Merge pull request ByteStorage#302 from ByteStorage/backup

Data Backup

db/engine/db.go

@@ -8,6 +8,7 @@ import (
 	"github.com/ByteStorage/FlyDB/config"
 	data2 "github.com/ByteStorage/FlyDB/db/data"
 	"github.com/ByteStorage/FlyDB/db/index"
+	"github.com/ByteStorage/FlyDB/lib/backup"
 	"github.com/ByteStorage/FlyDB/lib/const"
 	"go.uber.org/zap"
 	"io"
@@ -544,6 +545,15 @@ func (db *DB) loadIndexFromDataFiles() error {
 	return nil
 }
 
+// Backup the database to the specified directory
+func (db *DB) Backup(dir string) error {
+	db.lock.RLock()
+	defer db.lock.RUnlock()
+
+	// Create a backup directory
+	return backup.CopyDir(db.options.DirPath, dir)
+}
+
 // Clean the DB data directory after the test is complete
 func (db *DB) Clean() {
 	if db != nil {

db/engine/db_test.go

@@ -423,3 +423,30 @@ func TestDB_Sync(t *testing.T) {
 	err = db.Sync()
 	assert.Nil(t, err)
 }
+
+func TestDB_Backup(t *testing.T) {
+	opts := config.DefaultOptions
+	dir, _ := os.MkdirTemp("", "flydb-backup")
+	opts.DirPath = dir
+	opts.DataFileSize = 64 * 1024 * 1024
+	db, err := NewDB(opts)
+	defer destroyDB(db)
+	assert.Nil(t, err)
+	assert.NotNil(t, db)
+
+	for i := 1; i < 1000000; i++ {
+		err = db.Put(randkv.GetTestKey(i), randkv.RandomValue(128))
+		assert.Nil(t, err)
+	}
+
+	backupDir, _ := os.MkdirTemp("", "flydb-backup-test")
+	err = db.Backup(backupDir)
+	assert.Nil(t, err)
+
+	opts1 := config.DefaultOptions
+	opts1.DirPath = backupDir
+	db1, err := NewDB(opts1)
+	defer destroyDB(db1)
+	assert.Nil(t, err)
+	assert.NotNil(t, db1)
+}

lib/backup/backup.go

@@ -0,0 +1,87 @@
+package backup
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+)
+
+// CopyFile copies a file from src to dest.
+func copyFile(src, dest string, mode os.FileMode) error {
+	// Open the source file
+	srcFile, err := os.OpenFile(src, os.O_RDONLY, mode)
+	if err != nil {
+		return err
+	}
+	defer func(srcFile *os.File) {
+		err = srcFile.Close()
+		if err != nil {
+			panic(err)
+		}
+	}(srcFile)
+
+	// Create or open the destination file
+	destFile, err := os.OpenFile(dest, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, mode)
+	if err != nil {
+		// Close the source file if opening destination file fails
+		err = srcFile.Close()
+		if err != nil {
+			return err
+		}
+		return err
+	}
+	defer func(destFile *os.File) {
+		err = destFile.Close()
+		if err != nil {
+			panic(err)
+		}
+	}(destFile)
+
+	// Copy the contents of the source file to the destination file
+	if _, err = io.Copy(destFile, srcFile); err != nil {
+		return err
+	}
+
+	// Set permissions on destination files
+	return os.Chmod(dest, 0644)
+}
+
+// CopyDir copies a directory from src to dest.
+func CopyDir(src, dest string) error {
+	// Get the source directory information
+	srcInfo, err := os.Stat(src)
+	if err != nil {
+		return err
+	}
+
+	// Create the destination directory
+	if err = os.MkdirAll(dest, srcInfo.Mode()); err != nil {
+		return err
+	}
+
+	// Get the contents of the source directory
+	entries, err := os.ReadDir(src)
+	if err != nil {
+		return err
+	}
+
+	// Copy the contents of the source directory to the destination directory
+	for _, entry := range entries {
+		srcPath := filepath.Join(src, entry.Name())
+		destPath := filepath.Join(dest, entry.Name())
+
+		if entry.IsDir() {
+			// If it is a subdirectory, call CopyDir recursively
+			if err = CopyDir(srcPath, destPath); err != nil {
+				return err
+			}
+		} else {
+			// If it is a file, call copyFile to copy the file content
+			if err = copyFile(srcPath, destPath, entry.Type()); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}