diff options
| -rw-r--r-- | admin.go | 27 |
1 files changed, 21 insertions, 6 deletions
@@ -954,17 +954,28 @@ func makeEtag(path string, hash hash.Hash) string { return fmt.Sprintf(`"%s %x"`, path, hash.Sum(nil)) } +// This buffer pool is used to keep buffers for +// reading the config file during eTag header generation +var bufferPool = sync.Pool{ + New: func() any { + return new(bytes.Buffer) + }, +} + func handleConfig(w http.ResponseWriter, r *http.Request) error { switch r.Method { case http.MethodGet: w.Header().Set("Content-Type", "application/json") - // Set the ETag as a trailer header. - // The alternative is to write the config to a buffer, and - // then hash that. - w.Header().Set("Trailer", "ETag") - hash := etagHasher() - configWriter := io.MultiWriter(w, hash) + + // Read the config into a buffer instead of writing directly to + // the response writer, as we want to set the ETag as the header, + // not the trailer. + buf := bufferPool.Get().(*bytes.Buffer) + buf.Reset() + defer bufferPool.Put(buf) + + configWriter := io.MultiWriter(buf, hash) err := readConfig(r.URL.Path, configWriter) if err != nil { return APIError{HTTPStatus: http.StatusBadRequest, Err: err} @@ -973,6 +984,10 @@ func handleConfig(w http.ResponseWriter, r *http.Request) error { // we could consider setting up a sync.Pool for the summed // hashes to reduce GC pressure. w.Header().Set("Etag", makeEtag(r.URL.Path, hash)) + _, err = w.Write(buf.Bytes()) + if err != nil { + return APIError{HTTPStatus: http.StatusInternalServerError, Err: err} + } return nil |