ipld-eth-server/pkg/ipfs/fetcher.go
2019-12-02 13:24:58 -06:00

231 lines
7.1 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 ipfs
import (
"context"
"github.com/ethereum/go-ethereum/common"
"github.com/ipfs/go-block-format"
"github.com/ipfs/go-blockservice"
"github.com/ipfs/go-cid"
log "github.com/sirupsen/logrus"
)
// IPLDFetcher is an interface for fetching IPLDs
type IPLDFetcher interface {
FetchIPLDs(cids CIDWrapper) (*IPLDWrapper, error)
}
// EthIPLDFetcher is used to fetch ETH IPLD objects from IPFS
type EthIPLDFetcher struct {
BlockService blockservice.BlockService
}
// NewIPLDFetcher creates a pointer to a new IPLDFetcher
func NewIPLDFetcher(ipfsPath string) (*EthIPLDFetcher, error) {
blockService, err := InitIPFSBlockService(ipfsPath)
if err != nil {
return nil, err
}
return &EthIPLDFetcher{
BlockService: blockService,
}, nil
}
// FetchIPLDs is the exported method for fetching and returning all the IPLDS specified in the CIDWrapper
func (f *EthIPLDFetcher) FetchIPLDs(cids CIDWrapper) (*IPLDWrapper, error) {
log.Debug("fetching iplds")
blocks := &IPLDWrapper{
BlockNumber: cids.BlockNumber,
Headers: make([]blocks.Block, 0),
Uncles: make([]blocks.Block, 0),
Transactions: make([]blocks.Block, 0),
Receipts: make([]blocks.Block, 0),
StateNodes: make(map[common.Hash]blocks.Block),
StorageNodes: make(map[common.Hash]map[common.Hash]blocks.Block),
}
headersErr := f.fetchHeaders(cids, blocks)
if headersErr != nil {
return nil, headersErr
}
unclesErr := f.fetchUncles(cids, blocks)
if unclesErr != nil {
return nil, unclesErr
}
trxsErr := f.fetchTrxs(cids, blocks)
if trxsErr != nil {
return nil, trxsErr
}
rctsErr := f.fetchRcts(cids, blocks)
if rctsErr != nil {
return nil, rctsErr
}
storageErr := f.fetchStorage(cids, blocks)
if storageErr != nil {
return nil, storageErr
}
stateErr := f.fetchState(cids, blocks)
if stateErr != nil {
return nil, stateErr
}
return blocks, nil
}
// fetchHeaders fetches headers
// It uses the f.fetchBatch method
func (f *EthIPLDFetcher) fetchHeaders(cids CIDWrapper, blocks *IPLDWrapper) error {
log.Debug("fetching header iplds")
headerCids := make([]cid.Cid, 0, len(cids.Headers))
for _, c := range cids.Headers {
dc, err := cid.Decode(c)
if err != nil {
return err
}
headerCids = append(headerCids, dc)
}
blocks.Headers = f.fetchBatch(headerCids)
if len(blocks.Headers) != len(headerCids) {
log.Errorf("ipfs fetcher: number of header blocks returned (%d) does not match number expected (%d)", len(blocks.Headers), len(headerCids))
}
return nil
}
// fetchUncles fetches uncles
// It uses the f.fetchBatch method
func (f *EthIPLDFetcher) fetchUncles(cids CIDWrapper, blocks *IPLDWrapper) error {
log.Debug("fetching uncle iplds")
uncleCids := make([]cid.Cid, 0, len(cids.Uncles))
for _, c := range cids.Uncles {
dc, err := cid.Decode(c)
if err != nil {
return err
}
uncleCids = append(uncleCids, dc)
}
blocks.Uncles = f.fetchBatch(uncleCids)
if len(blocks.Uncles) != len(uncleCids) {
log.Errorf("ipfs fetcher: number of uncle blocks returned (%d) does not match number expected (%d)", len(blocks.Uncles), len(uncleCids))
}
return nil
}
// fetchTrxs fetches transactions
// It uses the f.fetchBatch method
func (f *EthIPLDFetcher) fetchTrxs(cids CIDWrapper, blocks *IPLDWrapper) error {
log.Debug("fetching transaction iplds")
trxCids := make([]cid.Cid, 0, len(cids.Transactions))
for _, c := range cids.Transactions {
dc, err := cid.Decode(c)
if err != nil {
return err
}
trxCids = append(trxCids, dc)
}
blocks.Transactions = f.fetchBatch(trxCids)
if len(blocks.Transactions) != len(trxCids) {
log.Errorf("ipfs fetcher: number of transaction blocks returned (%d) does not match number expected (%d)", len(blocks.Transactions), len(trxCids))
}
return nil
}
// fetchRcts fetches receipts
// It uses the f.fetchBatch method
func (f *EthIPLDFetcher) fetchRcts(cids CIDWrapper, blocks *IPLDWrapper) error {
log.Debug("fetching receipt iplds")
rctCids := make([]cid.Cid, 0, len(cids.Receipts))
for _, c := range cids.Receipts {
dc, err := cid.Decode(c)
if err != nil {
return err
}
rctCids = append(rctCids, dc)
}
blocks.Receipts = f.fetchBatch(rctCids)
if len(blocks.Receipts) != len(rctCids) {
log.Errorf("ipfs fetcher: number of receipt blocks returned (%d) does not match number expected (%d)", len(blocks.Receipts), len(rctCids))
}
return nil
}
// fetchState fetches state nodes
// It uses the single f.fetch method instead of the batch fetch, because it
// needs to maintain the data's relation to state keys
func (f *EthIPLDFetcher) fetchState(cids CIDWrapper, blocks *IPLDWrapper) error {
log.Debug("fetching state iplds")
for _, stateNode := range cids.StateNodes {
if stateNode.CID == "" || stateNode.Key == "" {
continue
}
dc, decodeErr := cid.Decode(stateNode.CID)
if decodeErr != nil {
return decodeErr
}
block, fetchErr := f.fetch(dc)
if fetchErr != nil {
return fetchErr
}
blocks.StateNodes[common.HexToHash(stateNode.Key)] = block
}
return nil
}
// fetchStorage fetches storage nodes
// It uses the single f.fetch method instead of the batch fetch, because it
// needs to maintain the data's relation to state and storage keys
func (f *EthIPLDFetcher) fetchStorage(cids CIDWrapper, blks *IPLDWrapper) error {
log.Debug("fetching storage iplds")
for _, storageNode := range cids.StorageNodes {
if storageNode.CID == "" || storageNode.Key == "" || storageNode.StateKey == "" {
continue
}
dc, decodeErr := cid.Decode(storageNode.CID)
if decodeErr != nil {
return decodeErr
}
blk, fetchErr := f.fetch(dc)
if fetchErr != nil {
return fetchErr
}
if blks.StorageNodes[common.HexToHash(storageNode.StateKey)] == nil {
blks.StorageNodes[common.HexToHash(storageNode.StateKey)] = make(map[common.Hash]blocks.Block)
}
blks.StorageNodes[common.HexToHash(storageNode.StateKey)][common.HexToHash(storageNode.Key)] = blk
}
return nil
}
// fetch is used to fetch a single cid
func (f *EthIPLDFetcher) fetch(cid cid.Cid) (blocks.Block, error) {
return f.BlockService.GetBlock(context.Background(), cid)
}
// fetchBatch is used to fetch a batch of IPFS data blocks by cid
// There is no guarantee all are fetched, and no error in such a case, so
// downstream we will need to confirm which CIDs were fetched in the result set
func (f *EthIPLDFetcher) fetchBatch(cids []cid.Cid) []blocks.Block {
fetchedBlocks := make([]blocks.Block, 0, len(cids))
blockChan := f.BlockService.GetBlocks(context.Background(), cids)
for block := range blockChan {
fetchedBlocks = append(fetchedBlocks, block)
}
return fetchedBlocks
}