cosmos-sdk/x/params/spec/02_subspace.md

39 lines
1.4 KiB
Markdown

<!--
order: 2
-->
# Subspace
`Subspace` is a prefixed subspace of the parameter store. Each module which uses the
parameter store will take a `Subspace` to isolate permission to access.
## Key
Parameter keys are human readable alphanumeric strings. A parameter for the key
`"ExampleParameter"` is stored under `[]byte("SubspaceName" + "/" + "ExampleParameter")`,
where `"SubspaceName"` is the name of the subspace.
Subkeys are secondary parameter keys those are used along with a primary parameter key.
Subkeys can be used for grouping or dynamic parameter key generation during runtime.
## KeyTable
All of the parameter keys that will be used should be registered at the compile
time. `KeyTable` is essentially a `map[string]attribute`, where the `string` is a parameter key.
Currently, `attribute` consists of a `reflect.Type`, which indicates the parameter
type to check that provided key and value are compatible and registered, as well as a function `ValueValidatorFn` to validate values.
Only primary keys have to be registered on the `KeyTable`. Subkeys inherit the
attribute of the primary key.
## ParamSet
Modules often define parameters as a proto message. The generated struct can implement
`ParamSet` interface to be used with the following methods:
* `KeyTable.RegisterParamSet()`: registers all parameters in the struct
* `Subspace.{Get, Set}ParamSet()`: Get to & Set from the struct
The implementor should be a pointer in order to use `GetParamSet()`.