Update Coordinator client, add datagram assembly.

logdog/client/coordinator/query.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package coordinator
 
 import (
+        "fmt"
         "time"
 
         "github.com/luci/luci-go/common/config"
         "github.com/luci/luci-go/common/proto/google"
         "github.com/luci/luci-go/logdog/api/endpoints/coordinator/logs/v1"
         "github.com/luci/luci-go/logdog/api/logpb"
         "github.com/luci/luci-go/logdog/common/types"
         "golang.org/x/net/context"
 )
 
@@ skipping 130 matching lines @@
         }
 
         // Iteratively query until either our query is done (Next is empty) or we are
         // asked to stop via callback.
         for {
                 resp, err := c.C.Query(ctx, &req)
                 if err != nil {
                         return normalizeError(err)
                 }
 
-                for _, s := range resp.Streams {
-                        if !cb(loadLogStream(resp.Project, types.StreamPath(s.Path), s.State, s.Desc)) {
+                for i, s := range resp.Streams {
+                        st, err := loadLogStream(resp.Project, types.StreamPath(s.Path), s.State, s.Desc)
+                        if err != nil {
+                                return fmt.Errorf("failed to load stream state #%d: %v", i, err)
+                        }
+
+                        if !cb(st) {
                                 return nil
                         }
                 }
 
                 // Advance our query cursor.
                 if resp.Next == "" {
                         return nil
                 }
                 req.Next = resp.Next
         }
 }