vochain/indexer: clear votePool in Commit

Otherwise the map just keeps increasing in size forever,
meaning that we do more and more busy work over time.
It's surprising that we hadn't caught this bug for a long time.

While here, initialize and clear both "by process ID" maps consistently.

vochain/indexer/indexer.go

@@ -100,6 +100,7 @@ func NewIndexer(dataDir string, app *vochain.BaseApplication, countLiveResults b
 		App:               app,
 		ignoreLiveResults: !countLiveResults,
 
+		votePool:         make(map[string]map[string]*state.Vote),
 		blockUpdateProcs: make(map[string]bool),
 	}
 	log.Infow("indexer initialization", "dataDir", dataDir, "liveResults", countLiveResults)
@@ -405,6 +406,7 @@ func (idx *Indexer) Commit(height uint32) error {
 			}
 		}()
 	}
+	clear(idx.votePool)
 
 	if err := idx.blockTx.Commit(); err != nil {
 		log.Errorw(err, "could not commit tx")
@@ -424,14 +426,14 @@ func (idx *Indexer) Commit(height uint32) error {
 func (idx *Indexer) Rollback() {
 	idx.blockMu.Lock()
 	defer idx.blockMu.Unlock()
-	idx.votePool = make(map[string]map[string]*state.Vote)
+	clear(idx.votePool)
+	clear(idx.blockUpdateProcs)
 	if idx.blockTx != nil {
 		if err := idx.blockTx.Rollback(); err != nil {
 			log.Errorw(err, "could not rollback tx")
 		}
 		idx.blockTx = nil
 	}
-	clear(idx.blockUpdateProcs)
 }
 
 // OnProcess indexer stores the processID