#9 refactored

main.go

@@ -8,99 +8,76 @@ import (
 	"time"
 )
 
+func checkError(err error, message string) {
+	if err != nil {
+		log.Fatalf("%s: %v", message, err)
+	}
+}
+
 func main() {
-	// Define the database directory and block size
 	dbDir := filepath.Join(".", "mydb")
-	blockSize := 128 // 128 bytes per block
+	blockSize := 128
+	const Filename = "datafile.dat"
 
-	// Initialize FileMgr
 	fm, err := kfile.NewFileMgr(dbDir, blockSize)
-	if err != nil {
-		log.Fatalf("Failed to initialize FileMgr: %v", err)
-	}
+	checkError(err, "Failed to initialize FileMgr")
 	defer func() {
-		err := fm.Close()
-		if err != nil {
-			log.Printf("Failed to close FileMgr: %v", err)
-		}
+		checkError(fm.Close(), "Failed to close FileMgr")
 	}()
 
-	// Append a new block to "datafile.dat"
-	blk, err := fm.Append("datafile.dat")
-	if err != nil {
-		log.Fatalf("Failed to append block: %v", err)
-	}
+	blk, err := fm.Append(Filename)
+	checkError(err, "Failed to append block")
 	fmt.Printf("Appended Block: %v\n", blk)
 
-	// Create a new Page and write data
-	page := kfile.NewPage(blockSize)
-	err = page.SetInt(0, 42)
-	if err != nil {
-		log.Fatalf("Failed to set int: %v", err)
-	}
-	err = page.SetString(4, "Hello, Go!")
-	if err != nil {
-		log.Fatalf("Failed to set string: %v", err)
-	}
+	pageManager := kfile.NewPageManager(blockSize)
+	newPage := kfile.NewPage(blockSize, Filename)
+	pageID := kfile.NewPageId(kfile.BlockId{Filename: Filename, Blknum: blk.Number()})
 
-	err = page.SetDate(15, time.Now())
-	if err != nil {
-		log.Fatalf("Failed to set string: %v", err)
-	}
-	err = page.SetBool(24, true)
-	if err != nil {
-		log.Fatalf("Failed to set string: %v", err)
-	}
-	err = page.SetDate(25, time.Now())
-	if err != nil {
-		log.Fatalf("Failed to set string: %v", err)
-	}
+	err = newPage.SetInt(0, 42)
+	checkError(err, "Failed to set int")
 
-	// Write the Page to the block
-	err = fm.Write(blk, page)
-	if err != nil {
-		log.Fatalf("Failed to write to block: %v", err)
-	}
-	fmt.Printf("Written to Block: %v\n", blk)
+	err = newPage.SetString(4, "Hello, Go!")
+	checkError(err, "Failed to set string")
 
-	// Read the Page from the block
-	readPage := kfile.NewPage(blockSize)
-	err = fm.Read(blk, readPage)
-	if err != nil {
-		log.Fatalf("Failed to read from block: %v", err)
-	}
+	currentTime := time.Now()
+	err = newPage.SetDate(15, currentTime)
+	checkError(err, "Failed to set date")
+
+	err = newPage.SetBool(50, true)
+	checkError(err, "Failed to set bool")
+
+	err = fm.Write(blk, newPage)
+	checkError(err, "Failed to write to block")
+
+	readPage := kfile.NewPage(blockSize, Filename)
+	pageManager.SetPage(pageID, readPage)
+
+	err = fm.Read(blk, pageManager, pageID)
+	checkError(err, "Failed to read from block")
 
-	// Retrieve data from the read Page
 	intVal, err := readPage.GetInt(0)
-	if err != nil {
-		log.Fatalf("Failed to get int: %v", err)
-	}
-	strVal, err := readPage.GetString(4, 10)
-	if err != nil {
-		log.Fatalf("Failed to get string: %v", err)
-	}
-	dateVal, err := readPage.GetDate(15)
-	if err != nil {
-		log.Fatalf("Failed to get string: %v", err)
-	}
-	boolVal, err := readPage.GetBool(25)
-	if err != nil {
-		log.Fatalf("Failed to get string: %v", err)
-	}
+	checkError(err, "Failed to get int")
+
+	strVal, err := readPage.GetString(4, len("Hello, Go!"))
+	checkError(err, "Failed to get string")
 
+	dateVal, err := readPage.GetDate(30)
+	checkError(err, "Failed to get date")
+
+	boolVal, err := readPage.GetBool(50)
+	checkError(err, "Failed to get bool")
+
+	fmt.Printf("Integer: %d, String: %s, Date: %s, Bool: %v\n",
+		intVal, strVal, dateVal, boolVal)
+
+	fmt.Printf("Stats - Blocks Read: %d, Blocks Written: %d\n", fm.BlocksRead(), fm.BlocksWritten())
 	stats := fm.ReadLog()
 	stats1 := fm.BlockSize()
 	stats2 := fm.BlocksRead()
 	stats3 := fm.BlocksWritten()
-
-	fmt.Printf("Read from Block: %v\n", blk)
-	fmt.Printf("Integer Value: %d\n", intVal)
-	fmt.Printf("String Value: %s\n", strVal)
-	fmt.Printf("Date Value: %s\n", dateVal)
-	fmt.Printf("Bool Value: %s\n", boolVal)
-	fmt.Printf("Stats Value: %s\n", stats)
-	fmt.Printf("Stats1 Value: %s\n", stats1)
-	fmt.Printf("Stats2 Value: %s\n", stats2)
-	fmt.Printf("Stats3Value: %s\n", stats3)
-	fmt.Printf("Stats4Value: %s\n", readPage.Contents())
+	fmt.Printf("Stats: %v\n", stats)
+	fmt.Printf("Block Size: %d\n", stats1)
+	fmt.Printf("Blocks Read: %d\n", stats2)
+	fmt.Printf("Blocks Written: %d\n", stats3)
+	fmt.Printf("Stats4Value: %v\n", readPage.Contents())
 }