mining/mining.go

   1 // Copyright (c) 2014-2016 The btcsuite developers
   2 // Use of this source code is governed by an ISC
   3 // license that can be found in the LICENSE file.
   4
   5 package mining
   6
   7 import (
   8         "time"
   9
  10         log "github.com/sirupsen/logrus"
  11
  12         "github.com/bytom/blockchain/account"
  13         "github.com/bytom/blockchain/txbuilder"
  14         "github.com/bytom/consensus"
  15         "github.com/bytom/consensus/algorithm"
  16         "github.com/bytom/consensus/difficulty"
  17         "github.com/bytom/errors"
  18         "github.com/bytom/protocol"
  19         "github.com/bytom/protocol/bc"
  20         "github.com/bytom/protocol/bc/legacy"
  21         "github.com/bytom/protocol/state"
  22         "github.com/bytom/protocol/validation"
  23         "github.com/bytom/protocol/vm/vmutil"
  24 )
  25
  26 // createCoinbaseTx returns a coinbase transaction paying an appropriate subsidy
  27 // based on the passed block height to the provided address.  When the address
  28 // is nil, the coinbase transaction will instead be redeemable by anyone.
  29 func createCoinbaseTx(accountManager *account.Manager, amount uint64, blockHeight uint64) (tx *legacy.Tx, err error) {
  30         amount += consensus.BlockSubsidy(blockHeight)
  31         unlockHeight := blockHeight + consensus.CoinbasePendingBlockNumber
  32
  33         var script []byte
  34         if accountManager == nil {
  35                 script, err = vmutil.CoinbaseProgram(nil, 0, unlockHeight)
  36         } else {
  37                 script, err = accountManager.GetCoinbaseControlProgram(unlockHeight)
  38         }
  39         if err != nil {
  40                 return
  41         }
  42
  43         builder := txbuilder.NewBuilder(time.Now())
  44         if err = builder.AddInput(legacy.NewCoinbaseInput([]byte(string(blockHeight)), nil), &txbuilder.SigningInstruction{}); err != nil {
  45                 return
  46         }
  47         if err = builder.AddOutput(legacy.NewTxOutput(*consensus.BTMAssetID, amount, script, nil)); err != nil {
  48                 return
  49         }
  50         _, txData, err := builder.Build()
  51         if err != nil {
  52                 return
  53         }
  54
  55         tx = &legacy.Tx{
  56                 TxData: *txData,
  57                 Tx:     legacy.MapTx(txData),
  58         }
  59         return
  60 }
  61
  62 // NewBlockTemplate returns a new block template that is ready to be solved
  63 func NewBlockTemplate(c *protocol.Chain, txPool *protocol.TxPool, accountManager *account.Manager) (*legacy.Block, error) {
  64         // Extend the most recently known best block.
  65         var err error
  66         preBlock := c.BestBlock()
  67         view := state.NewUtxoViewpoint()
  68
  69         preBcBlock := legacy.MapBlock(preBlock)
  70         nextBlockHeight := preBlock.BlockHeader.Height + 1
  71         nextBlockSeed := algorithm.CreateSeed(nextBlockHeight, preBcBlock.Seed, []*bc.Hash{&preBcBlock.ID})
  72         txDescs := txPool.GetTransactions()
  73         txEntries := make([]*bc.Tx, 0, len(txDescs))
  74         blockWeight := uint64(0)
  75         txFee := uint64(0)
  76
  77         var compareDiffBH *legacy.BlockHeader
  78         if compareDiffBlock, err := c.GetBlockByHeight(nextBlockHeight - consensus.BlocksPerRetarget); err == nil {
  79                 compareDiffBH = &compareDiffBlock.BlockHeader
  80         }
  81
  82         b := &legacy.Block{
  83                 BlockHeader: legacy.BlockHeader{
  84                         Version:           1,
  85                         Height:            nextBlockHeight,
  86                         PreviousBlockHash: preBlock.Hash(),
  87                         Seed:              *nextBlockSeed,
  88                         TimestampMS:       bc.Millis(time.Now()),
  89                         BlockCommitment:   legacy.BlockCommitment{},
  90                         Bits:              difficulty.CalcNextRequiredDifficulty(&preBlock.BlockHeader, compareDiffBH),
  91                 },
  92                 Transactions: make([]*legacy.Tx, 0, len(txDescs)),
  93         }
  94
  95         appendTx := func(tx *legacy.Tx, weight, fee uint64) {
  96                 b.Transactions = append([]*legacy.Tx{tx}, b.Transactions...)
  97                 txEntries = append([]*bc.Tx{tx.Tx}, txEntries...)
  98                 blockWeight += weight
  99                 txFee += fee
 100         }
 101
 102         bcBlock := legacy.MapBlock(b)
 103         for _, txDesc := range txDescs {
 104                 tx := txDesc.Tx.Tx
 105                 if blockWeight+txDesc.Weight > consensus.MaxBlockSzie-consensus.MaxTxSize {
 106                         break
 107                 }
 108                 if err := c.GetTransactionsUtxo(view, []*bc.Tx{tx}); err != nil {
 109                         log.WithField("error", err).Error("mining block generate skip tx due to")
 110                         txPool.RemoveTransaction(&tx.ID)
 111                         continue
 112                 }
 113                 if err := view.ApplyTransaction(bcBlock, tx); err != nil {
 114                         log.WithField("error", err).Error("mining block generate skip tx due to")
 115                         txPool.RemoveTransaction(&tx.ID)
 116                         continue
 117                 }
 118                 if _, err := validation.ValidateTx(tx, preBcBlock); err != nil {
 119                         log.WithField("error", err).Error("mining block generate skip tx due to")
 120                         txPool.RemoveTransaction(&tx.ID)
 121                         continue
 122                 }
 123
 124                 appendTx(txDesc.Tx, txDesc.Weight, txDesc.Fee)
 125         }
 126
 127         cbTx, err := createCoinbaseTx(accountManager, txFee, nextBlockHeight)
 128         if err != nil {
 129                 return nil, errors.Wrap(err, "fail on createCoinbaseTx")
 130         }
 131         appendTx(cbTx, 0, 0)
 132
 133         b.BlockHeader.BlockCommitment.TransactionsMerkleRoot, err = bc.MerkleRoot(txEntries)
 134         if err != nil {
 135                 return nil, errors.Wrap(err, "calculating tx merkle root")
 136         }
 137
 138         return b, nil
 139 }