LogDog: Update to archival V2.

server/internal/logdog/collector/collector.go

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package collector
 
 import (
         "bytes"
         "time"
 
@@ skipping 145 matching lines @@
 
         // be is the Bundle entry.
         be *logpb.ButlerLogBundle_Entry
         // path is the constructed path of the stream being processed.
         path types.StreamPath
 }
 
 // processLogStream processes an individual set of log messages belonging to the
 // same log stream.
 func (c *Collector) processLogStream(ctx context.Context, h *bundleEntryHandler) error {
+        // If this bundle has neither log entries nor a terminal index, it is junk and
+        // must be discarded.
+        //
+        // This is more important than a basic optimization, as it enforces that no
+        // zero-entry log streams can be ingested. Either some entries exist, or there
+        // is a promise of a terminal entry.
+        if len(h.be.Logs) == 0 && !h.be.Terminal {

[dnj, 2016/04/11 17:20:04]

Quick short-circuit here. Nothing really interesting.

+                log.Warningf(ctx, "Bundle entry is non-terminal and contains no logs; discarding.")
+                return nil
+        }
+
         if err := h.be.Desc.Validate(true); err != nil {
                 log.Errorf(log.SetError(ctx, err), "Invalid log stream descriptor.")
                 return err
         }
         h.path = types.StreamName(h.be.Desc.Prefix).Join(types.StreamName(h.be.Desc.Name))
         ctx = log.SetField(ctx, "path", h.path)
 
         if len(h.be.Secret) == 0 {
                 log.Errorf(ctx, "Missing secret.")
                 return errors.New("missing stream secret")
@@ skipping 150 matching lines @@
                 for _, e := range merr {
                         if hasTransientError(e) {
                                 return true
                         }
                 }
                 return false
         }
 
         return errors.IsTransient(err)
 }