// Copyright 2015 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 core
import (
"bytes"
"encoding/binary"
"fmt"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/rlp"
)
var (
headHeaderKey = []byte("LastHeader")
headBlockKey = []byte("LastBlock")
headFastKey = []byte("LastFast")
blockPrefix = []byte("block-")
blockNumPrefix = []byte("block-num-")
headerSuffix = []byte("-header")
bodySuffix = []byte("-body")
tdSuffix = []byte("-td")
ExpDiffPeriod = big.NewInt(100000)
blockHashPre = []byte("block-hash-") // [deprecated by eth/63]
mipmapPre = []byte("mipmap-log-bloom-")
MIPMapLevels = []uint64{1000000, 500000, 100000, 50000, 1000}
)
// CalcDifficulty is the difficulty adjustment algorithm. It returns
// the difficulty that a new block b should have when created at time
// given the parent block's time and difficulty.
func CalcDifficulty(time, parentTime uint64, parentNumber, parentDiff *big.Int) *big.Int {
diff := new(big.Int)
adjust := new(big.Int).Div(parentDiff, params.DifficultyBoundDivisor)
bigTime := new(big.Int)
bigParentTime := new(big.Int)
bigTime.SetUint64(time)
bigParentTime.SetUint64(parentTime)
if bigTime.Sub(bigTime, bigParentTime).Cmp(params.DurationLimit) < 0 {
diff.Add(parentDiff, adjust)
} else {
diff.Sub(parentDiff, adjust)
}
if diff.Cmp(params.MinimumDifficulty) < 0 {
diff = params.MinimumDifficulty
}
periodCount := new(big.Int).Add(parentNumber, common.Big1)
periodCount.Div(periodCount, ExpDiffPeriod)
if periodCount.Cmp(common.Big1) > 0 {
// diff = diff + 2^(periodCount - 2)
expDiff := periodCount.Sub(periodCount, common.Big2)
expDiff.Exp(common.Big2, expDiff, nil)
diff.Add(diff, expDiff)
diff = common.BigMax(diff, params.MinimumDifficulty)
}
return diff
}
// CalcGasLimit computes the gas limit of the next block after parent.
// The result may be modified by the caller.
// This is miner strategy, not consensus protocol.
func CalcGasLimit(parent *types.Block) *big.Int {
// contrib = (parentGasUsed * 3 / 2) / 1024
contrib := new(big.Int).Mul(parent.GasUsed(), big.NewInt(3))
contrib = contrib.Div(contrib, big.NewInt(2))
contrib = contrib.Div(contrib, params.GasLimitBoundDivisor)
// decay = parentGasLimit / 1024 -1
decay := new(big.Int).Div(parent.GasLimit(), params.GasLimitBoundDivisor)
decay.Sub(decay, big.NewInt(1))
/*
strategy: gasLimit of block-to-mine is set based on parent's
gasUsed value. if parentGasUsed > parentGasLimit * (2/3) then we
increase it, otherwise lower it (or leave it unchanged if it's right
at that usage) the amount increased/decreased depends on how far away
from parentGasLimit * (2/3) parentGasUsed is.
*/
gl := new(big.Int).Sub(parent.GasLimit(), decay)
gl = gl.Add(gl, contrib)
gl.Set(common.BigMax(gl, params.MinGasLimit))
// however, if we're now below the target (GenesisGasLimit) we increase the
// limit as much as we can (parentGasLimit / 1024 -1)
if gl.Cmp(params.GenesisGasLimit) < 0 {
gl.Add(parent.GasLimit(), decay)
gl.Set(common.BigMin(gl, params.GenesisGasLimit))
}
return gl
}
// GetCanonicalHash retrieves a hash assigned to a canonical block number.
func GetCanonicalHash(db ethdb.Database, number uint64) common.Hash {
data, _ := db.Get(append(blockNumPrefix, big.NewInt(int64(number)).Bytes()...))
if len(data) == 0 {
return common.Hash{}
}
return common.BytesToHash(data)
}
// GetHeadHeaderHash retrieves the hash of the current canonical head block's
// header. The difference between this and GetHeadBlockHash is that whereas the
// last block hash is only updated upon a full block import, the last header
// hash is updated already at header import, allowing head tracking for the
// light synchronization mechanism.
func GetHeadHeaderHash(db ethdb.Database) common.Hash {
data, _ := db.Get(headHeaderKey)
if len(data) == 0 {
return common.Hash{}
}
return common.BytesToHash(data)
}
// GetHeadBlockHash retrieves the hash of the current canonical head block.
func GetHeadBlockHash(db ethdb.Database) common.Hash {
data, _ := db.Get(headBlockKey)
if len(data) == 0 {
return common.Hash{}
}
return common.BytesToHash(data)
}
// GetHeadFastBlockHash retrieves the hash of the current canonical head block during
// fast synchronization. The difference between this and GetHeadBlockHash is that
// whereas the last block hash is only updated upon a full block import, the last
// fast hash is updated when importing pre-processed blocks.
func GetHeadFastBlockHash(db ethdb.Database) common.Hash {
data, _ := db.Get(headFastKey)
if len(data) == 0 {
return common.Hash{}
}
return common.BytesToHash(data)
}
// GetHeaderRLP retrieves a block header in its raw RLP database encoding, or nil
// if the header's not found.
func GetHeaderRLP(db ethdb.Database, hash common.Hash) rlp.RawValue {
data, _ := db.Get(append(append(blockPrefix, hash[:]...), headerSuffix...))
return data
}
// GetHeader retrieves the block header corresponding to the hash, nil if none
// found.
func GetHeader(db ethdb.Database, hash common.Hash) *types.Header {
data := GetHeaderRLP(db, hash)
if len(data) == 0 {
return nil
}
header := new(types.Header)
if err := rlp.Decode(bytes.NewReader(data), header); err != nil {
glog.V(logger.Error).Infof("invalid block header RLP for hash %x: %v", hash, err)
return nil
}
return header
}
// GetBodyRLP retrieves the block body (transactions and uncles) in RLP encoding.
func GetBodyRLP(db ethdb.Database, hash common.Hash) rlp.RawValue {
data, _ := db.Get(append(append(blockPrefix, hash[:]...), bodySuffix...))
return data
}
// GetBody retrieves the block body (transactons, uncles) corresponding to the
// hash, nil if none found.
func GetBody(db ethdb.Database, hash common.Hash) *types.Body {
data := GetBodyRLP(db, hash)
if len(data) == 0 {
return nil
}
body := new(types.Body)
if err := rlp.Decode(bytes.NewReader(data), body); err != nil {
glog.V(logger.Error).Infof("invalid block body RLP for hash %x: %v", hash, err)
return nil
}
return body
}
// GetTd retrieves a block's total difficulty corresponding to the hash, nil if
// none found.
func GetTd(db ethdb.Database, hash common.Hash) *big.Int {
data, _ := db.Get(append(append(blockPrefix, hash.Bytes()...), tdSuffix...))
if len(data) == 0 {
return nil
}
td := new(big.Int)
if err := rlp.Decode(bytes.NewReader(data), td); err != nil {
glog.V(logger.Error).Infof("invalid block total difficulty RLP for hash %x: %v", hash, err)
return nil
}
return td
}
// GetBlock retrieves an entire block corresponding to the hash, assembling it
// back from the stored header and body.
func GetBlock(db ethdb.Database, hash common.Hash) *types.Block {
// Retrieve the block header and body contents
header := GetHeader(db, hash)
if header == nil {
return nil
}
body := GetBody(db, hash)
if body == nil {
return nil
}
// Reassemble the block and return
return types.NewBlockWithHeader(header).WithBody(body.Transactions, body.Uncles)
}
// WriteCanonicalHash stores the canonical hash for the given block number.
func WriteCanonicalHash(db ethdb.Database, hash common.Hash, number uint64) error {
key := append(blockNumPrefix, big.NewInt(int64(number)).Bytes()...)
if err := db.Put(key, hash.Bytes()); err != nil {
glog.Fatalf("failed to store number to hash mapping into database: %v", err)
return err
}
return nil
}
// WriteHeadHeaderHash stores the head header's hash.
func WriteHeadHeaderHash(db ethdb.Database, hash common.Hash) error {
if err := db.Put(headHeaderKey, hash.Bytes()); err != nil {
glog.Fatalf("failed to store last header's hash into database: %v", err)
return err
}
return nil
}
// WriteHeadBlockHash stores the head block's hash.
func WriteHeadBlockHash(db ethdb.Database, hash common.Hash) error {
if err := db.Put(headBlockKey, hash.Bytes()); err != nil {
glog.Fatalf("failed to store last block's hash into database: %v", err)
return err
}
return nil
}
// WriteHeadFastBlockHash stores the fast head block's hash.
func WriteHeadFastBlockHash(db ethdb.Database, hash common.Hash) error {
if err := db.Put(headFastKey, hash.Bytes()); err != nil {
glog.Fatalf("failed to store last fast block's hash into database: %v", err)
return err
}
return nil
}
// WriteHeader serializes a block header into the database.
func WriteHeader(db ethdb.Database, header *types.Header) error {
data, err := rlp.EncodeToBytes(header)
if err != nil {
return err
}
key := append(append(blockPrefix, header.Hash().Bytes()...), headerSuffix...)
if err := db.Put(key, data); err != nil {
glog.Fatalf("failed to store header into database: %v", err)
return err
}
glog.V(logger.Debug).Infof("stored header #%v [%x…]", header.Number, header.Hash().Bytes()[:4])
return nil
}
// WriteBody serializes the body of a block into the database.
func WriteBody(db ethdb.Database, hash common.Hash, body *types.Body) error {
data, err := rlp.EncodeToBytes(body)
if err != nil {
return err
}
key := append(append(blockPrefix, hash.Bytes()...), bodySuffix...)
if err := db.Put(key, data); err != nil {
glog.Fatalf("failed to store block body into database: %v", err)
return err
}
glog.V(logger.Debug).Infof("stored block body [%x…]", hash.Bytes()[:4])
return nil
}
// WriteTd serializes the total difficulty of a block into the database.
func WriteTd(db ethdb.Database, hash common.Hash, td *big.Int) error {
data, err := rlp.EncodeToBytes(td)
if err != nil {
return err
}
key := append(append(blockPrefix, hash.Bytes()...), tdSuffix...)
if err := db.Put(key, data); err != nil {
glog.Fatalf("failed to store block total difficulty into database: %v", err)
return err
}
glog.V(logger.Debug).Infof("stored block total difficulty [%x…]: %v", hash.Bytes()[:4], td)
return nil
}
// WriteBlock serializes a block into the database, header and body separately.
func WriteBlock(db ethdb.Database, block *types.Block) error {
// Store the body first to retain database consistency
if err := WriteBody(db, block.Hash(), &types.Body{block.Transactions(), block.Uncles()}); err != nil {
return err
}
// Store the header too, signaling full block ownership
if err := WriteHeader(db, block.Header()); err != nil {
return err
}
return nil
}
// DeleteCanonicalHash removes the number to hash canonical mapping.
func DeleteCanonicalHash(db ethdb.Database, number uint64) {
db.Delete(append(blockNumPrefix, big.NewInt(int64(number)).Bytes()...))
}
// DeleteHeader removes all block header data associated with a hash.
func DeleteHeader(db ethdb.Database, hash common.Hash) {
db.Delete(append(append(blockPrefix, hash.Bytes()...), headerSuffix...))
}
// DeleteBody removes all block body data associated with a hash.
func DeleteBody(db ethdb.Database, hash common.Hash) {
db.Delete(append(append(blockPrefix, hash.Bytes()...), bodySuffix...))
}
// DeleteTd removes all block total difficulty data associated with a hash.
func DeleteTd(db ethdb.Database, hash common.Hash) {
db.Delete(append(append(blockPrefix, hash.Bytes()...), tdSuffix...))
}
// DeleteBlock removes all block data associated with a hash.
func DeleteBlock(db ethdb.Database, hash common.Hash) {
DeleteHeader(db, hash)
DeleteBody(db, hash)
DeleteTd(db, hash)
}
// [deprecated by eth/63]
// GetBlockByHashOld returns the old combined block corresponding to the hash
// or nil if not found. This method is only used by the upgrade mechanism to
// access the old combined block representation. It will be dropped after the
// network transitions to eth/63.
func GetBlockByHashOld(db ethdb.Database, hash common.Hash) *types.Block {
data, _ := db.Get(append(blockHashPre, hash[:]...))
if len(data) == 0 {
return nil
}
var block types.StorageBlock
if err := rlp.Decode(bytes.NewReader(data), &block); err != nil {
glog.V(logger.Error).Infof("invalid block RLP for hash %x: %v", hash, err)
return nil
}
return (*types.Block)(&block)
}
// returns a formatted MIP mapped key by adding prefix, canonical number and level
//
// ex. fn(98, 1000) = (prefix || 1000 || 0)
func mipmapKey(num, level uint64) []byte {
lkey := make([]byte, 8)
binary.BigEndian.PutUint64(lkey, level)
key := new(big.Int).SetUint64(num / level * level)
return append(mipmapPre, append(lkey, key.Bytes()...)...)
}
// WriteMapmapBloom writes each address included in the receipts' logs to the
// MIP bloom bin.
func WriteMipmapBloom(db ethdb.Database, number uint64, receipts types.Receipts) error {
batch := db.NewBatch()
for _, level := range MIPMapLevels {
key := mipmapKey(number, level)
bloomDat, _ := db.Get(key)
bloom := types.BytesToBloom(bloomDat)
for _, receipt := range receipts {
for _, log := range receipt.Logs {
bloom.Add(log.Address.Big())
}
}
batch.Put(key, bloom.Bytes())
}
if err := batch.Write(); err != nil {
return fmt.Errorf("mipmap write fail for: %d: %v", number, err)
}
return nil
}
// GetMipmapBloom returns a bloom filter using the number and level as input
// parameters. For available levels see MIPMapLevels.
func GetMipmapBloom(db ethdb.Database, number, level uint64) types.Bloom {
bloomDat, _ := db.Get(mipmapKey(number, level))
return types.BytesToBloom(bloomDat)
}
