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aliases.go
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aliases.go
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// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
// See the file LICENSE for licensing terms.
package ids
import (
"fmt"
"sync"
)
// Aliaser allows one to give an ID aliases and lookup the aliases given to an
// ID. An ID can have arbitrarily many aliases; two IDs may not have the same
// alias.
type Aliaser struct {
lock sync.RWMutex
dealias map[string]ID
aliases map[ID][]string
}
// Initialize the aliaser to have no aliases
func (a *Aliaser) Initialize() {
a.dealias = make(map[string]ID)
a.aliases = make(map[ID][]string)
}
// Lookup returns the ID associated with alias
func (a *Aliaser) Lookup(alias string) (ID, error) {
a.lock.RLock()
defer a.lock.RUnlock()
if ID, ok := a.dealias[alias]; ok {
return ID, nil
}
return ID{}, fmt.Errorf("there is no ID with alias %s", alias)
}
// Aliases returns the aliases of an ID
func (a *Aliaser) Aliases(id ID) []string {
a.lock.RLock()
defer a.lock.RUnlock()
return a.aliases[id]
}
// PrimaryAlias returns the first alias of [id]
func (a *Aliaser) PrimaryAlias(id ID) (string, error) {
a.lock.RLock()
defer a.lock.RUnlock()
aliases, exists := a.aliases[id]
if !exists || len(aliases) == 0 {
return "", fmt.Errorf("there is no alias for ID %s", id)
}
return aliases[0], nil
}
// Alias gives [id] the alias [alias]
func (a *Aliaser) Alias(id ID, alias string) error {
a.lock.Lock()
defer a.lock.Unlock()
if _, exists := a.dealias[alias]; exists {
return fmt.Errorf("%s is already used as an alias for an ID", alias)
}
a.dealias[alias] = id
a.aliases[id] = append(a.aliases[id], alias)
return nil
}
// RemoveAliases of the provided ID
func (a *Aliaser) RemoveAliases(id ID) {
a.lock.Lock()
defer a.lock.Unlock()
aliases := a.aliases[id]
delete(a.aliases, id)
for _, alias := range aliases {
delete(a.dealias, alias)
}
}