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package crr
import (
"net/url"
"sort"
"strings"
"time"
"github.com/aws/aws-sdk-go/aws"
)
// Endpoint represents an endpoint used in endpoint discovery.
type Endpoint struct {
Key string
Addresses WeightedAddresses
}
// WeightedAddresses represents a list of WeightedAddress.
type WeightedAddresses []WeightedAddress
// WeightedAddress represents an address with a given weight.
type WeightedAddress struct {
URL *url.URL
Expired time.Time
}
// HasExpired will return whether or not the endpoint has expired with
// the exception of a zero expiry meaning does not expire.
func (e WeightedAddress) HasExpired() bool {
return e.Expired.Before(time.Now())
}
// Add will add a given WeightedAddress to the address list of Endpoint.
func (e *Endpoint) Add(addr WeightedAddress) {
e.Addresses = append(e.Addresses, addr)
}
// Len returns the number of valid endpoints where valid means the endpoint
// has not expired.
func (e *Endpoint) Len() int {
validEndpoints := 0
for _, endpoint := range e.Addresses {
if endpoint.HasExpired() {
continue
}
validEndpoints++
}
return validEndpoints
}
// GetValidAddress will return a non-expired weight endpoint
func (e *Endpoint) GetValidAddress() (WeightedAddress, bool) {
for i := 0; i < len(e.Addresses); i++ {
we := e.Addresses[i]
if we.HasExpired() {
e.Addresses = append(e.Addresses[:i], e.Addresses[i+1:]...)
i--
continue
}
we.URL = cloneURL(we.URL)
return we, true
}
return WeightedAddress{}, false
}
// Prune will prune the expired addresses from the endpoint by allocating a new []WeightAddress.
// This is not concurrent safe, and should be called from a single owning thread.
func (e *Endpoint) Prune() bool {
validLen := e.Len()
if validLen == len(e.Addresses) {
return false
}
wa := make([]WeightedAddress, 0, validLen)
for i := range e.Addresses {
if e.Addresses[i].HasExpired() {
continue
}
wa = append(wa, e.Addresses[i])
}
e.Addresses = wa
return true
}
// Discoverer is an interface used to discovery which endpoint hit. This
// allows for specifics about what parameters need to be used to be contained
// in the Discoverer implementor.
type Discoverer interface {
Discover() (Endpoint, error)
}
// BuildEndpointKey will sort the keys in alphabetical order and then retrieve
// the values in that order. Those values are then concatenated together to form
// the endpoint key.
func BuildEndpointKey(params map[string]*string) string {
keys := make([]string, len(params))
i := 0
for k := range params {
keys[i] = k
i++
}
sort.Strings(keys)
values := make([]string, len(params))
for i, k := range keys {
if params[k] == nil {
continue
}
values[i] = aws.StringValue(params[k])
}
return strings.Join(values, ".")
}
func cloneURL(u *url.URL) (clone *url.URL) {
clone = &url.URL{}
*clone = *u
if u.User != nil {
user := *u.User
clone.User = &user
}
return clone
}
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