Documentation
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Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type RedisClient ¶
type RedisClient interface {
// Required to load and execute scripts
Eval(script string, keys []string, args ...interface{}) *redis.Cmd
EvalSha(sha1 string, keys []string, args ...interface{}) *redis.Cmd
ScriptExists(hashes ...string) *redis.BoolSliceCmd
ScriptLoad(script string) *redis.StringCmd
}
RedisClient is an interface that encompasses the various methods used by TokenBucket, and allows selecting among different Redis client implementations (e.g. regular Redis, Redis Cluster, sharded, etc.)
type TokenBucket ¶
type TokenBucket struct {
// contains filtered or unexported fields
}
TokenBucket implements a token-bucket limiter stored in a Redis database. It supports atomic operation with concurrent access.
func New ¶
func New(client RedisClient) *TokenBucket
New returns a new TokenBucket that uses the provided Redis client.
func (*TokenBucket) Call ¶
func (tb *TokenBucket) Call( ctx context.Context, prefix string, capacity int64, replenishRate float64, numTokens int, ) (bool, int64, error)
Call implements the actual token bucket algorithm. Given a bucket with capacity `capacity` and replenishment rate of `replenishRate` tokens per second, it will first ensure that the bucket has the correct number of tokens added (up to the maximum capacity) since the last time that this function was called. Then, it will attempt to remove `numTokens` from the bucket.
This function returns a boolean indicating whether it was able to remove all tokens from the bucket, the remaining number of tokens in the bucket, and any error that occurs.
func (*TokenBucket) Load ¶
func (tb *TokenBucket) Load(ctx context.Context) error
Load preloads any required Lua scripts into the Redis database, and updates the hash of the resulting script. Calling this function is optional, but will greatly reduce the network traffic to the Redis cluster since it only needs to pass a hash of the script and not the full script content.
Source Files