[errors] de-specialize Transient in favor of Tags.

tumble/process.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 tumble
 
 import (
         "bytes"
         "fmt"
         "math"
         "sync/atomic"
         "time"
 
         "github.com/luci/luci-go/appengine/memlock"
         "github.com/luci/luci-go/common/clock"
         "github.com/luci/luci-go/common/data/stringset"
         "github.com/luci/luci-go/common/errors"
         "github.com/luci/luci-go/common/logging"
+        "github.com/luci/luci-go/common/retry/transient"
         "github.com/luci/luci-go/common/sync/parallel"
 
         "github.com/luci/gae/filter/txnBuf"
         ds "github.com/luci/gae/service/datastore"
         "github.com/luci/gae/service/datastore/serialize"
         "github.com/luci/gae/service/info"
         mc "github.com/luci/gae/service/memcache"
 
         "golang.org/x/net/context"
 )
@@ skipping 197 matching lines @@
                                         "query":          qstr,
                                 }.Errorf(c, "Failure to run shard query.")
                                 errCount.inc()
                         }
                 })
 
                 logging.Infof(c, "cumulatively processed %d items with %d errors(s) and %d transient error(s)",
                         numProcessed, errCount, transientErrCount)
                 switch {
                 case transientErrCount > 0:
-                        return errors.WrapTransient(errors.New("transient error during shard processing"))
+                        return errors.New("transient error during shard processing", transient.Tag)
                 case errCount > 0:
                         return errors.New("encountered non-transient error during shard processing")
                 }
 
                 now := clock.Now(c)
                 didWork := numProcessed > 0
                 if didWork {
                         // Set our last key value for next round.
                         err = mc.Set(c, mc.NewItem(c, t.lastKey).SetValue(serialize.ToBytes(now.UTC())))
                         if err != nil {
@@ skipping 251 matching lines @@
                 prd.nextDelay = delay
         }
 
         // Enforce a no work lower bound.
         if delay < minNoWorkDelay {
                 delay = minNoWorkDelay
         }
 
         return delay
 }