/
handlers.go
49 lines (40 loc) · 1.42 KB
/
handlers.go
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// Copyright 2016 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.
package charmrevisionupdater
import (
"fmt"
"github.com/juju/errors"
"github.com/juju/names"
"github.com/juju/juju/charmstore"
"github.com/juju/juju/state"
)
// LatestCharmHandler exposes the functionality needed to deal with
// the latest info (from the store) for a charm.
type LatestCharmHandler interface {
// HandleLatest deals with the given charm info, treating it as the
// most up-to-date information for the charms most recent revision.
HandleLatest(names.ServiceTag, charmstore.CharmInfo) error
}
type newHandlerFunc func(*state.State) (LatestCharmHandler, error)
var registeredHandlers = map[string]newHandlerFunc{}
// RegisterLatestCharmHandler adds the factory func for the identified
// handler to the handler registry.
func RegisterLatestCharmHandler(name string, newHandler newHandlerFunc) error {
if _, ok := registeredHandlers[name]; ok {
msg := fmt.Sprintf(`"latest charm" handler %q already registered`, name)
return errors.NewAlreadyExists(nil, msg)
}
registeredHandlers[name] = newHandler
return nil
}
func createHandlers(st *state.State) ([]LatestCharmHandler, error) {
var handlers []LatestCharmHandler
for _, newHandler := range registeredHandlers {
handler, err := newHandler(st)
if err != nil {
return nil, errors.Trace(err)
}
handlers = append(handlers, handler)
}
return handlers, nil
}