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#pragma once
#include "histogram_snapshot.h"
namespace NMonitoring {
///////////////////////////////////////////////////////////////////////////
// IHistogramCollector
///////////////////////////////////////////////////////////////////////////
class IHistogramCollector {
public:
virtual ~IHistogramCollector() = default;
/**
* Store {@code count} times given {@code value} in this collector.
*/
virtual void Collect(double value, ui32 count) = 0;
/**
* Store given {@code value} in this collector.
*/
void Collect(double value) {
Collect(value, 1);
}
/**
* Add counts from snapshot into this collector
*/
void Collect(const IHistogramSnapshot& snapshot) {
for (ui32 i = 0; i < snapshot.Count(); i++) {
Collect(snapshot.UpperBound(i), snapshot.Value(i));
}
}
/**
* Reset collector values
*/
virtual void Reset() = 0;
/**
* @return snapshot of the state of this collector.
*/
virtual IHistogramSnapshotPtr Snapshot() const = 0;
};
using IHistogramCollectorPtr = THolder<IHistogramCollector>;
///////////////////////////////////////////////////////////////////////////
// free functions
///////////////////////////////////////////////////////////////////////////
/**
* <p>Creates histogram collector for a set of buckets with arbitrary
* bounds.</p>
*
* <p>Defines {@code bounds.size() + 1} buckets with these boundaries for
* bucket i:</p>
* <ul>
* <li>Upper bound (0 <= i < N-1): {@code bounds[i]}</li>
* <li>Lower bound (1 <= i < N): {@code bounds[i - 1]}</li>
* </ul>
*
* <p>For example, if the list of boundaries is:</p>
* <pre>0, 1, 2, 5, 10, 20</pre>
*
* <p>then there are five finite buckets with the following ranges:</p>
* <pre>(-INF, 0], (0, 1], (1, 2], (2, 5], (5, 10], (10, 20], (20, +INF)</pre>
*
* @param bounds array of upper bounds for buckets. Values must be sorted.
*/
IHistogramCollectorPtr ExplicitHistogram(TBucketBounds bounds);
/**
* <p>Creates histogram collector for a sequence of buckets that have a
* width proportional to the value of the lower bound.</p>
*
* <p>Defines {@code bucketsCount} buckets with these boundaries for bucket i:</p>
* <ul>
* <li>Upper bound (0 <= i < N-1): {@code scale * (base ^ i)}</li>
* <li>Lower bound (1 <= i < N): {@code scale * (base ^ (i - 1))}</li>
* </ul>
*
* <p>For example, if {@code bucketsCount=6}, {@code base=2}, and {@code scale=3},
* then the bucket ranges are as follows:</p>
*
* <pre>(-INF, 3], (3, 6], (6, 12], (12, 24], (24, 48], (48, +INF)</pre>
*
* @param bucketsCount the total number of buckets. The value must be >= 2.
* @param base the exponential growth factor for the buckets width.
* The value must be >= 1.0.
* @param scale the linear scale for the buckets. The value must be >= 1.0.
*/
IHistogramCollectorPtr ExponentialHistogram(
ui32 bucketsCount, double base, double scale = 1.0);
/**
* <p>Creates histogram collector for a sequence of buckets that all have
* the same width (except overflow and underflow).</p>
*
* <p>Defines {@code bucketsCount} buckets with these boundaries for bucket i:</p>
* <ul>
* <li>Upper bound (0 <= i < N-1): {@code startValue + bucketWidth * i}</li>
* <li>Lower bound (1 <= i < N): {@code startValue + bucketWidth * (i - 1)}</li>
* </ul>
*
* <p>For example, if {@code bucketsCount=6}, {@code startValue=5}, and
* {@code bucketWidth=15}, then the bucket ranges are as follows:</p>
*
* <pre>(-INF, 5], (5, 20], (20, 35], (35, 50], (50, 65], (65, +INF)</pre>
*
* @param bucketsCount the total number of buckets. The value must be >= 2.
* @param startValue the upper boundary of the first bucket.
* @param bucketWidth the difference between the upper and lower bounds for
* each bucket. The value must be >= 1.
*/
IHistogramCollectorPtr LinearHistogram(
ui32 bucketsCount, TBucketBound startValue, TBucketBound bucketWidth);
} // namespace NMonitoring
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