makesync: add checksum option, change mb -> kb, store cli version

main.go

@@ -62,9 +62,10 @@ var cli struct {
 	} `cmd:"" help:"Verify the correctness of an archive structure, without verifying individual tile contents."`
 
 	Makesync struct {
-		Input              string `arg:"" type:"existingfile"`
-		BlockSizeMegabytes int    `default:1 help:"The approximate block size, in megabytes. 0 means 1 tile = 1 block."`
-		HashFunction       string `default:fnv1a help:"The hash function."`
+		Input        string `arg:"" type:"existingfile"`
+		BlockSizeKb  int    `default:1000 help:"The approximate block size, in kilobytes. 0 means 1 tile = 1 block."`
+		HashFunction string `default:fnv1a help:"The hash function."`
+		Checksum     string `help:"Store a checksum in the syncfile."`
 	} `cmd:"" hidden:""`
 
 	Sync struct {
@@ -193,7 +194,7 @@ func main() {
 			logger.Fatalf("Failed to verify archive, %v", err)
 		}
 	case "makesync <input>":
-		err := pmtiles.Makesync(logger, cli.Makesync.Input, cli.Makesync.BlockSizeMegabytes)
+		err := pmtiles.Makesync(logger, version, cli.Makesync.Input, cli.Makesync.BlockSizeKb, cli.Makesync.Checksum)
 		if err != nil {
 			logger.Fatalf("Failed to makesync archive, %v", err)
 		}

pmtiles/makesync.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"bytes"
 	"context"
+	"crypto/md5"
 	"fmt"
 	"github.com/dustin/go-humanize"
 	"github.com/schollz/progressbar/v3"
@@ -30,12 +31,12 @@ type Result struct {
 	Hash  uint64
 }
 
-func Makesync(logger *log.Logger, file string, block_size_megabytes int) error {
+func Makesync(logger *log.Logger, cli_version string, file string, block_size_kb int, checksum string) error {
 	ctx := context.Background()
 	start := time.Now()
 
 	bucketURL, key, err := NormalizeBucketKey("", "", file)
-	block_size_bytes := uint64(1024 * 1024 * block_size_megabytes)
+	block_size_bytes := uint64(1000 * block_size_kb)
 
 	if err != nil {
 		return err
@@ -93,6 +94,23 @@ func Makesync(logger *log.Logger, file string, block_size_megabytes int) error {
 		panic(err)
 	}
 	defer output.Close()
+	output.Write([]byte(fmt.Sprintf("version=%s\n", cli_version)))
+
+	if checksum == "md5" {
+		localfile, err := os.Open(file)
+		if err != nil {
+			panic(err)
+		}
+		defer localfile.Close()
+		reader := bufio.NewReaderSize(localfile, 64*1024*1024)
+		md5hasher := md5.New()
+		if _, err := io.Copy(md5hasher, reader); err != nil {
+			panic(err)
+		}
+		md5checksum := md5hasher.Sum(nil)
+		fmt.Printf("Completed md5 in %v.\n", time.Since(start))
+		output.Write([]byte(fmt.Sprintf("md5=%x\n", md5checksum)))
+	}
 
 	output.Write([]byte("hash=fnv1a\n"))
 	output.Write([]byte(fmt.Sprintf("blocksize=%d\n", block_size_bytes)))