mirror of
https://github.com/0glabs/0g-chain.git
synced 2024-12-26 00:05:18 +00:00
29 lines
1.6 KiB
Go
29 lines
1.6 KiB
Go
/*
|
|
Migrate handles translating the state of the blockchain between software versions.
|
|
|
|
For example, as modules are changed over time the structure of the data they store changes. The data structure must be
|
|
migrated to the new structure of the newer versions.
|
|
|
|
There are two types of migration:
|
|
- **genesis migration** a script converts an exported genesis file from the old software to a new genesis file for the new software
|
|
- **in-place upgrade** a handler in the upgrade module converts data in the database itself from the old version to the new
|
|
|
|
Genesis migration starts a whole new blockchain (with new chain-id) for the new software version.
|
|
In-Place upgrade keeps the blockchain (and chain-id) the same for the new software version.
|
|
|
|
We only support migrations between mainnet 0g-chain releases.
|
|
We only support migrations from the previous mainnet 0g-chain version to the current. We don't support migrating between two old versions, use the old software version for this.
|
|
We only support migrations from old to new versions, not the other way around.
|
|
|
|
Genesis Migration
|
|
The process is:
|
|
- unmarshal the current genesis file into the old `GenesisState` type that has been copied into a `legacy` folder (ideally using the old codec version)
|
|
- convert that `GenesisState` to the current `GenesisState` type
|
|
- marshal it to json (using current codec)
|
|
|
|
On each release we can delete the previous releases migration and old GenesisState type.
|
|
eg 0g-chain-3 migrates `auth.GenesisState` from 0g-chain-2 to `auth.GenesisState` from 0g-chain-3,
|
|
but for 0g-chain-4 we don't need to keep around 0g-chain-2's `auth.GenesisState` type.
|
|
*/
|
|
package migrate
|