Handler: add NewMapped, AddMapped

The Handler now supports serving multiple packfiles, possibly with
different prefixes. Precedence is given by order in which packfiles are
registered.

cmd/packserver/go.mod

@@ -1,15 +1,15 @@
 module src.lwithers.me.uk/go/htpack/cmd/packserver
 
-go 1.26.0
+go 1.22
 
 require (
-	github.com/spf13/cobra v1.10.2
+	github.com/spf13/cobra v1.8.1
-	src.lwithers.me.uk/go/htpack v1.5.0
+	src.lwithers.me.uk/go/htpack v1.3.3
 )
 
 require (
+	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
-	github.com/spf13/pflag v1.0.10 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
-	golang.org/x/sys v0.47.0 // indirect
+	golang.org/x/sys v0.22.0 // indirect
-	google.golang.org/protobuf v1.36.12 // indirect
 )

cmd/packserver/go.sum

@@ -1,19 +1,45 @@
-github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
+github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
-github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/gogo/protobuf v1.3.2 h1:Ov1cvc58UF3b5XjBnZv7+opcTcQFZebYjWzi34vdm4Q=
-github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
+github.com/gogo/protobuf v1.3.2/go.mod h1:P1XiOD3dCwIKUDQYPy72D8LYyHL2YPYrpS2s69NZV8Q=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/kisielk/errcheck v1.5.0/go.mod h1:pFxgyoBC7bSaBwPgfKdkLd5X25qrDl4LWUI2bnpBCr8=
+github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
-github.com/spf13/cobra v1.10.2 h1:DMTTonx5m65Ic0GOoRY2c16WCbHxOOw6xxezuLaBpcU=
+github.com/spf13/cobra v1.8.1 h1:e5/vxKd/rZsfSJMUX1agtjeTDf+qv1/JdBF8gg5k9ZM=
-github.com/spf13/cobra v1.10.2/go.mod h1:7C1pvHqHw5A4vrJfjNwvOdzYu0Gml16OCs2GRiTUUS4=
+github.com/spf13/cobra v1.8.1/go.mod h1:wHxEcudfqmLYa8iTfL+OuZPbBZkmvliBWKIezN3kD9Y=
-github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
-github.com/spf13/pflag v1.0.10 h1:4EBh2KAYBwaONj6b2Ye1GiHfwjqyROoF4RwYO+vPwFk=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
-github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
-go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
-golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/sys v0.47.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
-google.golang.org/protobuf v1.36.12 h1:pJOKDDOyeXErUroCihFAd5LQuwXBSpVnKGrj5o/fwxc=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-google.golang.org/protobuf v1.36.12/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
+golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20200226121028-0de0cce0169b/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
+golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20200619180055-7c47624df98f/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
+golang.org/x/tools v0.0.0-20210106214847-113979e3529a/go.mod h1:emZCQorbCU4vsT4fOWvOPXz4eW1wZW4PmDk9uLelYpA=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-src.lwithers.me.uk/go/htpack v1.5.0 h1:2UYM4AGIPc/XgktmO6AxUyqFxzmYkqg/jINcDCsZsCk=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-src.lwithers.me.uk/go/htpack v1.5.0/go.mod h1:5dQlPdwV+ZeBAaFBdwiRI6/w5dpSgPsiotO4ZTYau88=
+src.lwithers.me.uk/go/htpack v1.3.3 h1:Xvl6qR9HfSblmCgPyu+ACQ9o3aLQSIy3l8CrMbzj/jc=
+src.lwithers.me.uk/go/htpack v1.3.3/go.mod h1:qKgCBgZ6iiiuYOxZkYOPVpXLBzp6gXEd4A0ksxgR6Nk=

cmd/packserver/main.go

@@ -55,10 +55,6 @@ func main() {
 		"Name of index file (index.html or similar)")
 	rootCmd.Flags().Duration("expiry", 0,
 		"Tell client how long it can cache data for; 0 means no caching")
-	rootCmd.Flags().Duration("expiry404", 0,
-		"Tell client how long it can cache 404 responses for; 0 means default (inherit from --expiry, max. 60s); -1 means no caching")
-	rootCmd.Flags().Bool("immutable", false,
-		"Tell client that cached assets are immutable (will not be revalidated on page reload)")
 	rootCmd.Flags().String("fallback-404", "",
 		"Name of file to return if response would be 404 (spa.html or similar)")
 	rootCmd.Flags().String("frames", "sameorigin",
@@ -139,35 +135,15 @@ func run(c *cobra.Command, args []string) error {
 
 	// parse expiry time
 	//  NB: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control
-	cacheControl200, cacheControl404 := "no-cache", "no-cache"
-	immutable, err := c.Flags().GetBool("immutable")
-	if err != nil {
-		return err
-	}
-	var immutableDirective string
-	if immutable {
-		immutableDirective = ", immutable"
-	}
-
 	expiry, err := c.Flags().GetDuration("expiry")
 	if err != nil {
 		return err
 	}
-	if expiry > 0 {
+	if expiry <= 0 {
-		cacheControl200 = fmt.Sprintf("public, max-age=%d%s", expiry/1e9, immutableDirective)
+		extraHeaders.Set("Cache-Control", "no-cache")
-	}
+	} else {
-
+		extraHeaders.Set("Cache-Control",
-	expiry404, err := c.Flags().GetDuration("expiry404")
+			fmt.Sprintf("public, max-age=%d", expiry/1e9))
-	if err != nil {
-		return err
-	}
-	switch {
-	case expiry404 == 0 && expiry == 0:
-	case expiry404 == 0 && expiry > 0:
-		expiry404 = min(60*time.Second, expiry)
-		fallthrough
-	case expiry404 > 0:
-		cacheControl404 = fmt.Sprintf("public, max-age=%d", expiry404/1e9)
 	}
 
 	// optional index file
@@ -223,7 +199,6 @@ func run(c *cobra.Command, args []string) error {
 		if err != nil {
 			return err
 		}
-		packHandler.SetCacheControl(cacheControl200, cacheControl404)
 		if indexFile != "" {
 			packHandler.SetIndex(indexFile)
 		}

go.mod

@@ -1,8 +1,9 @@
 module src.lwithers.me.uk/go/htpack
 
-go 1.26.0
+go 1.25.0
 
 require (
-	golang.org/x/sys v0.47.0
+	github.com/google/go-cmp v0.7.0
-	google.golang.org/protobuf v1.36.12
+	golang.org/x/sys v0.45.0
+	google.golang.org/protobuf v1.36.11
 )

go.sum

@@ -1,6 +1,6 @@
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
-golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
+golang.org/x/sys v0.45.0 h1:dO4czNzziLiiXplLQgBCEpCvXQ3dnkn0SdaZSYdQ+FY=
-golang.org/x/sys v0.47.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/sys v0.45.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
-google.golang.org/protobuf v1.36.12 h1:pJOKDDOyeXErUroCihFAd5LQuwXBSpVnKGrj5o/fwxc=
+google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
-google.golang.org/protobuf v1.36.12/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
+google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=

handler.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"net/http"
 	"path"
-	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
@@ -15,6 +14,7 @@ import (
 const (
 	encodingGzip   = "gzip"
 	encodingBrotli = "br"
+	encodingZstd   = "zstd"
 )
 
 // New returns a new handler. Standard security headers are set.
@@ -23,14 +23,21 @@ func New(packfile string) (*Handler, error) {
 	if err != nil {
 		return nil, err
 	}
+	return NewMapped("/", mapped), nil
+}
 
+// NewMapped returns a new handler, given an already-mapped datafile. Standard
+// security headers are set.
+//
+// Files are served under the directory prefix given by path, which may be
+// empty or "/" for the root path. Note the [Handler.ServeMapped] method may specify
+// additional files to be served under different paths, not affected by this
+// path.
+func NewMapped(path string, mapped *packed.Mapped) *Handler {
 	h := &Handler{
-		mapped:          mapped.Data,
+		files:     make(map[string]handlerFile),
-		dir:             mapped.Directory.Files,
+		headers:   make(map[string]string),
-		headers:         make(map[string]string),
+		startTime: time.Now(),
-		cacheControl200: "no-cache",
-		cacheControl404: "no-cache",
-		startTime:       time.Now(),
 	}
 
 	// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options
@@ -39,18 +46,24 @@ func New(packfile string) (*Handler, error) {
 	// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options
 	h.SetHeader("X-Content-Type-Options", "nosniff")
 
-	return h, nil
+	h.addFiles(path, mapped)
+
+	return h
 }
 
 // Handler implements http.Handler and allows options to be set.
 type Handler struct {
-	mapped          []byte
+	files     map[string]handlerFile
-	dir             map[string]*packed.File
+	headers   map[string]string
-	headers         map[string]string
+	startTime time.Time
-	cacheControl200 string
+	notFound  *handlerFile
-	cacheControl404 string
+}
-	startTime       time.Time
+
-	notFound        *packed.File
+// AddMapped serves up additional files from the given mapped packfile. The
+// given path is taken as a serving prefix. If a file for a given path already
+// exists, the existing file takes precedence.
+func (h *Handler) AddMapped(path string, mapped *packed.Mapped) {
+	h.addFiles(path, mapped)
 }
 
 // SetHeader allows a custom header to be set on HTTP responses. These are
@@ -79,11 +92,11 @@ func (h *Handler) SetHeader(key, value string) {
 // multiple times with different filenames (noting later calls would not
 // overwrite files matching earlier calls).
 func (h *Handler) SetIndex(filename string) {
-	for k, v := range h.dir {
+	for k, v := range h.files {
-		if filepath.Base(k) == filename {
+		if path.Base(k) == filename {
-			routeToAdd := filepath.Dir(k)
+			routeToAdd := path.Dir(k)
-			if _, exists := h.dir[routeToAdd]; !exists {
+			if _, exists := h.files[routeToAdd]; !exists {
-				h.dir[routeToAdd] = v
+				h.files[routeToAdd] = v
 			}
 		}
 	}
@@ -103,25 +116,60 @@ func (h *Handler) SetNotFound(notFound string) error {
 	}
 
 	notFound = path.Clean(notFound)
-	dir := h.dir[path.Clean(notFound)]
+	f, ok := h.files[path.Clean(notFound)]
-	if dir == nil {
+	if !ok {
 		return fmt.Errorf("no such resource %q", notFound)
 	}
-	h.notFound = dir
+	h.notFound = &f
 	return nil
 }
 
-// SetCacheControl allows control over the cache-control header. If not called,
+type handlerFile struct {
-// "Cache-Control: no-cache" is the default.
+	contentType, etag                string
-//
+	uncompressed, gzip, brotli, zstd []byte
-// The first and second arguments are required, and specify the header to use
+}
-// for 200 responses and 404 responses respectively.
+
-//
+func (h *Handler) addFiles(prefix string, mapped *packed.Mapped) {
-// TODO: could be expanded to take extra varargs for more specific control over
+	// our directory contains files like "/index.html". We will add
-// particular assets, like different expiry per content-type.
+	// a prefix, which might be "" or "/foo".
-func (h *Handler) SetCacheControl(hdr200, hdr404 string) {
+	prefix = path.Clean(prefix)
-	h.cacheControl200 = hdr200
+	prefix = strings.TrimSuffix(prefix, "/")
-	h.cacheControl404 = hdr404
+	switch {
+	case prefix == "":
+	case prefix == ".":
+		prefix = ""
+	case !strings.HasPrefix(prefix, "/"):
+		prefix = "/" + prefix
+	}
+
+	for filePath, file := range mapped.Directory.Files {
+		handlerPath := prefix + filePath
+		if _, exists := h.files[handlerPath]; exists {
+			// don't overwrite existing entries
+			continue
+		}
+		h.files[handlerPath] = buildHandlerFile(mapped.Data, file)
+	}
+}
+
+func buildHandlerFile(data []byte, file *packed.File) handlerFile {
+	byteSlice := func(fileData *packed.FileData) []byte {
+		if fileData == nil {
+			return nil
+		}
+		start := fileData.Offset
+		end := start + fileData.Length
+		return data[start:end]
+	}
+	hf := handlerFile{
+		contentType: file.ContentType,
+		etag:        file.Etag,
+	}
+	hf.uncompressed = byteSlice(file.Uncompressed)
+	hf.gzip = byteSlice(file.Gzip)
+	hf.brotli = byteSlice(file.Brotli)
+	hf.zstd = byteSlice(file.Zstd)
+	return hf
 }
 
 // ServeHTTP handles requests for files. It supports GET and HEAD methods, with
@@ -142,46 +190,48 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	info := h.dir[path.Clean(req.URL.Path)]
+	info, ok := h.files[path.Clean(req.URL.Path)]
-	if info == nil {
+	if !ok {
-		w.Header().Set("Cache-Control", h.cacheControl404)
 		if h.notFound == nil {
 			http.NotFound(w, req)
 			return
 		}
-		info = h.notFound
+		info = *h.notFound
 	}
 
 	// set standard headers
-	w.Header().Set("Cache-Control", h.cacheControl200)
 	w.Header().Set("Vary", "Accept-Encoding")
-	w.Header().Set("Etag", info.Etag)
+	w.Header().Set("Etag", info.etag)
-	w.Header().Set("Content-Type", info.ContentType)
+	w.Header().Set("Content-Type", info.contentType)
 	w.Header().Set("Accept-Ranges", "bytes")
 
 	// process etag / modtime
-	if clientHasCachedVersion(info.Etag, h.startTime, req) {
+	if clientHasCachedVersion(info.etag, h.startTime, req) {
 		w.WriteHeader(http.StatusNotModified)
 		return
 	}
 
 	// select compression
-	data := info.Uncompressed
+	data := info.uncompressed
-	gzip, brotli := acceptedEncodings(req)
+	gzip, brotli, zstd := acceptedEncodings(req)
-	if brotli && info.Brotli != nil {
+	switch {
-		data = info.Brotli
+	case zstd && info.zstd != nil:
+		data = info.zstd
+		w.Header().Set("Content-Encoding", encodingZstd)
+	case brotli && info.brotli != nil:
+		data = info.brotli
 		w.Header().Set("Content-Encoding", encodingBrotli)
-	} else if gzip && info.Gzip != nil {
+	case gzip && info.gzip != nil:
-		data = info.Gzip
+		data = info.gzip
 		w.Header().Set("Content-Encoding", encodingGzip)
 	}
 
 	// range support (single-part ranges only)
 	// https://developer.mozilla.org/en-US/docs/Web/HTTP/Range_requests#Single_part_ranges
-	offset, length, isPartial := getFileRange(data, req)
+	offset, length, isPartial := getFileRange(uint64(len(data)), req)
 	if isPartial {
 		w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d",
-			offset, offset+length-1, data.Length))
+			offset, offset+length-1, len(data)))
 	}
 
 	// now we know exactly what we're writing, finalise HTTP header
@@ -197,11 +247,10 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	offset += data.Offset
+	w.Write(data[offset : offset+length])
-	w.Write(h.mapped[offset : offset+length])
 }
 
-func acceptedEncodings(req *http.Request) (gzip, brotli bool) {
+func acceptedEncodings(req *http.Request) (gzip, brotli, zstd bool) {
 	encodings := req.Header.Get("Accept-Encoding")
 	for _, enc := range strings.Split(encodings, ",") {
 		switch strings.TrimSpace(enc) {
@@ -244,8 +293,8 @@ func clientHasCachedVersion(etag string, startTime time.Time, req *http.Request,
 
 // getFileRange returns the byte offset and length of the file to serve, along
 // with whether or not it's partial content.
-func getFileRange(data *packed.FileData, req *http.Request) (offset, length uint64, isPartial bool) {
+func getFileRange(dataLength uint64, req *http.Request) (offset, length uint64, isPartial bool) {
-	length = data.Length
+	length = dataLength
 
 	// only accept "Range: bytes=…"
 	r := req.Header.Get("Range")
@@ -272,8 +321,8 @@ func getFileRange(data *packed.FileData, req *http.Request) (offset, length uint
 	// validate the interval lies within the file
 	switch {
 	case from > to,
-		from >= data.Length,
+		from >= dataLength,
-		to >= data.Length:
+		to >= dataLength:
 		return
 	}
 

handler_test.go

@@ -0,0 +1,49 @@
+package htpack
+
+import (
+	"bytes"
+	"io"
+	"net/http/httptest"
+	"os"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"src.lwithers.me.uk/go/htpack/packed"
+)
+
+func TestHandler(t *testing.T) {
+	mapped, err := packed.MapAndLoad("packed/testdata/helloworld.pack")
+	if err != nil {
+		t.Fatal("loading test packfile:", err)
+	}
+	defer mapped.Close()
+
+	orig, err := os.ReadFile("packed/testdata/helloworld.txt")
+	if err != nil {
+		t.Fatal("loading test textfile:", err)
+	}
+
+	h := NewMapped("", mapped)
+	h.AddMapped("/foo", mapped)
+
+	testsv := httptest.NewServer(h)
+	defer testsv.Close()
+	cl := testsv.Client()
+	url := testsv.URL + "/helloworld.txt"
+
+	resp, err := cl.Get(url)
+	if err != nil {
+		t.Fatal("executing GET request:", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		t.Fatal("reading response body:", err)
+	}
+
+	if !bytes.Equal(body, orig) {
+		t.Error("difference in response (- got, + expected):")
+		t.Error(cmp.Diff(string(body), string(orig)))
+	}
+}

packed/packed.pb.go

@@ -168,6 +168,8 @@ type File struct {
 	Gzip *FileData `protobuf:"bytes,4,opt,name=gzip,proto3" json:"gzip,omitempty"`
 	// Brotli compressed version of the file.
 	Brotli *FileData `protobuf:"bytes,5,opt,name=brotli,proto3" json:"brotli,omitempty"`
+	// Zstd compressed version of the file.
+	Zstd *FileData `protobuf:"bytes,6,opt,name=zstd,proto3" json:"zstd,omitempty"`
 }
 
 func (x *File) Reset() {
@@ -237,6 +239,13 @@ func (x *File) GetBrotli() *FileData {
 	return nil
 }
 
+func (x *File) GetZstd() *FileData {
+	if x != nil {
+		return x.Zstd
+	}
+	return nil
+}
+
 // FileData records the position of the file data within the pack.
 type FileData struct {
 	state         protoimpl.MessageState
@@ -321,7 +330,7 @@ var file_packed_proto_rawDesc = []byte{
 	0x75, 0x65, 0x18, 0x02, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x1c, 0x2e, 0x6c, 0x77, 0x69, 0x74, 0x68,
 	0x65, 0x72, 0x73, 0x2e, 0x68, 0x74, 0x70, 0x61, 0x63, 0x6b, 0x2e, 0x70, 0x61, 0x63, 0x6b, 0x65,
 	0x64, 0x2e, 0x46, 0x69, 0x6c, 0x65, 0x52, 0x05, 0x76, 0x61, 0x6c, 0x75, 0x65, 0x3a, 0x02, 0x38,
-	0x01, 0x22, 0xf3, 0x01, 0x0a, 0x04, 0x46, 0x69, 0x6c, 0x65, 0x12, 0x21, 0x0a, 0x0c, 0x63, 0x6f,
+	0x01, 0x22, 0xa9, 0x02, 0x0a, 0x04, 0x46, 0x69, 0x6c, 0x65, 0x12, 0x21, 0x0a, 0x0c, 0x63, 0x6f,
 	0x6e, 0x74, 0x65, 0x6e, 0x74, 0x5f, 0x74, 0x79, 0x70, 0x65, 0x18, 0x01, 0x20, 0x01, 0x28, 0x09,
 	0x52, 0x0b, 0x63, 0x6f, 0x6e, 0x74, 0x65, 0x6e, 0x74, 0x54, 0x79, 0x70, 0x65, 0x12, 0x12, 0x0a,
 	0x04, 0x65, 0x74, 0x61, 0x67, 0x18, 0x02, 0x20, 0x01, 0x28, 0x09, 0x52, 0x04, 0x65, 0x74, 0x61,
@@ -336,13 +345,17 @@ var file_packed_proto_rawDesc = []byte{
 	0x06, 0x62, 0x72, 0x6f, 0x74, 0x6c, 0x69, 0x18, 0x05, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x20, 0x2e,
 	0x6c, 0x77, 0x69, 0x74, 0x68, 0x65, 0x72, 0x73, 0x2e, 0x68, 0x74, 0x70, 0x61, 0x63, 0x6b, 0x2e,
 	0x70, 0x61, 0x63, 0x6b, 0x65, 0x64, 0x2e, 0x46, 0x69, 0x6c, 0x65, 0x44, 0x61, 0x74, 0x61, 0x52,
-	0x06, 0x62, 0x72, 0x6f, 0x74, 0x6c, 0x69, 0x22, 0x3a, 0x0a, 0x08, 0x46, 0x69, 0x6c, 0x65, 0x44,
+	0x06, 0x62, 0x72, 0x6f, 0x74, 0x6c, 0x69, 0x12, 0x34, 0x0a, 0x04, 0x7a, 0x73, 0x74, 0x64, 0x18,
-	0x61, 0x74, 0x61, 0x12, 0x16, 0x0a, 0x06, 0x6f, 0x66, 0x66, 0x73, 0x65, 0x74, 0x18, 0x01, 0x20,
+	0x06, 0x20, 0x01, 0x28, 0x0b, 0x32, 0x20, 0x2e, 0x6c, 0x77, 0x69, 0x74, 0x68, 0x65, 0x72, 0x73,
-	0x01, 0x28, 0x06, 0x52, 0x06, 0x6f, 0x66, 0x66, 0x73, 0x65, 0x74, 0x12, 0x16, 0x0a, 0x06, 0x6c,
+	0x2e, 0x68, 0x74, 0x70, 0x61, 0x63, 0x6b, 0x2e, 0x70, 0x61, 0x63, 0x6b, 0x65, 0x64, 0x2e, 0x46,
-	0x65, 0x6e, 0x67, 0x74, 0x68, 0x18, 0x02, 0x20, 0x01, 0x28, 0x06, 0x52, 0x06, 0x6c, 0x65, 0x6e,
+	0x69, 0x6c, 0x65, 0x44, 0x61, 0x74, 0x61, 0x52, 0x04, 0x7a, 0x73, 0x74, 0x64, 0x22, 0x3a, 0x0a,
-	0x67, 0x74, 0x68, 0x42, 0x22, 0x5a, 0x20, 0x73, 0x72, 0x63, 0x2e, 0x6c, 0x77, 0x69, 0x74, 0x68,
+	0x08, 0x46, 0x69, 0x6c, 0x65, 0x44, 0x61, 0x74, 0x61, 0x12, 0x16, 0x0a, 0x06, 0x6f, 0x66, 0x66,
-	0x65, 0x72, 0x73, 0x2e, 0x6d, 0x65, 0x2e, 0x75, 0x6b, 0x2f, 0x68, 0x74, 0x70, 0x61, 0x63, 0x6b,
+	0x73, 0x65, 0x74, 0x18, 0x01, 0x20, 0x01, 0x28, 0x06, 0x52, 0x06, 0x6f, 0x66, 0x66, 0x73, 0x65,
-	0x2f, 0x70, 0x61, 0x63, 0x6b, 0x65, 0x64, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+	0x74, 0x12, 0x16, 0x0a, 0x06, 0x6c, 0x65, 0x6e, 0x67, 0x74, 0x68, 0x18, 0x02, 0x20, 0x01, 0x28,
+	0x06, 0x52, 0x06, 0x6c, 0x65, 0x6e, 0x67, 0x74, 0x68, 0x42, 0x22, 0x5a, 0x20, 0x73, 0x72, 0x63,
+	0x2e, 0x6c, 0x77, 0x69, 0x74, 0x68, 0x65, 0x72, 0x73, 0x2e, 0x6d, 0x65, 0x2e, 0x75, 0x6b, 0x2f,
+	0x68, 0x74, 0x70, 0x61, 0x63, 0x6b, 0x2f, 0x70, 0x61, 0x63, 0x6b, 0x65, 0x64, 0x62, 0x06, 0x70,
+	0x72, 0x6f, 0x74, 0x6f, 0x33,
 }
 
 var (
@@ -370,12 +383,13 @@ var file_packed_proto_depIdxs = []int32{
 	3, // 1: lwithers.htpack.packed.File.uncompressed:type_name -> lwithers.htpack.packed.FileData
 	3, // 2: lwithers.htpack.packed.File.gzip:type_name -> lwithers.htpack.packed.FileData
 	3, // 3: lwithers.htpack.packed.File.brotli:type_name -> lwithers.htpack.packed.FileData
-	2, // 4: lwithers.htpack.packed.Directory.FilesEntry.value:type_name -> lwithers.htpack.packed.File
+	3, // 4: lwithers.htpack.packed.File.zstd:type_name -> lwithers.htpack.packed.FileData
-	5, // [5:5] is the sub-list for method output_type
+	2, // 5: lwithers.htpack.packed.Directory.FilesEntry.value:type_name -> lwithers.htpack.packed.File
-	5, // [5:5] is the sub-list for method input_type
+	6, // [6:6] is the sub-list for method output_type
-	5, // [5:5] is the sub-list for extension type_name
+	6, // [6:6] is the sub-list for method input_type
-	5, // [5:5] is the sub-list for extension extendee
+	6, // [6:6] is the sub-list for extension type_name
-	0, // [0:5] is the sub-list for field type_name
+	6, // [6:6] is the sub-list for extension extendee
+	0, // [0:6] is the sub-list for field type_name
 }
 
 func init() { file_packed_proto_init() }

packed/packed.proto

@@ -47,6 +47,9 @@ message File {
 
 	// Brotli compressed version of the file.
 	FileData brotli = 5;
+
+	// Zstd compressed version of the file.
+	FileData zstd = 6;
 }
 
 // FileData records the position of the file data within the pack.