Local Server Push + push intermediates without routes

build.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"path"
 	"sort"
 	"time"
 
@@ -31,13 +32,22 @@ type (
 		modTime time.Time
 	}
 
+	linkHeader struct {
+		file string
+		as   string
+	}
+
 	// TODO: add all headers including cache-control and
 	// service worker so no regex matching is needed at runtime
 
 	// PushHeaders are the link headers to send for a route
-	PushHeaders map[string][]string
+	PushHeaders map[string][]linkHeader
 )
 
+func (l linkHeader) String() string {
+	return fmt.Sprintf("<%s>; rel=preload; as=%s", l.file, l.as)
+}
+
 var files = make(map[string]*file)
 
 func loadBuilds(config *ProjectConfig, root http.Dir, routes Routes, version string, createTemplate createTemplateFn) builds {
@@ -152,42 +162,61 @@ func newBuild(config *ProjectConfig, configOrder int, name string, requirements
 	pushHeaders := PushHeaders{}
 	prefix := version + name + "/"
 
-	for path, fragment := range routes {
+	for file, assets := range pushManifest {
+		headers := []linkHeader{}
+
+		for p, asset := range assets {
+			link := linkHeader{
+				file: path.Join(prefix, p),
+				as:   asset.Type,
+			}
+			headers = append(headers, link)
+		}
+
+		pushHeaders[path.Join(prefix, file)] = headers
+	}
+
+	for route, fragment := range routes {
 		set := map[string]struct{}{}
-		headers := []string{
-			fmt.Sprintf("<%s%s>; rel=preload; as=%s", prefix, "bower_components/webcomponentsjs/webcomponents-loader.js", "script"),
-			fmt.Sprintf("<%s%s>; rel=preload; as=%s", prefix, config.Shell, "document"),
+		headers := []linkHeader{
+			{
+				file: path.Join(prefix, "bower_components/webcomponentsjs/webcomponents-loader.js"),
+				as:   "script",
+			},
+			{
+				file: path.Join(prefix, config.Shell),
+				as:   "document",
+			},
 		}
-		set[headers[0]] = struct{}{}
-		set[headers[1]] = struct{}{}
-		for path, asset := range pushManifest[config.Shell] {
-			link := fmt.Sprintf("<%s%s>; rel=preload; as=%s", prefix, path, asset.Type)
-			if _, found := set[link]; !found {
-				set[link] = struct{}{}
+		set[headers[0].String()] = struct{}{}
+		set[headers[1].String()] = struct{}{}
+		for p, asset := range pushManifest[config.Shell] {
+			link := linkHeader{
+				file: path.Join(prefix, p),
+				as:   asset.Type,
+			}
+			if _, found := set[link.String()]; !found {
+				set[link.String()] = struct{}{}
 				headers = append(headers, link)
 			}
 		}
 
-		headers = append(headers, fmt.Sprintf("<%s%s>; rel=preload; as=%s", prefix, fragment, "document"))
-		for path, asset := range pushManifest[fragment] {
-			link := fmt.Sprintf("<%s%s>; rel=preload; as=%s", prefix, path, asset.Type)
-			if _, found := set[link]; !found {
-				set[link] = struct{}{}
+		headers = append(headers, linkHeader{
+			file: path.Join(prefix, fragment),
+			as:   "document",
+		})
+		for p, asset := range pushManifest[fragment] {
+			link := linkHeader{
+				file: path.Join(prefix, p),
+				as:   asset.Type,
+			}
+			if _, found := set[link.String()]; !found {
+				set[link.String()] = struct{}{}
 				headers = append(headers, link)
 			}
 		}
 
-		pushHeaders[path] = headers
-	}
-
-	// update paths to account for the build folder name
-	manifest := Manifest{}
-	for path, assets := range pushManifest {
-		adjusted := make(map[string]AssetOpt, len(assets))
-		for assetPath, asset := range assets {
-			adjusted[prefix+assetPath] = asset
-		}
-		manifest[prefix+path] = adjusted
+		pushHeaders[route] = headers
 	}
 
 	build := build{

capabilities.go

@@ -120,7 +120,7 @@ func (c capability) String() string {
 	return strings.Join(val, ", ")
 }
 
-func (p *prpl) browserCapabilities(userAgentString string) capability {
+func (p *PRPL) browserCapabilities(userAgentString string) capability {
 	client := p.parser.Parse(userAgentString)
 
 	predicate, ok := browserPredicates[client.UserAgent.Family]

prpl.go

@@ -8,7 +8,7 @@ import (
 
 type (
 	// prpl is an instance of the prpl-server service
-	prpl struct {
+	PRPL struct {
 		http.Handler
 		parser         *uaparser.Parser
 		config         *ProjectConfig
@@ -18,15 +18,16 @@ type (
 		version        string
 		staticHandlers map[string]http.Handler
 		createTemplate createTemplateFn
+		shouldPush     func(r *http.Request) bool
 	}
 
 	// optionFn provides functional option configuration
-	optionFn func(*prpl) error
+	optionFn func(*PRPL) error
 )
 
 // New creates a new prpl instance
-func New(options ...optionFn) (*prpl, error) {
-	p := prpl{
+func New(options ...optionFn) (*PRPL, error) {
+	p := PRPL{
 		parser:         uaparser.NewFromSaved(),
 		root:           http.Dir("."),
 		version:        "/static/",
@@ -60,39 +61,39 @@ func New(options ...optionFn) (*prpl, error) {
 
 // WithVersion sets the version prefix
 func WithVersion(version string) optionFn {
-	return func(p *prpl) error {
+	return func(p *PRPL) error {
 		p.version = "/" + version + "/"
 		return nil
 	}
 }
 
 // WithRoutes sets the route -> fragment mapping
 func WithRoutes(routes Routes) optionFn {
-	return func(p *prpl) error {
+	return func(p *PRPL) error {
 		p.routes = routes
 		return nil
 	}
 }
 
 // WithRoot sets the root directory
 func WithRoot(root http.Dir) optionFn {
-	return func(p *prpl) error {
+	return func(p *PRPL) error {
 		p.root = root
 		return nil
 	}
 }
 
 // WithConfig sets the project configuration
 func WithConfig(config *ProjectConfig) optionFn {
-	return func(p *prpl) error {
+	return func(p *PRPL) error {
 		p.config = config
 		return nil
 	}
 }
 
 // WithConfigFile loads the project configuration
 func WithConfigFile(filename string) optionFn {
-	return func(p *prpl) error {
+	return func(p *PRPL) error {
 		config, err := ConfigFromFile(filename)
 		if err != nil {
 			return err
@@ -105,7 +106,7 @@ func WithConfigFile(filename string) optionFn {
 // WithUAParserFile allows the uaparser configuration
 // to be overriden from the inbuilt settings
 func WithUAParserFile(regexFile string) optionFn {
-	return func(p *prpl) error {
+	return func(p *PRPL) error {
 		parser, err := uaparser.New(regexFile)
 		if err != nil {
 			return err
@@ -118,7 +119,7 @@ func WithUAParserFile(regexFile string) optionFn {
 // WithUAParserBytes allows the uaparser configuration
 // to be overriden from the inbuilt settings
 func WithUAParserBytes(data []byte) optionFn {
-	return func(p *prpl) error {
+	return func(p *PRPL) error {
 		parser, err := uaparser.NewFromBytes(data)
 		if err != nil {
 			return err
@@ -133,7 +134,7 @@ func WithUAParserBytes(data []byte) optionFn {
 // the manifest.json file per tenant or to serve specific
 // images based on host headers etc ...
 func WithStaticHandler(path string, handler http.Handler) optionFn {
-	return func(p *prpl) error {
+	return func(p *PRPL) error {
 		p.staticHandlers[path] = handler
 		return nil
 	}
@@ -143,8 +144,17 @@ func WithStaticHandler(path string, handler http.Handler) optionFn {
 // into a template so that the output can be transformed if
 // required
 func WithRouteTemplate(factory createTemplateFn) optionFn {
-	return func(p *prpl) error {
+	return func(p *PRPL) error {
 		p.createTemplate = factory
 		return nil
 	}
 }
+
+// WithShouldPush specifies when the server should do a direct HTTP server push
+// instead of just setting the server push Link header.
+func WithShouldPush(shouldPush func(*http.Request) bool) optionFn {
+	return func(p *PRPL) error {
+		p.shouldPush = shouldPush
+		return nil
+	}
+}

server.go

@@ -7,7 +7,13 @@ import (
 	"net/http"
 )
 
-func (p *prpl) createHandler() http.Handler {
+var (
+	CacheImmutable    = "public, max-age=31536000, immutable"
+	CacheNever        = "public, max-age=0"
+	CacheNeverPrivate = "private, max-age=0"
+)
+
+func (p *PRPL) createHandler() http.Handler {
 	m := http.NewServeMux()
 
 	for _, build := range p.builds {
@@ -24,7 +30,7 @@ func (p *prpl) createHandler() http.Handler {
 	return m
 }
 
-func (p *prpl) routeHandler(w http.ResponseWriter, r *http.Request) {
+func (p *PRPL) routeHandler(w http.ResponseWriter, r *http.Request) {
 	capabilities := p.browserCapabilities(r.UserAgent())
 	build := p.builds.findBuild(capabilities)
 	if build == nil {
@@ -33,59 +39,68 @@ func (p *prpl) routeHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	h := w.Header()
-	h.Set("Cache-Control", "public, max-age=0")
-	build.addHeaders(w, h, r.URL.Path)
+	h.Set("Cache-Control", CacheNever)
+	build.addHeaders(p, w, r)
 	build.template.Render(w, r)
 }
 
-func (p *prpl) staticHandler(next http.Handler) http.Handler {
+func (p *PRPL) staticHandler(next http.Handler) http.Handler {
 	fn := func(w http.ResponseWriter, r *http.Request) {
 		// TODO: Service worker location should be configurable.
 		h := w.Header()
 		if strings.HasSuffix(r.URL.Path, "service-worker.js") {
 			h.Set("Service-Worker-Allowed", "/")
-			h.Set("Cache-Control", "private, max-age=0")
+			h.Set("Cache-Control", CacheNeverPrivate)
 		} else {
-			h.Set("Cache-Control", "public, max-age=31536000, immutable")
+			h.Set("Cache-Control", CacheImmutable)
 		}
 
+		capabilities := p.browserCapabilities(r.UserAgent())
+		build := p.builds.findBuild(capabilities)
+		if build == nil {
+			http.Error(w, "This browser is not supported", http.StatusInternalServerError)
+			return
+		}
+
+		build.addHeaders(p, w, r)
+
 		file, found := files[r.URL.Path]
 		if !found {
 			next.ServeHTTP(w, r)
 			return
 		}
 
-		// TODO: if using original prpl-server-node strategy
-		// add the push headers for *this* push-manifest entry
-		// build.addHeaders(w, h, r.URL.Path)
-
 		content := bytes.NewReader(file.data)
 		http.ServeContent(w, r, r.URL.Path, file.modTime, content)
 	}
 
 	return http.HandlerFunc(fn)
 }
 
-func (b *build) addHeaders(w http.ResponseWriter, header http.Header, filename string) {
-	if links, ok := b.pushHeaders[filename]; ok {
-		// TODO: use actual push if server supports it
-		// need to add content type to push header info
-		// if pusher, ok := w.(http.Pusher); ok {
-		/*
-			for _, url := range headers {
-				pusher.Push(url, &http.PushOptions{
-					Header: http.Header{
-						"Cache-Control": []string{"public, max-age=31536000, immutable"},
-						"Content-Type":  []string{"TODO: file content type here"},
-					},
-				})
-			}
-		*/
-		// } else {
-		// otherwise hope there is a proxy that will do it for us
+func (b *build) addHeaders(p *PRPL, w http.ResponseWriter, r *http.Request) {
+	header := w.Header()
+	filename := r.URL.Path
+
+	links, ok := b.pushHeaders[filename]
+	if !ok {
+		links, ok = b.pushHeaders[p.version+filename]
+		if !ok {
+			return
+		}
+	}
+
+	if pusher, ok := w.(http.Pusher); ok && p.shouldPush != nil && p.shouldPush(r) {
 		for _, link := range links {
-			header.Add("Link", link)
+			pusher.Push(link.file, &http.PushOptions{
+				Header: http.Header{
+					"Cache-Control": []string{CacheImmutable},
+					//"Content-Type":  []string{"TODO: file content type here"},
+				},
+			})
 		}
-		// }
+	}
+
+	for _, link := range links {
+		header.Add("Link", link.String())
 	}
 }