11945: Disable collection cache.

[arvados.git] / services / keep-web / handler.go

diff --git a/services/keep-web/handler.go b/services/keep-web/handler.go
index ecc698256a2e8d4b3f815f5ba73b92c5077f900f..769c2f59ce9a79effcb2e094fd166978941bfa3a 100644 (file)
--- a/services/keep-web/handler.go
+++ b/services/keep-web/handler.go
@@ -1,3 +1,7 @@
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
 package main
 
 import (
@@ -165,7 +169,7 @@ func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
                h.serveStatus(w, r)
                return
        } else if len(pathParts) >= 1 && strings.HasPrefix(pathParts[0], "c=") {
-               // /c=ID/PATH...
+               // /c=ID[/PATH...]
                targetID = parseCollectionIDFromURL(pathParts[0][2:])
                stripParts = 1
        } else if len(pathParts) >= 2 && pathParts[0] == "collections" {
@@ -321,18 +325,30 @@ func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
        }, kc)
        openPath := "/" + strings.Join(targetPath, "/")
        if f, err := fs.Open(openPath); os.IsNotExist(err) {
+               // Requested non-existent path
                statusCode = http.StatusNotFound
        } else if err != nil {
+               // Some other (unexpected) error
                statusCode, statusText = http.StatusInternalServerError, err.Error()
        } else if stat, err := f.Stat(); err != nil {
+               // Can't get Size/IsDir (shouldn't happen with a collectionFS!)
                statusCode, statusText = http.StatusInternalServerError, err.Error()
        } else if stat.IsDir() && !strings.HasSuffix(r.URL.Path, "/") {
+               // If client requests ".../dirname", redirect to
+               // ".../dirname/". This way, relative links in the
+               // listing for "dirname" can always be "fnm", never
+               // "dirname/fnm".
                h.seeOtherWithCookie(w, r, basename+"/", credentialsOK)
        } else if stat.IsDir() {
                h.serveDirectory(w, r, collection.Name, fs, openPath, stripParts)
        } else {
                http.ServeContent(w, r, basename, stat.ModTime(), f)
-               if int64(w.WroteBodyBytes()) != stat.Size() {
+               if r.Header.Get("Range") == "" && int64(w.WroteBodyBytes()) != stat.Size() {
+                       // If we wrote fewer bytes than expected, it's
+                       // too late to change the real response code
+                       // or send an error message to the client, but
+                       // at least we can try to put some useful
+                       // debugging info in the logs.
                        n, err := f.Read(make([]byte, 1024))
                        statusCode, statusText = http.StatusInternalServerError, fmt.Sprintf("f.Size()==%d but only wrote %d bytes; read(1024) returns %d, %s", stat.Size(), w.WroteBodyBytes(), n, err)
 
@@ -377,9 +393,13 @@ the entire collection with wget, try:</P>
 
 <H2>File Listing</H2>
 
+{{if .Files}}
 <UL>
 {{range .Files}}  <LI>{{.Size | printf "%15d  " | nbsp}}<A href="{{.Name}}">{{.Name}}</A></LI>{{end}}
 </UL>
+{{else}}
+<P>(No files; this collection is empty.)</P>
+{{end}}
 
 <HR noshade>
 <DIV class="footer">