LogDog: Handle archive failures.

appengine/logdog/coordinator/logStream.go

Index: appengine/logdog/coordinator/logStream.go
diff --git a/appengine/logdog/coordinator/logStream.go b/appengine/logdog/coordinator/logStream.go
index 4285bd3e4f25dd4708d0e45025d41964cb9ca775..80032b5e961c5adcaf43d7d261a1ed73994d6d16 100644
--- a/appengine/logdog/coordinator/logStream.go
+++ b/appengine/logdog/coordinator/logStream.go
@@ -114,7 +114,12 @@ type LogStream struct {
 	Source []string
 
 	// TerminalIndex is the log stream index of the last log entry in the stream.
-	// If the value is -1, the log is still streaming.
+	//
+	// If the value is <0:

[Vadim Sh., 2016/03/31 22:29:59]

typo: "If" is not needed here

[dnj, 2016/04/01 22:57:04]

Acknowledged.

+	//	- If the log is in the LSPending state, the stream is still streaming
+	//	  without a known terminal index.
+	//	- If the log is in LSArchived state, it means that the stream's archival
+	//	  has completed, but had no log entries.
 	TerminalIndex int64 `gae:",noindex"`
 
 	// ArchiveIndexURL is the Google Storage URL where the log stream's index is
@@ -140,6 +145,11 @@ type LogStream struct {
 	// ArchiveWhole is true if archival is complete and the archived log stream
 	// was not missing any entries.
 	ArchiveWhole bool
+	// ArchiveErrors is the number of errors encountered during archival. This
+	// will be incremented when incomplete archival is permitted, but the archival
+	// still failed due to an error (e.g., data corruption). If this exceeds a
+	// threshold, the stream may be marked archived even if the archival failed.
+	ArchiveErrors int
 
 	// _ causes datastore to ignore unrecognized fields and strip them in future
 	// writes.
@@ -353,6 +363,12 @@ func (s *LogStream) Terminated() bool {
 	return s.State >= LSTerminated
 }
 
+// Streaming returns true if this log stream is still streaming without a known
+// terminal index.
+func (s *LogStream) Streaming() bool {
+	return (s.State == LSPending && s.TerminalIndex < 0)
+}
+
 // Archived returns true if this stream has been archived. A stream is archived
 // if it has any of its archival properties set.
 func (s *LogStream) Archived() bool {