github.com/amazechain/amc@v0.1.3/modules/state/plain_state_reader.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 state
    18  
    19  import (
    20  	"bytes"
    21  	"encoding/binary"
    22  	"github.com/amazechain/amc/common/account"
    23  	"github.com/amazechain/amc/common/types"
    24  	"github.com/amazechain/amc/modules"
    25  	"github.com/ledgerwatch/erigon-lib/kv"
    26  )
    27  
    28  var _ StateReader = (*PlainStateReader)(nil)
    29  
    30  // PlainStateReader reads data from so called "plain state".
    31  // Data in the plain state is stored using un-hashed account/storage items
    32  // as opposed to the "normal" state that uses hashes of merkle paths to store items.
    33  type PlainStateReader struct {
    34  	db kv.Getter
    35  }
    36  
    37  func NewPlainStateReader(db kv.Getter) *PlainStateReader {
    38  	return &PlainStateReader{
    39  		db: db,
    40  	}
    41  }
    42  
    43  func (r *PlainStateReader) ReadAccountData(address types.Address) (*account.StateAccount, error) {
    44  	enc, err := r.db.GetOne(modules.Account, address.Bytes())
    45  	if err != nil {
    46  		return nil, err
    47  	}
    48  	if len(enc) == 0 {
    49  		return nil, nil
    50  	}
    51  	var a account.StateAccount
    52  	if err = a.DecodeForStorage(enc); err != nil {
    53  		return nil, err
    54  	}
    55  	return &a, nil
    56  }
    57  
    58  func (r *PlainStateReader) ReadAccountStorage(address types.Address, incarnation uint16, key *types.Hash) ([]byte, error) {
    59  	compositeKey := modules.PlainGenerateCompositeStorageKey(address.Bytes(), incarnation, key.Bytes())
    60  	enc, err := r.db.GetOne(modules.Storage, compositeKey)
    61  	if err != nil {
    62  		return nil, err
    63  	}
    64  	if len(enc) == 0 {
    65  		return nil, nil
    66  	}
    67  	return enc, nil
    68  }
    69  
    70  func (r *PlainStateReader) ReadAccountCode(address types.Address, incarnation uint16, codeHash types.Hash) ([]byte, error) {
    71  	if bytes.Equal(codeHash.Bytes(), emptyCodeHash) {
    72  		return nil, nil
    73  	}
    74  	code, err := r.db.GetOne(modules.Code, codeHash.Bytes())
    75  	if len(code) == 0 {
    76  		return nil, nil
    77  	}
    78  	return code, err
    79  }
    80  
    81  func (r *PlainStateReader) ReadAccountCodeSize(address types.Address, incarnation uint16, codeHash types.Hash) (int, error) {
    82  	code, err := r.ReadAccountCode(address, incarnation, codeHash)
    83  	return len(code), err
    84  }
    85  
    86  func (r *PlainStateReader) ReadAccountIncarnation(address types.Address) (uint16, error) {
    87  	b, err := r.db.GetOne(modules.IncarnationMap, address.Bytes())
    88  	if err != nil {
    89  		return 0, err
    90  	}
    91  	if len(b) == 0 {
    92  		return 0, nil
    93  	}
    94  	return binary.BigEndian.Uint16(b), nil
    95  }