feat: add graphql

pkg/es/driver/disk-store/disk-store.go

@@ -53,11 +53,9 @@ func (es *diskStore) Save(ctx context.Context, agg event.Aggregate) (uint64, err
 	}
 
 	var last uint64
-
-	if last, err = l.w.LastIndex(); err != nil {
+	if last, err = l.LastIndex(); err != nil {
 		return 0, err
 	}
-
 	if agg.StreamVersion() != last {
 		return 0, fmt.Errorf("current version wrong %d != %d", agg.StreamVersion(), last)
 	}
@@ -75,7 +73,7 @@ func (es *diskStore) Save(ctx context.Context, agg event.Aggregate) (uint64, err
 		batch.Write(e.EventMeta().Position, b)
 	}
 
-	err = l.w.WriteBatch(batch)
+	err = l.WriteBatch(batch)
 	if err != nil {
 		return 0, err
 	}
@@ -92,8 +90,7 @@ func (es *diskStore) Append(ctx context.Context, streamID string, events event.E
 	}
 
 	var last uint64
-
-	if last, err = l.w.LastIndex(); err != nil {
+	if last, err = l.LastIndex(); err != nil {
 		return 0, err
 	}
 
@@ -111,7 +108,7 @@ func (es *diskStore) Append(ctx context.Context, streamID string, events event.E
 		batch.Write(pos, b)
 	}
 
-	err = l.w.WriteBatch(batch)
+	err = l.WriteBatch(batch)
 	if err != nil {
 		return 0, err
 	}
@@ -125,22 +122,20 @@ func (es *diskStore) Load(ctx context.Context, agg event.Aggregate) error {
 
 	var i, first, last uint64
 
-	if first, err = l.w.FirstIndex(); err != nil {
+	if first, err = l.FirstIndex(); err != nil {
 		return err
 	}
-	if last, err = l.w.LastIndex(); err != nil {
+	if last, err = l.LastIndex(); err != nil {
 		return err
 	}
-
 	if first == 0 || last == 0 {
 		return nil
 	}
 
 	var b []byte
 	events := make([]event.Event, last-i)
-
 	for i = 0; first+i <= last; i++ {
-		b, err = l.w.Read(first + i)
+		b, err = l.Read(first + i)
 		if err != nil {
 			return err
 		}
@@ -149,7 +144,6 @@ func (es *diskStore) Load(ctx context.Context, agg event.Aggregate) error {
 			return err
 		}
 	}
-
 	event.Append(agg, events...)
 
 	return nil
@@ -161,14 +155,12 @@ func (es *diskStore) Read(ctx context.Context, streamID string, pos, count int64
 	}
 
 	var first, last, start uint64
-
-	if first, err = l.w.FirstIndex(); err != nil {
+	if first, err = l.FirstIndex(); err != nil {
 		return nil, err
 	}
-	if last, err = l.w.LastIndex(); err != nil {
+	if last, err = l.LastIndex(); err != nil {
 		return nil, err
 	}
-
 	if first == 0 || last == 0 {
 		return nil, nil
 	}
@@ -190,7 +182,7 @@ func (es *diskStore) Read(ctx context.Context, streamID string, pos, count int64
 	for i := range events {
 		var b []byte
 
-		b, err = l.w.Read(start)
+		b, err = l.Read(start)
 		if err != nil {
 			return events, err
 		}
@@ -209,25 +201,25 @@ func (es *diskStore) Read(ctx context.Context, streamID string, pos, count int64
 			break
 		}
 	}
-
 	event.SetStreamID(streamID, events...)
 
 	return events, nil
 }
-
-func (es *diskStore) readLog(name string) (*eventLog, error) {
-	return newEventLog(name, filepath.Join(es.path, name))
+func (es *diskStore) FirstIndex(ctx context.Context, streamID string) (uint64, error) {
+	l, err := es.readLog(streamID)
+	if err != nil {
+		return 0, err
+	}
+	return l.FirstIndex()
+}
+func (es *diskStore) LastIndex(ctx context.Context, streamID string) (uint64, error) {
+	l, err := es.readLog(streamID)
+	if err != nil {
+		return 0, err
+	}
+	return l.LastIndex()
 }
 
-type eventLog struct {
-	name string
-	path string
-	w    *wal.Log
-}
-
-func newEventLog(name, path string) (*eventLog, error) {
-	var err error
-	el := &eventLog{name: name, path: path}
-	el.w, err = wal.Open(path, wal.DefaultOptions)
-	return el, err
+func (es *diskStore) readLog(name string) (*wal.Log, error) {
+	return wal.Open(filepath.Join(es.path, name), wal.DefaultOptions)
 }

pkg/es/driver/driver.go

@@ -15,4 +15,6 @@ type EventStore interface {
 	Load(ctx context.Context, agg event.Aggregate) error
 	Read(ctx context.Context, streamID string, pos, count int64) (event.Events, error)
 	Append(ctx context.Context, streamID string, events event.Events) (uint64, error)
+	FirstIndex(ctx context.Context, streamID string) (uint64, error)
+	LastIndex(ctx context.Context, streamID string) (uint64, error)
 }

pkg/es/driver/mem-store/mem-store.go

@@ -140,3 +140,19 @@ func (m *memstore) Save(ctx context.Context, agg event.Aggregate) (uint64, error
 
 	return uint64(len(events)), nil
 }
+
+func (m *memstore) FirstIndex(ctx context.Context, streamID string) (uint64, error) {
+	stream, err := m.state.Copy(ctx)
+	if err != nil {
+		return 0, err
+	}
+	return stream.streams[streamID].First().EventMeta().Position, nil
+}
+func (m *memstore) LastIndex(ctx context.Context, streamID string) (uint64, error) {
+	stream, err := m.state.Copy(ctx)
+	if err != nil {
+		return 0, err
+	}
+	return stream.streams[streamID].Last().EventMeta().Position, nil
+
+}

pkg/es/event/events.go

@@ -131,9 +131,10 @@ type Meta struct {
 	Position uint64
 }
 
-func (m Meta) Time() time.Time {
+func (m Meta) Created() time.Time {
 	return ulid.Time(m.EventID.Time())
 }
+func (m Meta) ID() string { return m.EventID.String() }
 
 type _nilEvent struct{}
 

pkg/es/service/service.go

@@ -0,0 +1,139 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/sour-is/ev/pkg/es/driver"
+	"github.com/sour-is/ev/pkg/es/event"
+)
+
+type service struct {
+	es driver.EventStore
+}
+
+func New(ctx context.Context, es driver.EventStore) (*service, error) {
+	if err := event.Register(ctx, &PostEvent{}); err != nil {
+		return nil, err
+	}
+	return &service{es}, nil
+}
+
+func (s *service) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+
+	name, tags, _ := strings.Cut(r.URL.Path, "/")
+	if name == "" {
+		w.WriteHeader(http.StatusNotFound)
+		return
+	}
+
+	switch r.Method {
+	case http.MethodGet:
+		var pos, count int64 = -1, -99
+		qry := r.URL.Query()
+
+		if i, err := strconv.ParseInt(qry.Get("idx"), 10, 64); err == nil {
+			pos = i
+		}
+		if i, err := strconv.ParseInt(qry.Get("n"), 10, 64); err == nil {
+			count = i
+		}
+
+		log.Print("GET topic=", name, " idx=", pos, " n=", count)
+		events, err := s.es.Read(ctx, "post-"+name, pos, count)
+		if err != nil {
+			log.Print(err)
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+
+		for i := range events {
+			fmt.Fprintln(w, events[i])
+		}
+
+		return
+	case http.MethodPost, http.MethodPut:
+		b, err := io.ReadAll(io.LimitReader(r.Body, 64*1024))
+		if err != nil {
+			log.Print(err)
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+		r.Body.Close()
+
+		if name == "" {
+			w.WriteHeader(http.StatusNotFound)
+			return
+		}
+
+		events := event.NewEvents(&PostEvent{
+			Payload: b,
+			Tags:    fields(tags),
+		})
+		_, err = s.es.Append(r.Context(), "post-"+name, events)
+		if err != nil {
+			log.Print(err)
+
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+
+		m := events.First().EventMeta()
+		w.WriteHeader(http.StatusAccepted)
+		log.Print("POST topic=", name, " tags=", tags, " idx=", m.Position, " id=", m.EventID)
+		fmt.Fprintf(w, "OK %d %s", m.Position, m.EventID)
+	default:
+		w.WriteHeader(http.StatusMethodNotAllowed)
+	}
+}
+
+type PostEvent struct {
+	Payload []byte
+	Tags    []string
+
+	eventMeta event.Meta
+}
+
+func (e *PostEvent) EventMeta() event.Meta {
+	if e == nil {
+		return event.Meta{}
+	}
+	return e.eventMeta
+}
+func (e *PostEvent) SetEventMeta(eventMeta event.Meta) {
+	if e == nil {
+		return
+	}
+	e.eventMeta = eventMeta
+}
+func (e *PostEvent) String() string {
+	var b bytes.Buffer
+
+	// b.WriteString(e.eventMeta.StreamID)
+	// b.WriteRune('@')
+	b.WriteString(strconv.FormatUint(e.eventMeta.Position, 10))
+	b.WriteRune('\t')
+
+	b.WriteString(e.eventMeta.EventID.String())
+	b.WriteRune('\t')
+	b.WriteString(string(e.Payload))
+	if len(e.Tags) > 0 {
+		b.WriteRune('\t')
+		b.WriteString(strings.Join(e.Tags, ","))
+	}
+
+	return b.String()
+}
+func fields(s string) []string {
+	if s == "" {
+		return nil
+	}
+	return strings.Split(s, "/")
+}

pkg/locker/locker.go

@@ -6,6 +6,7 @@ type Locked[T any] struct {
 	state chan *T
 }
 
+// New creates a new locker for the given value.
 func New[T any](initial *T) *Locked[T] {
 	s := &Locked[T]{}
 	s.state = make(chan *T, 1)
@@ -13,6 +14,7 @@ func New[T any](initial *T) *Locked[T] {
 	return s
 }
 
+// Modify will call the function with the locked value
 func (s *Locked[T]) Modify(ctx context.Context, fn func(*T) error) error {
 	if ctx.Err() != nil {
 		return ctx.Err()
@@ -27,6 +29,7 @@ func (s *Locked[T]) Modify(ctx context.Context, fn func(*T) error) error {
 	}
 }
 
+// Copy will return a shallow copy of the locked object.
 func (s *Locked[T]) Copy(ctx context.Context) (T, error) {
 	var t T
 

pkg/playground/playground.go

@@ -0,0 +1,62 @@
+package playground
+
+import (
+	"html/template"
+	"net/http"
+)
+
+var page = template.Must(template.New("graphiql").Parse(`<!DOCTYPE html>
+<html>
+<head>
+	<meta charset=utf-8/>
+	<meta name="viewport" content="user-scalable=no, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, minimal-ui">
+	<link rel="shortcut icon" href="https://graphcool-playground.netlify.com/favicon.png">
+	<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/graphql-playground-react@{{ .version }}/build/static/css/index.css"
+		integrity="{{ .cssSRI }}" crossorigin="anonymous"/>
+	<link rel="shortcut icon" href="https://cdn.jsdelivr.net/npm/graphql-playground-react@{{ .version }}/build/favicon.png"
+		integrity="{{ .faviconSRI }}" crossorigin="anonymous"/>
+	<script src="https://cdn.jsdelivr.net/npm/graphql-playground-react@{{ .version }}/build/static/js/middleware.js"
+		integrity="{{ .jsSRI }}" crossorigin="anonymous"></script>
+	<title>{{.title}}</title>
+</head>
+<body>
+<style type="text/css">
+	html { font-family: "Open Sans", sans-serif; overflow: hidden; }
+	body { margin: 0; background: #172a3a; }
+</style>
+<div id="root"/>
+<script type="text/javascript">
+	window.addEventListener('load', function (event) {
+		const root = document.getElementById('root');
+		root.classList.add('playgroundIn');
+		const wsProto = location.protocol == 'https:' ? 'wss:' : 'ws:'
+		GraphQLPlayground.init(root, {
+			endpoint: location.protocol + '//' + location.host + '{{.endpoint}}',
+			subscriptionsEndpoint: wsProto + '//' + location.host + '{{.endpoint }}',
+           shareEnabled: true,
+			settings: {
+				'request.credentials': 'same-origin'
+			}
+		})
+	})
+</script>
+</body>
+</html>
+`))
+
+func Handler(title string, endpoint string) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Add("Content-Type", "text/html")
+		err := page.Execute(w, map[string]string{
+			"title":      title,
+			"endpoint":   endpoint,
+			"version":    "1.7.26",
+			"cssSRI":     "sha256-dKnNLEFwKSVFpkpjRWe+o/jQDM6n/JsvQ0J3l5Dk3fc=",
+			"faviconSRI": "sha256-GhTyE+McTU79R4+pRO6ih+4TfsTOrpPwD8ReKFzb3PM=",
+			"jsSRI":      "sha256-SG9YAy4eywTcLckwij7V4oSCG3hOdV1m+2e1XuNxIgk=",
+		})
+		if err != nil {
+			panic(err)
+		}
+	}
+}