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AmrSaberAmrSaber
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Implement export/import functionality
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‎README.md‎

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@@ -47,6 +47,7 @@ Unlike traditional databases, KV is designed for simplicity and speed. No server
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- [Version Control & History](#version-control--history)
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- [Output Formats](#output-formats)
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- [Batch Operations & Multiple Keys](#batch-operations--multiple-keys)
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- [Backup & Restore](#backup--restore)
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- [Utility Commands](#utility-commands)
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- [Configuration](#configuration)
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- [Data Storage](#data-storage)
@@ -430,6 +431,66 @@ kv unlock --all --password "mypass"
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# none of the changes are applied (all-or-nothing behavior)
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```
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### Backup & Restore
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> **Note:** Export creates a complete snapshot of your database including all keys, values, encryption, hidden state, TTL settings, and full history. Import completely replaces your current database with the imported one, creating a backup of your current database first.
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```bash
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# Export database to a file
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kv db export backup.db
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# Output: Database exported to: backup.db
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# Export to absolute path
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kv db export /path/to/backups/kv-backup-2025-10-20.db
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# Overwrite existing backup file
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kv db export backup.db --force
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# Export to stdout (useful for piping)
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kv db export - > backup.db
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# Or simply:
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kv db export > backup.db
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# Import database from a file (replaces current database)
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kv db import backup.db
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# Output:
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# Current database backed up to: /path/to/kv.db.backup
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# Database imported successfully
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# Import from stdin
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cat backup.db | kv db import -
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# Or simply:
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kv db import < backup.db
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# Practical examples:
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# Create daily backups
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kv db export ~/backups/kv-$(date +%Y-%m-%d).db
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# Transfer database between machines
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# On source machine:
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kv db export - | ssh user@remote 'kv db import -'
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# Compress backup
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kv db export - | gzip > kv-backup.db.gz
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# Restore from compressed backup
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gunzip -c kv-backup.db.gz | kv db import -
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```
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**What gets preserved in export/import:**
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- All keys and values (plain text, encrypted, and hidden)
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- Password-encrypted keys (with their encryption intact)
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- Hidden/visible state
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- TTL and expiration settings
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- Complete version history for all keys
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- All configuration and metadata
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**Safety features:**
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- Import automatically creates a backup at `<db-path>.backup` before replacing
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- Import validates the file is a valid database before proceeding
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- Export fails if file exists (use `--force` to override)
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- Export validates destination directory exists
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### Utility Commands
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```bash

‎src/cmd/db.go‎

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package cmd
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import "github.com/spf13/cobra"
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// dbCmd represents the db command
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var dbCmd = &cobra.Command{
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Use: "db",
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Short: "Database operations",
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}
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func init() {
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rootCmd.AddCommand(dbCmd)
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}

‎src/cmd/export.go‎

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package cmd
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import (
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"fmt"
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"io"
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"os"
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"path/filepath"
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"github.com/AmrSaber/kv/src/common"
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"github.com/spf13/cobra"
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)
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var exportFlags = struct{ force bool }{}
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// exportCmd represents the export command
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var exportCmd = &cobra.Command{
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Use: "export <file-path>",
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Short: "Export database to a file",
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Long: `Export the entire database to a binary file.
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The exported file captures the complete state of the database and can be
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imported later using the 'import' command to restore the exact state.
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Use "-" as the file path to write to stdout (useful for piping).`,
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Example: ` # Export database to a file
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kv db export my-backup
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# Export to stdout
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kv db export > backup.db # Or using "-" as file name
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# Export to absolute path
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kv db export /path/to/backup
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# Overwrite existing file
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kv db export backup.db --force`,
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Args: cobra.MaximumNArgs(1),
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Run: func(cmd *cobra.Command, args []string) {
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// Handle stdout
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if len(args) == 0 || args[0] == "-" {
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exportToStdout()
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return
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}
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destPath := common.NormalizePath(args[0])
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// Check if directory exists
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dir := filepath.Dir(destPath)
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if _, err := os.Stat(dir); os.IsNotExist(err) {
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common.Fail("Directory does not exist: %s", dir)
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}
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// Check if file already exists
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if _, err := os.Stat(destPath); err == nil {
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if !exportFlags.force {
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common.Fail("File already exists: %s (use --force to overwrite)", destPath)
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}
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// Remove existing file when --force is used
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err = os.Remove(destPath)
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common.FailOn(err)
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}
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// Export using VACUUM INTO
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db := common.GetDB()
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_, err := db.Exec("VACUUM INTO ?", destPath)
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common.FailOn(err)
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fmt.Printf("Database exported to: %s\n", destPath)
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},
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}
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func exportToStdout() {
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// Create a temporary file for VACUUM INTO
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tmpFile, err := os.CreateTemp("", "kv-export-*")
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common.FailOn(err)
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tmpPath := tmpFile.Name()
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err = tmpFile.Close()
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common.FailOn(err)
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defer func() { _ = os.Remove(tmpPath) }()
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// Export to temp file
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db := common.GetDB()
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_, err = db.Exec("VACUUM INTO ?", tmpPath)
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common.FailOn(err)
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// Copy temp file to stdout
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file, err := os.Open(tmpPath)
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common.FailOn(err)
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defer func() { _ = file.Close() }()
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_, err = io.Copy(os.Stdout, file)
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common.FailOn(err)
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}
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func init() {
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dbCmd.AddCommand(exportCmd)
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exportCmd.Flags().BoolVarP(&exportFlags.force, "force", "f", false, "Overwrite existing file if it exists")
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}

‎src/cmd/import.go‎

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package cmd
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import (
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"fmt"
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"io"
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"os"
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"github.com/AmrSaber/kv/src/common"
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"github.com/spf13/cobra"
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_ "modernc.org/sqlite"
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)
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// importCmd represents the import command
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var importCmd = &cobra.Command{
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Use: "import <file-path>",
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Short: "Import database from a file",
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Long: `Import a database from a binary file and replace the current database.
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The imported file must be a valid database file created with the 'export' command.
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This will completely replace the current database with the imported one.
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WARNING: This operation is destructive. The current database will be backed up
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to <db-path>.backup before importing.
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Use "-" as the file path to read from stdin (useful for piping).`,
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Example: ` # Import database from a file
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kv db import backup.db
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# Import from stdin - you also get UUOC award :)
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cat backup.db | kv db import # Or use "-" as file name
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# Import from absolute path
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kv db import /path/to/backup`,
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Args: cobra.MaximumNArgs(1),
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Run: func(cmd *cobra.Command, args []string) {
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sourcePath := "-"
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if len(args) > 0 {
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sourcePath = args[0]
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}
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// Handle stdin
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if sourcePath == "-" {
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// Create temporary file for stdin content
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tmpFile, err := os.CreateTemp("", "kv-import-*")
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common.FailOn(err)
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defer func() { _ = os.Remove(tmpFile.Name()) }()
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// Copy stdin to temp file
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_, err = io.Copy(tmpFile, os.Stdin)
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common.FailOn(err)
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err = tmpFile.Close()
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common.FailOn(err)
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sourcePath = tmpFile.Name()
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} else {
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sourcePath = common.NormalizePath(sourcePath)
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// Check if source file exists
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if _, err := os.Stat(sourcePath); os.IsNotExist(err) {
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common.Fail("File does not exist: %s", sourcePath)
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}
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}
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// Validate source is a valid SQLite database
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if err := common.ValidateSqliteFile(sourcePath); err != nil {
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common.Fail("Invalid database file: %v", err)
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}
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// Get destination path
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destPath := common.GetDBPath()
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backupPath := destPath + ".backup"
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// Vacuum current database to commit all WAL changes to main file
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db := common.GetDB()
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_, err := db.Exec("VACUUM")
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common.FailOn(err)
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// Close database connection
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common.CloseDB()
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// Remove old backup if exists
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_ = os.Remove(backupPath)
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// Backup current database if it exists
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if _, err := os.Stat(destPath); err == nil {
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err = os.Rename(destPath, backupPath)
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if err != nil {
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common.Fail("Failed to backup current database: %v", err)
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}
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fmt.Printf("Current database backed up to: %s\n", backupPath)
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}
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// Remove WAL files (should be empty after VACUUM, but remove just in case)
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_ = os.Remove(destPath + "-wal")
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_ = os.Remove(destPath + "-shm")
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// Copy source to destination
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err = common.CopyFile(sourcePath, destPath)
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if err != nil {
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if _, err := os.Stat(backupPath); err == nil {
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_ = os.Remove(destPath)
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_ = os.Rename(backupPath, destPath)
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}
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common.Fail("Failed to import database: %v", err)
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}
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// Reopen database (migrations will run automatically)
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common.GetDB()
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fmt.Println("Database imported successfully")
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},
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}
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func init() {
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dbCmd.AddCommand(importCmd)
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}

‎src/common/db.go‎

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@@ -16,8 +16,15 @@ var pragmas = []string{
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`PRAGMA busy_timeout = 5000`,
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}
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func CloseDB() {
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if db != nil {
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_ = db.Close()
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db = nil
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}
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}
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func ClearDB() {
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dbPath := path.Dir(getDBPath())
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dbPath := path.Dir(GetDBPath())
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err := os.RemoveAll(dbPath)
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FailOn(err)
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}
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}
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func openDB() *sql.DB {
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dbPath := getDBPath()
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dbPath := GetDBPath()
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_ = os.MkdirAll(path.Dir(dbPath), os.ModeDir|os.ModePerm)
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db, err := sql.Open("sqlite", dbPath+"?_txlock=immediate")
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return db
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}
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func getDBPath() string {
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func GetDBPath() string {
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scope := gap.NewScope(gap.User, "kv")
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6673
dbPath, err := scope.DataPath("kv.db")
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FailOn(err)
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6976
return dbPath
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}
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func ValidateSqliteFile(path string) error {
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testDB, err := sql.Open("sqlite", path+"?mode=ro")
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if err != nil {
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return err
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}
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defer func() { _ = testDB.Close() }()
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// Try to query to ensure it's actually valid
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return testDB.Ping()
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}

‎src/common/files.go‎

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package common
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import (
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"io"
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"os"
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"path/filepath"
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)
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func CopyFile(src, dst string) error {
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sourceFile, err := os.Open(src)
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if err != nil {
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return err
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}
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defer func() { _ = sourceFile.Close() }()
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destFile, err := os.Create(dst)
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if err != nil {
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return err
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}
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defer func() { _ = destFile.Close() }()
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_, err = io.Copy(destFile, sourceFile)
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return err
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}
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func NormalizePath(path string) string {
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if len(path) > 0 && path[0] == '~' {
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home, err := os.UserHomeDir()
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FailOn(err)
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path = filepath.Join(home, path[1:])
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}
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// Make path absolute
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absPath, err := filepath.Abs(path)
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FailOn(err)
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return absPath
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}

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