wp

storage/write_preparer.go

@@ -9,6 +9,10 @@ import (
 	"gordenko.dev/dima/qb/util"
 )
 
+type Packable interface {
+	Pack(io.Writer)
+}
+
 type WritePreparer struct {
 	pagePreparer *PageIngester
 	//dataPagePayloadBound int
@@ -39,15 +43,19 @@ type PreparedData struct {
 	Commits      []any
 }
 
+// const (
+// 	prefixSize = 9
+// 	crc32Size  = 4
+// )
+
 func (s *WritePreparer) Prepare(input []any) PreparedData {
 	s.w.Write([]byte{
 		0, 0, 0, 0, 0, 0, 0, 0, 0, // size (max 9 byte)
-		0, 0, 0, 0, // crc32
 	})
 
 	hasher := util.NewHasher()
 
-	w := io.MultiWriter(s.w, hasher)
+	multi := io.MultiWriter(s.w, hasher)
 
 	// 1. Пакую всі дані в  WAL буфер запису
 	for _, untyped := range input {
@@ -58,7 +66,7 @@ func (s *WritePreparer) Prepare(input []any) PreparedData {
 				MetricType: x.MetricType,
 				FracDigits: x.FracDigits,
 			}
-			rec.Pack(w)
+			rec.Pack(multi)
 			s.commits = append(s.commits, MetricAddCommited{
 				MetricID: x.MetricID,
 				ResultCh: x.ResultCh,
@@ -76,7 +84,7 @@ func (s *WritePreparer) Prepare(input []any) PreparedData {
 				FreeIndexPages: x.FreeIndexPages,
 				FreeDataPages:  x.FreeDataPages,
 			}
-			rec.Pack(w)
+			rec.Pack(multi)
 			s.commits = append(s.commits, MetricDeleteCommited{
 				MetricID: x.MetricID,
 				ResultCh: x.ResultCh,
@@ -90,7 +98,7 @@ func (s *WritePreparer) Prepare(input []any) PreparedData {
 				ValuesRewindOffset:     x.ValuesRewindOffset,
 				Values:                 x.Values,
 			}
-			rec.Pack(w)
+			rec.Pack(multi)
 			// Дані для Worker
 			s.commits = append(s.commits, MeasuresAppendCommited{
 				MetricID:     x.MetricID,
@@ -188,9 +196,9 @@ func (s *WritePreparer) Prepare(input []any) PreparedData {
 				ChangedIndexLevels: changedIndexPages,
 			}
 
-			fmt.Printf("%#v\ns", rec.ChangedIndexLevels[0].IndexPageTail)
+			//fmt.Printf("%#v\ns", rec.ChangedIndexLevels[0].IndexPageTail)
 
-			rec.Pack(w)
+			rec.Pack(multi)
 			// Дані для Worker
 			s.commits = append(s.commits, MeasuresAppendWithGrowCommited{
 				MetricID:     x.MetricID,
@@ -213,7 +221,7 @@ func (s *WritePreparer) Prepare(input []any) PreparedData {
 				FreeIndexPages: x.FreeIndexPages,
 				FreeDataPages:  x.FreeDataPages,
 			}
-			rec.Pack(w)
+			rec.Pack(multi)
 			s.commits = append(s.commits, MeasuresDeleteCommited{
 				MetricID: x.MetricID,
 				ResultCh: x.ResultCh,
@@ -222,19 +230,11 @@ func (s *WritePreparer) Prepare(input []any) PreparedData {
 		}
 	}
 	// 2. Додаю розмір пакету і чексуму
-
+	packet := finalizePacket(s.w, hasher.Sum32())
 	//s.written += int64(len(packet)) + 12
-
-	packet := s.w.Bytes()
-	// write size
-	payloadSize := len(packet) - 13
-	start := 9 - bin.CountVarSize(payloadSize)
-	bin.PutVarSize(packet[start:], payloadSize)
-	// CRC32
-	bin.PutUint32(packet[9:], hasher.Sum32())
 	//
 	return PreparedData{
-		Packet:       packet[start:],
+		Packet:       packet,
 		WriteToIndex: s.indexPages,
 		WriteToData:  s.dataPages,
 		Commits:      s.commits,
@@ -260,3 +260,13 @@ func getIndexRecords(buf []byte, count int) (list []IndexRecord) {
 	}
 	return
 }
+
+func finalizePacket(w *bytes.Buffer, checksum uint32) []byte {
+	bin.WriteUint32(w, checksum)
+	packet := w.Bytes()
+	bodySize := len(packet) - 13 // 9 bytes prefix + 4 bytes crc32
+	// cut empty bytes at start
+	start := 9 - bin.CountVarSize(bodySize)
+	bin.PutVarSize(packet[start:], bodySize)
+	return packet[start:]
+}