diff options
Diffstat (limited to 'libgo/go/net/http/fs.go')
| -rw-r--r-- | libgo/go/net/http/fs.go | 211 |
1 files changed, 124 insertions, 87 deletions
diff --git a/libgo/go/net/http/fs.go b/libgo/go/net/http/fs.go index 1392ca68ad6..f35dd32c305 100644 --- a/libgo/go/net/http/fs.go +++ b/libgo/go/net/http/fs.go @@ -17,7 +17,6 @@ import ( "strconv" "strings" "time" - "unicode/utf8" ) // A Dir implements http.FileSystem using the native file @@ -58,32 +57,6 @@ type File interface { Seek(offset int64, whence int) (int64, error) } -// Heuristic: b is text if it is valid UTF-8 and doesn't -// contain any unprintable ASCII or Unicode characters. -func isText(b []byte) bool { - for len(b) > 0 && utf8.FullRune(b) { - rune, size := utf8.DecodeRune(b) - if size == 1 && rune == utf8.RuneError { - // decoding error - return false - } - if 0x7F <= rune && rune <= 0x9F { - return false - } - if rune < ' ' { - switch rune { - case '\n', '\r', '\t': - // okay - default: - // binary garbage - return false - } - } - b = b[size:] - } - return true -} - func dirList(w ResponseWriter, f File) { w.Header().Set("Content-Type", "text/html; charset=utf-8") fmt.Fprintf(w, "<pre>\n") @@ -104,6 +77,126 @@ func dirList(w ResponseWriter, f File) { fmt.Fprintf(w, "</pre>\n") } +// ServeContent replies to the request using the content in the +// provided ReadSeeker. The main benefit of ServeContent over io.Copy +// is that it handles Range requests properly, sets the MIME type, and +// handles If-Modified-Since requests. +// +// If the response's Content-Type header is not set, ServeContent +// first tries to deduce the type from name's file extension and, +// if that fails, falls back to reading the first block of the content +// and passing it to DetectContentType. +// The name is otherwise unused; in particular it can be empty and is +// never sent in the response. +// +// If modtime is not the zero time, ServeContent includes it in a +// Last-Modified header in the response. If the request includes an +// If-Modified-Since header, ServeContent uses modtime to decide +// whether the content needs to be sent at all. +// +// The content's Seek method must work: ServeContent uses +// a seek to the end of the content to determine its size. +// +// Note that *os.File implements the io.ReadSeeker interface. +func ServeContent(w ResponseWriter, req *Request, name string, modtime time.Time, content io.ReadSeeker) { + size, err := content.Seek(0, os.SEEK_END) + if err != nil { + Error(w, "seeker can't seek", StatusInternalServerError) + return + } + _, err = content.Seek(0, os.SEEK_SET) + if err != nil { + Error(w, "seeker can't seek", StatusInternalServerError) + return + } + serveContent(w, req, name, modtime, size, content) +} + +// if name is empty, filename is unknown. (used for mime type, before sniffing) +// if modtime.IsZero(), modtime is unknown. +// content must be seeked to the beginning of the file. +func serveContent(w ResponseWriter, r *Request, name string, modtime time.Time, size int64, content io.ReadSeeker) { + if checkLastModified(w, r, modtime) { + return + } + + code := StatusOK + + // If Content-Type isn't set, use the file's extension to find it. + if w.Header().Get("Content-Type") == "" { + ctype := mime.TypeByExtension(filepath.Ext(name)) + if ctype == "" { + // read a chunk to decide between utf-8 text and binary + var buf [1024]byte + n, _ := io.ReadFull(content, buf[:]) + b := buf[:n] + ctype = DetectContentType(b) + _, err := content.Seek(0, os.SEEK_SET) // rewind to output whole file + if err != nil { + Error(w, "seeker can't seek", StatusInternalServerError) + return + } + } + w.Header().Set("Content-Type", ctype) + } + + // handle Content-Range header. + // TODO(adg): handle multiple ranges + sendSize := size + if size >= 0 { + ranges, err := parseRange(r.Header.Get("Range"), size) + if err == nil && len(ranges) > 1 { + err = errors.New("multiple ranges not supported") + } + if err != nil { + Error(w, err.Error(), StatusRequestedRangeNotSatisfiable) + return + } + if len(ranges) == 1 { + ra := ranges[0] + if _, err := content.Seek(ra.start, os.SEEK_SET); err != nil { + Error(w, err.Error(), StatusRequestedRangeNotSatisfiable) + return + } + sendSize = ra.length + code = StatusPartialContent + w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", ra.start, ra.start+ra.length-1, size)) + } + + w.Header().Set("Accept-Ranges", "bytes") + if w.Header().Get("Content-Encoding") == "" { + w.Header().Set("Content-Length", strconv.FormatInt(sendSize, 10)) + } + } + + w.WriteHeader(code) + + if r.Method != "HEAD" { + if sendSize == -1 { + io.Copy(w, content) + } else { + io.CopyN(w, content, sendSize) + } + } +} + +// modtime is the modification time of the resource to be served, or IsZero(). +// return value is whether this request is now complete. +func checkLastModified(w ResponseWriter, r *Request, modtime time.Time) bool { + if modtime.IsZero() { + return false + } + + // The Date-Modified header truncates sub-second precision, so + // use mtime < t+1s instead of mtime <= t to check for unmodified. + if t, err := time.Parse(TimeFormat, r.Header.Get("If-Modified-Since")); err == nil && modtime.Before(t.Add(1*time.Second)) { + w.WriteHeader(StatusNotModified) + return true + } + w.Header().Set("Last-Modified", modtime.UTC().Format(TimeFormat)) + return false +} + // name is '/'-separated, not filepath.Separator. func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirect bool) { const indexPage = "/index.html" @@ -148,14 +241,11 @@ func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirec } } - if t, err := time.Parse(TimeFormat, r.Header.Get("If-Modified-Since")); err == nil && !d.ModTime().After(t) { - w.WriteHeader(StatusNotModified) - return - } - w.Header().Set("Last-Modified", d.ModTime().UTC().Format(TimeFormat)) - // use contents of index.html for directory, if present if d.IsDir() { + if checkLastModified(w, r, d.ModTime()) { + return + } index := name + indexPage ff, err := fs.Open(index) if err == nil { @@ -174,60 +264,7 @@ func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirec return } - // serve file - size := d.Size() - code := StatusOK - - // If Content-Type isn't set, use the file's extension to find it. - if w.Header().Get("Content-Type") == "" { - ctype := mime.TypeByExtension(filepath.Ext(name)) - if ctype == "" { - // read a chunk to decide between utf-8 text and binary - var buf [1024]byte - n, _ := io.ReadFull(f, buf[:]) - b := buf[:n] - if isText(b) { - ctype = "text/plain; charset=utf-8" - } else { - // generic binary - ctype = "application/octet-stream" - } - f.Seek(0, os.SEEK_SET) // rewind to output whole file - } - w.Header().Set("Content-Type", ctype) - } - - // handle Content-Range header. - // TODO(adg): handle multiple ranges - ranges, err := parseRange(r.Header.Get("Range"), size) - if err == nil && len(ranges) > 1 { - err = errors.New("multiple ranges not supported") - } - if err != nil { - Error(w, err.Error(), StatusRequestedRangeNotSatisfiable) - return - } - if len(ranges) == 1 { - ra := ranges[0] - if _, err := f.Seek(ra.start, os.SEEK_SET); err != nil { - Error(w, err.Error(), StatusRequestedRangeNotSatisfiable) - return - } - size = ra.length - code = StatusPartialContent - w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", ra.start, ra.start+ra.length-1, d.Size())) - } - - w.Header().Set("Accept-Ranges", "bytes") - if w.Header().Get("Content-Encoding") == "" { - w.Header().Set("Content-Length", strconv.FormatInt(size, 10)) - } - - w.WriteHeader(code) - - if r.Method != "HEAD" { - io.CopyN(w, f, size) - } + serveContent(w, r, d.Name(), d.ModTime(), d.Size(), f) } // localRedirect gives a Moved Permanently response. |