implement R2Object / R2Objects

examples/r2-image-server/go.mod

@@ -1,12 +1,7 @@
-module github.com/syumai/workers/examples/simple-json-server
+module github.com/syumai/workers/examples/r2-image-server
 
 go 1.18
 
-require (
+require github.com/syumai/workers v0.0.0-00010101000000-000000000000
-	github.com/mailru/easyjson v0.7.7
-	github.com/syumai/workers v0.0.0-00010101000000-000000000000
-)
 
 replace github.com/syumai/workers => ../../
-
-require github.com/josharian/intern v1.0.0 // indirect

examples/r2-image-server/go.sum

@@ -1,4 +0,0 @@
-github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
-github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
-github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=
-github.com/mailru/easyjson v0.7.7/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=

examples/r2-image-server/jsutil.go

@@ -8,10 +8,51 @@ import (
 )
 
 var (
-	global      = js.Global()
+	global              = js.Global()
-	objectClass = global.Get("Object")
+	objectClass         = global.Get("Object")
+	promiseClass        = global.Get("Promise")
+	uint8ArrayClass     = global.Get("Uint8Array")
+	errorClass          = global.Get("Error")
+	readableStreamClass = global.Get("ReadableStream")
 )
 
+func newObject() js.Value {
+	return objectClass.New()
+}
+
+func newUint8Array(size int) js.Value {
+	return uint8ArrayClass.New(size)
+}
+
+func newPromise(fn js.Func) js.Value {
+	return promiseClass.New(fn)
+}
+
+func awaitPromise(promiseVal js.Value) (js.Value, error) {
+	resultCh := make(chan js.Value)
+	errCh := make(chan error)
+	var then, catch js.Func
+	then = js.FuncOf(func(_ js.Value, args []js.Value) any {
+		defer then.Release()
+		result := args[0]
+		resultCh <- result
+		return js.Undefined()
+	})
+	catch = js.FuncOf(func(_ js.Value, args []js.Value) any {
+		defer catch.Release()
+		result := args[0]
+		errCh <- fmt.Errorf("failed on promise: %s", result.Call("toString").String())
+		return js.Undefined()
+	})
+	promiseVal.Call("then", then).Call("catch", catch)
+	select {
+	case result := <-resultCh:
+		return result, nil
+	case err := <-errCh:
+		return js.Value{}, err
+	}
+}
+
 // dateToTime converts JavaScript side's Data object into time.Time.
 func dateToTime(v js.Value) (time.Time, error) {
 	milliStr := v.Call("getTime").Call("toString").String()

examples/r2-image-server/main.go

@@ -1,13 +1,45 @@
 package main
 
 import (
+	"fmt"
+	"io"
 	"net/http"
 
 	"github.com/syumai/workers"
-	"github.com/syumai/workers/examples/simple-json-server/app"
 )
 
-func main() {
+// bucketName is R2 bucket name defined in wrangler.toml.
-	http.HandleFunc("/hello", app.HelloHandler)
+const bucketName = "BUCKET"
-	workers.Serve(nil) // use http.DefaultServeMux
+
+func handleErr(w http.ResponseWriter, msg string) {
+	w.WriteHeader(http.StatusInternalServerError)
+	w.Write([]byte(msg))
+}
+
+// This example is based on implementation in syumai/workers-playground
+// * https://github.com/syumai/workers-playground/blob/e32881648ccc055e3690a0d9c750a834261c333e/r2-image-viewer/src/index.ts#L30
+func handler(w http.ResponseWriter, req *http.Request) {
+	bucket, err := NewR2Bucket(bucketName)
+	if err != nil {
+		handleErr(w, "failed to get R2Bucket\n")
+		return
+	}
+	imgPath := req.URL.Path
+	imgObj, err := bucket.Get(imgPath)
+	if err != nil {
+		handleErr(w, "failed to get R2Object\n")
+		return
+	}
+	w.Header().Set("Cache-Control", "public, max-age=14400")
+	w.Header().Set("ETag", fmt.Sprintf("W/%s", imgObj.HTTPETag))
+	contentType := "application/octet-stream"
+	if imgObj.HTTPMetadata.ContentType != nil {
+		contentType = *imgObj.HTTPMetadata.ContentType
+	}
+	w.Header().Set("Content-Type", contentType)
+	io.Copy(w, imgObj.Body)
+}
+
+func main() {
+	workers.Serve(http.HandlerFunc(handler))
 }

examples/r2-image-server/r2bucket.go

@@ -10,11 +10,11 @@ import (
 // - https://developers.cloudflare.com/r2/runtime-apis/#bucket-method-definitions
 // - https://github.com/cloudflare/workers-types/blob/3012f263fb1239825e5f0061b267c8650d01b717/index.d.ts#L1006
 type R2Bucket interface {
-	Head(key string)
+	Head(key string) (*R2Object, error)
-	Get(key string) *R2Object
+	Get(key string) (*R2Object, error)
-	Put(key string, value io.Reader)
+	Put(key string, value io.Reader) error
-	Delete(key string)
+	Delete(key string) error
-	List() []*R2Object
+	List() (*R2Objects, error)
 }
 
 type r2Bucket struct {
@@ -23,24 +23,45 @@ type r2Bucket struct {
 
 var _ R2Bucket = &r2Bucket{}
 
-func (r *r2Bucket) Head(key string) {
+func (r *r2Bucket) Head(key string) (*R2Object, error) {
+	p := r.instance.Call("head", key)
+	v, err := awaitPromise(p)
+	if err != nil {
+		return nil, err
+	}
+	if v.IsNull() {
+		return nil, nil
+	}
+	return toR2Object(v)
+}
+
+func (r *r2Bucket) Get(key string) (*R2Object, error) {
+	p := r.instance.Call("get", key)
+	v, err := awaitPromise(p)
+	if err != nil {
+		return nil, err
+	}
+	if v.IsNull() {
+		return nil, nil
+	}
+	return toR2Object(v)
+}
+
+func (r *r2Bucket) Put(key string, value io.Reader) error {
 	panic("implement me")
 }
 
-func (r *r2Bucket) Get(key string) *R2Object {
+func (r *r2Bucket) Delete(key string) error {
-	return nil
-}
-
-func (r *r2Bucket) Put(key string, value io.Reader) {
 	panic("implement me")
 }
 
-func (r *r2Bucket) Delete(key string) {
+func (r *r2Bucket) List() (*R2Objects, error) {
-	panic("implement me")
+	p := r.instance.Call("list")
-}
+	v, err := awaitPromise(p)
-
+	if err != nil {
-func (r *r2Bucket) List() []*R2Object {
+		return nil, err
-	panic("implement me")
+	}
+	return toR2Objects(v)
 }
 
 func NewR2Bucket(varName string) (R2Bucket, error) {

examples/r2-image-server/r2object.go

@@ -1,13 +1,17 @@
 package main
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"syscall/js"
 	"time"
 )
 
+// R2Object represents JavaScript side's R2Object.
+// * https://github.com/cloudflare/workers-types/blob/3012f263fb1239825e5f0061b267c8650d01b717/index.d.ts#L1094
 type R2Object struct {
+	instance       js.Value
 	Key            string
 	Version        string
 	Size           int
@@ -16,7 +20,9 @@ type R2Object struct {
 	Uploaded       time.Time
 	HTTPMetadata   R2HTTPMetadata
 	CustomMetadata map[string]string
-	Body           io.Reader
+	// Body is a body of R2Object.
+	// This value becomes nil when `Head` method of R2Bucket is called.
+	Body io.Reader
 }
 
 // TODO: implement
@@ -24,7 +30,15 @@ type R2Object struct {
 // func (o *R2Object) WriteHTTPMetadata(headers http.Header) {
 // }
 
-// toR2Object converts JavaScript side's R2Object to R2Object.
+func (o *R2Object) BodyUsed() (bool, error) {
+	v := o.instance.Get("bodyUsed")
+	if v.IsUndefined() {
+		return false, errors.New("bodyUsed doesn't exist for this R2Object")
+	}
+	return v.Bool(), nil
+}
+
+// toR2Object converts JavaScript side's R2Object to *R2Object.
 // * https://github.com/cloudflare/workers-types/blob/3012f263fb1239825e5f0061b267c8650d01b717/index.d.ts#L1094
 func toR2Object(v js.Value) (*R2Object, error) {
 	uploaded, err := dateToTime(v.Get("uploaded"))
@@ -35,7 +49,13 @@ func toR2Object(v js.Value) (*R2Object, error) {
 	if err != nil {
 		return nil, fmt.Errorf("error converting httpMetadata: %w", err)
 	}
+	bodyVal := v.Get("body")
+	var body io.Reader
+	if !bodyVal.IsUndefined() {
+		body = convertStreamReaderToReader(v.Get("body").Call("getReader"))
+	}
 	return &R2Object{
+		instance:       v,
 		Key:            v.Get("key").String(),
 		Version:        v.Get("version").String(),
 		Size:           v.Get("size").Int(),
@@ -44,7 +64,7 @@ func toR2Object(v js.Value) (*R2Object, error) {
 		Uploaded:       uploaded,
 		HTTPMetadata:   r2Meta,
 		CustomMetadata: strRecordToMap(v.Get("customMetadata")),
-		Body:           convertStreamReaderToReader(v.Get("body").Call("getReader")),
+		Body:           body,
 	}, nil
 }
 

examples/r2-image-server/r2objects.go

@@ -1,5 +1,40 @@
 package main
 
+import (
+	"fmt"
+	"syscall/js"
+)
+
+// R2Objects represents JavaScript side's R2Objects.
+// * https://github.com/cloudflare/workers-types/blob/3012f263fb1239825e5f0061b267c8650d01b717/index.d.ts#L1121
 type R2Objects struct {
-	Objects []*R2Object
+	Objects           []*R2Object
+	Truncated         bool
+	Cursor            *string
+	DelimitedPrefixes []string
+}
+
+// toR2Objects converts JavaScript side's R2Objects to *R2Objects.
+// * https://github.com/cloudflare/workers-types/blob/3012f263fb1239825e5f0061b267c8650d01b717/index.d.ts#L1121
+func toR2Objects(v js.Value) (*R2Objects, error) {
+	objectsVal := v.Get("objects")
+	objects := make([]*R2Object, objectsVal.Length())
+	for i := 0; i < len(objects); i++ {
+		obj, err := toR2Object(objectsVal.Index(i))
+		if err != nil {
+			return nil, fmt.Errorf("error converting to R2Object: %w", err)
+		}
+		objects[i] = obj
+	}
+	prefixesVal := objectsVal.Get("delimitedPrefixes")
+	prefixes := make([]string, prefixesVal.Length())
+	for i := 0; i < len(prefixes); i++ {
+		prefixes[i] = prefixesVal.Index(i).String()
+	}
+	return &R2Objects{
+		Objects:           objects,
+		Truncated:         objectsVal.Get("truncated").Bool(),
+		Cursor:            maybeString(objectsVal.Get("cursor")),
+		DelimitedPrefixes: prefixes,
+	}, nil
 }

examples/r2-image-server/wrangler.toml

@@ -1,4 +1,4 @@
-name = "simple-json-server"
+name = "r2-image-server"
 main = "./worker.mjs"
 compatibility_date = "2022-05-13"
 compatibility_flags = [
@@ -7,3 +7,8 @@ compatibility_flags = [
 
 [build]
 command = "make build"
+
+[[r2_buckets]]
+binding = 'BUCKET'
+bucket_name = 'r2-image-viewer'
+preview_bucket_name = 'r2-image-viewer-dev'