feat(create): Add --piece-size flags

README.md

@@ -171,6 +171,17 @@ mkbrr create path/to/file -t https://example-tracker.com/announce --exclude "*.n
 
 # Create a torrent including only specific file patterns (comma-separated)
 mkbrr create path/to/video-folder -t https://example-tracker.com/announce --include "*.mkv,*.mp4"
+
+# Create with a specific piece size (e.g., 4 MiB) - alternative to -l/--piece-length
+mkbrr create path/to/file -t https://example-tracker.com/announce --piece-size 4MiB
+
+# Create limiting max piece size (e.g., 8 MiB) - alternative to -m/--max-piece-length
+mkbrr create path/to/file -t https://example-tracker.com/announce --max-piece-size 8MiB
+
+# Note on --piece-size:
+# The specified size is rounded up to the nearest power of 2 (e.g., 14k becomes 16KiB).
+# The final piece size is then clamped between 64 KiB (minimum) and 128 MiB (maximum).
+# So, --piece-size 14k will result in 64 KiB pieces due to the minimum limit.
 ```
 
 > [!NOTE]
@@ -450,4 +461,4 @@ Summary
 
 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
 
-See [LICENSE](LICENSE) for the full license text.
+See [LICENSE](LICENSE) for the full license text.

cmd/create.go

@@ -15,27 +15,29 @@ import (
 )
 
 var (
-	trackerURL        string
-	isPrivate         bool
-	comment           string
-	pieceLengthExp    *uint // for 2^n piece length, nil means automatic
-	maxPieceLengthExp *uint // for maximum 2^n piece length, nil means no limit
-	outputPath        string
-	webSeeds          []string
-	noDate            bool
-	noCreator         bool
-	source            string
-	verbose           bool
-	batchFile         string
-	presetName        string
-	presetFile        string
-	entropy           bool
-	quiet             bool
-	skipPrefix        bool
-	excludePatterns   []string
-	includePatterns   []string
+	trackerURL      string
+	isPrivate       bool
+	comment         string
+	pieceSizeStr    string
+	maxPieceSizeStr string
+	outputPath      string
+	webSeeds        []string
+	noDate          bool
+	noCreator       bool
+	source          string
+	verbose         bool
+	batchFile       string
+	presetName      string
+	presetFile      string
+	entropy         bool
+	quiet           bool
+	skipPrefix      bool
+	excludePatterns []string
+	includePatterns []string
 )
 
+var defaultPieceLength, defaultMaxPieceLength uint
+
 var createCmd = &cobra.Command{
 	Use:   "create [path]",
 	Short: "Create a new torrent file",
@@ -83,18 +85,10 @@ func init() {
 
 	// piece length flag allows setting a fixed piece size of 2^n bytes
 	// if not specified, piece length is calculated automatically based on total size
-	var defaultPieceLength, defaultMaxPieceLength uint
-	createCmd.Flags().UintVarP(&defaultPieceLength, "piece-length", "l", 0, "set piece length to 2^n bytes (16-27, automatic if not specified)")
-	createCmd.Flags().UintVarP(&defaultMaxPieceLength, "max-piece-length", "m", 0, "limit maximum piece length to 2^n bytes (16-27, unlimited if not specified)")
-	createCmd.PreRun = func(cmd *cobra.Command, args []string) {
-		if cmd.Flags().Changed("piece-length") {
-			pieceLengthExp = &defaultPieceLength
-		}
-		if cmd.Flags().Changed("max-piece-length") {
-			maxPieceLengthExp = &defaultMaxPieceLength
-		}
-	}
-
+	createCmd.Flags().UintVarP(&defaultPieceLength, "piece-length", "l", 0, "set piece length to 2^n bytes (16-27, alternative to --piece-size)")
+	createCmd.Flags().StringVar(&pieceSizeStr, "piece-size", "", "set piece size (e.g., \"4M\", \"8192k\", alternative to --piece-length). Value is rounded up to the nearest power of 2 and clamped between 64KiB-128MiB.")
+	createCmd.Flags().UintVarP(&defaultMaxPieceLength, "max-piece-length", "m", 0, "limit maximum piece length to 2^n bytes (16-27, alternative to --max-piece-size)")
+	createCmd.Flags().StringVar(&maxPieceSizeStr, "max-piece-size", "", "limit maximum piece size (e.g., \"16M\", \"16384k\", alternative to --max-piece-length)")
 	createCmd.Flags().StringVarP(&outputPath, "output", "o", "", "set output path (default: <name>.torrent)")
 	createCmd.Flags().StringVarP(&source, "source", "s", "", "add source string")
 	createCmd.Flags().BoolVarP(&noDate, "no-date", "d", false, "don't write creation date")
@@ -117,6 +111,43 @@ Flags:
 }
 
 func runCreate(cmd *cobra.Command, args []string) error {
+	pieceLengthChanged := cmd.Flags().Changed("piece-length")
+	pieceSizeChanged := cmd.Flags().Changed("piece-size")
+	maxPieceLengthChanged := cmd.Flags().Changed("max-piece-length")
+	maxPieceSizeChanged := cmd.Flags().Changed("max-piece-size")
+
+	if pieceLengthChanged && pieceSizeChanged {
+		return fmt.Errorf("cannot use both --piece-length and --piece-size")
+	}
+	if maxPieceLengthChanged && maxPieceSizeChanged {
+		return fmt.Errorf("cannot use both --max-piece-length and --max-piece-size")
+	}
+
+	var userPieceLengthExp *uint
+	var userMaxPieceLengthExp *uint
+	var userPieceSize *uint64
+	var userMaxPieceSize *uint64
+
+	if pieceLengthChanged {
+		userPieceLengthExp = &defaultPieceLength
+	} else if pieceSizeChanged {
+		parsedSize, err := torrent.ParseSize(pieceSizeStr)
+		if err != nil {
+			return fmt.Errorf("invalid --piece-size value: %w", err)
+		}
+		userPieceSize = &parsedSize
+	}
+
+	if maxPieceLengthChanged {
+		userMaxPieceLengthExp = &defaultMaxPieceLength
+	} else if maxPieceSizeChanged {
+		parsedMaxSize, err := torrent.ParseSize(maxPieceSizeStr)
+		if err != nil {
+			return fmt.Errorf("invalid --max-piece-size value: %w", err)
+		}
+		userMaxPieceSize = &parsedMaxSize
+	}
+
 	if cpuprofile, _ := cmd.Flags().GetString("cpuprofile"); cpuprofile != "" {
 		f, err := os.Create(cpuprofile)
 		if err != nil {
@@ -259,12 +290,26 @@ func runCreate(cmd *cobra.Command, args []string) error {
 		if cmd.Flags().Changed("comment") {
 			opts.Comment = comment
 		}
-		if cmd.Flags().Changed("piece-length") {
-			opts.PieceLengthExp = pieceLengthExp
+		opts.PieceLengthExp = userPieceLengthExp
+		opts.MaxPieceLength = userMaxPieceLengthExp
+		opts.PieceSize = userPieceSize
+		opts.MaxPieceSize = userMaxPieceSize
+
+		if pieceLengthChanged || pieceSizeChanged {
+			if pieceLengthChanged {
+				opts.PieceSize = nil
+			} else {
+				opts.PieceLengthExp = nil
+			}
 		}
-		if cmd.Flags().Changed("max-piece-length") {
-			opts.MaxPieceLength = maxPieceLengthExp
+		if maxPieceLengthChanged || maxPieceSizeChanged {
+			if maxPieceLengthChanged {
+				opts.MaxPieceSize = nil
+			} else {
+				opts.MaxPieceLength = nil
+			}
 		}
+
 		if cmd.Flags().Changed("source") {
 			opts.Source = source
 		}
@@ -298,8 +343,10 @@ func runCreate(cmd *cobra.Command, args []string) error {
 			WebSeeds:        webSeeds,
 			IsPrivate:       isPrivate,
 			Comment:         comment,
-			PieceLengthExp:  pieceLengthExp,
-			MaxPieceLength:  maxPieceLengthExp,
+			PieceLengthExp:  userPieceLengthExp,
+			MaxPieceLength:  userMaxPieceLengthExp,
+			PieceSize:       userPieceSize,
+			MaxPieceSize:    userMaxPieceSize,
 			Source:          source,
 			NoDate:          noDate,
 			NoCreator:       noCreator,

internal/torrent/batch.go

@@ -69,8 +69,8 @@ func (j *BatchJob) ToCreateOptions(verbose bool, quiet bool, version string) Cre
 type BatchResult struct {
 	Error    error
 	Info     *TorrentInfo
-	Job      BatchJob
 	Trackers []string
+	Job      BatchJob
 	Success  bool
 }