[assetserver] Add linux platform implementation (#2543)

v2/internal/frontend/desktop/linux/frontend.go

@@ -78,7 +78,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
-	"net/http"
 	"net/url"
 	"os"
 	"runtime"
@@ -88,6 +87,7 @@ import (
 	"unsafe"
 
 	"github.com/wailsapp/wails/v2/pkg/assetserver"
+	"github.com/wailsapp/wails/v2/pkg/assetserver/webview"
 
 	"github.com/wailsapp/wails/v2/internal/binding"
 	"github.com/wailsapp/wails/v2/internal/frontend"
@@ -166,11 +166,8 @@ func NewFrontend(ctx context.Context, appoptions *options.App, myLogger *logger.
 		}
 		result.assets = assets
 
-		// Start 10 processors to handle requests in parallel
-		for i := 0; i < 10; i++ {
 		go result.startRequestProcessor()
 	}
-	}
 
 	go result.startMessageProcessor()
 
@@ -461,50 +458,16 @@ func processMessage(message *C.char) {
 	messageBuffer <- goMessage
 }
 
-var requestBuffer = make(chan unsafe.Pointer, 100)
+var requestBuffer = make(chan webview.Request, 100)
 
 func (f *Frontend) startRequestProcessor() {
 	for request := range requestBuffer {
-		f.processRequest(request)
+		f.assets.ServeWebViewRequest(request)
-		C.g_object_unref(C.gpointer(request))
+		request.Release()
 	}
 }
 
 //export processURLRequest
 func processURLRequest(request unsafe.Pointer) {
-	// Increment reference counter to allow async processing, will be decremented after the processing
+	requestBuffer <- webview.NewRequest(request)
-	// has been finished by a worker.
-	C.g_object_ref(C.gpointer(request))
-	requestBuffer <- request
-}
-
-func (f *Frontend) processRequest(request unsafe.Pointer) {
-	req := (*C.WebKitURISchemeRequest)(request)
-	uri := C.webkit_uri_scheme_request_get_uri(req)
-	goURI := C.GoString(uri)
-
-	rw := &webKitResponseWriter{req: req}
-	defer rw.Close()
-
-	f.assets.ProcessHTTPRequestLegacy(
-		rw,
-		func() (*http.Request, error) {
-			method := webkit_uri_scheme_request_get_http_method(req)
-			r, err := http.NewRequest(method, goURI, nil)
-			if err != nil {
-				return nil, err
-			}
-			r.Header = webkit_uri_scheme_request_get_http_headers(req)
-
-			if r.URL.Host != f.startURL.Host {
-				if r.Body != nil {
-					r.Body.Close()
-				}
-
-				return nil, fmt.Errorf("Expected host '%s' in request, but was '%s'", f.startURL.Host, r.URL.Host)
-			}
-
-			return r, nil
-		})
-
 }

v2/internal/frontend/desktop/linux/webkit2.go

@@ -12,10 +12,12 @@ import (
 
 	"github.com/wailsapp/wails/v2/pkg/options"
 	"github.com/wailsapp/wails/v2/pkg/options/linux"
+
+	"github.com/wailsapp/wails/v2/pkg/assetserver/webview"
 )
 
 func validateWebKit2Version(options *options.App) {
-	if C.webkit_get_major_version() == 2 && C.webkit_get_minor_version() >= webkit2MinMinorVersion {
+	if C.webkit_get_major_version() == 2 && C.webkit_get_minor_version() >= webview.Webkit2MinMinorVersion {
 		return
 	}
 
@@ -24,6 +26,6 @@ func validateWebKit2Version(options *options.App) {
 		msg = options.Linux.Messages
 	}
 
-	v := fmt.Sprintf("2.%d.0", webkit2MinMinorVersion)
+	v := fmt.Sprintf("2.%d.0", webview.Webkit2MinMinorVersion)
 	showModalDialogAndExit("WebKit2GTK", fmt.Sprintf(msg.WebKit2GTKMinRequired, v))
 }

v2/pkg/assetserver/webview/request_linux.go

@@ -0,0 +1,85 @@
+//go:build linux
+// +build linux
+
+package webview
+
+/*
+#cgo linux pkg-config: gtk+-3.0 webkit2gtk-4.0 gio-unix-2.0
+
+#include "gtk/gtk.h"
+#include "webkit2/webkit2.h"
+*/
+import "C"
+
+import (
+	"io"
+	"net/http"
+	"unsafe"
+)
+
+// NewRequest creates as new WebViewRequest based on a pointer to an `WebKitURISchemeRequest`
+//
+// Please make sure to call Release() when finished using the request.
+func NewRequest(webKitURISchemeRequest unsafe.Pointer) Request {
+	webkitReq := (*C.WebKitURISchemeRequest)(webKitURISchemeRequest)
+	req := &request{req: webkitReq}
+	req.AddRef()
+	return req
+}
+
+var _ Request = &request{}
+
+type request struct {
+	req *C.WebKitURISchemeRequest
+
+	header http.Header
+	body   io.ReadCloser
+	rw     *responseWriter
+}
+
+func (r *request) AddRef() error {
+	C.g_object_ref(C.gpointer(r.req))
+	return nil
+}
+
+func (r *request) Release() error {
+	C.g_object_unref(C.gpointer(r.req))
+	return nil
+}
+
+func (r *request) URL() (string, error) {
+	return C.GoString(C.webkit_uri_scheme_request_get_uri(r.req)), nil
+}
+
+func (r *request) Method() (string, error) {
+	return webkit_uri_scheme_request_get_http_method(r.req), nil
+}
+
+func (r *request) Header() (http.Header, error) {
+	if r.header != nil {
+		return r.header, nil
+	}
+
+	r.header = webkit_uri_scheme_request_get_http_headers(r.req)
+	return r.header, nil
+}
+
+func (r *request) Body() (io.ReadCloser, error) {
+	if r.body != nil {
+		return r.body, nil
+	}
+
+	// WebKit2GTK has currently no support for request bodies.
+	r.body = http.NoBody
+
+	return r.body, nil
+}
+
+func (r *request) Response() ResponseWriter {
+	if r.rw != nil {
+		return r.rw
+	}
+
+	r.rw = &responseWriter{req: r.req}
+	return r.rw
+}

v2/pkg/assetserver/webview/responsewriter.go

@@ -1,9 +1,20 @@
 package webview
 
 import (
+	"errors"
 	"net/http"
 )
 
+const (
+	HeaderContentLength = "Content-Length"
+	HeaderContentType   = "Content-Type"
+)
+
+var (
+	errRequestStopped   = errors.New("request has been stopped")
+	errResponseFinished = errors.New("response has been finished")
+)
+
 // A ResponseWriter interface is used by an HTTP handler to
 // construct an HTTP response for the WebView.
 type ResponseWriter interface {

v2/pkg/assetserver/webview/responsewriter_darwin.go

@@ -69,16 +69,10 @@ import "C"
 
 import (
 	"encoding/json"
-	"errors"
 	"net/http"
 	"unsafe"
 )
 
-var (
-	errRequestStopped   = errors.New("request has been stopped")
-	errResponseFinished = errors.New("response has been finished")
-)
-
 var _ ResponseWriter = &responseWriter{}
 
 type responseWriter struct {

v2/pkg/assetserver/webview/responsewriter_linux.go

@@ -1,7 +1,7 @@
 //go:build linux
 // +build linux
 
-package linux
+package webview
 
 /*
 #cgo linux pkg-config: gtk+-3.0 webkit2gtk-4.0 gio-unix-2.0
@@ -20,28 +20,31 @@ import (
 	"strconv"
 	"syscall"
 	"unsafe"
-
-	"github.com/wailsapp/wails/v2/pkg/assetserver"
 )
 
-type webKitResponseWriter struct {
+type responseWriter struct {
 	req *C.WebKitURISchemeRequest
 
 	header      http.Header
 	wroteHeader bool
+	finished    bool
 
 	w    io.WriteCloser
 	wErr error
 }
 
-func (rw *webKitResponseWriter) Header() http.Header {
+func (rw *responseWriter) Header() http.Header {
 	if rw.header == nil {
 		rw.header = http.Header{}
 	}
 	return rw.header
 }
 
-func (rw *webKitResponseWriter) Write(buf []byte) (int, error) {
+func (rw *responseWriter) Write(buf []byte) (int, error) {
+	if rw.finished {
+		return 0, errResponseFinished
+	}
+
 	rw.WriteHeader(http.StatusOK)
 	if rw.wErr != nil {
 		return 0, rw.wErr
@@ -49,14 +52,14 @@ func (rw *webKitResponseWriter) Write(buf []byte) (int, error) {
 	return rw.w.Write(buf)
 }
 
-func (rw *webKitResponseWriter) WriteHeader(code int) {
+func (rw *responseWriter) WriteHeader(code int) {
-	if rw.wroteHeader {
+	if rw.wroteHeader || rw.finished {
 		return
 	}
 	rw.wroteHeader = true
 
 	contentLength := int64(-1)
-	if sLen := rw.Header().Get(assetserver.HeaderContentLength); sLen != "" {
+	if sLen := rw.Header().Get(HeaderContentLength); sLen != "" {
 		if pLen, _ := strconv.ParseInt(sLen, 10, 64); pLen > 0 {
 			contentLength = pLen
 		}
@@ -72,7 +75,7 @@ func (rw *webKitResponseWriter) WriteHeader(code int) {
 	}
 	rw.w = w
 
-	stream := C.g_unix_input_stream_new(C.int(rFD), gtkBool(true))
+	stream := C.g_unix_input_stream_new(C.int(rFD), C.gboolean(1))
 	defer C.g_object_unref(C.gpointer(stream))
 
 	if err := webkit_uri_scheme_request_finish(rw.req, code, rw.Header(), stream, contentLength); err != nil {
@@ -81,13 +84,22 @@ func (rw *webKitResponseWriter) WriteHeader(code int) {
 	}
 }
 
-func (rw *webKitResponseWriter) Close() {
+func (rw *responseWriter) Finish() error {
+	if !rw.wroteHeader {
+		rw.WriteHeader(http.StatusNotImplemented)
+	}
+
+	if rw.finished {
+		return nil
+	}
+	rw.finished = true
 	if rw.w != nil {
 		rw.w.Close()
 	}
+	return nil
 }
 
-func (rw *webKitResponseWriter) finishWithError(code int, err error) {
+func (rw *responseWriter) finishWithError(code int, err error) {
 	if rw.w != nil {
 		rw.w.Close()
 		rw.w = &nopCloser{io.Discard}

v2/pkg/assetserver/webview/webkit2_36.go

@@ -1,6 +1,6 @@
 //go:build linux && webkit2_36
 
-package linux
+package webview
 
 /*
 #cgo linux pkg-config: gtk+-3.0 webkit2gtk-4.0 libsoup-2.4
@@ -15,11 +15,9 @@ import (
 	"net/http"
 	"strings"
 	"unsafe"
-
-	"github.com/wailsapp/wails/v2/pkg/assetserver"
 )
 
-const webkit2MinMinorVersion = 36
+const Webkit2MinMinorVersion = 36
 
 func webkit_uri_scheme_request_get_http_method(req *C.WebKitURISchemeRequest) string {
 	method := C.GoString(C.webkit_uri_scheme_request_get_http_method(req))
@@ -51,7 +49,7 @@ func webkit_uri_scheme_request_finish(req *C.WebKitURISchemeRequest, code int, h
 	C.webkit_uri_scheme_response_set_status(resp, C.guint(code), cReason)
 	C.free(unsafe.Pointer(cReason))
 
-	cMimeType := C.CString(header.Get(assetserver.HeaderContentType))
+	cMimeType := C.CString(header.Get(HeaderContentType))
 	C.webkit_uri_scheme_response_set_content_type(resp, cMimeType)
 	C.free(unsafe.Pointer(cMimeType))
 

v2/pkg/assetserver/webview/webkit2_legacy.go

@@ -1,6 +1,6 @@
 //go:build linux && !webkit2_36
 
-package linux
+package webview
 
 /*
 #cgo linux pkg-config: gtk+-3.0 webkit2gtk-4.0
@@ -14,11 +14,9 @@ import (
 	"fmt"
 	"net/http"
 	"unsafe"
-
-	"github.com/wailsapp/wails/v2/pkg/assetserver"
 )
 
-const webkit2MinMinorVersion = 0
+const Webkit2MinMinorVersion = 0
 
 func webkit_uri_scheme_request_get_http_method(_ *C.WebKitURISchemeRequest) string {
 	return http.MethodGet
@@ -33,7 +31,7 @@ func webkit_uri_scheme_request_finish(req *C.WebKitURISchemeRequest, code int, h
 		return fmt.Errorf("StatusCodes not supported: %d - %s", code, http.StatusText(code))
 	}
 
-	cMimeType := C.CString(header.Get(assetserver.HeaderContentType))
+	cMimeType := C.CString(header.Get(HeaderContentType))
 	C.webkit_uri_scheme_request_finish(req, stream, C.gint64(streamLength), cMimeType)
 	C.free(unsafe.Pointer(cMimeType))
 	return nil