func (m *Multi) Get(key string, opts store.GetOptions) ([]byte, store.Stat, error) {
r := retry.New(10)
for r.Next() {
f, err := m.getFile(key)
if err != nil {
return nil, store.Stat{}, err
}
if f == nil {
return nil, store.Stat{}, store.ErrNotFound
}
data, err := m.reconstruct(f, opts)
if err != nil {
f2, err2 := m.getFile(key)
if err2 != nil {
return nil, store.Stat{}, err2
}
if f2 == nil || f2.PrefixID != f.PrefixID {
// someone wrote to this file and removed some pieces as we
// were reading it; retry the read.
continue
}
return nil, store.Stat{}, err
}
return data, store.Stat{
SHA256: f.SHA256,
Size: int64(f.Size),
WriteTime: f.WriteTime,
}, err
}
return nil, store.Stat{}, ErrTooManyRetries
}
func (h *Server) serveObjectDelete(w http.ResponseWriter, r *http.Request, obj string) {
canceller := makeCanceller(w)
defer canceller.Close()
doRetry := true
retr := retry.New(10)
for retr.Next() {
doRetry = false
from, err := parseIfMatch(r.Header.Get("If-Match"))
if err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
if from.Any {
// TODO: make the CAS interface rich enough to handle this
// without Stat
st, err := h.store.Stat(obj, canceller.Cancel)
if err != nil {
if err == store.ErrNotFound {
http.Error(w, "not found", http.StatusNotFound)
return
}
log.Printf("Couldn't Stat(%#v): %v", obj, err)
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
from = store.CASV{Present: true, SHA256: st.SHA256}
doRetry = true
}
err = h.store.CAS(obj, from, store.CASV{Present: false}, canceller.Cancel)
if err != nil {
if err == store.ErrCASFailure {
if doRetry {
continue
} else {
http.Error(w, err.Error(),
http.StatusPreconditionFailed)
return
}
}
log.Printf("Couldn't CAS(%#v): %v", obj, err)
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
w.WriteHeader(http.StatusNoContent)
return
}
http.Error(w, "too many retries", http.StatusInternalServerError)
}