar file.');
-      });
-
-      // Untar the archive into the destination directory.
-      return runProcess(pathTo7zip, ['x', tarFile], workingDir: destination);
-    }).then((result) {
-      if (result.exitCode != exit_codes.SUCCESS) {
-        throw new Exception(
-            'Could not un-tar (exit code ${result.exitCode}). ' 'Error:\n'
-                '${result.stdout.join("\n")}\n' '${result.stderr.join("\n")}');
-      }
-      return true;
-    });
-  });
-}
-
-/// Create a .tar.gz archive from a list of entries.
-///
-/// Each entry can be a [String], [Directory], or [File] object. The root of
-/// the archive is considered to be [baseDir], which defaults to the current
-/// working directory.
-///
-/// Returns a [ByteStream] that emits the contents of the archive.
-ByteStream createTarGz(List contents, {baseDir}) {
-  return new ByteStream(futureStream(new Future.sync(() {
-    var buffer = new StringBuffer();
-    buffer.write('Creating .tag.gz stream containing:\n');
-    contents.forEach((file) => buffer.write('$file\n'));
-    log.fine(buffer.toString());
-
-    if (baseDir == null) baseDir = path.current;
-    baseDir = path.absolute(baseDir);
-    contents = contents.map((entry) {
-      entry = path.absolute(entry);
-      if (!path.isWithin(baseDir, entry)) {
-        throw new ArgumentError('Entry $entry is not inside $baseDir.');
-      }
-      return path.relative(entry, from: baseDir);
-    }).toList();
-
-    if (Platform.operatingSystem != "windows") {
-      var args = ["--create", "--gzip", "--directory", baseDir];
-      args.addAll(contents);
-      // TODO(nweiz): It's possible that enough command-line arguments will
-      // make the process choke, so at some point we should save the arguments
-      // to a file and pass them in via --files-from for tar and -i@filename
-      // for 7zip.
-      return startProcess("tar", args).then((process) => process.stdout);
-    }
-
-    // Don't use [withTempDir] here because we don't want to delete the temp
-    // directory until the returned stream has closed.
-    var tempDir = createSystemTempDir();
-    return new Future.sync(() {
-      // Create the tar file.
-      var tarFile = path.join(tempDir, "intermediate.tar");
-      var args = ["a", "-w$baseDir", tarFile];
-      args.addAll(contents.map((entry) => '-i!$entry'));
-
-      // We're passing 'baseDir' both as '-w' and setting it as the working
-      // directory explicitly here intentionally. The former ensures that the
-      // files added to the archive have the correct relative path in the
-      // archive. The latter enables relative paths in the "-i" args to be
-      // resolved.
-      return runProcess(pathTo7zip, args, workingDir: baseDir).then((_) {
-        // GZIP it. 7zip doesn't support doing both as a single operation.
-        // Send the output to stdout.
-        args = ["a", "unused", "-tgzip", "-so", tarFile];
-        return startProcess(pathTo7zip, args);
-      }).then((process) => process.stdout);
-    }).then((stream) {
-      return stream.transform(onDoneTransformer(() => deleteEntry(tempDir)));
-    }).catchError((e) {
-      deleteEntry(tempDir);
-      throw e;
-    });
-  })));
-}
-
-/// Contains the results of invoking a [Process] and waiting for it to complete.
-class PubProcessResult {
-  final List<String> stdout;
-  final List<String> stderr;
-  final int exitCode;
-
-  PubProcessResult(String stdout, String stderr, this.exitCode)
-      : this.stdout = _toLines(stdout),
-        this.stderr = _toLines(stderr);
-
-  // TODO(rnystrom): Remove this and change to returning one string.
-  static List<String> _toLines(String output) {
-    var lines = splitLines(output);
-    if (!lines.isEmpty && lines.last == "") lines.removeLast();
-    return lines;
-  }
-
-  bool get success => exitCode == exit_codes.SUCCESS;
-}
-
-/// Gets a [Uri] for [uri], which can either already be one, or be a [String].
-Uri _getUri(uri) {
-  if (uri is Uri) return uri;
-  return Uri.parse(uri);
-}