Module zebrad::commands::copy_state

copy-state subcommand - copies state from one directory to another (debug only)

Copying state helps Zebra developers modify and debug cached state formats.

In order to test a new state format, blocks must be identical when they are:

• read from the old format,
• written to the new format, and
• read from the new format.

The “old” and “new” states can also use the same format. This tests the low-level state API’s performance.

Command Structure

Copying cached state uses the following services and tasks:

Tasks:

• Old to New Copy Task
  • queries the source state for blocks, copies those blocks to the target state, then reads the copied blocks from the target state.

Services:

• Source Old State Service
  • fetches blocks from the best finalized chain from permanent storage, in the old format
• Target New State Service
  • writes best finalized chain blocks to permanent storage, in the new format
  • only performs essential contextual verification of blocks, to make sure that block data hasn’t been corrupted by receiving blocks in the new format
  • fetches blocks from the best finalized chain from permanent storage, in the new format

Structs

• CopyStateCmd
  copy cached chain state (expert users only)

Constants

• PROGRESS_HEIGHT_INTERVAL 🔒
  How often we log info-level progress messages
• _DERIVE_Command_FOR_CopyStateCmd 🔒