Problem: memiavl restore not fast enough (#1241)

* Problem: memiavl restore not fast enough

Solution:
- increase channel buffer size to improve parallisation

it reduce restore time by 44% when testing with testnet, thanks @yzang2019 for sharing the finding.

* Update CHANGELOG.md

Signed-off-by: yihuang <huang@crypto.com>

* fix unit test

---------

Signed-off-by: yihuang <huang@crypto.com>

CHANGELOG.md

@@ -17,6 +17,7 @@
 ### Improvements
 
 - [#1239](https://github.com/crypto-org-chain/cronos/pull/1239) Refactor websocket/subscription system to improve performance and stability.
+- [#1241](https://github.com/crypto-org-chain/cronos/pull/1241) Improve parallelization of memiavl restoration.
 
 
 *October 17, 2023*

memiavl/import.go

@@ -8,6 +8,8 @@ import (
 	"path/filepath"
 )
 
+const NodeChannelBuffer = 2048
+
 type MultiTreeImporter struct {
 	dir         string
 	snapshotDir string
@@ -100,7 +102,7 @@ type TreeImporter struct {
 }
 
 func NewTreeImporter(dir string, version int64) *TreeImporter {
-	nodesChan := make(chan *ExportNode)
+	nodesChan := make(chan *ExportNode, NodeChannelBuffer)
 	quitChan := make(chan error)
 	go func() {
 		defer close(quitChan)

memiavl/snapshot_test.go

@@ -179,9 +179,9 @@ func testSnapshotRoundTrip(t *testing.T, db *DB) {
 		require.NoError(t, importer.Add(item))
 	}
 
-	require.NoError(t, exporter.Close())
 	require.NoError(t, importer.Finalize())
 	require.NoError(t, importer.Close())
+	require.NoError(t, exporter.Close())
 
 	db2, err := Load(restoreDir, Options{})
 	require.NoError(t, err)