cmd/swarm: support exporting, importing chunk db (#14868)

cmd/swarm/main.go

@@ -240,12 +240,65 @@ Removes a path from the manifest
 			},
 		},
 		{
-			Action:    cleandb,
+			Name:      "db",
+			Usage:     "manage the local chunk database",
+			ArgsUsage: "db COMMAND",
+			Description: `
+Manage the local chunk database.
+`,
+			Subcommands: []cli.Command{
+				{
+					Action:    dbExport,
+					Name:      "export",
+					Usage:     "export a local chunk database as a tar archive (use - to send to stdout)",
+					ArgsUsage: "<chunkdb> <file>",
+					Description: `
+Export a local chunk database as a tar archive (use - to send to stdout).
+
+    swarm db export ~/.ethereum/swarm/bzz-KEY/chunks chunks.tar
+
+The export may be quite large, consider piping the output through the Unix
+pv(1) tool to get a progress bar:
+
+    swarm db export ~/.ethereum/swarm/bzz-KEY/chunks - | pv > chunks.tar
+`,
+				},
+				{
+					Action:    dbImport,
+					Name:      "import",
+					Usage:     "import chunks from a tar archive into a local chunk database (use - to read from stdin)",
+					ArgsUsage: "<chunkdb> <file>",
+					Description: `
+Import chunks from a tar archive into a local chunk database (use - to read from stdin).
+
+    swarm db import ~/.ethereum/swarm/bzz-KEY/chunks chunks.tar
+
+The import may be quite large, consider piping the input through the Unix
+pv(1) tool to get a progress bar:
+
+    pv chunks.tar | swarm db import ~/.ethereum/swarm/bzz-KEY/chunks -
+`,
+				},
+				{
+					Action:    dbClean,
+					Name:      "clean",
+					Usage:     "remove corrupt entries from a local chunk database",
+					ArgsUsage: "<chunkdb>",
+					Description: `
+Remove corrupt entries from a local chunk database.
+`,
+				},
+			},
+		},
+		{
+			Action: func(ctx *cli.Context) {
+				utils.Fatalf("ERROR: 'swarm cleandb' has been removed, please use 'swarm db clean'.")
+			},
 			Name:      "cleandb",
-			Usage:     "Cleans database of corrupted entries",
+			Usage:     "DEPRECATED: use 'swarm db clean'",
 			ArgsUsage: " ",
 			Description: `
-Cleans database of corrupted entries.
+DEPRECATED: use 'swarm db clean'.
 `,
 		},
 	}