]> Cypherpunks repositories - gostls13.git/commitdiff
http: ServeFile to handle Range header for partial requests
authorAndrew Gerrand <adg@golang.org>
Thu, 9 Dec 2010 21:51:13 +0000 (08:51 +1100)
committerAndrew Gerrand <adg@golang.org>
Thu, 9 Dec 2010 21:51:13 +0000 (08:51 +1100)
and send Content-Length.

Also includes some testing of the server code.

R=rsc
CC=golang-dev
https://golang.org/cl/2831041

src/pkg/http/fs.go
src/pkg/http/fs_test.go [new file with mode: 0644]
src/pkg/http/testdata/file [new file with mode: 0644]

index b3047f18275243edef48fe824b4b3a89d4583951..72db946dfffbbe5ccce2ac7fc9c917627a38390c 100644 (file)
@@ -12,6 +12,7 @@ import (
        "mime"
        "os"
        "path"
+       "strconv"
        "strings"
        "time"
        "utf8"
@@ -130,6 +131,9 @@ func serveFile(w ResponseWriter, r *Request, name string, redirect bool) {
        }
 
        // serve file
+       size := d.Size
+       code := StatusOK
+
        // use extension to find content type.
        ext := path.Ext(name)
        if ctype := mime.TypeByExtension(ext); ctype != "" {
@@ -137,16 +141,40 @@ func serveFile(w ResponseWriter, r *Request, name string, redirect bool) {
        } else {
                // read first chunk to decide between utf-8 text and binary
                var buf [1024]byte
-               n, _ := io.ReadFull(f, buf[0:])
-               b := buf[0:n]
+               n, _ := io.ReadFull(f, buf[:])
+               b := buf[:n]
                if isText(b) {
                        w.SetHeader("Content-Type", "text-plain; charset=utf-8")
                } else {
                        w.SetHeader("Content-Type", "application/octet-stream") // generic binary
                }
-               w.Write(b)
+               f.Seek(0, 0) // rewind to output whole file
+       }
+
+       // handle Content-Range header.
+       // TODO(adg): handle multiple ranges
+       ranges, err := parseRange(r.Header["Range"], size)
+       if err != nil || len(ranges) > 1 {
+               Error(w, err.String(), StatusRequestedRangeNotSatisfiable)
+               return
+       }
+       if len(ranges) == 1 {
+               ra := ranges[0]
+               if _, err := f.Seek(ra.start, 0); err != nil {
+                       Error(w, err.String(), StatusRequestedRangeNotSatisfiable)
+                       return
+               }
+               size = ra.length
+               code = StatusPartialContent
+               w.SetHeader("Content-Range", fmt.Sprintf("%d-%d/%d", ra.start, ra.start+ra.length, d.Size))
        }
-       io.Copy(w, f)
+
+       w.SetHeader("Accept-Ranges", "bytes")
+       w.SetHeader("Content-Length", strconv.Itoa64(size))
+
+       w.WriteHeader(code)
+
+       io.Copyn(w, f, size)
 }
 
 // ServeFile replies to the request with the contents of the named file or directory.
@@ -174,3 +202,62 @@ func (f *fileHandler) ServeHTTP(w ResponseWriter, r *Request) {
        path = path[len(f.prefix):]
        serveFile(w, r, f.root+"/"+path, true)
 }
+
+// httpRange specifies the byte range to be sent to the client.
+type httpRange struct {
+       start, length int64
+}
+
+// parseRange parses a Range header string as per RFC 2616.
+func parseRange(s string, size int64) ([]httpRange, os.Error) {
+       if s == "" {
+               return nil, nil // header not present
+       }
+       const b = "bytes="
+       if !strings.HasPrefix(s, b) {
+               return nil, os.NewError("invalid range")
+       }
+       var ranges []httpRange
+       for _, ra := range strings.Split(s[len(b):], ",", -1) {
+               i := strings.Index(ra, "-")
+               if i < 0 {
+                       return nil, os.NewError("invalid range")
+               }
+               start, end := ra[:i], ra[i+1:]
+               var r httpRange
+               if start == "" {
+                       // If no start is specified, end specifies the
+                       // range start relative to the end of the file.
+                       i, err := strconv.Atoi64(end)
+                       if err != nil {
+                               return nil, os.NewError("invalid range")
+                       }
+                       if i > size {
+                               i = size
+                       }
+                       r.start = size - i
+                       r.length = size - r.start
+               } else {
+                       i, err := strconv.Atoi64(start)
+                       if err != nil || i > size || i < 0 {
+                               return nil, os.NewError("invalid range")
+                       }
+                       r.start = i
+                       if end == "" {
+                               // If no end is specified, range extends to end of the file.
+                               r.length = size - r.start
+                       } else {
+                               i, err := strconv.Atoi64(end)
+                               if err != nil || r.start > i {
+                                       return nil, os.NewError("invalid range")
+                               }
+                               if i >= size {
+                                       i = size - 1
+                               }
+                               r.length = i - r.start + 1
+                       }
+               }
+               ranges = append(ranges, r)
+       }
+       return ranges, nil
+}
diff --git a/src/pkg/http/fs_test.go b/src/pkg/http/fs_test.go
new file mode 100644 (file)
index 0000000..0f71356
--- /dev/null
@@ -0,0 +1,172 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package http
+
+import (
+       "fmt"
+       "io/ioutil"
+       "net"
+       "os"
+       "sync"
+       "testing"
+)
+
+var ParseRangeTests = []struct {
+       s      string
+       length int64
+       r      []httpRange
+}{
+       {"", 0, nil},
+       {"foo", 0, nil},
+       {"bytes=", 0, nil},
+       {"bytes=5-4", 10, nil},
+       {"bytes=0-2,5-4", 10, nil},
+       {"bytes=0-9", 10, []httpRange{{0, 10}}},
+       {"bytes=0-", 10, []httpRange{{0, 10}}},
+       {"bytes=5-", 10, []httpRange{{5, 5}}},
+       {"bytes=0-20", 10, []httpRange{{0, 10}}},
+       {"bytes=15-,0-5", 10, nil},
+       {"bytes=-5", 10, []httpRange{{5, 5}}},
+       {"bytes=-15", 10, []httpRange{{0, 10}}},
+       {"bytes=0-499", 10000, []httpRange{{0, 500}}},
+       {"bytes=500-999", 10000, []httpRange{{500, 500}}},
+       {"bytes=-500", 10000, []httpRange{{9500, 500}}},
+       {"bytes=9500-", 10000, []httpRange{{9500, 500}}},
+       {"bytes=0-0,-1", 10000, []httpRange{{0, 1}, {9999, 1}}},
+       {"bytes=500-600,601-999", 10000, []httpRange{{500, 101}, {601, 399}}},
+       {"bytes=500-700,601-999", 10000, []httpRange{{500, 201}, {601, 399}}},
+}
+
+func TestParseRange(t *testing.T) {
+       for _, test := range ParseRangeTests {
+               r := test.r
+               ranges, err := parseRange(test.s, test.length)
+               if err != nil && r != nil {
+                       t.Errorf("parseRange(%q) returned error %q", test.s, err)
+               }
+               if len(ranges) != len(r) {
+                       t.Errorf("len(parseRange(%q)) = %d, want %d", test.s, len(ranges), len(r))
+                       continue
+               }
+               for i := range r {
+                       if ranges[i].start != r[i].start {
+                               t.Errorf("parseRange(%q)[%d].start = %d, want %d", test.s, i, ranges[i].start, r[i].start)
+                       }
+                       if ranges[i].length != r[i].length {
+                               t.Errorf("parseRange(%q)[%d].length = %d, want %d", test.s, i, ranges[i].length, r[i].length)
+                       }
+               }
+       }
+}
+
+const (
+       testFile       = "testdata/file"
+       testFileLength = 11
+)
+
+var (
+       serverOnce sync.Once
+       serverAddr string
+)
+
+func startServer(t *testing.T) {
+       serverOnce.Do(func() {
+               HandleFunc("/ServeFile", func(w ResponseWriter, r *Request) {
+                       ServeFile(w, r, "testdata/file")
+               })
+               l, err := net.Listen("tcp", "127.0.0.1:0")
+               if err != nil {
+                       t.Fatal("listen:", err)
+               }
+               serverAddr = l.Addr().String()
+               go Serve(l, nil)
+       })
+}
+
+var ServeFileRangeTests = []struct {
+       start, end int
+       r          string
+       code       int
+}{
+       {0, testFileLength, "", StatusOK},
+       {0, 5, "0-4", StatusPartialContent},
+       {2, testFileLength, "2-", StatusPartialContent},
+       {testFileLength - 5, testFileLength, "-5", StatusPartialContent},
+       {3, 8, "3-7", StatusPartialContent},
+       {0, 0, "20-", StatusRequestedRangeNotSatisfiable},
+}
+
+func TestServeFile(t *testing.T) {
+       startServer(t)
+       var err os.Error
+
+       file, err := ioutil.ReadFile(testFile)
+       if err != nil {
+               t.Fatal("reading file:", err)
+       }
+
+       // set up the Request (re-used for all tests)
+       var req Request
+       req.Header = make(map[string]string)
+       if req.URL, err = ParseURL("http://" + serverAddr + "/ServeFile"); err != nil {
+               t.Fatal("ParseURL:", err)
+       }
+       req.Method = "GET"
+
+       // straight GET
+       _, body := getBody(t, req)
+       if !equal(body, file) {
+               t.Fatalf("body mismatch: got %q, want %q", body, file)
+       }
+
+       // Range tests
+       for _, rt := range ServeFileRangeTests {
+               req.Header["Range"] = "bytes=" + rt.r
+               if rt.r == "" {
+                       req.Header["Range"] = ""
+               }
+               r, body := getBody(t, req)
+               if r.StatusCode != rt.code {
+                       t.Errorf("range=%q: StatusCode=%d, want %d", rt.r, r.StatusCode, rt.code)
+               }
+               if rt.code == StatusRequestedRangeNotSatisfiable {
+                       continue
+               }
+               h := fmt.Sprintf("%d-%d/%d", rt.start, rt.end, testFileLength)
+               if rt.r == "" {
+                       h = ""
+               }
+               if r.Header["Content-Range"] != h {
+                       t.Errorf("header mismatch: range=%q: got %q, want %q", rt.r, r.Header["Content-Range"], h)
+               }
+               if !equal(body, file[rt.start:rt.end]) {
+                       t.Errorf("body mismatch: range=%q: got %q, want %q", rt.r, body, file[rt.start:rt.end])
+               }
+       }
+}
+
+func getBody(t *testing.T, req Request) (*Response, []byte) {
+       r, err := send(&req)
+       if err != nil {
+               t.Fatal(req.URL.String(), "send:", err)
+       }
+       b, err := ioutil.ReadAll(r.Body)
+       if err != nil {
+               t.Fatal("reading Body:", err)
+       }
+       return r, b
+}
+
+func equal(a, b []byte) bool {
+       if len(a) != len(b) {
+               return false
+       }
+       for i := range a {
+               if a[i] != b[i] {
+                       return false
+               }
+       }
+       return true
+}
diff --git a/src/pkg/http/testdata/file b/src/pkg/http/testdata/file
new file mode 100644 (file)
index 0000000..11f11f9
--- /dev/null
@@ -0,0 +1 @@
+0123456789