Struct MeteringQueue 

pub struct MeteringQueue {
    config: MeteringConfiguration,
    queue: VecDeque<(NanoTimestamp, u64)>,
}

Struct to keep track of some sequential metered actions and compute rate limits.

The queue uses a time based decay and prunes metering information after corresponding expiration time has passed.

Fields

config: MeteringConfiguration

Metering configuration of the queue.

queue: VecDeque<(NanoTimestamp, u64)>

Ring buffer keeping track of action execution timestamp and its metered value.

Implementations

impl MeteringQueue

pub fn new(config: MeteringConfiguration) -> Self

Generate a new MeteringQueue for provided MeteringConfiguration.

pub fn clean(&mut self)

Prune expired metering information from the queue.

pub fn push(&mut self, value: &u64)

Add new metering value to the queue, after prunning expired metering information. If no threshold has been set, the insert is ignored.

pub fn total(&self) -> u64

Compute the current metered values total.

pub fn sleep_time(&self) -> Option<u64>

Compute sleep time for current metered values total, based on the metering configuration.

The sleep time increases linearly, based on configuration sleep step. For example, in a raw count metering model, if we set the configuration with threshold = 6 and sleep_step = 250, when total = 10, returned sleep time will be 1000 ms.

Sleep times table for the above example:

Total	Sleep Time (ms)
0	0
4	0
6	0
7	250
8	500
9	750
10	1000
14	2000
18	3000

Trait Implementations

impl Debug for MeteringQueue

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

Formats the value using the given formatter.