Struct FeatureContext 

pub struct FeatureContext { /* private fields */ }

Application context passed to feature flag evaluation.

Contains arbitrary key-value data used to evaluate feature flag conditions. The identity fields determine which fields are used for rollout bucketing.

Implementations

impl FeatureContext

pub fn new() -> Self

pub fn identity_fields(&mut self, fields: Vec<&str>)

Set the fields used to compute this context’s rollout identity.

Fields are sorted lexicographically before hashing. Calling this resets the cached identity value.

pub fn insert(&mut self, key: &str, value: impl Into<Value>)

Insert a key-value pair into the context.

pub fn get(&self, key: &str) -> Option<&Value>

Get a context value by key.

pub fn has(&self, key: &str) -> bool

Check if a key is present in the context.

pub fn id(&self) -> u64

Compute and return this context’s rollout identity.

The result is cached and reset when identity fields or context data change. When no identity fields are set, all context keys are used (non-deterministic rollout across contexts with different keys). The id value is mostly used to id % 100 <= rollout.

pub fn bucket_id(&self, feature_name: Option<&str>) -> u64

The id a percentage rollout buckets this context on.

Without a feature name this is id. With one, the name is hashed as one more identity entry in front of the identity fields, so each feature has its own rollout population; see FEATURE_BUCKETING_EPOCH for which features use it.

Trait Implementations

impl Default for FeatureContext

fn default() -> Self

Returns the “default value” for a type.