Enum BucketValue 

pub enum BucketValue {
    Counter(CounterType),
    Distribution(DistributionValue),
    Set(SetValue),
    Gauge(GaugeValue),
}

The aggregated value of a metric bucket.

Variants

Counter(CounterType)

Counts instances of an event (MetricType::Counter).

Counters can be incremented and decremented. The default operation is to increment a counter by 1, although increments by larger values are equally possible.

Serialization

This variant serializes to a double precision float.

Aggregation

Counters aggregate by folding individual values into a single sum value per bucket. The sum is ingested and stored directly.

Distribution(DistributionValue)

Builds a statistical distribution over values reported (MetricType::Distribution).

Based on individual reported values, distributions allow to query the maximum, minimum, or average of the reported values, as well as statistical quantiles. With an increasing number of values in the distribution, its accuracy becomes approximate.

Serialization

This variant serializes to a list of double precision floats, see DistributionValue.

Aggregation

During ingestion, all individual reported values are collected in a lossless format. In storage, these values are compressed into data sketches that allow to query quantiles. Separately, the count and sum of the reported values is stored, which makes distributions a strict superset of counters.

Set(SetValue)

Counts the number of unique reported values.

Sets represent arbitrary discrete values as hashes and track their deduplicated count. With an increasing number of unique values in the set, its accuracy becomes approximate. It is not possible to query individual values from a set.

Serialization

This variant serializes to a list of 32-bit integers.

Aggregation

Set values are represented as 32-bit integer hashes of the original value. Buckets merge by taking the union of these hashes.

Internally, set metrics are stored in data sketches that expose an approximate cardinality.

Gauge(GaugeValue)

Stores absolute snapshots of values.

In addition to plain counters, gauges store a snapshot of the maximum, minimum and sum of all values, as well as the last reported value. Note that the “last” component of this aggregation is not commutative. Which value is preserved as last value is implementation-defined.

Serialization

This variant serializes to a structure with named fields, see GaugeValue.

Aggregation

Gauges aggregate by folding each of the components based on their semantics:

• last assumes the newly added value
• min retains the smaller value
• max retains the larger value
• sum adds the new value to the existing sum
• count adds the count of the newly added gauge (defaulting to 1)

Implementations

impl BucketValue

pub fn counter(value: CounterType) -> Self

Returns a bucket value representing a counter with the given value.

pub fn distribution(value: DistributionType) -> Self

Returns a bucket value representing a distribution with a single given value.

pub fn set(value: SetType) -> Self

Returns a bucket value representing a set with a single given hash value.

pub fn set_from_str(string: &str) -> Self

Returns a bucket value representing a set with the 32-bit hash of the given string.

pub fn set_from_display(display: impl Display) -> Self

Returns a bucket value representing a set with a single given value.

pub fn gauge(value: GaugeType) -> Self

Returns a bucket value representing a gauge with a single given value.

pub fn ty(&self) -> MetricType

Returns the type of this value.

pub fn len(&self) -> usize

Returns the number of raw data points in this value.

pub fn is_empty(&self) -> bool

Returns true if this bucket contains no values.

pub fn cost(&self) -> usize

Estimates the number of bytes needed to encode the bucket value.

Note that this does not necessarily match the exact memory footprint of the value, because data structures have a memory overhead.

pub fn merge(&mut self, other: Self) -> Result<(), Self>

Merges the given bucket_value into self.

Returns Ok(()) if the two bucket values can be merged. This is the case when both bucket values are of the same variant. Otherwise, this returns Err(other).

Trait Implementations

impl Clone for BucketValue

fn clone(&self) -> BucketValue

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BucketValue

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for BucketValue

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'a> From<&'a BucketValue> for BucketViewValue<'a>

fn from(value: &'a BucketValue) -> Self

Converts to this type from the input type.

impl PartialEq for BucketValue

fn eq(&self, other: &BucketValue) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for BucketValue

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for BucketValue