Merge pull request #93 from aki-0421/avoid-memory-error

Support stream in fetch pkg

_examples/stream-large-file/.gitignore

@@ -0,0 +1,3 @@
+build
+node_modules
+.wrangler

_examples/stream-large-file/Makefile

@@ -0,0 +1,12 @@
+.PHONY: dev
+dev:
+	wrangler dev
+
+.PHONY: build
+build:
+	go run ../../cmd/workers-assets-gen
+	tinygo build -o ./build/app.wasm -target wasm -no-debug ./...
+
+.PHONY: deploy
+deploy:
+	wrangler deploy

_examples/stream-large-file/README.md

@@ -0,0 +1,18 @@
+# stream-large-file
+
+## Development
+
+### Requirements
+
+This project requires these tools to be installed globally.
+
+* wrangler
+* tinygo
+
+### Commands
+
+```
+make dev     # run dev server
+make build   # build Go Wasm binary
+make deploy # deploy worker
+```

_examples/stream-large-file/go.mod

@@ -0,0 +1,7 @@
+module github.com/syumai/workers/_examples/stream
+
+go 1.21.3
+
+require github.com/syumai/workers v0.0.0
+
+replace github.com/syumai/workers => ../../

_examples/stream-large-file/go.sum

@@ -0,0 +1,2 @@
+github.com/syumai/workers v0.1.0 h1:z5QfQR2X+PCKzom7RodpI5J4D5YF7NT7Qwzb9AM9dgY=
+github.com/syumai/workers v0.1.0/go.mod h1:alXIDhTyeTwSzh0ZgQ3cb9HQPyyYfIejupE4Z3efr14=

_examples/stream-large-file/main.go

@@ -0,0 +1,26 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/syumai/workers"
+	"github.com/syumai/workers/cloudflare/fetch"
+)
+
+func main() {
+	http.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
+		cli := fetch.NewClient().HTTPClient(fetch.RedirectModeFollow)
+		resp, err := cli.Get("http://tyo.download.datapacket.com/1000mb.bin")
+		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			fmt.Fprintf(w, "err: %v", err)
+			return
+		}
+		defer resp.Body.Close()
+
+		io.Copy(w, resp.Body)
+	})
+	workers.Serve(nil)
+}

_examples/stream-large-file/wrangler.toml

@@ -0,0 +1,6 @@
+name = "stream-large-file"
+main = "./build/worker.mjs"
+compatibility_date = "2023-12-01"
+
+[build]
+command = "make build"

cloudflare/fetch/bind.go

@@ -3,6 +3,7 @@ package fetch
 import (
 	"errors"
 	"net/http"
+	"strconv"
 	"syscall/js"
 
 	"github.com/syumai/workers/internal/jshttp"
@@ -15,8 +16,8 @@ func fetch(namespace js.Value, req *http.Request, init *RequestInit) (*http.Resp
 	if namespace.IsUndefined() {
 		return nil, errors.New("fetch function not found")
 	}
-	fetchObj := namespace.Get("fetch")
+	fetchFunc := namespace.Get("fetch")
-	promise := fetchObj.Invoke(
+	promise := fetchFunc.Invoke(
 		// The Request object to fetch.
 		// Docs: https://developers.cloudflare.com/workers/runtime-apis/request
 		jshttp.ToJSRequest(req),
@@ -30,5 +31,18 @@ func fetch(namespace js.Value, req *http.Request, init *RequestInit) (*http.Resp
 		return nil, err
 	}
 
-	return jshttp.ToResponse(jsRes)
+	// Create TransformStream
+	ts := js.Global().Get("IdentityTransformStream").New()
+	readable := ts.Get("readable")
+	writable := ts.Get("writable")
+	jsRes.Get("body").Call("pipeTo", writable)
+
+	// Create response
+	res := new(http.Response)
+	res.StatusCode = jsRes.Get("status").Int()
+	res.Status = strconv.Itoa(res.StatusCode) + " " + jsRes.Get("statusText").String()
+	res.Header = jshttp.ToHeader(jsRes.Get("headers"))
+	res.Body = jsutil.ConvertReadableStreamToReadCloser(readable)
+
+	return res, nil
 }