github.com/linapex/ethereum-dpos-chinese@v0.0.0-20190316121959-b78b3a4a1ece/core/rawdb/accessors_metadata.go (about)

     1  
     2  //<developer>
     3  //    <name>linapex 曹一峰</name>
     4  //    <email>linapex@163.com</email>
     5  //    <wx>superexc</wx>
     6  //    <qqgroup>128148617</qqgroup>
     7  //    <url>https://jsq.ink</url>
     8  //    <role>pku engineer</role>
     9  //    <date>2019-03-16 12:09:34</date>
    10  //</624342617072603136>
    11  
    12  
    13  package rawdb
    14  
    15  import (
    16  	"encoding/json"
    17  
    18  	"github.com/ethereum/go-ethereum/common"
    19  	"github.com/ethereum/go-ethereum/log"
    20  	"github.com/ethereum/go-ethereum/params"
    21  	"github.com/ethereum/go-ethereum/rlp"
    22  )
    23  
    24  //readdatabaseversion检索数据库的版本号。
    25  func ReadDatabaseVersion(db DatabaseReader) int {
    26  	var version int
    27  
    28  	enc, _ := db.Get(databaseVerisionKey)
    29  	rlp.DecodeBytes(enc, &version)
    30  
    31  	return version
    32  }
    33  
    34  //WriteDatabaseVersion存储数据库的版本号
    35  func WriteDatabaseVersion(db DatabaseWriter, version int) {
    36  	enc, _ := rlp.EncodeToBytes(version)
    37  	if err := db.Put(databaseVerisionKey, enc); err != nil {
    38  		log.Crit("Failed to store the database version", "err", err)
    39  	}
    40  }
    41  
    42  //readchainconfig根据给定的genesis散列检索共识设置。
    43  func ReadChainConfig(db DatabaseReader, hash common.Hash) *params.ChainConfig {
    44  	data, _ := db.Get(configKey(hash))
    45  	if len(data) == 0 {
    46  		return nil
    47  	}
    48  	var config params.ChainConfig
    49  	if err := json.Unmarshal(data, &config); err != nil {
    50  		log.Error("Invalid chain config JSON", "hash", hash, "err", err)
    51  		return nil
    52  	}
    53  	return &config
    54  }
    55  
    56  //writechainconfig将链配置设置写入数据库。
    57  func WriteChainConfig(db DatabaseWriter, hash common.Hash, cfg *params.ChainConfig) {
    58  	if cfg == nil {
    59  		return
    60  	}
    61  	data, err := json.Marshal(cfg)
    62  	if err != nil {
    63  		log.Crit("Failed to JSON encode chain config", "err", err)
    64  	}
    65  	if err := db.Put(configKey(hash), data); err != nil {
    66  		log.Crit("Failed to store chain config", "err", err)
    67  	}
    68  }
    69  
    70  //readpreimage检索所提供哈希的单个preimage。
    71  func ReadPreimage(db DatabaseReader, hash common.Hash) []byte {
    72  	data, _ := db.Get(preimageKey(hash))
    73  	return data
    74  }
    75  
    76  //writepreimages将提供的一组preimages写入数据库。“数字”是
    77  //current block number, and is used for debug messages only.
    78  func WritePreimages(db DatabaseWriter, number uint64, preimages map[common.Hash][]byte) {
    79  	for hash, preimage := range preimages {
    80  		if err := db.Put(preimageKey(hash), preimage); err != nil {
    81  			log.Crit("Failed to store trie preimage", "err", err)
    82  		}
    83  	}
    84  	preimageCounter.Inc(int64(len(preimages)))
    85  	preimageHitCounter.Inc(int64(len(preimages)))
    86  }
    87