From 4d828e1a3195e55365c865aa3a78af9668742643 Mon Sep 17 00:00:00 2001 From: Ivan Topolnjak Date: Mon, 24 Apr 2017 13:54:40 +0200 Subject: Prepare for the major cleanup Moved all the original files from src/main to src/legacy-main, same with test files. Also removed the autoweave module, examples and bench as I'm planning to have them in separate repositories. --- .../legacy-main/scala/kamon/util/Sequencer.scala | 40 ++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 kamon-core/src/legacy-main/scala/kamon/util/Sequencer.scala (limited to 'kamon-core/src/legacy-main/scala/kamon/util/Sequencer.scala') diff --git a/kamon-core/src/legacy-main/scala/kamon/util/Sequencer.scala b/kamon-core/src/legacy-main/scala/kamon/util/Sequencer.scala new file mode 100644 index 00000000..f368e54f --- /dev/null +++ b/kamon-core/src/legacy-main/scala/kamon/util/Sequencer.scala @@ -0,0 +1,40 @@ +/* + * ========================================================================================= + * Copyright © 2013-2014 the kamon project + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software distributed under the + * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, + * either express or implied. See the License for the specific language governing permissions + * and limitations under the License. + * ========================================================================================= + */ + +package kamon.util + +/** + * This class implements an extremely efficient, thread-safe way to generate a + * incrementing sequence of Longs with a simple Long overflow protection. + */ +class Sequencer { + private val CloseToOverflow = Long.MaxValue - 1000000000 + private val sequenceNumber = new PaddedAtomicLong(1L) + + def next(): Long = { + val current = sequenceNumber.getAndIncrement + + // check if this value is getting close to overflow? + if (current > CloseToOverflow) { + sequenceNumber.set(current - CloseToOverflow) // we need maintain the order + } + current + } +} + +object Sequencer { + def apply(): Sequencer = new Sequencer() +} \ No newline at end of file -- cgit v1.2.3