rclone/lib/http/serve/serve.go

91 lines
2.6 KiB
Go

// Package serve deals with serving objects over HTTP
package serve
import (
"fmt"
"io"
"net/http"
"path"
"strconv"
"github.com/rclone/rclone/fs"
"github.com/rclone/rclone/fs/accounting"
)
// Object serves an fs.Object via HEAD or GET
func Object(w http.ResponseWriter, r *http.Request, o fs.Object) {
if r.Method != "HEAD" && r.Method != "GET" {
http.Error(w, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
return
}
// Show that we accept ranges
w.Header().Set("Accept-Ranges", "bytes")
// Set content length since we know how long the object is
if o.Size() >= 0 {
w.Header().Set("Content-Length", strconv.FormatInt(o.Size(), 10))
}
// Set content type
mimeType := fs.MimeType(r.Context(), o)
if mimeType == "application/octet-stream" && path.Ext(o.Remote()) == "" {
// Leave header blank so http server guesses
} else {
w.Header().Set("Content-Type", mimeType)
}
if r.Method == "HEAD" {
return
}
// Decode Range request if present
code := http.StatusOK
size := o.Size()
var options []fs.OpenOption
if rangeRequest := r.Header.Get("Range"); rangeRequest != "" {
//fs.Debugf(nil, "Range: request %q", rangeRequest)
option, err := fs.ParseRangeOption(rangeRequest)
if err != nil {
fs.Debugf(o, "Get request parse range request error: %v", err)
http.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
return
}
options = append(options, option)
offset, limit := option.Decode(o.Size())
end := o.Size() // exclusive
if limit >= 0 {
end = offset + limit
}
if end > o.Size() {
end = o.Size()
}
size = end - offset
// fs.Debugf(nil, "Range: offset=%d, limit=%d, end=%d, size=%d (object size %d)", offset, limit, end, size, o.Size())
// Content-Range: bytes 0-1023/146515
w.Header().Set("Content-Range", fmt.Sprintf("bytes %d-%d/%d", offset, end-1, o.Size()))
// fs.Debugf(nil, "Range: Content-Range: %q", w.Header().Get("Content-Range"))
code = http.StatusPartialContent
}
w.Header().Set("Content-Length", strconv.FormatInt(size, 10))
file, err := o.Open(r.Context(), options...)
if err != nil {
fs.Debugf(o, "Get request open error: %v", err)
http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
return
}
tr := accounting.Stats(r.Context()).NewTransfer(o)
defer func() {
tr.Done(r.Context(), err)
}()
in := tr.Account(r.Context(), file) // account the transfer (no buffering)
w.WriteHeader(code)
n, err := io.Copy(w, in)
if err != nil {
fs.Errorf(o, "Didn't finish writing GET request (wrote %d/%d bytes): %v", n, size, err)
return
}
}