package config import ( "bytes" "sync" "time" "github.com/asim/go-micro/v3/config/loader" "github.com/asim/go-micro/v3/config/loader/memory" "github.com/asim/go-micro/v3/config/reader" "github.com/asim/go-micro/v3/config/reader/json" "github.com/asim/go-micro/v3/config/source" ) type config struct { exit chan bool opts Options sync.RWMutex // the current snapshot snap *loader.Snapshot // the current values vals reader.Values } type watcher struct { lw loader.Watcher rd reader.Reader path []string value reader.Value } func newConfig(opts ...Option) (Config, error) { var c config c.Init(opts...) go c.run() return &c, nil } func (c *config) Init(opts ...Option) error { c.opts = Options{ Reader: json.NewReader(), } c.exit = make(chan bool) for _, o := range opts { o(&c.opts) } // default loader uses the configured reader if c.opts.Loader == nil { c.opts.Loader = memory.NewLoader(memory.WithReader(c.opts.Reader)) } err := c.opts.Loader.Load(c.opts.Source...) if err != nil { return err } c.snap, err = c.opts.Loader.Snapshot() if err != nil { return err } c.vals, err = c.opts.Reader.Values(c.snap.ChangeSet) if err != nil { return err } return nil } func (c *config) Options() Options { return c.opts } func (c *config) run() { watch := func(w loader.Watcher) error { for { // get changeset snap, err := w.Next() if err != nil { return err } c.Lock() if c.snap.Version >= snap.Version { c.Unlock() continue } // save c.snap = snap // set values c.vals, _ = c.opts.Reader.Values(snap.ChangeSet) c.Unlock() } } for { w, err := c.opts.Loader.Watch() if err != nil { time.Sleep(time.Second) continue } done := make(chan bool) // the stop watch func go func() { select { case <-done: case <-c.exit: } w.Stop() }() // block watch if err := watch(w); err != nil { // do something better time.Sleep(time.Second) } // close done chan close(done) // if the config is closed exit select { case <-c.exit: return default: } } } func (c *config) Map() map[string]interface{} { c.RLock() defer c.RUnlock() return c.vals.Map() } func (c *config) Scan(v interface{}) error { c.RLock() defer c.RUnlock() return c.vals.Scan(v) } // sync loads all the sources, calls the parser and updates the config func (c *config) Sync() error { if err := c.opts.Loader.Sync(); err != nil { return err } snap, err := c.opts.Loader.Snapshot() if err != nil { return err } c.Lock() defer c.Unlock() c.snap = snap vals, err := c.opts.Reader.Values(snap.ChangeSet) if err != nil { return err } c.vals = vals return nil } func (c *config) Close() error { select { case <-c.exit: return nil default: close(c.exit) } return nil } func (c *config) Get(path ...string) reader.Value { c.RLock() defer c.RUnlock() // did sync actually work? if c.vals != nil { return c.vals.Get(path...) } // no value return newValue() } func (c *config) Set(val interface{}, path ...string) { c.Lock() defer c.Unlock() if c.vals != nil { c.vals.Set(val, path...) } return } func (c *config) Del(path ...string) { c.Lock() defer c.Unlock() if c.vals != nil { c.vals.Del(path...) } return } func (c *config) Bytes() []byte { c.RLock() defer c.RUnlock() if c.vals == nil { return []byte{} } return c.vals.Bytes() } func (c *config) Load(sources ...source.Source) error { if err := c.opts.Loader.Load(sources...); err != nil { return err } snap, err := c.opts.Loader.Snapshot() if err != nil { return err } c.Lock() defer c.Unlock() c.snap = snap vals, err := c.opts.Reader.Values(snap.ChangeSet) if err != nil { return err } c.vals = vals return nil } func (c *config) Watch(path ...string) (Watcher, error) { value := c.Get(path...) w, err := c.opts.Loader.Watch(path...) if err != nil { return nil, err } return &watcher{ lw: w, rd: c.opts.Reader, path: path, value: value, }, nil } func (c *config) String() string { return "config" } func (w *watcher) Next() (reader.Value, error) { for { s, err := w.lw.Next() if err != nil { return nil, err } // only process changes if bytes.Equal(w.value.Bytes(), s.ChangeSet.Data) { continue } v, err := w.rd.Values(s.ChangeSet) if err != nil { return nil, err } w.value = v.Get() return w.value, nil } } func (w *watcher) Stop() error { return w.lw.Stop() }