Merge pull request #8 from nowthisnews/lczaplinski/refactor

Simplify HttpServer logic

actions/bulk_write_job.go

@@ -0,0 +1,61 @@
+package actions
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/pkg/errors"
+	"github.com/scoiatael/archai/simplejson"
+)
+
+type BulkWriteJob struct {
+	Schema  []interface{} `json:"schema"`
+	Objects []interface{} `json:"data"`
+	Stream  string        `json:"stream"`
+}
+
+func (wj BulkWriteJob) MarshalJSON() ([]byte, error) {
+	return json.Marshal(map[string]interface{}{"schema": wj.Schema,
+		"data":   wj.Objects,
+		"stream": wj.Stream,
+	})
+}
+
+func makeObjectWithSchema(obj interface{}, schema []interface{}) (simplejson.Object, error) {
+	object_with_schema := make(simplejson.Object)
+	object, conv := obj.([]interface{})
+	if !conv {
+		return object_with_schema, fmt.Errorf("Failed to convert obj to array")
+	}
+	for j, name := range schema {
+		name, conv := name.(string)
+		if !conv {
+			return object_with_schema, fmt.Errorf("%d: Failed to convert schema value to string", j)
+		}
+		if len(object) <= j {
+			return object_with_schema, fmt.Errorf("%d: Not enough values", j)
+		}
+		object_with_schema[name] = object[j]
+	}
+	return object_with_schema, nil
+}
+
+func (wj BulkWriteJob) Run(c Context) error {
+	c.Telemetry().Incr("bulk_write.aggregate.attempt", []string{"stream:" + wj.Stream})
+	for i, obj := range wj.Objects {
+		object, err := makeObjectWithSchema(obj, wj.Schema)
+		if err != nil {
+			return errors.Wrap(err, fmt.Sprintf("HTTP server splitting payload to bulk_write event at %d", i))
+		}
+		payload, err := json.Marshal(object)
+		if err != nil {
+			return errors.Wrap(err, fmt.Sprintf("HTTP server marshalling payload to bulk_write event at %d", i))
+		}
+		if err := persistEvent(wj.Stream, payload, "http; bulk_write_job", c); err != nil {
+			return errors.Wrap(err, "HTTP server bulk_writing events")
+		}
+		c.Telemetry().Incr("write", []string{"stream:" + wj.Stream})
+	}
+	c.Telemetry().Incr("bulk_write.aggregate.write", []string{"stream:" + wj.Stream})
+	return nil
+}

actions/context.go

@@ -18,6 +18,7 @@ type HttpHandler interface {
 }
 
 type Context interface {
+	BackgroundJobs() chan Action
 	Persistence() persistence.Provider
 	Migrations() map[string]persistence.Migration
 	Version() string

actions/handlers/context.go

@@ -0,0 +1,16 @@
+package handlers
+
+import (
+	"github.com/scoiatael/archai/telemetry"
+	"github.com/scoiatael/archai/types"
+)
+
+type Context interface {
+	ReadEvents(string, string, int) ([]types.Event, error)
+	ListStreams() ([]string, error)
+	Telemetry() telemetry.Datadog
+}
+
+type Handler struct {
+	Context
+}

actions/handlers/get_stream.go

@@ -0,0 +1,44 @@
+package handlers
+
+import (
+	"github.com/pkg/errors"
+	"github.com/scoiatael/archai/http"
+	"github.com/scoiatael/archai/simplejson"
+	"github.com/scoiatael/archai/types"
+)
+
+func serializeEvents(events []types.Event) (simplejson.Object, error) {
+	root := make(simplejson.Object)
+	results := make([]simplejson.Object, len(events))
+	cursor := make(simplejson.Object)
+	for i, ev := range events {
+		payload, err := simplejson.Read(ev.Blob)
+		if err != nil {
+			return root, errors.Wrap(err, "HTTP server marshalling response with read events")
+		}
+		results[i] = payload
+		cursor["next"] = ev.ID
+	}
+	root["results"] = results
+	root["cursor"] = cursor
+	return root, nil
+}
+
+func (gs Handler) GetStream(ctx http.GetContext) {
+	stream := ctx.GetSegment("id")
+	events, err := gs.Context.ReadEvents(
+		stream,
+		ctx.StringParam("cursor"),
+		ctx.IntParam("amount", 10),
+	)
+	if err != nil {
+		ctx.ServerErr(errors.Wrap(err, "GetStream Handle ReadEvents"))
+		return
+	}
+	json, err := serializeEvents(events)
+	if err != nil {
+		ctx.ServerErr(err)
+	}
+	gs.Context.Telemetry().Incr("read", []string{"stream:" + stream})
+	ctx.SendJson(json)
+}

actions/handlers/get_streams.go

@@ -0,0 +1,18 @@
+package handlers
+
+import (
+	"github.com/pkg/errors"
+	"github.com/scoiatael/archai/http"
+	"github.com/scoiatael/archai/simplejson"
+)
+
+func (gs Handler) GetStreams(ctx http.GetContext) {
+	streams, err := gs.Context.ListStreams()
+	if err != nil {
+		ctx.ServerErr(errors.Wrap(err, "GetStreams Handle .ListStreams"))
+		return
+	}
+	view := make(simplejson.Object)
+	view["streams"] = streams
+	ctx.SendJson(view)
+}

actions/http_server.go

@@ -3,13 +3,11 @@ package actions
 import (
 	"encoding/json"
 	"fmt"
-	"log"
-	"reflect"
-	"time"
 
 	"github.com/pkg/errors"
+	"github.com/scoiatael/archai/actions/handlers"
 	"github.com/scoiatael/archai/http"
-	"github.com/scoiatael/archai/simplejson"
+	"github.com/scoiatael/archai/types"
 )
 
 // TODO: This should not be an action. Maybe introduce Job type?
@@ -18,183 +16,60 @@ type HttpServer struct {
 	Port int
 }
 
-type BackgroundJob interface {
-	Run(c Context)
+type HandlerContext struct {
+	Context
 }
 
-func persistEvent(stream string, payload []byte, origin string, c Context) error {
-	var err error
-	for i := 0; i < c.Retries(); i += 1 {
-		action := WriteEvent{Stream: stream, Payload: payload, Meta: make(map[string]string)}
-		action.Meta["origin"] = origin
-		action.Meta["compressed"] = "false"
-		action.Meta["time"] = string(time.Now().Unix())
-		err = action.Run(c)
-		if err == nil {
-			break
-		}
-		time.Sleep(c.Backoff(i))
-		c.Telemetry().Incr("persist.retries", []string{"stream" + stream})
-		log.Println("Retrying persistEvent, because of", err)
-	}
-	return err
-}
-
-type WriteJob struct {
-	payload simplejson.Object
-	stream  string
+func (c HandlerContext) ReadEvents(stream string, cursor string, amount int) ([]types.Event, error) {
+	re := ReadEvents{Stream: stream, Cursor: cursor, Amount: amount}
+	err := re.Run(c)
+	return re.Events, errors.Wrap(err, "HandlerContext ReadEvents .Run")
 }
 
-func (wj WriteJob) Run(c Context) {
-	payload, err := json.Marshal(wj.payload)
-	err = errors.Wrap(err, "HTTP server marshalling payload to write event")
+func (c HandlerContext) ListStreams() ([]string, error) {
+	session, err := c.Persistence().Session()
 	if err != nil {
-		c.HandleErr(err)
-		return
-	}
-	err = persistEvent(wj.stream, payload, "http; write_job", c)
-	if err != nil {
-		c.HandleErr(errors.Wrap(err, "HTTP server writing event"))
-	} else {
-		c.Telemetry().Incr("write", []string{"stream:" + wj.stream})
-	}
-}
-
-type BulkWriteJob struct {
-	schema  []interface{}
-	objects []interface{}
-	stream  string
-}
-
-func makeObjectWithSchema(obj interface{}, schema []interface{}) (simplejson.Object, error) {
-	object_with_schema := make(simplejson.Object)
-	object, conv := obj.([]interface{})
-	if !conv {
-		return object_with_schema, fmt.Errorf("Failed to convert obj to array")
-	}
-	for j, name := range schema {
-		name, conv := name.(string)
-		if !conv {
-			return object_with_schema, fmt.Errorf("%d: Failed to convert schema value to string", j)
-		}
-		if len(object) <= j {
-			return object_with_schema, fmt.Errorf("%d: Not enough values", j)
-		}
-		object_with_schema[name] = object[j]
-	}
-	return object_with_schema, nil
-}
-
-func (wj BulkWriteJob) Run(c Context) {
-	c.Telemetry().Incr("bulk_write.aggregate", []string{"stream:" + wj.stream})
-	for i, obj := range wj.objects {
-		object, err := makeObjectWithSchema(obj, wj.schema)
-		err = errors.Wrap(err, fmt.Sprintf("HTTP server splitting payload to bulk_write event at %d", i))
-		if err != nil {
-			c.HandleErr(err)
-			return
-		}
-		payload, err := json.Marshal(object)
-		err = errors.Wrap(err, fmt.Sprintf("HTTP server marshalling payload to bulk_write event at %d", i))
-		if err != nil {
-			c.HandleErr(err)
-			return
-		}
-		err = persistEvent(wj.stream, payload, "http; bulk_write_job", c)
-		if err != nil {
-			c.HandleErr(errors.Wrap(err, "HTTP server bulk_writing events"))
-		} else {
-			c.Telemetry().Incr("write", []string{"stream:" + wj.stream})
-		}
-	}
-}
-
-func writer(jobs <-chan BackgroundJob, c Context) {
-	for j := range jobs {
-		j.Run(c)
+		return []string{}, errors.Wrap(err, "HandlerContext ListStreams .Persistence.Session")
 	}
+	return session.ListStreams()
 }
 
 func (hs HttpServer) Run(c Context) error {
 	handler := c.HttpHandler()
-	jobs := make(chan BackgroundJob, 50)
-	for w := 0; w < c.Concurrency(); w++ {
-		go writer(jobs, c)
-	}
-	handler.Get("/_check", func(ctx http.GetContext) {
-		ctx.SendJson("OK")
-	})
-	handler.Get("/streams", func(ctx http.GetContext) {
-		session, err := c.Persistence().Session()
-		err = errors.Wrap(err, "Obtaining session failed")
-		if err != nil {
-			ctx.ServerErr(err)
-			return
-		}
-		streams, err := session.ListStreams()
-		view := make(simplejson.Object)
-		view["streams"] = streams
-		ctx.SendJson(view)
-	})
-	handler.Get("/stream/:id", func(ctx http.GetContext) {
-		stream := ctx.GetSegment("id")
-		action := ReadEvents{Stream: stream}
-		action.Cursor = ctx.StringParam("cursor")
-		action.Amount = ctx.IntParam("amount", 10)
-		err := errors.Wrap(action.Run(c), "HTTP server reading events")
-		if err != nil {
-			ctx.ServerErr(err)
-			return
-		}
-		root := make(simplejson.Object)
-		events := make(simplejson.ObjectArray, len(action.Events))
-		for i, ev := range action.Events {
-			events[i] = make(simplejson.Object)
-			events[i]["ID"] = ev.ID
-			payload, err := simplejson.Read(ev.Blob)
-			err = errors.Wrap(err, "HTTP server marshalling response with read events")
-			if err != nil {
-				c.HandleErr(err)
-				ctx.ServerErr(err)
-			}
-			events[i]["blob"] = payload
-		}
-		root["results"] = events
-		c.Telemetry().Incr("read", []string{"stream:" + stream})
-		ctx.SendJson(root)
-	})
+	jobs := c.BackgroundJobs()
+	handler_context := handlers.Handler{HandlerContext{c}}
+	handler.Get("/_check", func(ctx http.GetContext) { ctx.SendJson("OK") })
+	handler.Get("/streams", handler_context.GetStreams)
+	handler.Get("/stream/:id", handler_context.GetStream)
 	handler.Post("/bulk/stream/:id", func(ctx http.PostContext) {
 		var err error
 		stream := ctx.GetSegment("id")
-		body, err := ctx.JsonBodyParams()
+
+		job := BulkWriteJob{}
+		err = ctx.ReadJSON(&job)
+
 		if err != nil {
-			// Error was already sent
-			return
-		}
-		objects, conv := body["data"].([]interface{})
-		if !conv {
-			ctx.ServerErr(fmt.Errorf("'data' field is not an Array (is %v)", reflect.TypeOf(body["data"])))
-			return
-		}
-		schema, conv := body["schema"].([]interface{})
-		if !conv {
-			ctx.ServerErr(fmt.Errorf("'schema' field is not an Array (is %v)", reflect.TypeOf(body["schema"])))
+			ctx.ServerErr(fmt.Errorf("Expected body, encountered: %v", err))
 			return
 		}
 
-		jobs <- BulkWriteJob{stream: stream, objects: objects, schema: schema}
+		job.Stream = stream
+
+		jobs <- job
+		c.Telemetry().Gauge("jobs.len", []string{}, len(jobs))
 		ctx.SendJson("OK")
 	})
 	handler.Post("/stream/:id", func(ctx http.PostContext) {
 		var err error
 		stream := ctx.GetSegment("id")
 		body, err := ctx.JsonBodyParams()
 		if err != nil {
-			// Error was already sent
+			ctx.ServerErr(fmt.Errorf("Expected body, encountered: %v", err))
 			return
 		}
 
-		jobs <- WriteJob{stream: stream, payload: body}
+		jobs <- WriteJob{Stream: stream, Payload: body}
+		c.Telemetry().Gauge("jobs.len", []string{}, len(jobs))
 		ctx.SendJson("OK")
 	})