Moving to FNV hash

maxpert · Oct 9, 2022 · e9b10e9 · e9b10e9
1 parent 6009d55
commit e9b10e9
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Showing 2 changed files with 9 additions and 5 deletions.
diff --git a/db/change_log_event.go b/db/change_log_event.go
@@ -1,7 +1,7 @@
 package db
 
 import (
-	"hash/crc64"
+	"hash/fnv"
 	"sort"
 	"sync"
 
@@ -10,7 +10,6 @@ import (
 
 var tablePKColumnsCache = make(map[string][]string)
 var tablePKColumnsLock = sync.RWMutex{}
-var crc64Table = crc64.MakeTable(crc64.ECMA)
 
 type ChangeLogEvent struct {
 	Id        int64
@@ -29,7 +28,7 @@ func (e *ChangeLogEvent) Unmarshal(data []byte) error {
 }
 
 func (e *ChangeLogEvent) Hash() (uint64, error) {
-	hasher := crc64.New(crc64Table)
+	hasher := fnv.New64()
 	enc := cbor.NewEncoder(hasher)
 	err := enc.StartIndefiniteArray()
 	if err != nil {

diff --git a/snapshot/db_snapshot.go b/snapshot/db_snapshot.go
@@ -3,7 +3,7 @@ package snapshot
 import (
 	"errors"
 	"fmt"
-	"hash/crc64"
+	"hash/fnv"
 	"io"
 	"os"
 	"path"
@@ -71,6 +71,11 @@ func (n *NatsDBSnapshot) SaveSnapshot(conn *nats.Conn) error {
 	}
 	defer rfl.Close()
 
+	err = blb.Delete(FileName)
+	if err != nil {
+		return err
+	}
+
 	info, err := blb.Put(&nats.ObjectMeta{
 		Name: FileName,
 		Headers: map[string][]string{
@@ -168,7 +173,7 @@ func fileHash(p string) (string, error) {
 	}
 	defer f.Close()
 
-	h := crc64.New(crc64.MakeTable(crc64.ECMA))
+	h := fnv.New64()
 	if _, err := io.Copy(h, f); err != nil {
 		return "", err
 	}