| Index: state/apiserver/resource.go |
| === added file 'state/apiserver/resource.go' |
| --- state/apiserver/resource.go 1970-01-01 00:00:00 +0000 |
| +++ state/apiserver/resource.go 2013-05-24 17:53:15 +0000 |
| @@ -0,0 +1,82 @@ |
| +// Copyright 2013 Canonical Ltd. |
| +// Licensed under the AGPLv3, see LICENCE file for details. |
| + |
| +package apiserver |
| + |
| +import ( |
| + "launchpad.net/juju-core/log" |
| + "strconv" |
| + "sync" |
| +) |
| + |
| +// resource represents the interface provided by state watchers and pingers. |
| +type resource interface { |
| + Stop() error |
| +} |
| + |
| +// resources holds all the resources for a connection. |
| +type resources struct { |
| + mu sync.Mutex |
| + maxId uint64 |
| + rs map[string]*srvResource |
| +} |
| + |
| +// srvResource holds the details of a resource. It also implements the |
| +// Stop RPC method for all resources. |
| +type srvResource struct { |
| + rs *resources |
| + resource resource |
| + id string |
| +} |
| + |
| +// Stop stops the given resource. It causes any outstanding |
| +// Next calls to return a CodeStopped error. |
| +// Any subsequent Next calls will return a CodeNotFound |
| +// error because the resource will no longer exist. |
| +func (r *srvResource) Stop() error { |
| + err := r.resource.Stop() |
| + r.rs.mu.Lock() |
| + defer r.rs.mu.Unlock() |
| + delete(r.rs.rs, r.id) |
| + return err |
| +} |
| + |
| +func newResources() *resources { |
| + return &resources{ |
| + rs: make(map[string]*srvResource), |
| + } |
| +} |
| + |
| +// get returns the srvResource registered with the given |
| +// id, or nil if there is no such resource. |
| +func (rs *resources) get(id string) *srvResource { |
| + rs.mu.Lock() |
| + defer rs.mu.Unlock() |
| + return rs.rs[id] |
| +} |
| + |
| +// register records the given watcher and returns |
| +// a srvResource instance for it. |
| +func (rs *resources) register(r resource) *srvResource { |
| + rs.mu.Lock() |
| + defer rs.mu.Unlock() |
| + rs.maxId++ |
| + sr := &srvResource{ |
| + rs: rs, |
| + id: strconv.FormatUint(rs.maxId, 10), |
| + resource: r, |
| + } |
| + rs.rs[sr.id] = sr |
| + return sr |
| +} |
| + |
| +func (rs *resources) stopAll() { |
| + rs.mu.Lock() |
| + defer rs.mu.Unlock() |
| + for _, r := range rs.rs { |
| + if err := r.resource.Stop(); err != nil { |
| + log.Errorf("state/api: error stopping %T resource: %v", r, err) |
| + } |
| + } |
| + rs.rs = make(map[string]*srvResource) |
| +} |
