Initial commit

.gitignore

@@ -0,0 +1,2 @@
+cover.out
+cover.html

.golangci.yaml

@@ -0,0 +1,38 @@
+linters:
+  enable-all: true
+  disable:
+    # re-enable when working
+    - rowserrcheck
+    - wastedassign
+    # maybe enable these
+    - wrapcheck
+    # leave these disabled
+    - cyclop
+    - deadcode
+    - dupl
+    - exhaustivestruct
+    - exhaustruct
+    - forbidigo
+    - forcetypeassert
+    - funlen
+    - gochecknoglobals
+    - gocognit
+    - goconst
+    - godox
+    - golint
+    - gomnd
+    - ifshort
+    - interfacer
+    - lll
+    - maintidx
+    - maligned
+    - nilnil
+    - nestif
+    - nlreturn
+    - nolintlint
+    - nosnakecase
+    - scopelint
+    - structcheck
+    - thelper
+    - varcheck
+    - varnamelen

bus.go

@@ -0,0 +1,136 @@
+package bus
+
+import (
+	"fmt"
+	"reflect"
+	"sync"
+
+	"github.com/gopatchy/metadata"
+)
+
+type Bus struct {
+	mu        sync.Mutex
+	keyViews  map[string]map[uintptr]chan<- any
+	typeViews map[string]map[uintptr]chan<- any
+}
+
+func NewBus() *Bus {
+	return &Bus{
+		keyViews:  map[string]map[uintptr]chan<- any{},
+		typeViews: map[string]map[uintptr]chan<- any{},
+	}
+}
+
+func (b *Bus) Announce(t string, obj any) {
+	key := getObjKey(t, obj)
+
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	announce(obj, b.keyViews[key])
+	announce(obj, b.typeViews[t])
+}
+
+func (b *Bus) Delete(t string, id string) {
+	key := getKey(t, id)
+
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	for _, c := range b.keyViews[key] {
+		close(c)
+	}
+
+	delete(b.keyViews, key)
+
+	announce(id, b.typeViews[t])
+}
+
+func (b *Bus) SubscribeKey(t, id string, initial any) <-chan any {
+	key := getKey(t, id)
+
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	ret := make(chan any, 100)
+
+	ret <- initial
+
+	if _, has := b.keyViews[key]; !has {
+		b.keyViews[key] = map[uintptr]chan<- any{}
+	}
+
+	b.keyViews[key][chanID(ret)] = ret
+
+	return ret
+}
+
+func (b *Bus) SubscribeType(t string, initial any) <-chan any {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	ret := make(chan any, 100)
+
+	ret <- initial
+
+	if _, has := b.typeViews[t]; !has {
+		b.typeViews[t] = map[uintptr]chan<- any{}
+	}
+
+	b.typeViews[t][chanID(ret)] = ret
+
+	return ret
+}
+
+func (b *Bus) UnsubscribeKey(t, id string, c <-chan any) {
+	key := getKey(t, id)
+
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if cw, has := b.keyViews[key][chanID(c)]; has {
+		close(cw)
+		delete(b.keyViews[key], chanID(c))
+	}
+
+	if len(b.keyViews[key]) == 0 {
+		delete(b.keyViews, key)
+	}
+}
+
+func (b *Bus) UnsubscribeType(t string, c <-chan any) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if cw, has := b.typeViews[t][chanID(c)]; has {
+		close(cw)
+		delete(b.typeViews[t], chanID(c))
+	}
+
+	if len(b.typeViews[t]) == 0 {
+		delete(b.typeViews, t)
+	}
+}
+
+func getObjKey(t string, obj any) string {
+	return getKey(t, metadata.GetMetadata(obj).ID)
+}
+
+func getKey(t string, id string) string {
+	return fmt.Sprintf("%s:%s", t, id)
+}
+
+func announce(obj any, chans map[uintptr]chan<- any) {
+	for id, c := range chans {
+		select {
+		case c <- obj:
+		default:
+			close(c)
+			delete(chans, id)
+		}
+	}
+}
+
+func chanID(c <-chan any) uintptr {
+	return reflect.ValueOf(c).Pointer()
+}

bus_test.go

@@ -0,0 +1,149 @@
+package bus_test
+
+import (
+	"testing"
+
+	"github.com/gopatchy/bus"
+	"github.com/gopatchy/metadata"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBus(t *testing.T) {
+	t.Parallel()
+
+	bus := bus.NewBus()
+
+	// Announce with no subscribers
+	bus.Announce("busTest1", &busTest{
+		Metadata: metadata.Metadata{
+			ID: "id-nosub",
+		},
+	})
+
+	// Complex subscription layout
+	c1a := bus.SubscribeKey("busTest1", "id-overlap", nil)
+	require.Nil(t, <-c1a)
+
+	defer bus.UnsubscribeKey("busTest1", "id-overlap", c1a)
+
+	c2a := bus.SubscribeKey("busTest2", "id-overlap", nil)
+	require.Nil(t, <-c2a)
+
+	defer bus.UnsubscribeKey("busTest2", "id-overlap", c2a)
+
+	c2b := bus.SubscribeKey("busTest2", "id-dupe", nil)
+	require.Nil(t, <-c2b)
+
+	defer bus.UnsubscribeKey("busTest2", "id-dupe", c2b)
+
+	c2c := bus.SubscribeKey("busTest2", "id-dupe", nil)
+	require.Nil(t, <-c2c)
+
+	defer bus.UnsubscribeKey("busTest2", "id-dupe", c2c)
+
+	ct1 := bus.SubscribeType("busTest1", nil)
+	require.Nil(t, <-ct1)
+
+	defer bus.UnsubscribeType("busTest1", ct1)
+
+	ct2 := bus.SubscribeType("busTest2", nil)
+	require.Nil(t, <-ct2)
+
+	defer bus.UnsubscribeType("busTest2", ct2)
+
+	// Overlapping IDs but not types
+	bus.Announce("busTest1", &busTest{
+		Metadata: metadata.Metadata{
+			ID: "id-overlap",
+		},
+	})
+
+	msg := <-c1a
+	require.Equal(t, "id-overlap", msg.(*busTest).ID)
+
+	msg = <-ct1
+	require.Equal(t, "id-overlap", msg.(*busTest).ID)
+
+	select {
+	case msg := <-c2a:
+		require.Fail(t, "unexpected message", msg)
+	case msg := <-ct2:
+		require.Fail(t, "unexpected message", msg)
+	default:
+	}
+
+	bus.Announce("busTest2", &busTest{
+		Metadata: metadata.Metadata{
+			ID: "id-overlap",
+		},
+	})
+
+	select {
+	case msg := <-c1a:
+		require.Fail(t, "unexpected message", msg)
+	case msg := <-ct1:
+		require.Fail(t, "unexpected message", msg)
+	default:
+	}
+
+	msg = <-c2a
+	require.Equal(t, "id-overlap", msg.(*busTest).ID)
+
+	msg = <-ct2
+	require.Equal(t, "id-overlap", msg.(*busTest).ID)
+
+	bus.Announce("busTest2", &busTest{
+		Metadata: metadata.Metadata{
+			ID: "id-dupe",
+		},
+	})
+
+	msg = <-c2b
+	require.Equal(t, "id-dupe", msg.(*busTest).ID)
+
+	msg = <-c2c
+	require.Equal(t, "id-dupe", msg.(*busTest).ID)
+
+	msg = <-ct2
+	require.Equal(t, "id-dupe", msg.(*busTest).ID)
+}
+
+func TestBusDelete(t *testing.T) {
+	t.Parallel()
+
+	bus := bus.NewBus()
+
+	c := bus.SubscribeKey("busTest", "id1", nil)
+	require.Nil(t, <-c)
+
+	defer bus.UnsubscribeKey("busTest", "id1", c)
+
+	ct := bus.SubscribeType("busTest", nil)
+	require.Nil(t, <-ct)
+
+	defer bus.UnsubscribeType("busTest", ct)
+
+	bus.Announce("busTest", &busTest{
+		Metadata: metadata.Metadata{
+			ID: "id1",
+		},
+	})
+
+	msg := <-c
+	require.Equal(t, "id1", msg.(*busTest).ID)
+
+	msg = <-ct
+	require.Equal(t, "id1", msg.(*busTest).ID)
+
+	bus.Delete("busTest", "id1")
+
+	_, ok := <-c
+	require.False(t, ok)
+
+	id := (<-ct).(string)
+	require.Equal(t, "id1", id)
+}
+
+type busTest struct {
+	metadata.Metadata
+}

go.mod

@@ -0,0 +1,16 @@
+module github.com/gopatchy/bus
+
+go 1.19
+
+require (
+	github.com/gopatchy/metadata v0.0.0-20230420053349-25837551c11d
+	github.com/stretchr/testify v1.8.2
+	go.uber.org/goleak v1.2.1
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,26 @@
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/gopatchy/metadata v0.0.0-20230420053349-25837551c11d h1:chunoM47vkWSanIvLx4uRSkLMG6chDZOy09L2tt/bv8=
+github.com/gopatchy/metadata v0.0.0-20230420053349-25837551c11d/go.mod h1:VgD33raUShjDePCDBo55aj+eSXFtUEpMzs+Ie39g2zo=
+github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rogpeppe/go-internal v1.8.1-0.20211023094830-115ce09fd6b4 h1:Ha8xCaq6ln1a+R91Km45Oq6lPXj2Mla6CRJYcuV2h1w=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
+github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+go.uber.org/goleak v1.2.1 h1:NBol2c7O1ZokfZ0LEU9K6Whx/KnwvepVetCUhtKja4A=
+go.uber.org/goleak v1.2.1/go.mod h1:qlT2yGI9QafXHhZZLxlSuNsMw3FFLxBr+tBRlmO1xH4=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

justfile

@@ -0,0 +1,18 @@
+go := env_var_or_default('GOCMD', 'go')
+
+default: tidy test
+
+tidy:
+	{{go}} mod tidy
+	goimports -l -w .
+	gofumpt -l -w .
+	{{go}} fmt ./...
+
+test:
+	{{go}} vet ./...
+	golangci-lint run ./...
+	{{go}} test -race -coverprofile=cover.out -timeout=60s -parallel=10 ./...
+	{{go}} tool cover -html=cover.out -o=cover.html
+
+todo:
+	-git grep -e TODO --and --not -e ignoretodo

pkg_test.go

@@ -0,0 +1,11 @@
+package bus_test
+
+import (
+	"testing"
+
+	"go.uber.org/goleak"
+)
+
+func TestMain(m *testing.M) {
+	goleak.VerifyTestMain(m)
+}