github.com/linapex/ethereum-go-chinese@v0.0.0-20190316121929-f8b7a73c3fa1/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 19:16:35</date>
    10  //</624450079469604864>
    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) *uint64 {
    26  	var version uint64
    27  
    28  	enc, _ := db.Get(databaseVerisionKey)
    29  	if len(enc) == 0 {
    30  		return nil
    31  	}
    32  	if err := rlp.DecodeBytes(enc, &version); err != nil {
    33  		return nil
    34  	}
    35  
    36  	return &version
    37  }
    38  
    39  //WriteDatabaseVersion存储数据库的版本号
    40  func WriteDatabaseVersion(db DatabaseWriter, version uint64) {
    41  	enc, err := rlp.EncodeToBytes(version)
    42  	if err != nil {
    43  		log.Crit("Failed to encode database version", "err", err)
    44  	}
    45  	if err = db.Put(databaseVerisionKey, enc); err != nil {
    46  		log.Crit("Failed to store the database version", "err", err)
    47  	}
    48  }
    49  
    50  //readchainconfig根据给定的genesis散列检索共识设置。
    51  func ReadChainConfig(db DatabaseReader, hash common.Hash) *params.ChainConfig {
    52  	data, _ := db.Get(configKey(hash))
    53  	if len(data) == 0 {
    54  		return nil
    55  	}
    56  	var config params.ChainConfig
    57  	if err := json.Unmarshal(data, &config); err != nil {
    58  		log.Error("Invalid chain config JSON", "hash", hash, "err", err)
    59  		return nil
    60  	}
    61  	return &config
    62  }
    63  
    64  //writechainconfig将链配置设置写入数据库。
    65  func WriteChainConfig(db DatabaseWriter, hash common.Hash, cfg *params.ChainConfig) {
    66  	if cfg == nil {
    67  		return
    68  	}
    69  	data, err := json.Marshal(cfg)
    70  	if err != nil {
    71  		log.Crit("Failed to JSON encode chain config", "err", err)
    72  	}
    73  	if err := db.Put(configKey(hash), data); err != nil {
    74  		log.Crit("Failed to store chain config", "err", err)
    75  	}
    76  }
    77  
    78  //readpreimage检索所提供哈希的单个preimage。
    79  func ReadPreimage(db DatabaseReader, hash common.Hash) []byte {
    80  	data, _ := db.Get(preimageKey(hash))
    81  	return data
    82  }
    83  
    84  //writepreimages将提供的一组preimages写入数据库。
    85  func WritePreimages(db DatabaseWriter, preimages map[common.Hash][]byte) {
    86  	for hash, preimage := range preimages {
    87  		if err := db.Put(preimageKey(hash), preimage); err != nil {
    88  			log.Crit("Failed to store trie preimage", "err", err)
    89  		}
    90  	}
    91  	preimageCounter.Inc(int64(len(preimages)))
    92  	preimageHitCounter.Inc(int64(len(preimages)))
    93  }
    94