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author | Ivan Topolnak <itopolnak@despegar.com> | 2014-03-07 18:08:01 -0300 |
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committer | Ivan Topolnjak <ivantopo@gmail.com> | 2014-03-11 21:14:53 -0300 |
commit | b6af84ab6b60b4ca6c0389c8c3622db3d3c27915 (patch) | |
tree | 1f89896820e36d59daadef7699b434de1051be42 /kamon-core/src/main/scala/kamon/metrics/instruments/HdrRecorder.scala | |
parent | ccbcc55282251b5e6d4f41384730232a8f0e7d05 (diff) | |
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multiple fixes to the custom metrics collection facilities
Diffstat (limited to 'kamon-core/src/main/scala/kamon/metrics/instruments/HdrRecorder.scala')
-rw-r--r-- | kamon-core/src/main/scala/kamon/metrics/instruments/HdrRecorder.scala | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/kamon-core/src/main/scala/kamon/metrics/instruments/HdrRecorder.scala b/kamon-core/src/main/scala/kamon/metrics/instruments/HdrRecorder.scala new file mode 100644 index 00000000..28520030 --- /dev/null +++ b/kamon-core/src/main/scala/kamon/metrics/instruments/HdrRecorder.scala @@ -0,0 +1,78 @@ +/* + * ========================================================================================= + * Copyright © 2013 the kamon project <http://kamon.io/> + * + * 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 org.HdrHistogram + +import java.util.concurrent.atomic.AtomicLongFieldUpdater +import scala.annotation.tailrec +import kamon.metrics.{ Scale, MetricSnapshot, MetricSnapshotLike, MetricRecorder } + +/** + * This implementation aims to be used for real time data collection where data snapshots are taken often over time. + * The snapshotAndReset() operation extracts all the recorded values from the histogram and resets the counts, but still + * leave it in a consistent state even in the case of concurrent modification while the snapshot is being taken. + */ +class HdrRecorder(highestTrackableValue: Long, significantValueDigits: Int, scale: Scale) + extends AtomicHistogram(1L, highestTrackableValue, significantValueDigits) with MetricRecorder { + + import HdrRecorder.totalCountUpdater + + def record(value: Long): Unit = recordValue(value) + + def collect(): MetricSnapshotLike = { + val entries = Vector.newBuilder[MetricSnapshot.Measurement] + val countsLength = counts.length() + + @tailrec def iterate(index: Int, previousValue: Long, nrOfRecordings: Long, bucketLimit: Long, increment: Long): Long = { + if (index < countsLength) { + val currentValue = previousValue + increment + val countAtValue = counts.getAndSet(index, 0) + + if (countAtValue > 0) + entries += MetricSnapshot.Measurement(currentValue, countAtValue) + + if (currentValue == bucketLimit) + iterate(index + 1, currentValue, nrOfRecordings + countAtValue, (bucketLimit << 1) + 1, increment << 1) + else + iterate(index + 1, currentValue, nrOfRecordings + countAtValue, bucketLimit, increment) + } else { + nrOfRecordings + } + } + + val nrOfRecordings = iterate(0, -1, 0, subBucketMask, 1) + + def tryUpdateTotalCount: Boolean = { + val previousTotalCount = getTotalCount + val newTotalCount = previousTotalCount - nrOfRecordings + + totalCountUpdater.compareAndSet(this, previousTotalCount, newTotalCount) + } + + while (!tryUpdateTotalCount) {} + + MetricSnapshot(nrOfRecordings, scale, entries.result()) + } + +} + +object HdrRecorder { + val totalCountUpdater = AtomicLongFieldUpdater.newUpdater(classOf[AtomicHistogram], "totalCount") + + def apply(highestTrackableValue: Long, significantValueDigits: Int, scale: Scale): HdrRecorder = + new HdrRecorder(highestTrackableValue, significantValueDigits, scale) + +} |