seaweedfs/weed/server/filer_server_handlers_read.go
Chris Lu 7f74577db1 add Last-Modified to HEAD requests
to work better with restic
2019-01-02 14:23:25 -08:00

253 lines
6.5 KiB
Go

package weed_server
import (
"io"
"mime"
"mime/multipart"
"net/http"
"net/url"
"path"
"strconv"
"strings"
"github.com/chrislusf/seaweedfs/weed/filer2"
"github.com/chrislusf/seaweedfs/weed/glog"
"github.com/chrislusf/seaweedfs/weed/util"
)
func (fs *FilerServer) GetOrHeadHandler(w http.ResponseWriter, r *http.Request, isGetMethod bool) {
path := r.URL.Path
if strings.HasSuffix(path, "/") && len(path) > 1 {
path = path[:len(path)-1]
}
entry, err := fs.filer.FindEntry(filer2.FullPath(path))
if err != nil {
if path == "/" {
fs.listDirectoryHandler(w, r)
return
}
glog.V(1).Infof("Not found %s: %v", path, err)
w.WriteHeader(http.StatusNotFound)
return
}
if entry.IsDirectory() {
if fs.option.DisableDirListing {
w.WriteHeader(http.StatusMethodNotAllowed)
return
}
fs.listDirectoryHandler(w, r)
return
}
if len(entry.Chunks) == 0 {
glog.V(1).Infof("no file chunks for %s, attr=%+v", path, entry.Attr)
w.WriteHeader(http.StatusNoContent)
return
}
w.Header().Set("Accept-Ranges", "bytes")
if r.Method == "HEAD" {
w.Header().Set("Content-Length", strconv.FormatInt(int64(filer2.TotalSize(entry.Chunks)), 10))
w.Header().Set("Last-Modified", entry.Attr.Mtime.Format(http.TimeFormat))
return
}
if len(entry.Chunks) == 1 {
fs.handleSingleChunk(w, r, entry)
return
}
fs.handleMultipleChunks(w, r, entry)
}
func (fs *FilerServer) handleSingleChunk(w http.ResponseWriter, r *http.Request, entry *filer2.Entry) {
fileId := entry.Chunks[0].FileId
urlString, err := fs.filer.MasterClient.LookupFileId(fileId)
if err != nil {
glog.V(1).Infof("operation LookupFileId %s failed, err: %v", fileId, err)
w.WriteHeader(http.StatusNotFound)
return
}
if fs.option.RedirectOnRead {
http.Redirect(w, r, urlString, http.StatusFound)
return
}
u, _ := url.Parse(urlString)
q := u.Query()
for key, values := range r.URL.Query() {
for _, value := range values {
q.Add(key, value)
}
}
u.RawQuery = q.Encode()
request := &http.Request{
Method: r.Method,
URL: u,
Proto: r.Proto,
ProtoMajor: r.ProtoMajor,
ProtoMinor: r.ProtoMinor,
Header: r.Header,
Body: r.Body,
Host: r.Host,
ContentLength: r.ContentLength,
}
glog.V(3).Infoln("retrieving from", u)
resp, do_err := util.Do(request)
if do_err != nil {
glog.V(0).Infoln("failing to connect to volume server", do_err.Error())
writeJsonError(w, r, http.StatusInternalServerError, do_err)
return
}
defer resp.Body.Close()
for k, v := range resp.Header {
w.Header()[k] = v
}
w.WriteHeader(resp.StatusCode)
io.Copy(w, resp.Body)
}
func (fs *FilerServer) handleMultipleChunks(w http.ResponseWriter, r *http.Request, entry *filer2.Entry) {
mimeType := entry.Mime
if mimeType == "" {
if ext := path.Ext(entry.Name()); ext != "" {
mimeType = mime.TypeByExtension(ext)
}
}
if mimeType != "" {
w.Header().Set("Content-Type", mimeType)
}
setEtag(w, filer2.ETag(entry.Chunks))
totalSize := int64(filer2.TotalSize(entry.Chunks))
rangeReq := r.Header.Get("Range")
if rangeReq == "" {
w.Header().Set("Content-Length", strconv.FormatInt(totalSize, 10))
if err := fs.writeContent(w, entry, 0, int(totalSize)); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
return
}
//the rest is dealing with partial content request
//mostly copy from src/pkg/net/http/fs.go
ranges, err := parseRange(rangeReq, totalSize)
if err != nil {
http.Error(w, err.Error(), http.StatusRequestedRangeNotSatisfiable)
return
}
if sumRangesSize(ranges) > totalSize {
// The total number of bytes in all the ranges
// is larger than the size of the file by
// itself, so this is probably an attack, or a
// dumb client. Ignore the range request.
return
}
if len(ranges) == 0 {
return
}
if len(ranges) == 1 {
// RFC 2616, Section 14.16:
// "When an HTTP message includes the content of a single
// range (for example, a response to a request for a
// single range, or to a request for a set of ranges
// that overlap without any holes), this content is
// transmitted with a Content-Range header, and a
// Content-Length header showing the number of bytes
// actually transferred.
// ...
// A response to a request for a single range MUST NOT
// be sent using the multipart/byteranges media type."
ra := ranges[0]
w.Header().Set("Content-Length", strconv.FormatInt(ra.length, 10))
w.Header().Set("Content-Range", ra.contentRange(totalSize))
w.WriteHeader(http.StatusPartialContent)
err = fs.writeContent(w, entry, ra.start, int(ra.length))
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
return
}
// process multiple ranges
for _, ra := range ranges {
if ra.start > totalSize {
http.Error(w, "Out of Range", http.StatusRequestedRangeNotSatisfiable)
return
}
}
sendSize := rangesMIMESize(ranges, mimeType, totalSize)
pr, pw := io.Pipe()
mw := multipart.NewWriter(pw)
w.Header().Set("Content-Type", "multipart/byteranges; boundary="+mw.Boundary())
sendContent := pr
defer pr.Close() // cause writing goroutine to fail and exit if CopyN doesn't finish.
go func() {
for _, ra := range ranges {
part, e := mw.CreatePart(ra.mimeHeader(mimeType, totalSize))
if e != nil {
pw.CloseWithError(e)
return
}
if e = fs.writeContent(part, entry, ra.start, int(ra.length)); e != nil {
pw.CloseWithError(e)
return
}
}
mw.Close()
pw.Close()
}()
if w.Header().Get("Content-Encoding") == "" {
w.Header().Set("Content-Length", strconv.FormatInt(sendSize, 10))
}
w.WriteHeader(http.StatusPartialContent)
if _, err := io.CopyN(w, sendContent, sendSize); err != nil {
http.Error(w, "Internal Error", http.StatusInternalServerError)
return
}
}
func (fs *FilerServer) writeContent(w io.Writer, entry *filer2.Entry, offset int64, size int) error {
chunkViews := filer2.ViewFromChunks(entry.Chunks, offset, size)
fileId2Url := make(map[string]string)
for _, chunkView := range chunkViews {
urlString, err := fs.filer.MasterClient.LookupFileId(chunkView.FileId)
if err != nil {
glog.V(1).Infof("operation LookupFileId %s failed, err: %v", chunkView.FileId, err)
return err
}
fileId2Url[chunkView.FileId] = urlString
}
for _, chunkView := range chunkViews {
urlString := fileId2Url[chunkView.FileId]
_, err := util.ReadUrlAsStream(urlString, chunkView.Offset, int(chunkView.Size), func(data []byte) {
w.Write(data)
})
if err != nil {
glog.V(1).Infof("read %s failed, err: %v", chunkView.FileId, err)
return err
}
}
return nil
}