core: refactor read and write valid sections (#1808)

core/chain_indexer.go

@@ -18,7 +18,6 @@ package core
 
 import (
 	"context"
-	"encoding/binary"
 	"errors"
 	"fmt"
 	"sync"
@@ -410,18 +409,15 @@ func (c *ChainIndexer) AddChildIndexer(indexer *ChainIndexer) {
 // loadValidSections reads the number of valid sections from the index database
 // and caches is into the local state.
 func (c *ChainIndexer) loadValidSections() {
-	data, _ := c.indexDb.Get([]byte("count"))
+	storedSections := rawdb.ReadValidSections(c.indexDb)
-	if len(data) == 8 {
+	if storedSections != nil {
-		c.storedSections = binary.BigEndian.Uint64(data[:])
+		c.storedSections = *storedSections
 	}
 }
 
 // setValidSections writes the number of valid sections to the index database
 func (c *ChainIndexer) setValidSections(sections uint64) {
-	// Set the current number of valid sections in the database
+	rawdb.WriteValidSections(c.indexDb, sections)
-	var data [8]byte
-	binary.BigEndian.PutUint64(data[:], sections)
-	c.indexDb.Put([]byte("count"), data[:])
 
 	// Remove any reorged sections, caching the valids in the mean time
 	for c.storedSections > sections {

core/rawdb/accessors_xdc.go

@@ -17,6 +17,8 @@
 package rawdb
 
 import (
+	"encoding/binary"
+
 	"github.com/XinFinOrg/XDPoSChain/common"
 	"github.com/XinFinOrg/XDPoSChain/ethdb"
 	"github.com/XinFinOrg/XDPoSChain/log"
@@ -79,3 +81,23 @@ func DeleteectionHead(db ethdb.KeyValueWriter, section uint64) {
 		log.Crit("Failed to delete section head", "err", err)
 	}
 }
+
+// ReadValidSections retrieves the number of valid sections from database.
+func ReadValidSections(db ethdb.KeyValueReader) *uint64 {
+	data, err := db.Get(validSectionsKey)
+	if err != nil || len(data) != 8 {
+		return nil
+	}
+	storedSections := binary.BigEndian.Uint64(data[:])
+	return &storedSections
+}
+
+// WriteValidSections writes the number of valid sections into database
+func WriteValidSections(db ethdb.KeyValueWriter, sections uint64) {
+	// Set the current number of valid sections in the database
+	var data [8]byte
+	binary.BigEndian.PutUint64(data[:], sections)
+	if err := db.Put(validSectionsKey, data[:]); err != nil {
+		log.Crit("Failed to store valid sections", "err", err)
+	}
+}

core/rawdb/schema.go

@@ -83,6 +83,7 @@ var (
 	xdposV2Prefix = []byte("XDPoS-V2-")
 
 	sectionHeadKeyPrefix = []byte("shead")
+	validSectionsKey     = []byte("count")
 
 	preimageCounter    = metrics.NewRegisteredCounter("db/preimage/total", nil)
 	preimageHitCounter = metrics.NewRegisteredCounter("db/preimage/hits", nil)