[milo] {buildbucket,buildbot,swarming,logdog} -> backends/*.

milo/appengine/swarming/buildLog.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 swarming
-
-import (
-        "fmt"
-        "path"
-        "sort"
-
-        "golang.org/x/net/context"
-
-        mc "github.com/luci/gae/service/memcache"
-        "github.com/luci/luci-go/common/logging"
-)
-
-// swarmingBuildLogImpl is the implementation for getting a log name from
-// a swarming build via annotee.  It returns the full text of the specific log,
-// and whether or not it has been closed.
-func swarmingBuildLogImpl(c context.Context, svc swarmingService, taskID, logname string) (string, bool, error) {
-        server := svc.getHost()
-        cached, err := mc.GetKey(c, path.Join("swarmingLog", server, taskID, logname))
-        switch {
-        case err == mc.ErrCacheMiss:
-
-        case err != nil:
-                logging.WithError(err).Errorf(c, "failed to fetch log with key %s from memcache", cached.Key())
-
-        default:
-                logging.Debugf(c, "Cache hit for step log %s/%s/%s", server, taskID, logname)
-                return string(cached.Value()), false, nil
-        }
-
-        fetchParams := swarmingFetchParams{
-                fetchRes: true, // Needed so we can validate that this is a Milo build.
-                fetchLog: true,
-        }
-        fr, err := swarmingFetch(c, svc, taskID, fetchParams)
-        if err != nil {
-                return "", false, err
-        }
-
-        // Decode the data using annotee.
-        s, err := streamsFromAnnotatedLog(c, fr.log)
-        if err != nil {
-                return "", false, err
-        }
-
-        k := fmt.Sprintf("steps%s", logname)
-        stream, ok := s.Streams[k]
-        if !ok {
-                var keys []string
-                for sk := range s.Streams {
-                        keys = append(keys, sk)
-                }
-                sort.Strings(keys)
-                return "", false, fmt.Errorf("stream %q not found; available streams: %q", k, keys)
-        }
-
-        if stream.Closed {
-                cached.SetValue([]byte(stream.Text))
-                if err := mc.Set(c, cached); err != nil {
-                        logging.Errorf(c, "Failed to write log with key %s to memcache: %s", cached.Key(), err)
-                }
-        }
-
-        return stream.Text, stream.Closed, nil
-}