Package com.pervasivecode.utils.stats.histogram

Class ConcurrentHistogram<T>

java.lang.Object

com.pervasivecode.utils.stats.histogram.ConcurrentHistogram<T>

Type Parameters:

T - The type of value counted by this Histogram.

All Implemented Interfaces:

BucketingSystem<T>, Histogram<T>, MutableHistogram<T>

public class ConcurrentHistogram<T>
extends Object
implements MutableHistogram<T>

A thread-safe Histogram based on the AtomicLongArray class.

See Also:

BucketingSystem

Constructor Summary

Constructors

Constructor	Description
ConcurrentHistogram(BucketSelector<T> bucketer)

Method Summary

Modifier and Type	Method	Description
T	bucketUpperBound(int index)	Get the upper-bound value of the specified bucket.
long	countInBucket(int index)	Get the number of elements that were counted in the specified bucket.
void	countValue(T value)	Count the specified value by assigning it to a bucket and incrementing the stored count of values that belong to that bucket.
int	numBuckets()	Get the total number of buckets.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConcurrentHistogram

public ConcurrentHistogram(BucketSelector<T> bucketer)

Method Detail

numBuckets

public int numBuckets()

Description copied from interface: BucketingSystem

Get the total number of buckets. This will not be smaller than 1.

Specified by:

numBuckets in interface BucketingSystem<T>

Returns:

The number of buckets.

bucketUpperBound

public T bucketUpperBound(int index)

Description copied from interface: BucketingSystem

Get the upper-bound value of the specified bucket.

The first bucket has an index of 0. The last bucket has no upper bound, so passing the last index value in index is not allowed and will result in an IllegalArgumentException being thrown. In other words, if there are 10 buckets in a given instance, there are only 9 upper bound values, so the valid index values are 0 through 8 inclusive.

A BucketingSystem with only one bucket is valid (all values fall in that bucket), but would have no upper bound values, so this method would always throw an IllegalArgumentException (for index value 0) or an IndexOutOfBoundsException (for all other values of index).

Specified by:

bucketUpperBound in interface BucketingSystem<T>

Parameters:

index - The bucket index to examine. This must be a value from zero through the next-to-last bucket index.

Returns:

The upper bound value of the specified bucket. This will not be null.

countInBucket

public long countInBucket(int index)

Description copied from interface: Histogram

Get the number of elements that were counted in the specified bucket. The first bucket has an index of 0.

Specified by:

countInBucket in interface Histogram<T>

Parameters:

index - The bucket number to examine.

Returns:

The count of values in the specified bucket.

countValue

public void countValue(T value)

Description copied from interface: MutableHistogram

Count the specified value by assigning it to a bucket and incrementing the stored count of values that belong to that bucket.

Specified by:

countValue in interface MutableHistogram<T>

Parameters:

value - The value to count. This must not be null.