github.com/yinchengtsinghua/golang-Eos-dpos-Ethereum@v0.0.0-20190121132951-92cc4225ed8e/core/rawdb/accessors_chain.go

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//版权所有2018 Go Ethereum作者
//此文件是Go以太坊库的一部分。
//
//Go-Ethereum库是免费软件：您可以重新分发它和/或修改
//根据GNU发布的较低通用公共许可证的条款
//自由软件基金会，或者许可证的第3版，或者
//（由您选择）任何更高版本。
//
//Go以太坊图书馆的发行目的是希望它会有用，
//但没有任何保证；甚至没有
//适销性或特定用途的适用性。见
//GNU较低的通用公共许可证，了解更多详细信息。
//
//你应该收到一份GNU较低级别的公共许可证副本
//以及Go以太坊图书馆。如果没有，请参见<http://www.gnu.org/licenses/>。

package rawdb

import (
	"bytes"
	"encoding/binary"
	"math/big"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/log"
	"github.com/ethereum/go-ethereum/rlp"
)

//readCanonicalHash检索分配给规范块号的哈希。
func ReadCanonicalHash(db DatabaseReader, number uint64) common.Hash {
	data, _ := db.Get(headerHashKey(number))
	if len(data) == 0 {
		return common.Hash{}
	}
	return common.BytesToHash(data)
}

//WriteCanonicalHash存储分配给规范块号的哈希。
func WriteCanonicalHash(db DatabaseWriter, hash common.Hash, number uint64) {
	if err := db.Put(headerHashKey(number), hash.Bytes()); err != nil {
		log.Crit("Failed to store number to hash mapping", "err", err)
	}
}

//DeleteConnicalHash删除到哈希规范映射的数字。
func DeleteCanonicalHash(db DatabaseDeleter, number uint64) {
	if err := db.Delete(headerHashKey(number)); err != nil {
		log.Crit("Failed to delete number to hash mapping", "err", err)
	}
}

//readheadernumber返回分配给哈希的头编号。
func ReadHeaderNumber(db DatabaseReader, hash common.Hash) *uint64 {
	data, _ := db.Get(headerNumberKey(hash))
	if len(data) != 8 {
		return nil
	}
	number := binary.BigEndian.Uint64(data)
	return &number
}

//readHeaderHash检索当前规范头的哈希。
func ReadHeadHeaderHash(db DatabaseReader) common.Hash {
	data, _ := db.Get(headHeaderKey)
	if len(data) == 0 {
		return common.Hash{}
	}
	return common.BytesToHash(data)
}

//WriteHeaderHash存储当前规范头的哈希。
func WriteHeadHeaderHash(db DatabaseWriter, hash common.Hash) {
	if err := db.Put(headHeaderKey, hash.Bytes()); err != nil {
		log.Crit("Failed to store last header's hash", "err", err)
	}
}

//readheadblockhash检索当前规范头块的哈希。
func ReadHeadBlockHash(db DatabaseReader) common.Hash {
	data, _ := db.Get(headBlockKey)
	if len(data) == 0 {
		return common.Hash{}
	}
	return common.BytesToHash(data)
}

//WriteHeadBlockHash存储头块的哈希。
func WriteHeadBlockHash(db DatabaseWriter, hash common.Hash) {
	if err := db.Put(headBlockKey, hash.Bytes()); err != nil {
		log.Crit("Failed to store last block's hash", "err", err)
	}
}

//readHeadFastBlockHash检索当前快速同步头块的哈希。
func ReadHeadFastBlockHash(db DatabaseReader) common.Hash {
	data, _ := db.Get(headFastBlockKey)
	if len(data) == 0 {
		return common.Hash{}
	}
	return common.BytesToHash(data)
}

//WriteHeadFastBlockHash存储当前快速同步头块的哈希。
func WriteHeadFastBlockHash(db DatabaseWriter, hash common.Hash) {
	if err := db.Put(headFastBlockKey, hash.Bytes()); err != nil {
		log.Crit("Failed to store last fast block's hash", "err", err)
	}
}

//readfasttriegrogress检索快速同步以允许的尝试次数节点
//在重新启动时报告正确的数字。
func ReadFastTrieProgress(db DatabaseReader) uint64 {
	data, _ := db.Get(fastTrieProgressKey)
	if len(data) == 0 {
		return 0
	}
	return new(big.Int).SetBytes(data).Uint64()
}

//WriteFastTrieProgress存储要支持的快速同步Trie进程计数器
//重新启动时检索。
func WriteFastTrieProgress(db DatabaseWriter, count uint64) {
	if err := db.Put(fastTrieProgressKey, new(big.Int).SetUint64(count).Bytes()); err != nil {
		log.Crit("Failed to store fast sync trie progress", "err", err)
	}
}

//readheaderrlp以其原始RLP数据库编码检索块头。
func ReadHeaderRLP(db DatabaseReader, hash common.Hash, number uint64) rlp.RawValue {
	data, _ := db.Get(headerKey(number, hash))
	return data
}

//散列头验证与散列对应的块头是否存在。
func HasHeader(db DatabaseReader, hash common.Hash, number uint64) bool {
	if has, err := db.Has(headerKey(number, hash)); !has || err != nil {
		return false
	}
	return true
}

//readheader检索与哈希对应的块头。
func ReadHeader(db DatabaseReader, hash common.Hash, number uint64) *types.Header {
	data := ReadHeaderRLP(db, hash, number)
	if len(data) == 0 {
		return nil
	}
	header := new(types.Header)
	if err := rlp.Decode(bytes.NewReader(data), header); err != nil {
		log.Error("Invalid block header RLP", "hash", hash, "err", err)
		return nil
	}
	return header
}

//WriteHeader将一个块头存储到数据库中，还存储哈希-
//到数字映射。
func WriteHeader(db DatabaseWriter, header *types.Header) {
//写入哈希->数字映射
	var (
		hash    = header.Hash()
		number  = header.Number.Uint64()
		encoded = encodeBlockNumber(number)
	)
	key := headerNumberKey(hash)
	if err := db.Put(key, encoded); err != nil {
		log.Crit("Failed to store hash to number mapping", "err", err)
	}
//写入编码的头
	data, err := rlp.EncodeToBytes(header)
	if err != nil {
		log.Crit("Failed to RLP encode header", "err", err)
	}
	key = headerKey(number, hash)
	if err := db.Put(key, data); err != nil {
		log.Crit("Failed to store header", "err", err)
	}
}

//DeleteHeader删除与哈希关联的所有块头数据。
func DeleteHeader(db DatabaseDeleter, hash common.Hash, number uint64) {
	if err := db.Delete(headerKey(number, hash)); err != nil {
		log.Crit("Failed to delete header", "err", err)
	}
	if err := db.Delete(headerNumberKey(hash)); err != nil {
		log.Crit("Failed to delete hash to number mapping", "err", err)
	}
}

//readbodyrlp以rlp编码方式检索块体（事务和uncles）。
func ReadBodyRLP(db DatabaseReader, hash common.Hash, number uint64) rlp.RawValue {
	data, _ := db.Get(blockBodyKey(number, hash))
	return data
}

//writebodyrlp将RLP编码的块体存储到数据库中。
func WriteBodyRLP(db DatabaseWriter, hash common.Hash, number uint64, rlp rlp.RawValue) {
	if err := db.Put(blockBodyKey(number, hash), rlp); err != nil {
		log.Crit("Failed to store block body", "err", err)
	}
}

//hasbody验证哈希对应的块体的存在。
func HasBody(db DatabaseReader, hash common.Hash, number uint64) bool {
	if has, err := db.Has(blockBodyKey(number, hash)); !has || err != nil {
		return false
	}
	return true
}

//readbody检索与哈希相对应的块体。
func ReadBody(db DatabaseReader, hash common.Hash, number uint64) *types.Body {
	data := ReadBodyRLP(db, hash, number)
	if len(data) == 0 {
		return nil
	}
	body := new(types.Body)
	if err := rlp.Decode(bytes.NewReader(data), body); err != nil {
		log.Error("Invalid block body RLP", "hash", hash, "err", err)
		return nil
	}
	return body
}

//WriteBody将块体存储到数据库中。
func WriteBody(db DatabaseWriter, hash common.Hash, number uint64, body *types.Body) {
	data, err := rlp.EncodeToBytes(body)
	if err != nil {
		log.Crit("Failed to RLP encode body", "err", err)
	}
	WriteBodyRLP(db, hash, number, data)
}

//DeleteBody删除与哈希关联的所有块体数据。
func DeleteBody(db DatabaseDeleter, hash common.Hash, number uint64) {
	if err := db.Delete(blockBodyKey(number, hash)); err != nil {
		log.Crit("Failed to delete block body", "err", err)
	}
}

//readtd检索与哈希相对应的块的总难度。
func ReadTd(db DatabaseReader, hash common.Hash, number uint64) *big.Int {
	data, _ := db.Get(headerTDKey(number, hash))
	if len(data) == 0 {
		return nil
	}
	td := new(big.Int)
	if err := rlp.Decode(bytes.NewReader(data), td); err != nil {
		log.Error("Invalid block total difficulty RLP", "hash", hash, "err", err)
		return nil
	}
	return td
}

//writetd将块的总难度存储到数据库中。
func WriteTd(db DatabaseWriter, hash common.Hash, number uint64, td *big.Int) {
	data, err := rlp.EncodeToBytes(td)
	if err != nil {
		log.Crit("Failed to RLP encode block total difficulty", "err", err)
	}
	if err := db.Put(headerTDKey(number, hash), data); err != nil {
		log.Crit("Failed to store block total difficulty", "err", err)
	}
}

//deletetd删除与哈希关联的所有块总难度数据。
func DeleteTd(db DatabaseDeleter, hash common.Hash, number uint64) {
	if err := db.Delete(headerTDKey(number, hash)); err != nil {
		log.Crit("Failed to delete block total difficulty", "err", err)
	}
}

//readReceipts检索属于块的所有事务收据。
func ReadReceipts(db DatabaseReader, hash common.Hash, number uint64) types.Receipts {
//检索扁平收据切片
	data, _ := db.Get(blockReceiptsKey(number, hash))
	if len(data) == 0 {
		return nil
	}
//将revcepts从其存储表单转换为内部表示形式
	storageReceipts := []*types.ReceiptForStorage{}
	if err := rlp.DecodeBytes(data, &storageReceipts); err != nil {
		log.Error("Invalid receipt array RLP", "hash", hash, "err", err)
		return nil
	}
	receipts := make(types.Receipts, len(storageReceipts))
	for i, receipt := range storageReceipts {
		receipts[i] = (*types.Receipt)(receipt)
	}
	return receipts
}

//WriteReceipts存储属于某个块的所有交易记录收据。
func WriteReceipts(db DatabaseWriter, hash common.Hash, number uint64, receipts types.Receipts) {
//将收据转换为其存储表单并将其序列化
	storageReceipts := make([]*types.ReceiptForStorage, len(receipts))
	for i, receipt := range receipts {
		storageReceipts[i] = (*types.ReceiptForStorage)(receipt)
	}
	bytes, err := rlp.EncodeToBytes(storageReceipts)
	if err != nil {
		log.Crit("Failed to encode block receipts", "err", err)
	}
//存储扁平收据切片
	if err := db.Put(blockReceiptsKey(number, hash), bytes); err != nil {
		log.Crit("Failed to store block receipts", "err", err)
	}
}

//删除收据删除与块哈希关联的所有收据数据。
func DeleteReceipts(db DatabaseDeleter, hash common.Hash, number uint64) {
	if err := db.Delete(blockReceiptsKey(number, hash)); err != nil {
		log.Crit("Failed to delete block receipts", "err", err)
	}
}

//readblock检索与哈希相对应的整个块，对其进行组装
//从存储的标题和正文返回。如果标题或正文不能
//收回零。
//
//注意，由于头和块体同时下载，因此头和块体
//规范散列可以存储在数据库中，但主体数据尚未存储。
func ReadBlock(db DatabaseReader, hash common.Hash, number uint64) *types.Block {
	header := ReadHeader(db, hash, number)
	if header == nil {
		return nil
	}
	body := ReadBody(db, hash, number)
	if body == nil {
		return nil
	}
	return types.NewBlockWithHeader(header).WithBody(body.Transactions, body.Uncles)
}

//WriteBlock将块分别序列化到数据库、头和正文中。
func WriteBlock(db DatabaseWriter, block *types.Block) {
	WriteBody(db, block.Hash(), block.NumberU64(), block.Body())
	WriteHeader(db, block.Header())
}

//删除块删除与哈希关联的所有块数据。
func DeleteBlock(db DatabaseDeleter, hash common.Hash, number uint64) {
	DeleteReceipts(db, hash, number)
	DeleteHeader(db, hash, number)
	DeleteBody(db, hash, number)
	DeleteTd(db, hash, number)
}

//findcommonancestor返回两个块头的最后一个公共祖先
func FindCommonAncestor(db DatabaseReader, a, b *types.Header) *types.Header {
	for bn := b.Number.Uint64(); a.Number.Uint64() > bn; {
		a = ReadHeader(db, a.ParentHash, a.Number.Uint64()-1)
		if a == nil {
			return nil
		}
	}
	for an := a.Number.Uint64(); an < b.Number.Uint64(); {
		b = ReadHeader(db, b.ParentHash, b.Number.Uint64()-1)
		if b == nil {
			return nil
		}
	}
	for a.Hash() != b.Hash() {
		a = ReadHeader(db, a.ParentHash, a.Number.Uint64()-1)
		if a == nil {
			return nil
		}
		b = ReadHeader(db, b.ParentHash, b.Number.Uint64()-1)
		if b == nil {
			return nil
		}
	}
	return a
}