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 a config for changes
-	//Watch(context.Context) (Watcher, error)
+	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
 }
 

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 = fillValues(reflect.ValueOf(src), c.opts.StructTag); err == nil {
-		if err = c.fillValues(valueOf); err == nil {
+			err = mergo.Merge(dst, src, mopts...)
-			err = mergo.Merge(c.opts.Struct, 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
+}

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")
 	}
-
+	_ = conf
-	t.Logf("%#+v\n", conf)
+	//t.Logf("%#+v\n", conf)
 }

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
+	}
+}

util/router/compile.go

@@ -8,18 +8,18 @@ const (
 
 // Template is a compiled representation of path templates.
 type Template struct {
-	// Verb is a VERB part in the template
+	// Version is the version number of the format.
-	Verb string
+	Version int
-	// Original template (example: /v1/a_bit_of_everything)
+	// OpCodes is a sequence of operations.
-	Template string
-	// OpCodes is a sequence of operations
 	OpCodes []int
 	// Pool is a constant pool
 	Pool []string
-	// Fields is a list of field paths bound in this template
+	// Verb is a VERB part in the template.
+	Verb string
+	// Fields is a list of field paths bound in this template.
 	Fields []string
-	// Version is the version number of the format
+	// Original template (example: /v1/a_bit_of_everything)
-	Version int
+	Template string
 }
 
 // Compiler compiles utilities representation of path templates into marshallable operations.
@@ -29,9 +29,15 @@ type Compiler interface {
 }
 
 type op struct {
-	str     string
+	// code is the opcode of the operation
 	code OpCode
-	operand int
+
+	// str is a string operand of the code.
+	// num is ignored if str is not empty.
+	str string
+
+	// num is a numeric operand of the code.
+	num int
 }
 
 func (w wildcard) compile() []op {
@@ -62,7 +68,7 @@ func (v variable) compile() []op {
 	}
 	ops = append(ops, op{
 		code: OpConcatN,
-		operand: len(v.segments),
+		num:  len(v.segments),
 	}, op{
 		code: OpCapture,
 		str:  v.path,
@@ -77,7 +83,6 @@ func (t template) Compile() Template {
 		rawOps = append(rawOps, s.compile()...)
 	}
 
-	// ops := make([]int, 0, len(rawOps))
 	var (
 		ops    []int
 		pool   []string
@@ -87,8 +92,12 @@ func (t template) Compile() Template {
 	for _, op := range rawOps {
 		ops = append(ops, int(op.code))
 		if op.str == "" {
-			ops = append(ops, op.operand)
+			ops = append(ops, op.num)
 		} else {
+			// eof segment literal represents the "/" path pattern
+			if op.str == eof {
+				op.str = ""
+			}
 			if _, ok := consts[op.str]; !ok {
 				consts[op.str] = len(pool)
 				pool = append(pool, op.str)

util/router/compile_test.go

@@ -21,6 +21,13 @@ func TestCompile(t *testing.T) {
 		fields []string
 	}{
 		{},
+		{
+			segs: []segment{
+				literal(eof),
+			},
+			ops:  []int{int(OpLitPush), 0},
+			pool: []string{""},
+		},
 		{
 			segs: []segment{
 				wildcard{},

util/router/parse.go

@@ -3,11 +3,8 @@ package router
 // download from https://raw.githubusercontent.com/grpc-ecosystem/grpc-gateway/master/protoc-gen-grpc-gateway/httprule/parse.go
 
 import (
-	"context"
 	"fmt"
 	"strings"
-
-	"github.com/unistack-org/micro/v3/logger"
 )
 
 // InvalidTemplateError indicates that the path template is not valid.
@@ -83,8 +80,30 @@ func tokenize(path string) (tokens []string, verb string) {
 	}
 
 	l := len(tokens)
+	// See
+	// https://github.com/grpc-ecosystem/grpc-gateway/pull/1947#issuecomment-774523693 ;
+	// although normal and backwards-compat logic here is to use the last index
+	// of a colon, if the final segment is a variable followed by a colon, the
+	// part following the colon must be a verb. Hence if the previous token is
+	// an end var marker, we switch the index we're looking for to Index instead
+	// of LastIndex, so that we correctly grab the remaining part of the path as
+	// the verb.
+	var penultimateTokenIsEndVar bool
+	switch l {
+	case 0, 1:
+		// Not enough to be variable so skip this logic and don't result in an
+		// invalid index
+	default:
+		penultimateTokenIsEndVar = tokens[l-2] == "}"
+	}
 	t := tokens[l-1]
-	if idx := strings.LastIndex(t, ":"); idx == 0 {
+	var idx int
+	if penultimateTokenIsEndVar {
+		idx = strings.Index(t, ":")
+	} else {
+		idx = strings.LastIndex(t, ":")
+	}
+	if idx == 0 {
 		tokens, verb = tokens[:l-1], t[1:]
 	} else if idx > 0 {
 		tokens[l-1], verb = t[:idx], t[idx+1:]
@@ -101,22 +120,17 @@ type parser struct {
 
 // topLevelSegments is the target of this parser.
 func (p *parser) topLevelSegments() ([]segment, error) {
-	if logger.V(logger.TraceLevel) {
+	if _, err := p.accept(typeEOF); err == nil {
-		logger.Trace(context.TODO(), "Parsing %q", p.tokens)
+		p.tokens = p.tokens[:0]
+		return []segment{literal(eof)}, nil
 	}
 	segs, err := p.segments()
 	if err != nil {
 		return nil, err
 	}
-	if logger.V(logger.TraceLevel) {
-		logger.Trace(context.TODO(), "accept segments: %q; %q", p.accepted, p.tokens)
-	}
 	if _, err := p.accept(typeEOF); err != nil {
 		return nil, fmt.Errorf("unexpected token %q after segments %q", p.tokens[0], strings.Join(p.accepted, ""))
 	}
-	if logger.V(logger.TraceLevel) {
-		logger.Trace(context.TODO(), "accept eof: %q; %q", p.accepted, p.tokens)
-	}
 	return segs, nil
 }
 
@@ -126,9 +140,6 @@ func (p *parser) segments() ([]segment, error) {
 		return nil, err
 	}
 
-	if logger.V(logger.TraceLevel) {
-		logger.Trace(context.TODO(), "accept segment: %q; %q", p.accepted, p.tokens)
-	}
 	segs := []segment{s}
 	for {
 		if _, err := p.accept("/"); err != nil {
@@ -139,9 +150,6 @@ func (p *parser) segments() ([]segment, error) {
 			return segs, err
 		}
 		segs = append(segs, s)
-		if logger.V(logger.TraceLevel) {
-			logger.Trace(context.TODO(), "accept segment: %q; %q", p.accepted, p.tokens)
-		}
 	}
 }
 

util/router/parse_test.go

@@ -4,7 +4,6 @@ package router
 
 import (
 	"context"
-	"flag"
 	"fmt"
 	"reflect"
 	"testing"
@@ -16,6 +15,7 @@ func TestTokenize(t *testing.T) {
 	for _, spec := range []struct {
 		src    string
 		tokens []string
+		verb   string
 	}{
 		{
 			src:    "",
@@ -84,11 +84,39 @@ func TestTokenize(t *testing.T) {
 				eof,
 			},
 		},
+		{
+			src: "v1/a/{endpoint}:a",
+			tokens: []string{
+				"v1", "/",
+				"a", "/",
+				"{", "endpoint", "}",
+				eof,
+			},
+			verb: "a",
+		},
+		{
+			src: "v1/a/{endpoint}:b:c",
+			tokens: []string{
+				"v1", "/",
+				"a", "/",
+				"{", "endpoint", "}",
+				eof,
+			},
+			verb: "b:c",
+		},
 	} {
 		tokens, verb := tokenize(spec.src)
 		if got, want := tokens, spec.tokens; !reflect.DeepEqual(got, want) {
 			t.Errorf("tokenize(%q) = %q, _; want %q, _", spec.src, got, want)
 		}
+
+		switch {
+		case spec.verb != "":
+			if got, want := verb, spec.verb; !reflect.DeepEqual(got, want) {
+				t.Errorf("tokenize(%q) = %q, _; want %q, _", spec.src, got, want)
+			}
+
+		default:
 			if got, want := verb, ""; got != want {
 				t.Errorf("tokenize(%q) = _, %q; want _, %q", spec.src, got, want)
 			}
@@ -103,13 +131,27 @@ func TestTokenize(t *testing.T) {
 			}
 		}
 	}
+}
 
 func TestParseSegments(t *testing.T) {
-	flag.Set("v", "3")
 	for _, spec := range []struct {
 		tokens []string
 		want   []segment
 	}{
+		{
+			tokens: []string{eof},
+			want: []segment{
+				literal(eof),
+			},
+		},
+		{
+			// Note: this case will never arise as tokenize() will never return such a sequence of tokens
+			// and even if it does it will be treated as [eof]
+			tokens: []string{eof, "v1", eof},
+			want: []segment{
+				literal(eof),
+			},
+		},
 		{
 			tokens: []string{"v1", eof},
 			want: []segment{
@@ -251,7 +293,6 @@ func TestParseSegments(t *testing.T) {
 }
 
 func TestParseSegmentsWithErrors(t *testing.T) {
-	flag.Set("v", "3")
 	for _, spec := range []struct {
 		tokens []string
 	}{
@@ -275,10 +316,6 @@ func TestParseSegmentsWithErrors(t *testing.T) {
 			// invalid percent-encoding
 			tokens: []string{"a%2z", eof},
 		},
-		{
-			// empty segments
-			tokens: []string{eof},
-		},
 		{
 			// unterminated variable
 			tokens: []string{"{", "name", eof},

util/router/runtime.go

@@ -23,9 +23,9 @@ type rop struct {
 	operand int
 }
 
-// Pattern is a template pattern of http request paths defined in github.com/googleapis/googleapis/google/api/http.proto.
+// Pattern is a template pattern of http request paths defined in
+// https://github.com/googleapis/googleapis/blob/master/google/api/http.proto
 type Pattern struct {
-	verb string
 	// ops is a list of operations
 	ops []rop
 	// pool is a constant pool indexed by the operands or vars
@@ -36,32 +36,16 @@ type Pattern struct {
 	stacksize int
 	// tailLen is the length of the fixed-size segments after a deep wildcard
 	tailLen int
-	// assumeColonVerb indicates whether a path suffix after a final
+	// verb is the VERB part of the path pattern. It is empty if the pattern does not have VERB part.
-	// colon may only be interpreted as a verb.
+	verb string
-	assumeColonVerb bool
 }
 
-type patternOptions struct {
-	assumeColonVerb bool
-}
-
-// PatternOpt is an option for creating Patterns.
-type PatternOpt func(*patternOptions)
-
 // NewPattern returns a new Pattern from the given definition values.
 // "ops" is a sequence of op codes. "pool" is a constant pool.
 // "verb" is the verb part of the pattern. It is empty if the pattern does not have the part.
 // "version" must be 1 for now.
 // It returns an error if the given definition is invalid.
-//nolint:gocyclo
+func NewPattern(version int, ops []int, pool []string, verb string) (Pattern, error) {
-func NewPattern(version int, ops []int, pool []string, verb string, opts ...PatternOpt) (Pattern, error) {
-	options := patternOptions{
-		assumeColonVerb: true,
-	}
-	for _, o := range opts {
-		o(&options)
-	}
-
 	if version != 1 {
 		if logger.V(logger.TraceLevel) {
 			logger.Trace(context.TODO(), "unsupported version: %d", version)
@@ -165,7 +149,6 @@ func NewPattern(version int, ops []int, pool []string, verb string, opts ...Patt
 		stacksize: maxstack,
 		tailLen:   tailLen,
 		verb:      verb,
-		assumeColonVerb: options.assumeColonVerb,
 	}, nil
 }
 
@@ -185,7 +168,7 @@ func MustPattern(p Pattern, err error) Pattern {
 //nolint:gocyclo
 func (p Pattern) Match(components []string, verb string) (map[string]string, error) {
 	if p.verb != verb {
-		if p.assumeColonVerb || p.verb != "" {
+		if p.verb != "" {
 			return nil, ErrNotMatch
 		}
 		if len(components) == 0 {
@@ -274,11 +257,3 @@ func (p Pattern) String() string {
 	}
 	return "/" + segs
 }
-
-// AssumeColonVerbOpt indicates whether a path suffix after a final
-// colon may only be interpreted as a verb.
-func AssumeColonVerbOpt(val bool) PatternOpt {
-	return PatternOpt(func(o *patternOptions) {
-		o.assumeColonVerb = val
-	})
-}

util/router/types.go

@@ -8,9 +8,9 @@ import (
 )
 
 type template struct {
+	segments []segment
 	verb     string
 	template string
-	segments []segment
 }
 
 type segment interface {