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