Struct: ratelimit.TokenBucket

import "../ibm-cos-sdk-go-v2/aws/ratelimit"

Overview

TokenBucket provides a concurrency safe utility for adding and removing tokens from the available token bucket.

Implemented Interfaces

types.AnalyticsFilter, aws.CredentialsProvider, v4.HTTPPresigner, s3.HTTPPresignerV4, types.MetricsFilter, s3.PresignPost, customizations.S3ExpressCredentialsProvider, arn.S3ObjectLambdaARN, types.SelectObjectContentEventStream

Constructor Functions collapse

Method Summary collapse

Function Details

func NewTokenBucket(i uint) *TokenBucket

NewTokenBucket returns an initialized TokenBucket with the capacity specified.



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// File 'aws/ratelimit/token_bucket.go', line 17


func NewTokenBucket(i uint) *TokenBucket {
	return &TokenBucket{
		remainingTokens: i,
		maxCapacity:     i,
		minCapacity:     1,
	}
}

Method Details

func (t *TokenBucket) Capacity() uint

Capacity returns the maximum capacity of tokens that the bucket could contain.



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// File 'aws/ratelimit/token_bucket.go', line 55


func (t *TokenBucket) Capacity() uint {
	t.mu.Lock()
	defer t.mu.Unlock()

	return t.maxCapacity
}

func (t *TokenBucket) Refund(amount uint)

Refund returns the amount of tokens back to the available token bucket, up to the initial capacity.



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// File 'aws/ratelimit/token_bucket.go', line 45


func (t *TokenBucket) Refund(amount uint) {
	t.mu.Lock()
	defer t.mu.Unlock()

	// Capacity cannot exceed max capacity.
	t.remainingTokens = uintMin(t.remainingTokens+amount, t.maxCapacity)
}

func (t *TokenBucket) Remaining() uint

Remaining returns the number of tokens that remaining in the bucket.



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// File 'aws/ratelimit/token_bucket.go', line 63


func (t *TokenBucket) Remaining() uint {
	t.mu.Lock()
	defer t.mu.Unlock()

	return t.remainingTokens
}

func (t *TokenBucket) Resize(size uint) uint

Resize adjusts the size of the token bucket. Returns the capacity remaining.



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// File 'aws/ratelimit/token_bucket.go', line 71


func (t *TokenBucket) Resize(size uint) uint {
	t.mu.Lock()
	defer t.mu.Unlock()

	t.maxCapacity = uintMax(size, t.minCapacity)

	// Capacity needs to be capped at max capacity, if max size reduced.
	t.remainingTokens = uintMin(t.remainingTokens, t.maxCapacity)

	return t.remainingTokens
}

func (t *TokenBucket) Retrieve(amount uint) (available uint, retrieved bool)

Retrieve attempts to reduce the available tokens by the amount requested. If there are tokens available true will be returned along with the number of available tokens remaining. If amount requested is larger than the available capacity, false will be returned along with the available capacity. If the amount is less than the available capacity, the capacity will be reduced by that amount, and the remaining capacity and true will be returned.



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// File 'aws/ratelimit/token_bucket.go', line 31


func (t *TokenBucket) Retrieve(amount uint) (available uint, retrieved bool) {
	t.mu.Lock()
	defer t.mu.Unlock()

	if amount > t.remainingTokens {
		return t.remainingTokens, false
	}

	t.remainingTokens -= amount
	return t.remainingTokens, true
}