Merge pull request #417 from ahrtr/surgery_clear_element_20230310

Add cobra style `surgery clear-page-elements` command

cmd/bbolt/command_root.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"github.com/spf13/cobra"
+)
+
+const (
+	cliName        = "bbolt"
+	cliDescription = "A simple command line tool for inspecting bbolt databases"
+)
+
+func NewRootCommand() *cobra.Command {
+	rootCmd := &cobra.Command{
+		Use:     cliName,
+		Short:   cliDescription,
+		Version: "dev",
+	}
+
+	rootCmd.AddCommand(
+		newSurgeryCobraCommand(),
+	)
+
+	return rootCmd
+}

cmd/bbolt/command_surgery_cobra.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"go.etcd.io/bbolt/internal/common"
+	"go.etcd.io/bbolt/internal/surgeon"
+)
+
+var (
+	surgeryTargetDBFilePath string
+	surgeryPageId           uint64
+	surgeryStartElementIdx  int
+	surgeryEndElementIdx    int
+)
+
+func newSurgeryCobraCommand() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "surgery <subcommand>",
+		Short: "surgery related commands",
+	}
+
+	cmd.AddCommand(newSurgeryClearPageElementsCommand())
+
+	return cmd
+}
+
+func newSurgeryClearPageElementsCommand() *cobra.Command {
+	clearElementCmd := &cobra.Command{
+		Use:   "clear-page-elements <bbolt-file> [options]",
+		Short: "Clears elements from the given page, which can be a branch or leaf page",
+		Args: func(cmd *cobra.Command, args []string) error {
+			if len(args) == 0 {
+				return errors.New("db file path not provided")
+			}
+			if len(args) > 1 {
+				return errors.New("too many arguments")
+			}
+			return nil
+		},
+
+		RunE: surgeryClearPageElementFunc,
+	}
+
+	clearElementCmd.Flags().StringVar(&surgeryTargetDBFilePath, "output", "", "path to the target db file")
+	clearElementCmd.Flags().Uint64VarP(&surgeryPageId, "pageId", "", 0, "page id")
+	clearElementCmd.Flags().IntVarP(&surgeryStartElementIdx, "from-index", "", 0, "start element index (included) to clear, starting from 0")
+	clearElementCmd.Flags().IntVarP(&surgeryEndElementIdx, "to-index", "", 0, "end element index (excluded) to clear, starting from 0, -1 means to the end of page")
+
+	return clearElementCmd
+}
+
+func surgeryClearPageElementFunc(cmd *cobra.Command, args []string) error {
+	srcDBPath := args[0]
+
+	if err := copyFile(srcDBPath, surgeryTargetDBFilePath); err != nil {
+		return fmt.Errorf("[clear-page-element] copy file failed: %w", err)
+	}
+
+	if surgeryPageId < 2 {
+		return fmt.Errorf("the pageId must be at least 2, but got %d", surgeryPageId)
+	}
+
+	needAbandonFreelist, err := surgeon.ClearPageElements(surgeryTargetDBFilePath, common.Pgid(surgeryPageId), surgeryStartElementIdx, surgeryEndElementIdx, false)
+	if err != nil {
+		return fmt.Errorf("clear-page-element command failed: %w", err)
+	}
+
+	if needAbandonFreelist {
+		fmt.Fprintf(os.Stdout, "WARNING: The clearing has abandoned some pages that are not yet referenced from free list.\n")
+		fmt.Fprintf(os.Stdout, "Please consider executing `./bbolt surgery abandon-freelist ...`\n")
+	}
+
+	fmt.Fprintf(os.Stdout, "All elements in [%d, %d) in page %d were cleared\n", surgeryStartElementIdx, surgeryEndElementIdx, surgeryPageId)
+	return nil
+}