path: root/core/rawdb/accessors_metadata.go

// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package rawdb

import (
    "encoding/json"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/ethdb"
    "github.com/ethereum/go-ethereum/log"
    "github.com/ethereum/go-ethereum/params"
    "github.com/ethereum/go-ethereum/rlp"
)

// ReadDatabaseVersion retrieves the version number of the database.
func ReadDatabaseVersion(db ethdb.KeyValueReader) *uint64 {
    var version uint64

    enc, _ := db.Get(databaseVerisionKey)
    if len(enc) == 0 {
        return nil
    }
    if err := rlp.DecodeBytes(enc, &version); err != nil {
        return nil
    }

    return &version
}

// WriteDatabaseVersion stores the version number of the database
func WriteDatabaseVersion(db ethdb.KeyValueWriter, version uint64) {
    enc, err := rlp.EncodeToBytes(version)
    if err != nil {
        log.Crit("Failed to encode database version", "err", err)
    }
    if err = db.Put(databaseVerisionKey, enc); err != nil {
        log.Crit("Failed to store the database version", "err", err)
    }
}

// ReadChainConfig retrieves the consensus settings based on the given genesis hash.
func ReadChainConfig(db ethdb.KeyValueReader, hash common.Hash) *params.ChainConfig {
    data, _ := db.Get(configKey(hash))
    if len(data) == 0 {
        return nil
    }
    var config params.ChainConfig
    if err := json.Unmarshal(data, &config); err != nil {
        log.Error("Invalid chain config JSON", "hash", hash, "err", err)
        return nil
    }
    return &config
}

// WriteChainConfig writes the chain config settings to the database.
func WriteChainConfig(db ethdb.KeyValueWriter, hash common.Hash, cfg *params.ChainConfig) {
    if cfg == nil {
        return
    }
    data, err := json.Marshal(cfg)
    if err != nil {
        log.Crit("Failed to JSON encode chain config", "err", err)
    }
    if err := db.Put(configKey(hash), data); err != nil {
        log.Crit("Failed to store chain config", "err", err)
    }
}

// ReadPreimage retrieves a single preimage of the provided hash.
func ReadPreimage(db ethdb.KeyValueReader, hash common.Hash) []byte {
    data, _ := db.Get(preimageKey(hash))
    return data
}

// WritePreimages writes the provided set of preimages to the database.
func WritePreimages(db ethdb.KeyValueWriter, preimages map[common.Hash][]byte) {
    for hash, preimage := range preimages {
        if err := db.Put(preimageKey(hash), preimage); err != nil {
            log.Crit("Failed to store trie preimage", "err", err)
        }
    }
    preimageCounter.Inc(int64(len(preimages)))
    preimageHitCounter.Inc(int64(len(preimages)))
}