wp

database/snapshot.go

@@ -8,6 +8,7 @@ import (
 	"path/filepath"
 
 	bin "gordenko.dev/dima/bin/little"
+	"gordenko.dev/dima/qb/atree"
 	"gordenko.dev/dima/qb/util"
 )
 
@@ -70,35 +71,15 @@ func writeSnapshot(in writeSnapshotIn) (err error) {
 		}
 	}
 	// free index pages
-	_, err = bin.WriteVarSize(dst, in.FrozenIndexPagesCount)
+	err = writeFreePages(dst, in.FrozenIndexPagesCount, in.IndexPageNumbers)
 	if err != nil {
 		return
 	}
-	_, err = bin.WriteVarSize(dst, len(in.IndexPageNumbers))
-	if err != nil {
-		return
-	}
-	for _, pageNo := range in.IndexPageNumbers {
-		err = bin.WriteUint32(dst, pageNo)
-		if err != nil {
-			return
-		}
-	}
 	// free data pages
-	_, err = bin.WriteVarSize(dst, in.FrozenDataPagesCount)
+	err = writeFreePages(dst, in.FrozenDataPagesCount, in.DataPageNumbers)
 	if err != nil {
 		return
 	}
-	_, err = bin.WriteVarSize(dst, len(in.DataPageNumbers))
-	if err != nil {
-		return
-	}
-	for _, pageNo := range in.DataPageNumbers {
-		err = bin.WriteUint32(dst, pageNo)
-		if err != nil {
-			return
-		}
-	}
 	// CRC32
 	bin.WriteUint32(file, hasher.Sum32())
 
@@ -196,8 +177,11 @@ func readSnapshot(fileName string) (out readSnapshotOut, err error) {
 	for range metricsQty {
 		var (
 			metricID uint32
-			metric   = &ReplayMetric{
-				buffer: make([]byte, minBufferSize),
+			buf      = make([]byte, atree.DataPageSize)
+			// для простоти створюю буфер максимального розміру
+			metric = &ReplayMetric{
+				buf:     buf,
+				databuf: buf[:atree.DataPagePayloadSize],
 			}
 		)
 		metricID, err = bin.ReadUint32(src)
@@ -211,40 +195,15 @@ func readSnapshot(fileName string) (out readSnapshotOut, err error) {
 		metrics[metricID] = metric
 	}
 	// index pages
-	frozenIndexPagesCount, err = bin.ReadVarSize(src)
+	frozenIndexPagesCount, indexPageNumbers, err = readFreePages(src)
 	if err != nil {
 		return
 	}
-	indexPageNumbersCount, err := bin.ReadVarSize(src)
-	if err != nil {
-		return
-	}
-	for range indexPageNumbersCount {
-		var pageNo uint32
-		pageNo, err = bin.ReadUint32(src)
-		if err != nil {
-			return
-		}
-		indexPageNumbers = append(indexPageNumbers, pageNo)
-	}
 	// data pages
-	frozenDataPagesCount, err = bin.ReadVarSize(src)
+	frozenDataPagesCount, dataPageNumbers, err = readFreePages(src)
 	if err != nil {
 		return
 	}
-	dataPageNumbersCount, err := bin.ReadVarSize(src)
-	if err != nil {
-		return
-	}
-	for range dataPageNumbersCount {
-		var pageNo uint32
-		pageNo, err = bin.ReadUint32(src)
-		if err != nil {
-			return
-		}
-		dataPageNumbers = append(dataPageNumbers, pageNo)
-	}
-
 	// verify CRC32
 	expectedCRC, err := bin.ReadUint32(bufferedReader)
 	if err != nil {
@@ -267,3 +226,47 @@ func readSnapshot(fileName string) (out readSnapshotOut, err error) {
 		DataPageNumbers:       dataPageNumbers,
 	}, nil
 }
+
+// HELPERS
+
+func writeFreePages(dst io.Writer, frozenPagesCount int, pageNumbers []uint32) (err error) {
+	_, err = bin.WriteVarSize(dst, frozenPagesCount)
+	if err != nil {
+		return
+	}
+	_, err = bin.WriteVarSize(dst, len(pageNumbers))
+	if err != nil {
+		return
+	}
+	for _, pageNo := range pageNumbers {
+		err = bin.WriteUint32(dst, pageNo)
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+func readFreePages(src io.Reader) (_ int, _ []uint32, err error) {
+	var (
+		frozenPagesCount int
+		pageNumbers      []uint32
+	)
+	frozenPagesCount, err = bin.ReadVarSize(src)
+	if err != nil {
+		return
+	}
+	pageNumbersCount, err := bin.ReadVarSize(src)
+	if err != nil {
+		return
+	}
+	for range pageNumbersCount {
+		var pageNo uint32
+		pageNo, err = bin.ReadUint32(src)
+		if err != nil {
+			return
+		}
+		pageNumbers = append(pageNumbers, pageNo)
+	}
+	return frozenPagesCount, pageNumbers, nil
+}