/
balancefactor.go
42 lines (33 loc) · 1.22 KB
/
balancefactor.go
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package consistenthash
import (
"fmt"
"github.com/zalando/skipper/filters"
"github.com/zalando/skipper/loadbalancer"
)
type consistentHashBalanceFactor struct {
balanceFactor float64
}
// NewConsistentHashBalanceFactor creates a filter Spec, whose instances
// set the balancer factor used by the `consistentHash` algorithm to avoid
// popular hashes overloading a single endpoint
func NewConsistentHashBalanceFactor() filters.Spec { return &consistentHashBalanceFactor{} }
func (*consistentHashBalanceFactor) Name() string {
return filters.ConsistentHashBalanceFactorName
}
func (*consistentHashBalanceFactor) CreateFilter(args []interface{}) (filters.Filter, error) {
if len(args) != 1 {
return nil, filters.ErrInvalidFilterParameters
}
value, ok := args[0].(float64)
if !ok {
return nil, filters.ErrInvalidFilterParameters
}
if value < 1 {
return nil, fmt.Errorf("invalid consistentHashBalanceFactor filter value, must be >=1 but got %f", value)
}
return &consistentHashBalanceFactor{value}, nil
}
func (c *consistentHashBalanceFactor) Request(ctx filters.FilterContext) {
ctx.StateBag()[loadbalancer.ConsistentHashBalanceFactor] = c.balanceFactor
}
func (*consistentHashBalanceFactor) Response(filters.FilterContext) {}