Struct hdrhistogram_c::Histogram

pub struct Histogram { /* fields omitted */ }

Instance of a Histogram.

Methods

impl Histogram

fn init(
    lowest_trackable_value: u64,
    highest_trackable_value: u64,
    significant_figures: u32
) -> Result<Histogram>

Create a new Histogram instance. lowest_trackable_value..highest_trackable_value defines the range of values in the Histogram. lowest_trackable_value must be >= 1. significant_figures defines the precision, and must be in the range 1..5.

HistogramErr is the catch-all failure case. It doesn't report much detail because the underlying library doesn't.

Example

let mut h = Histogram::init(1, 100000, 2).unwrap();
h.record_value(10);  // record a single count of '10'

fn reset(&mut self)

Zero all histogram state in place.

fn record_value(&mut self, value: u64) -> bool

Record a specific value. Returns true if successful.

h.record_value(5);
assert_eq!(h.total_count(), 1);

fn record_values(&mut self, value: u64, count: u64) -> bool

Record multiple counts of a specific value. Returns true if successful.

h.record_values(5, 10);
assert_eq!(h.total_count(), 10);

fn record_corrected_value(&mut self, value: u64, expected_interval: u64) -> bool

Record a value, correcting for coordinated omission. This should be used when accumulating latency measurements taked on a regular timebase (expected_interval). Any latency that's well above that interval implies some kind of outage in which sampled were lost. This corrects for those lost samples to preserve the integrity of the overall statistics.

fn record_corrected_values(
    &mut self,
    value: u64,
    count: u64,
    expected_interval: u64
) -> bool

As with record_corrected_value() but multiple counts of the value.

fn add(&mut self, other: &Histogram) -> u64

Sum two histograms, modifying self in place. Returns the number of samples dropped; samples will be dropped if they're out of the range lowest_trackable_value .. highest_trackable_value.

fn add_while_correcting_for_coordinated_omission(
    &mut self,
    other: &Histogram,
    expected_interval: u64
) -> u64

As with add but corrects of potential lost samples while doing periodic latency measurements, as in record_corrected_value. Only one correction should be applied.

fn total_count(&self) -> u64

Total of all counters

fn min(&self) -> u64

Smallest recorded value.

h.record_value(1);
h.record_value(5);
assert_eq!(h.min(), 1);

fn max(&self) -> u64

Largest recorded value.

h.record_value(1);
h.record_value(5);
assert_eq!(h.max(), 5);

fn value_at_percentile(&self, percentile: f64) -> u64

Value at a particular percentile (0-100).

h.record_values(20, 10);
h.record_value(40);
assert_eq!(h.value_at_percentile(50.0), 20);
assert_eq!(h.value_at_percentile(99.0), 40);

fn stddev(&self) -> f64

Standard deviation of values.

fn mean(&self) -> f64

Mean of values.

fn values_are_equivalent(&self, a: u64, b: u64) -> bool

Returns true if two values are the same according to the lowest, highest and significant figures parameters.

fn lowest_equivalent_value(&self, value: u64) -> u64

Lowest value equivalent to the given value.

fn count_at_value(&self, value: u64) -> u64

Count for a specific value.

fn linear_iter<'a>(&'a self, value_units_per_bucket: u64) -> LinearIter<'a>

Linear iterator over values. Results are returned in equally weighted buckets.

let mut h = Histogram::init(1, 100000, 3).unwrap();
for i in 1..100 { h.record_values(i, i); }
for (i, c) in h.linear_iter(1).enumerate() {    // 100 buckets
    println!("bucket {} = {}", i, c.count_added_in_this_iteration_step);
}

fn log_iter<'a>(
    &'a self,
    value_units_per_bucket: u64,
    log_base: f64
) -> LogIter<'a>

Logarithmic iterator over values. Results are returned in logarithmically weighted buckets.

fn recorded_iter<'a>(&'a self) -> RecordedIter<'a>

Iterator over recorded values.

fn percentile_iter<'a>(
    &'a self,
    ticks_per_half_distance: u32
) -> PercentileIter<'a>

Iterator over percentiles.

fn encode(&self) -> Result<String>

Encode Histogram state into a Base64 encoded string.

fn decode(base64: &String) -> Result<Histogram>

Decode Histogram state from a Base64 string generated by encode.

Trait Implementations

impl Send for Histogram

impl Drop for Histogram

fn drop(&mut self)

Executes the destructor for this type.

impl Clone for Histogram

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.