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/**
* Written by Gil Tene of Azul Systems, and released to the public domain,
* as explained at http://creativecommons.org/publicdomain/zero/1.0/
*
* @author Gil Tene
*/
package org.glowroot.shaded.HdrHistogram;
/**
* A floating point values High Dynamic Range (HDR) Histogram that is synchronized as a whole
*
* A {@link SynchronizedDoubleHistogram} is a variant of {@link org.glowroot.shaded.HdrHistogram.DoubleHistogram} that is
* synchronized as a whole, such that queries, copying, and addition operations are atomic with relation to
* modification on the {@link SynchronizedDoubleHistogram}, nd such that external accessors (e.g. iterations on the
* histogram data) that synchronize on the {@link SynchronizedDoubleHistogram} instance can safely assume that no
* modifications to the histogram data occur within their synchronized block.
*
* It is important to note that synchronization can result in blocking recoding calls. If non-blocking recoding
* operations are required, consider using {@link org.glowroot.shaded.HdrHistogram.ConcurrentDoubleHistogram}, or (recommended)
* {@link DoubleRecorder} which were intended for concurrent operations.
*
* {@link SynchronizedDoubleHistogram} supports the recording and analyzing sampled data value counts across a
* configurable dynamic range of floating point (double) values, with configurable value precision within the range.
* Dynamic range is expressed as a ratio between the highest and lowest non-zero values trackable within the histogram
* at any given time. Value precision is expressed as the number of significant [decimal] digits in the value recording,
* and provides control over value quantization behavior across the value range and the subsequent value resolution at
* any given level.
*
* Auto-ranging: Unlike integer value based histograms, the specific value range tracked by a {@link
* SynchronizedDoubleHistogram} is not specified upfront. Only the dynamic range of values that the histogram can
* cover is (optionally) specified. E.g. When a {@link ConcurrentDoubleHistogram} is created to track a dynamic range of
* 3600000000000 (enough to track values from a nanosecond to an hour), values could be recorded into into it in any
* consistent unit of time as long as the ratio between the highest and lowest non-zero values stays within the
* specified dynamic range, so recording in units of nanoseconds (1.0 thru 3600000000000.0), milliseconds (0.000001
* thru 3600000.0) seconds (0.000000001 thru 3600.0), hours (1/3.6E12 thru 1.0) will all work just as well.
*
* Auto-resizing: When constructed with no specified dynamic range (or when auto-resize is turned on with {@link
* SynchronizedDoubleHistogram#setAutoResize}) a {@link SynchronizedDoubleHistogram} will auto-resize its dynamic
* range to include recorded values as they are encountered. Note that recording calls that cause auto-resizing may
* take longer to execute, as resizing incurs allocation and copying of internal data structures.
*
* Attempts to record non-zero values that range outside of the specified dynamic range (or exceed the limits of
* of dynamic range when auto-resizing) may results in {@link ArrayIndexOutOfBoundsException} exceptions, either
* due to overflow or underflow conditions. These exceptions will only be thrown if recording the value would have
* resulted in discarding or losing the required value precision of values already recorded in the histogram.
*
* See package description for {@link org.glowroot.shaded.HdrHistogram} for details.
*/
public class SynchronizedDoubleHistogram extends DoubleHistogram {
/**
* Construct a new auto-resizing DoubleHistogram using a precision stated as a number of significant
* decimal digits.
*
* @param numberOfSignificantValueDigits Specifies the precision to use. This is the number of significant
* decimal digits to which the histogram will maintain value resolution
* and separation. Must be a non-negative integer between 0 and 5.
*/
public SynchronizedDoubleHistogram(final int numberOfSignificantValueDigits) {
this(2, numberOfSignificantValueDigits);
setAutoResize(true);
}
/**
* Construct a new DoubleHistogram with the specified dynamic range (provided in
* {@code highestToLowestValueRatio}) and using a precision stated as a number of significant
* decimal digits.
*
* @param highestToLowestValueRatio specifies the dynamic range to use
* @param numberOfSignificantValueDigits Specifies the precision to use. This is the number of significant
* decimal digits to which the histogram will maintain value resolution
* and separation. Must be a non-negative integer between 0 and 5.
*/
public SynchronizedDoubleHistogram(final long highestToLowestValueRatio, final int numberOfSignificantValueDigits) {
super(highestToLowestValueRatio, numberOfSignificantValueDigits, SynchronizedHistogram.class);
}
/**
* Construct a {@link SynchronizedDoubleHistogram} with the same range settings as a given source,
* duplicating the source's start/end timestamps (but NOT it's contents)
* @param source The source histogram to duplicate
*/
public SynchronizedDoubleHistogram(final ConcurrentDoubleHistogram source) {
super(source);
}
}