From ca9f6fb5ebdf0e2eefd79c6cbf9aa0046ccbc81c Mon Sep 17 00:00:00 2001 From: Vasiliy Tolstov Date: Tue, 3 Aug 2021 00:23:28 +0300 Subject: [PATCH] config: add watcher interface Signed-off-by: Vasiliy Tolstov --- config/config.go | 12 +++-- config/default.go | 115 ++++++++++++++++++++++++++++++++++++----- config/default_test.go | 56 +++++++++++++++++++- config/options.go | 71 +++++++++++++++++++++++++ 4 files changed, 236 insertions(+), 18 deletions(-) diff --git a/config/config.go b/config/config.go index 6cd4457a..d2a0262d 100644 --- a/config/config.go +++ b/config/config.go @@ -4,11 +4,15 @@ package config import ( "context" "errors" + "time" ) // DefaultConfig default config var DefaultConfig Config = NewConfig() +// DefaultWatcherInterval default interval for poll changes +var DefaultWatcherInterval = 5 * time.Second + var ( // ErrCodecMissing is returned when codec needed and not specified ErrCodecMissing = errors.New("codec missing") @@ -30,15 +34,17 @@ type Config interface { Load(context.Context, ...LoadOption) error // Save config to sources Save(context.Context, ...SaveOption) error - // Watch a value for changes - //Watch(context.Context) (Watcher, error) + // Watch a config for changes + Watch(context.Context, ...WatchOption) (Watcher, error) // String returns config type name String() string } // Watcher is the config watcher type Watcher interface { - // Next() (, error) + // Next blocks until update happens or error returned + Next() (map[string]interface{}, error) + // Stop stops watcher Stop() error } diff --git a/config/default.go b/config/default.go index 58b2098a..610abb5b 100644 --- a/config/default.go +++ b/config/default.go @@ -5,6 +5,7 @@ import ( "reflect" "strconv" "strings" + "time" "github.com/imdario/mergo" rutil "github.com/unistack-org/micro/v3/util/reflect" @@ -41,11 +42,15 @@ func (c *defaultConfig) Load(ctx context.Context, opts ...LoadOption) error { mopts = append(mopts, mergo.WithAppendSlice) } - src, err := rutil.Zero(c.opts.Struct) + dst := c.opts.Struct + if options.Struct != nil { + dst = options.Struct + } + + src, err := rutil.Zero(dst) if err == nil { - valueOf := reflect.ValueOf(src) - if err = c.fillValues(valueOf); err == nil { - err = mergo.Merge(c.opts.Struct, src, mopts...) + if err = fillValues(reflect.ValueOf(src), c.opts.StructTag); err == nil { + err = mergo.Merge(dst, src, mopts...) } } @@ -63,7 +68,7 @@ func (c *defaultConfig) Load(ctx context.Context, opts ...LoadOption) error { } //nolint:gocyclo -func (c *defaultConfig) fillValue(value reflect.Value, val string) error { +func fillValue(value reflect.Value, val string) error { if !rutil.IsEmpty(value) { return nil } @@ -80,10 +85,10 @@ func (c *defaultConfig) fillValue(value reflect.Value, val string) error { 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(mkey, kv[0]); err != nil { + if err := fillValue(mkey, kv[0]); err != nil { return err } - if err := c.fillValue(mval, kv[1]); err != nil { + if err := fillValue(mval, kv[1]); err != nil { return err } value.SetMapIndex(mkey, mval) @@ -93,7 +98,7 @@ func (c *defaultConfig) fillValue(value reflect.Value, val string) error { 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(nvalue, nval); err != nil { + if err := fillValue(nvalue, nval); err != nil { return err } value.Index(idx).Set(nvalue) @@ -182,7 +187,7 @@ func (c *defaultConfig) fillValue(value reflect.Value, val string) error { return nil } -func (c *defaultConfig) fillValues(valueOf reflect.Value) error { +func fillValues(valueOf reflect.Value, tname string) error { var values reflect.Value if valueOf.Kind() == reflect.Ptr { @@ -209,7 +214,7 @@ func (c *defaultConfig) fillValues(valueOf reflect.Value) error { switch value.Kind() { case reflect.Struct: value.Set(reflect.Indirect(reflect.New(value.Type()))) - if err := c.fillValues(value); err != nil { + if err := fillValues(value, tname); err != nil { return err } continue @@ -223,17 +228,17 @@ func (c *defaultConfig) fillValues(valueOf reflect.Value) error { value.Set(reflect.New(value.Type().Elem())) } value = value.Elem() - if err := c.fillValues(value); err != nil { + if err := fillValues(value, tname); err != nil { return err } continue } - tag, ok := field.Tag.Lookup(c.opts.StructTag) + tag, ok := field.Tag.Lookup(tname) if !ok { continue } - if err := c.fillValue(value, tag); err != nil { + if err := fillValue(value, tag); err != nil { return err } } @@ -265,6 +270,20 @@ func (c *defaultConfig) Name() string { return c.opts.Name } +func (c *defaultConfig) Watch(ctx context.Context, opts ...WatchOption) (Watcher, error) { + w := &defaultWatcher{ + opts: c.opts, + wopts: NewWatchOptions(opts...), + done: make(chan bool), + vchan: make(chan map[string]interface{}), + echan: make(chan error), + } + + go w.run() + + return w, nil +} + // NewConfig returns new default config source func NewConfig(opts ...Option) Config { options := NewOptions(opts...) @@ -273,3 +292,73 @@ func NewConfig(opts ...Option) Config { } return &defaultConfig{opts: options} } + +type defaultWatcher struct { + opts Options + wopts WatchOptions + done chan bool + ticker *time.Ticker + vchan chan map[string]interface{} + echan chan error +} + +func (w *defaultWatcher) run() { + ticker := time.NewTicker(w.wopts.Interval) + 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(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) + } + } + w.vchan <- dstmp + src = dst + } + } +} + +func (w *defaultWatcher) Next() (map[string]interface{}, error) { + select { + case <-w.done: + break + case v, ok := <-w.vchan: + if !ok { + break + } + return v, nil + } + return nil, ErrWatcherStopped +} + +func (w *defaultWatcher) Stop() error { + close(w.done) + return nil +} diff --git a/config/default_test.go b/config/default_test.go index b5b89376..66e3b193 100644 --- a/config/default_test.go +++ b/config/default_test.go @@ -4,6 +4,7 @@ import ( "context" "fmt" "testing" + "time" "github.com/unistack-org/micro/v3/config" ) @@ -17,6 +18,57 @@ type Cfg struct { IntValue int `default:"99"` } +func TestWatch(t *testing.T) { + ctx := context.Background() + + conf := &Cfg{IntValue: 10} + + cfg := config.NewConfig(config.Struct(conf)) + if err := cfg.Init(); err != nil { + t.Fatal(err) + } + if err := cfg.Load(ctx); err != nil { + t.Fatal(err) + } + + w, err := cfg.Watch(ctx, config.WatchInterval(500*time.Millisecond)) + if err != nil { + t.Fatal(err) + } + + defer func() { + _ = w.Stop() + }() + + done := make(chan struct{}) + + go func() { + for { + mp, err := w.Next() + if err != nil && err != config.ErrWatcherStopped { + t.Fatal(err) + } else if err == config.ErrWatcherStopped { + return + } + if len(mp) != 1 { + t.Fatal(fmt.Errorf("default watcher err: %v", mp)) + } + + v, ok := mp["IntValue"] + if !ok { + t.Fatal(fmt.Errorf("default watcher err: %v", v)) + } + if nv, ok := v.(int); !ok || nv != 99 { + t.Fatal(fmt.Errorf("default watcher err: %v", v)) + } + close(done) + return + } + }() + + <-done +} + func TestDefault(t *testing.T) { ctx := context.Background() conf := &Cfg{IntValue: 10} @@ -47,6 +99,6 @@ func TestDefault(t *testing.T) { if conf.StringValue != "after_load" { t.Fatal("AfterLoad option not working") } - - t.Logf("%#+v\n", conf) + _ = conf + //t.Logf("%#+v\n", conf) } diff --git a/config/options.go b/config/options.go index d16e81e2..a417f571 100644 --- a/config/options.go +++ b/config/options.go @@ -2,6 +2,7 @@ package config import ( "context" + "time" "github.com/unistack-org/micro/v3/codec" "github.com/unistack-org/micro/v3/logger" @@ -62,6 +63,7 @@ type LoadOption func(o *LoadOptions) // LoadOptions struct type LoadOptions struct { + Struct interface{} Override bool Append bool } @@ -88,13 +90,29 @@ func LoadAppend(b bool) LoadOption { } } +// LoadStruct override struct for loading +func LoadStruct(src interface{}) LoadOption { + return func(o *LoadOptions) { + o.Struct = src + } +} + // SaveOption function signature type SaveOption func(o *SaveOptions) // SaveOptions struct type SaveOptions struct { + Struct interface{} } +// SaveStruct override struct for save to config +func SaveStruct(src interface{}) SaveOption { + return func(o *SaveOptions) { + o.Struct = src + } +} + +// NewSaveOptions fill SaveOptions struct func NewSaveOptions(opts ...SaveOption) SaveOptions { options := SaveOptions{} for _, o := range opts { @@ -186,3 +204,56 @@ func Name(n string) Option { o.Name = n } } + +// WatchOptions struuct +type WatchOptions struct { + // Context used by non default options + Context context.Context + // Coalesce multiple events to one + Coalesce bool + // Interval to periodically pull changes if config source not supports async notify + Interval time.Duration + // Struct for filling + Struct interface{} +} + +type WatchOption func(*WatchOptions) + +func NewWatchOptions(opts ...WatchOption) WatchOptions { + options := WatchOptions{ + Context: context.Background(), + Interval: DefaultWatcherInterval, + } + for _, o := range opts { + o(&options) + } + return options +} + +// WatchContext pass context +func WatchContext(ctx context.Context) WatchOption { + return func(o *WatchOptions) { + o.Context = ctx + } +} + +// WatchCoalesce controls watch event combining +func WatchCoalesce(b bool) WatchOption { + return func(o *WatchOptions) { + o.Coalesce = b + } +} + +// WatchInterval specifies time.Duration for pulling changes +func WatchInterval(td time.Duration) WatchOption { + return func(o *WatchOptions) { + o.Interval = td + } +} + +// WatchStruct overrides struct for fill +func WatchStruct(src interface{}) WatchOption { + return func(o *WatchOptions) { + o.Struct = src + } +}