chore: minor refactors

rudrOwO · Nov 27, 2024 · 07d2e8d · 07d2e8d
1 parent 3217984
commit 07d2e8d
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Showing 5 changed files with 17 additions and 22 deletions.
diff --git a/cmd/sqlite/main.go b/cmd/sqlite/main.go
@@ -19,7 +19,7 @@ func main() {
 	switch userCommand {
 	case ".dbinfo":
 		fmt.Printf("database page size: %v\n", btree.PAGE_SIZE)
-		fmt.Printf("number of tables: %v", api.CountRows(sql.GetRootPageOFFSET("sqlite_schema")))
+		fmt.Printf("number of tables: %v", sql.ExecuteSelect("SELECT COUNT(*) FROM sqlite_schema"))
 	case ".tables":
 		fmt.Print(sql.ExecuteSelect("SELECT tbl_name FROM sqlite_schema WHERE tbl_name != 'sqlite_sequence'"))
 	default:

diff --git a/internal/api/countrows.go b/internal/api/countrows.go
@@ -5,7 +5,7 @@ import (
 )
 
 func CountRows(rootPageOffset int64) uint16 {
-	leafPagesChannel := make(chan btree.LeafTablePage, 100)
+	leafPagesChannel := make(chan btree.LeafTablePage, BTREE_BUFFER_SIZE)
 	go btree.LoadAllLeafTablePages(rootPageOffset, dbFile, leafPagesChannel, true)
 
 	cellsCount := uint16(0)

diff --git a/internal/api/dotcommands.go b/internal/api/dotcommands.go
diff --git a/internal/api/init.go b/internal/api/init.go
@@ -1,6 +1,7 @@
 package api
 
 import (
+	"encoding/binary"
 	"log"
 	"os"
 
@@ -9,6 +10,8 @@ import (
 
 var dbFile *os.File
 
+const BTREE_BUFFER_SIZE = 100
+
 func Init(fileName string) *os.File {
 	var err error
 	dbFile, err = os.Open(fileName)
@@ -19,3 +22,14 @@ func Init(fileName string) *os.File {
 	btree.PAGE_SIZE = int64(readPageSize())
 	return dbFile
 }
+
+func readPageSize() uint16 {
+	dbHeader := make([]byte, btree.SQLITE3_HEADER_SIZE)
+	_, err := dbFile.Read(dbHeader)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	pageSize := binary.BigEndian.Uint16(dbHeader[16:18])
+	return pageSize
+}
diff --git a/internal/api/scantable.go b/internal/api/scantable.go
@@ -6,7 +6,7 @@ import (
 )
 
 func ScanTable(columnIndicesToSerialize []int, rowLength int, rootPageOffset int64, filter func(row []any) bool, rowsChannel chan<- []any) {
-	leafPagesChannel := make(chan btree.LeafTablePage, 100)
+	leafPagesChannel := make(chan btree.LeafTablePage, BTREE_BUFFER_SIZE)
 	go btree.LoadAllLeafTablePages(rootPageOffset, dbFile, leafPagesChannel, true)
 
 	for page := range leafPagesChannel {