LogDog: Add log rendering view.

appengine/logdog/coordinator/service.go

 // Copyright 2015 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 coordinator
 
 import (
         "github.com/luci/luci-go/appengine/logdog/coordinator/config"
         "github.com/luci/luci-go/common/gcloud/gs"
         log "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/server/logdog/storage"
+        "github.com/luci/luci-go/server/logdog/storage/archive"
         "golang.org/x/net/context"
 )
 
 // Service is the base service container for LogDog handlers and endpoints. It
 // is primarily usable as a means of consistently stubbing out various external
 // components.
 type Service struct {
-        // StorageFunc is a function that generates an intermediate Storage instance
+        // IntermediateStorageFunc is a function that generates an intermediate Storage instance
         // for use by this service. If nil, the production intermediate Storage
         // instance will be used.
         //
         // This is provided for testing purposes.
-        StorageFunc func(context.Context) (storage.Storage, error)
+        IntermediateStorageFunc func(context.Context) (storage.Storage, error)
+
+        // ArchiveStorageFunc returns Archive storage for the specified log stream.
+        ArchiveStorageFunc func(context.Context, *LogStream) (storage.Storage, error)
 
         // GSClientFunc is a function that generates a Google Storage client instance
         // for use by this service. If nil, the production Google Storage Client will
         // be used.
         GSClientFunc func(context.Context) (gs.Client, error)
 }
 
-// Storage retrieves the configured Storage instance.
-func (s *Service) Storage(c context.Context) (storage.Storage, error) {
-        sf := s.StorageFunc
-        if sf == nil {
-                // Production: use BigTable storage.
-                sf = config.GetStorage
+// StorageForLogStream returns the Storage instance to use for a given
+// LogStream.
+//
+// The caller is responsible for calling Close on the returned Storage instance
+// when finished.
+func (s *Service) StorageForLogStream(c context.Context, ls *LogStream) (storage.Storage, error) {
+        if !ls.Archived() {
+                log.Debugf(c, "Log is not archived. Fetching from intermediate storage.")
+
+                // Logs are not archived. Fetch from intermediate storage.
+                return s.IntermediateStorage(c)
         }
 
-        st, err := sf(c)
+        log.Debugf(c, "Log is archived. Fetching from archive storage.")
+        return s.ArchiveStorage(c, ls)
+}
+
+// IntermediateStorage retrieves the configured intermediate Storage instance.
+// The caller is responsible for calling Close on the returned Storage instance
+// when finished.
+func (s *Service) IntermediateStorage(c context.Context) (storage.Storage, error) {
+        if sf := s.IntermediateStorageFunc; sf != nil {
+                return sf(c)
+        }
+
+        // Production: use BigTable storage.
+        st, err := config.GetStorage(c)
         if err != nil {
-                log.Errorf(log.SetError(c, err), "Failed to get Storage instance.")
+                log.Errorf(log.SetError(c, err), "Failed to get BigTable Storage instance.")
                 return nil, err
         }
         return st, nil
 }
 
-// GSClient instantiates a Google Storage client.
-func (s *Service) GSClient(c context.Context) (gs.Client, error) {
-        f := s.GSClientFunc
-        if f == nil {
-                f = gs.NewProdClient
+// ArchiveStorage retrieves the configured archive Storage instance.
+// The caller is responsible for calling Close on the returned Storage instance
+// when finished.
+func (s *Service) ArchiveStorage(c context.Context, ls *LogStream) (storage.Storage, error) {
+        if sf := s.ArchiveStorageFunc; sf != nil {
+                return sf(c, ls)
         }
 
-        gsc, err := f(c)
+        gs, err := s.GSClient(c)
         if err != nil {
-                log.Errorf(log.SetError(c, err), "Failed to get Google Storage client.")
+                log.WithError(err).Errorf(c, "Failed to create Google Storage client.")
+                return nil, err
+        }
+
+        st, err := archive.New(c, archive.Options{
+                IndexURL:  ls.ArchiveIndexURL,
+                StreamURL: ls.ArchiveStreamURL,
+                Client:    gs,
+        })
+        if err != nil {
+                log.WithError(err).Errorf(c, "Failed to create Google Storage storage instance.")
+                return nil, err
+        }
+        return st, nil
+}
+
+// GSClient instantiates a Google Storage client. The caller is responsible
+// for closing the client.
+func (s *Service) GSClient(c context.Context) (gs.Client, error) {
+        if f := s.GSClientFunc; f != nil {
+                return f(c)
+        }
+
+        gsc, err := gs.NewProdClient(c)
+        if err != nil {
+                log.Errorf(log.SetError(c, err), "Failed to get production Google Storage client.")
                 return nil, err
         }
         return gsc, nil
 }