Add instrumentation for tracking how long it takes barback to start.

sdk/lib/_internal/pub/lib/src/log.dart

Index: sdk/lib/_internal/pub/lib/src/log.dart
diff --git a/sdk/lib/_internal/pub/lib/src/log.dart b/sdk/lib/_internal/pub/lib/src/log.dart
index 0b93b3f3df26cee40c5b536b0bb67f05d22ec3c5..2cb537a032ab0f9ef5f8d2154556412ccca784bc 100644
--- a/sdk/lib/_internal/pub/lib/src/log.dart
+++ b/sdk/lib/_internal/pub/lib/src/log.dart
@@ -37,8 +37,8 @@ const _MAX_TRANSCRIPT = 10000;
 /// [recordTranscript()] is called.
 Transcript<Entry> _transcript;
 
-/// The currently-running progress indicator or `null` if there is none.
-Progress _progress;
+/// The currently-running progress indicators.
+final _progresses = new Set<Progress>();
 
 final _cyan = getSpecial('\u001b[36m');
 final _green = getSpecial('\u001b[32m');
@@ -222,29 +222,27 @@ void dumpTranscript() {
 }
 
 /// Prints [message] then displays an updated elapsed time until the future
-/// returned by [callback] completes. If anything else is logged during this
-/// (include another call to [progress]) that cancels the progress.
-Future progress(String message, Future callback()) {
+/// returned by [callback] completes.
+///
+/// If anything else is logged during this (include another call to [progress])

[Bob Nystrom, 2014/06/05 20:18:16]

"include" -> "including"

[nweiz, 2014/06/05 21:58:18]

Done.

[nweiz, 2014/06/05 21:58:19]

Done.

+/// that cancels the progress animation, although the total time will still be
+/// printed once it finishes. If [fine] is passed, the progress information will
+/// only be visible at [Level.FINE].
+Future progress(String message, Future callback(), {bool fine: false}) {

[Bob Nystrom, 2014/06/05 20:18:16]

Instead of a bool for fine, how about just taking a level which defaults to
message?

[nweiz, 2014/06/05 21:58:18]

That's how I started doing it, but properly supporting ERROR and WARNING is
weird, since there's no way for us to know if we should be printing the
animation to stderr or not. I figured that for progress bars the only important
distinction was whether or not it was visible by default.

   _stopProgress();
-  _progress = new Progress(message);
+  var progress = new Progress(message, fine: fine);;
+  _progresses.add(progress);
   return callback().whenComplete(() {
-    var message = _stopProgress();
-
-    // Add the progress message to the transcript.
-    if (_transcript != null && message != null) {
-      _transcript.add(new Entry(Level.MESSAGE, [message]));
-    }
+    progress.stop();
+    _progresses.remove(progress);
   });
 }
 
-/// Stops the running progress indicator, if currently running.
-///
-/// Returns the final progress message, if any, otherwise `null`.
-String _stopProgress() {
-  if (_progress == null) return null;
-  var message = _progress.stop();
-  _progress = null;
-  return message;
+/// Stops animating the running progress indicator, if currently running.
+void _stopProgress() {
+  for (var progress in _progresses) {
+    progress.stopAnimating();
+  }
 }
 
 /// Wraps [text] in the ANSI escape codes to make it bold when on a platform
@@ -333,6 +331,9 @@ void showAll() {
   _loggers[Level.FINE]    = _logToStderrWithLabel;
 }
 
+/// Returns whether or not logs at [level] will be printed.
+bool isLevelVisible(Level level) => _loggers[level] != null;
+
 /// Log function that prints the message to stdout.
 void _logToStdout(Entry entry) {
   _logToStream(stdout, entry, showLabel: false);