add support for including kvstore stats

index/firestorm/firestorm.go

@@ -75,6 +75,10 @@ func (f *Firestorm) Open() (err error) {
 		return
 	}
 
+	if ss, ok := f.store.(store.KVStoreStats); ok {
+		f.stats.kvStats = ss.Stats()
+	}
+
 	// start a reader
 	var kvreader store.KVReader
 	kvreader, err = f.store.Reader()

index/firestorm/stats.go

@@ -18,6 +18,7 @@ type indexStat struct {
 	f                                 *Firestorm
 	updates, deletes, batches, errors uint64
 	analysisTime, indexTime           uint64
+	kvStats                           json.Marshaler
 }
 
 func (i *indexStat) MarshalJSON() ([]byte, error) {
@@ -29,5 +30,8 @@ func (i *indexStat) MarshalJSON() ([]byte, error) {
 	m["analysis_time"] = atomic.LoadUint64(&i.analysisTime)
 	m["index_time"] = atomic.LoadUint64(&i.indexTime)
 	m["lookup_queue_len"] = len(i.f.lookuper.workChan)
+	if i.kvStats != nil {
+		m["kv"] = i.kvStats
+	}
 	return json.Marshal(m)
 }

index/store/boltdb/stats.go

@@ -0,0 +1,21 @@
+//  Copyright (c) 2014 Couchbase, Inc.
+//  Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
+//  except in compliance with the License. You may obtain a copy of the License at
+//    http://www.apache.org/licenses/LICENSE-2.0
+//  Unless required by applicable law or agreed to in writing, software distributed under the
+//  License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
+//  either express or implied. See the License for the specific language governing permissions
+//  and limitations under the License.
+
+package boltdb
+
+import "encoding/json"
+
+type stats struct {
+	s *Store
+}
+
+func (s *stats) MarshalJSON() ([]byte, error) {
+	bs := s.s.db.Stats()
+	return json.Marshal(bs)
+}

index/store/boltdb/store.go

@@ -18,6 +18,7 @@
 package boltdb
 
 import (
+	"encoding/json"
 	"fmt"
 
 	"github.com/blevesearch/bleve/index/store"
@@ -95,6 +96,12 @@ func (bs *Store) Writer() (store.KVWriter, error) {
 	}, nil
 }
 
+func (bs *Store) Stats() json.Marshaler {
+	return &stats{
+		s: bs,
+	}
+}
+
 func init() {
 	registry.RegisterKVStore(Name, New)
 }

index/store/kvstore.go

@@ -9,6 +9,8 @@
 
 package store
 
+import "encoding/json"
+
 // KVStore is an abstraction for working with KV stores
 type KVStore interface {
 
@@ -154,3 +156,10 @@ type KVBatch interface {
 	// Close frees resources
 	Close() error
 }
+
+// KVStoreStats is an optional interface that KVStores can implement
+// if they're able to report any useful stats
+type KVStoreStats interface {
+	// Stats returns a JSON serializable object representing stats for this KVStore
+	Stats() json.Marshaler
+}

index/store/metrics/store.go

@@ -213,6 +213,20 @@ func (s *Store) WriteJSON(w io.Writer) (err error) {
 		return
 	}
 
+	// see if the underlying implementation has its own stats
+	if o, ok := s.o.(store.KVStoreStats); ok {
+		storeStats := o.Stats()
+		var storeBytes []byte
+		storeBytes, err = json.Marshal(storeStats)
+		if err != nil {
+			return
+		}
+		_, err = fmt.Fprintf(w, `, "store": %s`, string(storeBytes))
+		if err != nil {
+			return
+		}
+	}
+
 	_, err = w.Write([]byte(`}`))
 	if err != nil {
 		return

index/upside_down/stats.go

@@ -17,6 +17,7 @@ import (
 type indexStat struct {
 	updates, deletes, batches, errors uint64
 	analysisTime, indexTime           uint64
+	kvStats                           json.Marshaler
 }
 
 func (i *indexStat) MarshalJSON() ([]byte, error) {
@@ -27,5 +28,8 @@ func (i *indexStat) MarshalJSON() ([]byte, error) {
 	m["errors"] = atomic.LoadUint64(&i.errors)
 	m["analysis_time"] = atomic.LoadUint64(&i.analysisTime)
 	m["index_time"] = atomic.LoadUint64(&i.indexTime)
+	if i.kvStats != nil {
+		m["kv"] = i.kvStats
+	}
 	return json.Marshal(m)
 }

index/upside_down/upside_down.go

@@ -310,6 +310,10 @@ func (udc *UpsideDownCouch) Open() (err error) {
 		return
 	}
 
+	if ss, ok := udc.store.(store.KVStoreStats); ok {
+		udc.stats.kvStats = ss.Stats()
+	}
+
 	// start a reader to look at the index
 	var kvreader store.KVReader
 	kvreader, err = udc.store.Reader()