config: minor changes to split config and watcher files

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

env.go

@@ -50,7 +50,7 @@ func (c *envConfig) Load(ctx context.Context, opts ...config.LoadOption) error {
 
 	src, err := rutil.Zero(c.opts.Struct)
 	if err == nil {
-		err = c.fillValues(ctx, reflect.ValueOf(src))
+		err = fillValues(ctx, reflect.ValueOf(src), c.opts.StructTag)
 	}
 	if err != nil && !c.opts.AllowFail {
 		return err
@@ -70,7 +70,7 @@ func (c *envConfig) Load(ctx context.Context, opts ...config.LoadOption) error {
 	return nil
 }
 
-func (c *envConfig) fillValue(ctx context.Context, value reflect.Value, val string) error {
+func fillValue(ctx context.Context, value reflect.Value, val string) error {
 	switch value.Kind() {
 	case reflect.Map:
 		t := value.Type()
@@ -84,10 +84,10 @@ func (c *envConfig) fillValue(ctx context.Context, value reflect.Value, val stri
 			kv := strings.FieldsFunc(nval, func(c rune) bool { return c == '=' })
 			mkey := reflect.Indirect(reflect.New(kt))
 			mval := reflect.Indirect(reflect.New(et))
-			if err := c.fillValue(ctx, mkey, kv[0]); err != nil {
+			if err := fillValue(ctx, mkey, kv[0]); err != nil {
 				return err
 			}
-			if err := c.fillValue(ctx, mval, kv[1]); err != nil {
+			if err := fillValue(ctx, mval, kv[1]); err != nil {
 				return err
 			}
 			value.SetMapIndex(mkey, mval)
@@ -97,7 +97,7 @@ func (c *envConfig) fillValue(ctx context.Context, value reflect.Value, val stri
 		value.Set(reflect.MakeSlice(reflect.SliceOf(value.Type().Elem()), len(nvals), len(nvals)))
 		for idx, nval := range nvals {
 			nvalue := reflect.Indirect(reflect.New(value.Type().Elem()))
-			if err := c.fillValue(ctx, nvalue, nval); err != nil {
+			if err := fillValue(ctx, nvalue, nval); err != nil {
 				return err
 			}
 			value.Index(idx).Set(nvalue)
@@ -237,7 +237,7 @@ func (c *envConfig) setValues(ctx context.Context, valueOf reflect.Value) error
 	return nil
 }
 
-func (c *envConfig) fillValues(ctx context.Context, valueOf reflect.Value) error {
+func fillValues(ctx context.Context, valueOf reflect.Value, structTag string) error {
 	var values reflect.Value
 
 	if valueOf.Kind() == reflect.Ptr {
@@ -264,7 +264,7 @@ func (c *envConfig) fillValues(ctx context.Context, valueOf reflect.Value) error
 		switch value.Kind() {
 		case reflect.Struct:
 			value.Set(reflect.Indirect(reflect.New(value.Type())))
-			if err := c.fillValues(ctx, value); err != nil {
+			if err := fillValues(ctx, value, structTag); err != nil {
 				return err
 			}
 			continue
@@ -278,12 +278,12 @@ func (c *envConfig) fillValues(ctx context.Context, valueOf reflect.Value) error
 				value.Set(reflect.New(value.Type().Elem()))
 			}
 			value = value.Elem()
-			if err := c.fillValues(ctx, value); err != nil {
+			if err := fillValues(ctx, value, structTag); err != nil {
 				return err
 			}
 			continue
 		}
-		tag, ok := field.Tag.Lookup(c.opts.StructTag)
+		tag, ok := field.Tag.Lookup(structTag)
 		if !ok {
 			continue
 		}
@@ -292,7 +292,7 @@ func (c *envConfig) fillValues(ctx context.Context, valueOf reflect.Value) error
 			continue
 		}
 
-		if err := c.fillValue(ctx, value, val); err != nil {
+		if err := fillValue(ctx, value, val); err != nil {
 			return err
 		}
 	}
@@ -328,6 +328,20 @@ func (c *envConfig) Name() string {
 	return c.opts.Name
 }
 
+func (c *envConfig) Watch(ctx context.Context, opts ...config.WatchOption) (config.Watcher, error) {
+	w := &envWatcher{
+		opts:  c.opts,
+		wopts: config.NewWatchOptions(opts...),
+		done:  make(chan struct{}),
+		vchan: make(chan map[string]interface{}),
+		echan: make(chan error),
+	}
+
+	go w.run()
+
+	return w, nil
+}
+
 func NewConfig(opts ...config.Option) config.Config {
 	options := config.NewOptions(opts...)
 	if len(options.StructTag) == 0 {

go.mod

@@ -4,5 +4,5 @@ go 1.16
 
 require (
 	github.com/imdario/mergo v0.3.12
-	github.com/unistack-org/micro/v3 v3.4.0
+	github.com/unistack-org/micro/v3 v3.5.9
 )

go.sum

@@ -1,12 +1,12 @@
-github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/ef-ds/deque v1.0.4/go.mod h1:gXDnTC3yqvBcHbq2lcExjtAcVrOnJCbMcZXmuj8Z4tg=
-github.com/google/uuid v1.2.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/golang-jwt/jwt v3.2.2+incompatible/go.mod h1:8pz2t5EyA70fFQQSrl6XZXzqecmYZeUEB8OUGHkxJ+I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/imdario/mergo v0.3.12 h1:b6R2BslTbIEToALKP7LxUvijTsNI9TAe80pLWN2g/HU=
 github.com/imdario/mergo v0.3.12/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/silas/dag v0.0.0-20210121180416-41cf55125c34/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
-github.com/unistack-org/micro/v3 v3.4.0 h1:z9F3lgAb2j4cZ1ib5qBj66JPYUAzR4sNIJqUDjVwyVQ=
-github.com/unistack-org/micro/v3 v3.4.0/go.mod h1:LXmPfbJnJNvL0kQs8HfnkV3Wya2Wb+C7keVq++RCZnk=
+github.com/unistack-org/micro/v3 v3.5.9 h1:9iIxGZ56bVME7E9hqKIHeSHXkn69M9KFyJfaUzi7B9k=
+github.com/unistack-org/micro/v3 v3.5.9/go.mod h1:zQnZPEy842kQNcyjmVys6tdMjty4PHdyUUKYm1wrg1s=
 golang.org/x/net v0.0.0-20210510120150-4163338589ed/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

watcher.go

@@ -0,0 +1,82 @@
+package env
+
+import (
+	"reflect"
+
+	"github.com/unistack-org/micro/v3/config"
+	"github.com/unistack-org/micro/v3/util/jitter"
+	rutil "github.com/unistack-org/micro/v3/util/reflect"
+)
+
+type envWatcher struct {
+	opts  config.Options
+	wopts config.WatchOptions
+	done  chan struct{}
+	vchan chan map[string]interface{}
+	echan chan error
+}
+
+func (w *envWatcher) run() {
+	ticker := jitter.NewTicker(w.wopts.MinInterval, w.wopts.MaxInterval)
+	defer ticker.Stop()
+
+	src := w.opts.Struct
+	if w.wopts.Struct != nil {
+		src = w.wopts.Struct
+	}
+
+	for {
+		select {
+		case <-w.done:
+			return
+		case <-ticker.C:
+			dst, err := rutil.Zero(src)
+			if err == nil {
+				err = fillValues(w.opts.Context, reflect.ValueOf(dst), w.opts.StructTag)
+			}
+			if err != nil {
+				w.echan <- err
+				return
+			}
+			srcmp, err := rutil.StructFieldsMap(src)
+			if err != nil {
+				w.echan <- err
+				return
+			}
+			dstmp, err := rutil.StructFieldsMap(dst)
+			if err != nil {
+				w.echan <- err
+				return
+			}
+			for sk, sv := range srcmp {
+				if reflect.DeepEqual(dstmp[sk], sv) {
+					delete(dstmp, sk)
+				}
+			}
+			if len(dstmp) > 0 {
+				w.vchan <- dstmp
+				src = dst
+			}
+		}
+	}
+}
+
+func (w *envWatcher) Next() (map[string]interface{}, error) {
+	select {
+	case <-w.done:
+		break
+	case err := <-w.echan:
+		return nil, err
+	case v, ok := <-w.vchan:
+		if !ok {
+			break
+		}
+		return v, nil
+	}
+	return nil, config.ErrWatcherStopped
+}
+
+func (w *envWatcher) Stop() error {
+	close(w.done)
+	return nil
+}