forked from cerc-io/ipld-eth-server
62 lines
1.8 KiB
Go
62 lines
1.8 KiB
Go
// VulcanizeDB
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// Copyright © 2019 Vulcanize
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Affero General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Affero General Public License for more details.
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// You should have received a copy of the GNU Affero General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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package retriever
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import (
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"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
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)
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// BlockRetriever is used to retrieve the first block for a given contract and the most recent block
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// It requires a vDB synced database with blocks, transactions, receipts, and logs
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type BlockRetriever interface {
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RetrieveFirstBlock() (int64, error)
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RetrieveMostRecentBlock() (int64, error)
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}
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type blockRetriever struct {
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db *postgres.DB
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}
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// NewBlockRetriever returns a new BlockRetriever
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func NewBlockRetriever(db *postgres.DB) BlockRetriever {
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return &blockRetriever{
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db: db,
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}
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}
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// RetrieveFirstBlock retrieves block number of earliest header in repo
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func (r *blockRetriever) RetrieveFirstBlock() (int64, error) {
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var firstBlock int
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err := r.db.Get(
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&firstBlock,
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"SELECT block_number FROM headers ORDER BY block_number LIMIT 1",
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)
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return int64(firstBlock), err
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}
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// RetrieveMostRecentBlock retrieves block number of latest header in repo
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func (r *blockRetriever) RetrieveMostRecentBlock() (int64, error) {
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var lastBlock int
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err := r.db.Get(
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&lastBlock,
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"SELECT block_number FROM headers ORDER BY block_number DESC LIMIT 1",
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)
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return int64(lastBlock), err
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}
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