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Unified Diff: sdk/lib/_internal/pub_generated/lib/src/transcript.dart

Issue 657673002: Regenerate pub sources. (Closed) Base URL: https://dart.googlecode.com/svn/branches/bleeding_edge/dart
Patch Set: Created 6 years, 2 months ago
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Index: sdk/lib/_internal/pub_generated/lib/src/transcript.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/transcript.dart b/sdk/lib/_internal/pub_generated/lib/src/transcript.dart
index 38702e135780e89293f80f8f789a4d6cd3e9f5a1..a2778c0c824a63236cd89258917885a961e988d4 100644
--- a/sdk/lib/_internal/pub_generated/lib/src/transcript.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/transcript.dart
@@ -1,30 +1,73 @@
+// 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.
+
library pub.transcript;
+
import 'dart:collection';
+
+/// A rolling transcript of entries of type [T].
+///
+/// It has a maximum number of entries. If entries are added that exceed that
+/// it discards entries from the *middle* of the transcript. Generally, in logs,
+/// the first and last entries are the most important, so it maintains those.
class Transcript<T> {
+ /// The maximum number of transcript entries.
final int max;
+
+ /// The number of entries that were discarded after reaching [max].
int get discarded => _discarded;
int _discarded = 0;
+
+ /// The earliest half of the entries.
+ ///
+ /// This will be empty until the maximum number of entries is hit at which
+ /// point the oldest half of the entries will be moved from [_newest] to
+ /// here.
final _oldest = new List<T>();
+
+ /// The most recent half of the entries.
final _newest = new Queue<T>();
+
+ /// Creates a new [Transcript] that can hold up to [max] entries.
Transcript(this.max);
+
+ /// Adds [entry] to the transcript.
+ ///
+ /// If the transcript already has the maximum number of entries, discards one
+ /// from the middle.
void add(T entry) {
if (discarded > 0) {
+ // We're already in "rolling" mode.
_newest.removeFirst();
_discarded++;
} else if (_newest.length == max) {
+ // We are crossing the threshold where we have to discard items. Copy
+ // the first half over to the oldest list.
while (_newest.length > max ~/ 2) {
_oldest.add(_newest.removeFirst());
}
+
+ // Discard the middle item.
_newest.removeFirst();
_discarded++;
}
+
_newest.add(entry);
}
+
+ /// Traverses the entries in the transcript from oldest to newest.
+ ///
+ /// Invokes [onEntry] for each item. When it reaches the point in the middle
+ /// where excess entries where dropped, invokes [onGap] with the number of
+ /// dropped entries. If no more than [max] entries were added, does not
+ /// invoke [onGap].
void forEach(void onEntry(T entry), [void onGap(int)]) {
if (_oldest.isNotEmpty) {
_oldest.forEach(onEntry);
if (onGap != null) onGap(discarded);
}
+
_newest.forEach(onEntry);
}
}
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