params

package
v1.0.0 Latest Latest
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Published: May 14, 2020 License: Apache-2.0 Imports: 17 Imported by: 0

Documentation

Overview

Package params provides a namespaced module parameter store.

There are two core components, Keeper and Subspace. Subspace is an isolated namespace for a parameter store, where keys are prefixed by pre-configured subspace names which modules provide. The Keeper has a permission to access all existing subspaces.

Subspace can be used by the individual keepers, who needs a private parameter store that the other keeper cannot modify. Keeper can be used by the Governance keeper, who need to modify any parameter in case of the proposal passes.

Basic Usage:

1. Declare constant module parameter keys and the globally unique Subspace name:

const (
	ModuleSubspace = "mymodule"
)

const (
	KeyParameter1 = "myparameter1"
	KeyParameter2 = "myparameter2"
)

2. Create a concrete parameter struct and define the validation functions:

type MyParams struct {
	MyParam1 int64 `json:"my_param1" yaml:"my_param1"`
	MyParam2 bool `json:"my_param2" yaml:"my_param2"`
}

func validateMyParam1(i interface{}) error {
	_, ok := i.(int64)
	if !ok {
		return fmt.Errorf("invalid parameter type: %T", i)
	}

	// validate (if necessary)...

	return nil
}

func validateMyParam2(i interface{}) error {
	_, ok := i.(bool)
	if !ok {
		return fmt.Errorf("invalid parameter type: %T", i)
	}

	// validate (if necessary)...

	return nil
}

3. Implement the params.ParamSet interface:

func (p *MyParams) ParamSetPairs() params.ParamSetPairs {
	return params.ParamSetPairs{
		{KeyParameter1, &p.MyParam1, validateMyParam1},
		{KeyParameter2, &p.MyParam2, validateMyParam2},
	}
}

func paramKeyTable() params.KeyTable {
	return params.NewKeyTable().RegisterParamSet(&MyParams{})
}

4. Have the module accept a Subspace in the constructor and set the KeyTable (if necessary):

func NewKeeper(..., paramSpace params.Subspace, ...) Keeper {
	// set KeyTable if it has not already been set
	if !paramSpace.HasKeyTable() {
		paramSpace = paramSpace.WithKeyTable(paramKeyTable())
	}

	return Keeper {
		// ...
		paramSpace: paramSpace,
	}
}

Now we have access to the module's parameters that are namespaced using the keys defined:

func InitGenesis(ctx sdk.Context, k Keeper, gs GenesisState) {
	// ...
	k.SetParams(ctx, gs.Params)
}

func (k Keeper) SetParams(ctx sdk.Context, params Params) {
	k.paramSpace.SetParamSet(ctx, &params)
}

func (k Keeper) GetParams(ctx sdk.Context) (params Params) {
	k.paramSpace.GetParamSet(ctx, &params)
	return params
}

func (k Keeper) MyParam1(ctx sdk.Context) (res int64) {
	k.paramSpace.Get(ctx, KeyParameter1, &res)
	return res
}

func (k Keeper) MyParam2(ctx sdk.Context) (res bool) {
	k.paramSpace.Get(ctx, KeyParameter2, &res)
	return res
}

NOTE: Any call to SetParamSet will panic or any call to Update will error if any given parameter value is invalid based on the registered value validation function.

Index

Constants

View Source
const (
	StoreKey     = types.StoreKey
	TStoreKey    = types.TStoreKey
	ModuleName   = types.ModuleName
	QuerierRoute = types.QuerierRoute
)

Variables

View Source
var (
	// functions aliases
	NewKeeper                 = keeper.NewKeeper
	NewParamSetPair           = types.NewParamSetPair
	NewKeyTable               = types.NewKeyTable
	NewQuerySubspaceParams    = types.NewQuerySubspaceParams
	NewQuerier                = keeper.NewQuerier
	NewSubspaceParamsResponse = types.NewSubspaceParamsResponse
)

Functions

func NewParamChangeProposalHandler added in v1.0.0

func NewParamChangeProposalHandler(k keeper.Keeper) govtypes.Handler

NewParamChangeProposalHandler creates a new governance Handler for a ParamChangeProposal

Types

type AppModule added in v1.0.0

type AppModule struct {
	AppModuleBasic
	// contains filtered or unexported fields
}

AppModule implements an application module for the distribution module.

func NewAppModule added in v1.0.0

func NewAppModule(k Keeper) AppModule

NewAppModule creates a new AppModule object

func (AppModule) BeginBlock added in v1.0.0

func (AppModule) BeginBlock(_ sdk.Context, _ abci.RequestBeginBlock)

BeginBlock performs a no-op.

func (AppModule) EndBlock added in v1.0.0

EndBlock performs a no-op.

func (AppModule) ExportGenesis added in v1.0.0

func (am AppModule) ExportGenesis(_ sdk.Context, _ codec.JSONMarshaler) json.RawMessage

ExportGenesis performs a no-op.

func (AppModule) GenerateGenesisState added in v1.0.0

func (AppModule) GenerateGenesisState(simState *module.SimulationState)

GenerateGenesisState performs a no-op.

func (AppModule) InitGenesis added in v1.0.0

InitGenesis performs a no-op.

func (AppModule) NewHandler added in v1.0.0

func (am AppModule) NewHandler() sdk.Handler

func (AppModule) NewQuerierHandler added in v1.0.0

func (am AppModule) NewQuerierHandler() sdk.Querier

NewQuerierHandler returns the x/params querier handler.

func (AppModule) ProposalContents added in v1.0.0

func (am AppModule) ProposalContents(simState module.SimulationState) []simtypes.WeightedProposalContent

ProposalContents returns all the params content functions used to simulate governance proposals.

func (AppModule) QuerierRoute added in v1.0.0

func (AppModule) QuerierRoute() string

QuerierRoute returns the x/param module's querier route name.

func (AppModule) RandomizedParams added in v1.0.0

func (AppModule) RandomizedParams(r *rand.Rand) []simtypes.ParamChange

RandomizedParams creates randomized distribution param changes for the simulator.

func (AppModule) RegisterInvariants added in v1.0.0

func (am AppModule) RegisterInvariants(_ sdk.InvariantRegistry)

func (AppModule) RegisterStoreDecoder added in v1.0.0

func (AppModule) RegisterStoreDecoder(sdr sdk.StoreDecoderRegistry)

RegisterStoreDecoder doesn't register any type.

func (AppModule) Route added in v1.0.0

func (AppModule) Route() string

func (AppModule) WeightedOperations added in v1.0.0

func (am AppModule) WeightedOperations(_ module.SimulationState) []simtypes.WeightedOperation

WeightedOperations returns the all the gov module operations with their respective weights.

type AppModuleBasic added in v1.0.0

type AppModuleBasic struct{}

AppModuleBasic defines the basic application module used by the params module.

func (AppModuleBasic) DefaultGenesis added in v1.0.0

func (AppModuleBasic) DefaultGenesis(_ codec.JSONMarshaler) json.RawMessage

DefaultGenesis returns default genesis state as raw bytes for the params module.

func (AppModuleBasic) GetQueryCmd added in v1.0.0

func (AppModuleBasic) GetQueryCmd(_ *codec.Codec) *cobra.Command

GetQueryCmd returns no root query command for the params module.

func (AppModuleBasic) GetTxCmd added in v1.0.0

func (AppModuleBasic) GetTxCmd(_ *codec.Codec) *cobra.Command

GetTxCmd returns no root tx command for the params module.

func (AppModuleBasic) Name added in v1.0.0

func (AppModuleBasic) Name() string

Name returns the params module's name.

func (AppModuleBasic) RegisterCodec added in v1.0.0

func (AppModuleBasic) RegisterCodec(cdc *codec.Codec)

RegisterCodec registers the params module's types for the given codec.

func (AppModuleBasic) RegisterRESTRoutes added in v1.0.0

func (AppModuleBasic) RegisterRESTRoutes(_ context.CLIContext, _ *mux.Router)

RegisterRESTRoutes registers the REST routes for the params module.

func (AppModuleBasic) ValidateGenesis added in v1.0.0

func (AppModuleBasic) ValidateGenesis(_ codec.JSONMarshaler, _ json.RawMessage) error

ValidateGenesis performs genesis state validation for the params module.

type Keeper

type Keeper = keeper.Keeper

type KeyTable added in v0.31.0

type KeyTable = types.KeyTable

type ParamSet added in v0.25.0

type ParamSet = types.ParamSet

type ParamSetPair added in v1.0.0

type ParamSetPair = types.ParamSetPair

type ParamSetPairs added in v0.31.0

type ParamSetPairs = types.ParamSetPairs

type QuerySubspaceParams added in v1.0.0

type QuerySubspaceParams = types.QuerySubspaceParams

type ReadOnlySubspace added in v0.25.0

type ReadOnlySubspace = types.ReadOnlySubspace

type Subspace added in v0.25.0

type Subspace = types.Subspace

type SubspaceParamsResponse added in v1.0.0

type SubspaceParamsResponse = types.SubspaceParamsResponse

Directories

Path Synopsis
cli
To prevent namespace collision between consumer modules, we define a type Subspace.
To prevent namespace collision between consumer modules, we define a type Subspace.

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