improve leveldb batch usage and pointer releasing in caches

database/versiondb/db.go

@@ -18,9 +18,10 @@ import (
 // database, writing changes to the underlying database only when commit is
 // called.
 type Database struct {
-	lock sync.RWMutex
-	mem  map[string]valueDelete
-	db   database.Database
+	lock  sync.RWMutex
+	mem   map[string]valueDelete
+	db    database.Database
+	batch database.Batch
 }
 
 type valueDelete struct {
@@ -31,8 +32,9 @@ type valueDelete struct {
 // New returns a new prefixed database
 func New(db database.Database) *Database {
 	return &Database{
-		mem: make(map[string]valueDelete, memdb.DefaultSize),
-		db:  db,
+		mem:   make(map[string]valueDelete, memdb.DefaultSize),
+		db:    db,
+		batch: db.NewBatch(),
 	}
 }
 
@@ -169,6 +171,7 @@ func (db *Database) SetDatabase(newDB database.Database) error {
 	}
 
 	db.db = newDB
+	db.batch = newDB.NewBatch()
 	return nil
 }
 
@@ -206,7 +209,9 @@ func (db *Database) Abort() {
 
 func (db *Database) abort() { db.mem = make(map[string]valueDelete, memdb.DefaultSize) }
 
-// CommitBatch returns a batch that will commit all pending writes to the underlying database
+// CommitBatch returns a batch that will commit all pending writes to the
+// underlying database. The returned batch should be written before future calls
+// to this DB unless the batch will never be written.
 func (db *Database) CommitBatch() (database.Batch, error) {
 	db.lock.Lock()
 	defer db.lock.Unlock()
@@ -219,21 +224,21 @@ func (db *Database) commitBatch() (database.Batch, error) {
 		return nil, database.ErrClosed
 	}
 
-	batch := db.db.NewBatch()
+	db.batch.Reset()
 	for key, value := range db.mem {
 		if value.delete {
-			if err := batch.Delete([]byte(key)); err != nil {
+			if err := db.batch.Delete([]byte(key)); err != nil {
 				return nil, err
 			}
-		} else if err := batch.Put([]byte(key), value.value); err != nil {
+		} else if err := db.batch.Put([]byte(key), value.value); err != nil {
 			return nil, err
 		}
 	}
-	if err := batch.Write(); err != nil {
+	if err := db.batch.Write(); err != nil {
 		return nil, err
 	}
 
-	return batch, nil
+	return db.batch, nil
 }
 
 // Close implements the database.Database interface

snow/engine/avalanche/state/unique_vertex.go

@@ -54,6 +54,8 @@ func (vtx *uniqueVertex) refresh() {
 func (vtx *uniqueVertex) Evict() {
 	if vtx.v != nil {
 		vtx.v.unique = false
+		// make sure the parents are able to be garbage collected
+		vtx.v.parents = nil
 	}
 }
 

vms/avm/unique_tx.go

@@ -85,7 +85,11 @@ func (tx *UniqueTx) refresh() {
 
 // Evict is called when this UniqueTx will no longer be returned from a cache
 // lookup
-func (tx *UniqueTx) Evict() { tx.unique = false } // Lock is already held here
+func (tx *UniqueTx) Evict() {
+	// Lock is already held here
+	tx.unique = false
+	tx.deps = nil
+}
 
 func (tx *UniqueTx) setStatus(status choices.Status) error {
 	tx.refresh()

vms/avm/vm.go

@@ -35,7 +35,7 @@ const (
 	batchSize      = 30
 	stateCacheSize = 10000
 	idCacheSize    = 10000
-	txCacheSize    = 100000
+	txCacheSize    = 10000
 	addressSep     = "-"
 )