// Fast path for blobpacked.
func fileInfoPacked(sh *search.Handler, src blob.Fetcher, req *http.Request, file blob.Ref) (packFileInfo fileInfo, ok bool) {
if sh == nil {
return fileInfo{whyNot: "no search"}, false
}
wf, ok := src.(blobserver.WholeRefFetcher)
if !ok {
return fileInfo{whyNot: "fetcher type"}, false
}
if req != nil && req.Header.Get("Range") != "" {
// TODO: not handled yet. Maybe not even important,
// considering rarity.
return fileInfo{whyNot: "range header"}, false
}
des, err := sh.Describe(&search.DescribeRequest{BlobRef: file})
if err != nil {
log.Printf("ui: fileInfoPacked: skipping fast path due to error from search: %v", err)
return fileInfo{whyNot: "search error"}, false
}
db, ok := des.Meta[file.String()]
if !ok || db.File == nil {
return fileInfo{whyNot: "search index doesn't know file"}, false
}
fi := db.File
if !fi.WholeRef.Valid() {
return fileInfo{whyNot: "no wholeref from search index"}, false
}
offset := int64(0)
rc, wholeSize, err := wf.OpenWholeRef(fi.WholeRef, offset)
if err == os.ErrNotExist {
return fileInfo{whyNot: "WholeRefFetcher returned ErrNotexist"}, false
}
if wholeSize != fi.Size {
log.Printf("ui: fileInfoPacked: OpenWholeRef size %d != index size %d; ignoring fast path", wholeSize, fi.Size)
return fileInfo{whyNot: "WholeRefFetcher and index don't agree"}, false
}
if err != nil {
log.Printf("ui: fileInfoPacked: skipping fast path due to error from WholeRefFetcher (%T): %v", src, err)
return fileInfo{whyNot: "WholeRefFetcher error"}, false
}
return fileInfo{
mime: fi.MIMEType,
name: fi.FileName,
size: fi.Size,
rs: readerutil.NewFakeSeeker(rc, fi.Size-offset),
close: rc.Close,
}, true
}
// ServeBlobRef serves a blob.
func ServeBlobRef(rw http.ResponseWriter, req *http.Request, blobRef blob.Ref, fetcher blob.Fetcher) {
rc, size, err := fetcher.Fetch(blobRef)
switch err {
case nil:
break
case os.ErrNotExist:
rw.WriteHeader(http.StatusNotFound)
fmt.Fprintf(rw, "Blob %q not found", blobRef)
return
default:
httputil.ServeError(rw, req, err)
return
}
defer rc.Close()
rw.Header().Set("Content-Type", "application/octet-stream")
var content io.ReadSeeker = readerutil.NewFakeSeeker(rc, int64(size))
rangeHeader := req.Header.Get("Range") != ""
const small = 32 << 10
var b *blob.Blob
if rangeHeader || size < small {
// Slurp to memory, so we can actually seek on it (for Range support),
// or if we're going to be showing it in the browser (below).
b, err = blob.FromReader(blobRef, rc, size)
if err != nil {
httputil.ServeError(rw, req, err)
return
}
content = b.Open()
}
if !rangeHeader && size < small {
// If it's small and all UTF-8, assume it's text and
// just render it in the browser. This is more for
// demos/debuggability than anything else. It isn't
// part of the spec.
if b.IsUTF8() {
rw.Header().Set("Content-Type", "text/plain; charset=utf-8")
}
}
http.ServeContent(rw, req, "", dummyModTime, content)
}