forked from centrifuge/go-substrate-rpc-client
/
event_provider.go
51 lines (39 loc) · 1.52 KB
/
event_provider.go
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package state
import (
libErr "github.com/Cerebellum-Network/go-substrate-rpc-client/v9/error"
"github.com/Cerebellum-Network/go-substrate-rpc-client/v9/rpc/state"
"github.com/Cerebellum-Network/go-substrate-rpc-client/v9/types"
)
const (
ErrEventStorageKeyCreation = libErr.Error("event storage key creation")
ErrEventStorageRetrieval = libErr.Error("event storage retrieval")
)
//go:generate mockery --name EventProvider --structname EventProviderMock --filename event_provider_mock.go --inpackage
// EventProvider is the interface used for retrieving event data from the storage.
type EventProvider interface {
GetStorageEvents(meta *types.Metadata, blockHash types.Hash) (*types.StorageDataRaw, error)
}
// eventProvider implements the EventProvider interface.
type eventProvider struct {
stateRPC state.State
}
// NewEventProvider creates a new EventProvider.
func NewEventProvider(stateRPC state.State) EventProvider {
return &eventProvider{stateRPC: stateRPC}
}
const (
storagePrefix = "System"
storageMethod = "Events"
)
// GetStorageEvents returns the event storage data found at the provided blockHash.
func (p *eventProvider) GetStorageEvents(meta *types.Metadata, blockHash types.Hash) (*types.StorageDataRaw, error) {
key, err := types.CreateStorageKey(meta, storagePrefix, storageMethod, nil)
if err != nil {
return nil, ErrEventStorageKeyCreation.Wrap(err)
}
storageData, err := p.stateRPC.GetStorageRaw(key, blockHash)
if err != nil {
return nil, ErrEventStorageRetrieval.Wrap(err)
}
return storageData, nil
}