ipld-eth-server/libraries/shared/fetcher/state_diff_fetcher.go

79 lines
2.5 KiB
Go

// VulcanizeDB
// Copyright © 2019 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package fetcher
import (
"fmt"
"github.com/ethereum/go-ethereum/statediff"
"github.com/vulcanize/vulcanizedb/pkg/eth/client"
)
// StateDiffFetcher is the state diff fetching interface
type StateDiffFetcher interface {
FetchStateDiffsAt(blockHeights []uint64) ([]statediff.Payload, error)
}
// BatchClient is an interface to a batch-fetching geth rpc client; created to allow mock insertion
type BatchClient interface {
BatchCall(batch []client.BatchElem) error
}
// stateDiffFetcher is the state diff fetching struct
type stateDiffFetcher struct {
// stateDiffFetcher is thread-safe as long as the underlying client is thread-safe, since it has/modifies no other state
// http.Client is thread-safe
client BatchClient
}
const method = "statediff_stateDiffAt"
// NewStateDiffFetcher returns a IStateDiffFetcher
func NewStateDiffFetcher(bc BatchClient) StateDiffFetcher {
return &stateDiffFetcher{
client: bc,
}
}
// FetchStateDiffsAt fetches the statediff payloads at the given block heights
// Calls StateDiffAt(ctx context.Context, blockNumber uint64) (*Payload, error)
func (fetcher *stateDiffFetcher) FetchStateDiffsAt(blockHeights []uint64) ([]statediff.Payload, error) {
batch := make([]client.BatchElem, 0)
for _, height := range blockHeights {
batch = append(batch, client.BatchElem{
Method: method,
Args: []interface{}{height},
Result: new(statediff.Payload),
})
}
batchErr := fetcher.client.BatchCall(batch)
if batchErr != nil {
return nil, fmt.Errorf("stateDiffFetcher err: %s", batchErr.Error())
}
results := make([]statediff.Payload, 0, len(blockHeights))
for _, batchElem := range batch {
if batchElem.Error != nil {
return nil, fmt.Errorf("stateDiffFetcher err: %s", batchElem.Error.Error())
}
payload, ok := batchElem.Result.(*statediff.Payload)
if ok {
results = append(results, *payload)
}
}
return results, nil
}