github.com/amazechain/amc@v0.1.3/modules/changeset/account_changeset.go (about)

     1  // Copyright 2023 The AmazeChain Authors
     2  // This file is part of the AmazeChain library.
     3  //
     4  // The AmazeChain library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The AmazeChain library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the AmazeChain library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package changeset
    18  
    19  import (
    20  	"bytes"
    21  	"encoding/binary"
    22  	"fmt"
    23  	"github.com/amazechain/amc/common/types"
    24  	"github.com/amazechain/amc/modules"
    25  	"sort"
    26  
    27  	"github.com/ledgerwatch/erigon-lib/common/length"
    28  	"github.com/ledgerwatch/erigon-lib/kv"
    29  )
    30  
    31  type Encoder func(blockN uint64, s *ChangeSet, f func(k, v []byte) error) error
    32  type Decoder func(dbKey, dbValue []byte) (blockN uint64, k, v []byte, err error)
    33  
    34  func NewAccountChangeSet() *ChangeSet {
    35  	return &ChangeSet{
    36  		Changes: make([]Change, 0),
    37  		keyLen:  length.Addr,
    38  	}
    39  }
    40  
    41  func EncodeAccounts(blockN uint64, s *ChangeSet, f func(k, v []byte) error) error {
    42  	sort.Sort(s)
    43  	newK := modules.EncodeBlockNumber(blockN)
    44  	for _, cs := range s.Changes {
    45  		newV := make([]byte, len(cs.Key)+len(cs.Value))
    46  		copy(newV, cs.Key)
    47  		copy(newV[len(cs.Key):], cs.Value)
    48  		if err := f(newK, newV); err != nil {
    49  			return err
    50  		}
    51  	}
    52  	return nil
    53  }
    54  
    55  func DecodeAccounts(dbKey, dbValue []byte) (uint64, []byte, []byte, error) {
    56  	blockN := binary.BigEndian.Uint64(dbKey)
    57  	if len(dbValue) < length.Addr {
    58  		return 0, nil, nil, fmt.Errorf("account changes purged for block %d", blockN)
    59  	}
    60  	k := dbValue[:length.Addr]
    61  	v := dbValue[length.Addr:]
    62  	return blockN, k, v, nil
    63  }
    64  
    65  func FindAccount(c kv.CursorDupSort, blockNumber uint64, key []byte) ([]byte, error) {
    66  	k := modules.EncodeBlockNumber(blockNumber)
    67  	v, err := c.SeekBothRange(k, key)
    68  	if err != nil {
    69  		return nil, err
    70  	}
    71  	_, k, v, err = DecodeAccounts(k, v)
    72  	if err != nil {
    73  		return nil, err
    74  	}
    75  	if !bytes.HasPrefix(k, key) {
    76  		return nil, nil
    77  	}
    78  	return v, nil
    79  }
    80  
    81  // GetModifiedAccounts returns a list of addresses that were modified in the block range
    82  // [startNum:endNum)
    83  func GetModifiedAccounts(db kv.Tx, startNum, endNum uint64) ([]types.Address, error) {
    84  	changedAddrs := make(map[types.Address]struct{})
    85  	if err := ForRange(db, modules.AccountChangeSet, startNum, endNum, func(blockN uint64, k, v []byte) error {
    86  		changedAddrs[types.BytesToAddress(k)] = struct{}{}
    87  		return nil
    88  	}); err != nil {
    89  		return nil, err
    90  	}
    91  
    92  	if len(changedAddrs) == 0 {
    93  		return nil, nil
    94  	}
    95  
    96  	idx := 0
    97  	result := make([]types.Address, len(changedAddrs))
    98  	for addr := range changedAddrs {
    99  		copy(result[idx][:], addr[:])
   100  		idx++
   101  	}
   102  
   103  	return result, nil
   104  }