feat: add memparse sub-command

This commit introduces a new sub-command `memparse` for analyzing
memory pages of processes. Using `memparse` without parameters will
display an overview of memory size of each process inside a container
checkpoint.

Signed-off-by: Kouame Behouba Manasse <behouba@gmail.com>

checkpointctl.go

@@ -40,6 +40,9 @@ func main() {
 	inspectCommand := setupInspect()
 	rootCommand.AddCommand(inspectCommand)
 
+	memparseCommand := setupMemParse()
+	rootCommand.AddCommand(memparseCommand)
+
 	rootCommand.Version = version
 
 	if err := rootCommand.Execute(); err != nil {
@@ -263,3 +266,33 @@ func cleanupTasks(tasks []task) {
 		}
 	}
 }
+
+func setupMemParse() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "memparse",
+		Short: "Analyze container checkpoint memory",
+		RunE:  memparse,
+		Args:  cobra.MinimumNArgs(1),
+	}
+
+	return cmd
+}
+
+func memparse(cmd *cobra.Command, args []string) error {
+	requiredFiles := []string{
+		metadata.SpecDumpFile, metadata.ConfigDumpFile,
+		filepath.Join(metadata.CheckpointDirectory, "pstree.img"),
+		filepath.Join(metadata.CheckpointDirectory, "core-"),
+		filepath.Join(metadata.CheckpointDirectory, "pagemap-"),
+		filepath.Join(metadata.CheckpointDirectory, "pages-"),
+		filepath.Join(metadata.CheckpointDirectory, "mm-"),
+	}
+
+	tasks, err := createTasks(args, requiredFiles)
+	if err != nil {
+		return err
+	}
+	defer cleanupTasks(tasks)
+
+	return showProcessMemorySizeTables(tasks)
+}

memparse.go

@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: Apache-2.0
+
+// This file is used to handle memory pages analysis of container checkpoints
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	metadata "github.com/checkpoint-restore/checkpointctl/lib"
+	"github.com/checkpoint-restore/go-criu/v6/crit"
+	"github.com/olekukonko/tablewriter"
+)
+
+// Display processes memory sizes within the given container checkpoints.
+func showProcessMemorySizeTables(tasks []task) error {
+	// Initialize the table
+	table := tablewriter.NewWriter(os.Stdout)
+	header := []string{
+		"PID",
+		"Process name",
+		"Memory size",
+	}
+	table.SetHeader(header)
+	table.SetAutoMergeCells(false)
+	table.SetRowLine(true)
+
+	// Function to recursively traverse the process tree and populate the table rows
+	var traverseTree func(*crit.PsTree, string) error
+	traverseTree = func(root *crit.PsTree, checkpointOutputDir string) error {
+		memReader, err := crit.NewMemoryReader(
+			filepath.Join(checkpointOutputDir, metadata.CheckpointDirectory),
+			root.PID, pageSize,
+		)
+		if err != nil {
+			return err
+		}
+
+		pagemapEntries := memReader.GetPagemapEntries()
+
+		var memSize int64
+
+		for _, entry := range pagemapEntries {
+			memSize += int64(*entry.NrPages) * int64(pageSize)
+		}
+
+		table.Append([]string{
+			fmt.Sprintf("%d", root.PID),
+			root.Comm,
+			metadata.ByteToString(memSize),
+		})
+
+		for _, child := range root.Children {
+			if err := traverseTree(child, checkpointOutputDir); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+
+	for _, task := range tasks {
+		// Clear the table before processing each checkpoint task
+		table.ClearRows()
+
+		c := crit.New(nil, nil, filepath.Join(task.outputDir, "checkpoint"), false, false)
+		psTree, err := c.ExplorePs()
+		if err != nil {
+			return fmt.Errorf("failed to get process tree: %w", err)
+		}
+
+		// Populate the table rows
+		if err := traverseTree(psTree, task.outputDir); err != nil {
+			return err
+		}
+
+		fmt.Printf("\nDisplaying processes memory sizes from %s\n\n", task.checkpointFilePath)
+		table.Render()
+	}
+
+	return nil
+}