github.com/MetalBlockchain/subnet-evm@v0.6.3/trie/preimages.go (about)

     1  // (c) 2022, Ava Labs, Inc.
     2  //
     3  // This file is a derived work, based on the go-ethereum library whose original
     4  // notices appear below.
     5  //
     6  // It is distributed under a license compatible with the licensing terms of the
     7  // original code from which it is derived.
     8  //
     9  // Much love to the original authors for their work.
    10  // **********
    11  // Copyright 2022 The go-ethereum Authors
    12  // This file is part of the go-ethereum library.
    13  //
    14  // The go-ethereum library is free software: you can redistribute it and/or modify
    15  // it under the terms of the GNU Lesser General Public License as published by
    16  // the Free Software Foundation, either version 3 of the License, or
    17  // (at your option) any later version.
    18  //
    19  // The go-ethereum library is distributed in the hope that it will be useful,
    20  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    21  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    22  // GNU Lesser General Public License for more details.
    23  //
    24  // You should have received a copy of the GNU Lesser General Public License
    25  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    26  
    27  package trie
    28  
    29  import (
    30  	"sync"
    31  
    32  	"github.com/MetalBlockchain/subnet-evm/core/rawdb"
    33  	"github.com/ethereum/go-ethereum/common"
    34  	"github.com/ethereum/go-ethereum/ethdb"
    35  )
    36  
    37  const defaultPreimagesLimit = 4 * 1024 * 1024 // 4 MB
    38  
    39  // preimageStore is the store for caching preimages of node key.
    40  type preimageStore struct {
    41  	lock          sync.RWMutex
    42  	disk          ethdb.KeyValueStore
    43  	preimages     map[common.Hash][]byte // Preimages of nodes from the secure trie
    44  	preimagesSize common.StorageSize     // Storage size of the preimages cache
    45  }
    46  
    47  // newPreimageStore initializes the store for caching preimages.
    48  func newPreimageStore(disk ethdb.KeyValueStore) *preimageStore {
    49  	return &preimageStore{
    50  		disk:      disk,
    51  		preimages: make(map[common.Hash][]byte),
    52  	}
    53  }
    54  
    55  // insertPreimage writes a new trie node pre-image to the memory database if it's
    56  // yet unknown. The method will NOT make a copy of the slice, only use if the
    57  // preimage will NOT be changed later on.
    58  func (store *preimageStore) insertPreimage(preimages map[common.Hash][]byte) {
    59  	store.lock.Lock()
    60  	defer store.lock.Unlock()
    61  
    62  	for hash, preimage := range preimages {
    63  		if _, ok := store.preimages[hash]; ok {
    64  			continue
    65  		}
    66  		store.preimages[hash] = preimage
    67  		store.preimagesSize += common.StorageSize(common.HashLength + len(preimage))
    68  	}
    69  }
    70  
    71  // preimage retrieves a cached trie node pre-image from memory. If it cannot be
    72  // found cached, the method queries the persistent database for the content.
    73  func (store *preimageStore) preimage(hash common.Hash) []byte {
    74  	store.lock.RLock()
    75  	preimage := store.preimages[hash]
    76  	store.lock.RUnlock()
    77  
    78  	if preimage != nil {
    79  		return preimage
    80  	}
    81  	return rawdb.ReadPreimage(store.disk, hash)
    82  }
    83  
    84  // commit flushes the cached preimages into the disk.
    85  func (store *preimageStore) commit(force bool) error {
    86  	store.lock.Lock()
    87  	defer store.lock.Unlock()
    88  
    89  	if store.preimagesSize <= defaultPreimagesLimit && !force {
    90  		return nil
    91  	}
    92  	batch := store.disk.NewBatch()
    93  	rawdb.WritePreimages(batch, store.preimages)
    94  	if err := batch.Write(); err != nil {
    95  		return err
    96  	}
    97  	store.preimages, store.preimagesSize = make(map[common.Hash][]byte), 0
    98  	return nil
    99  }
   100  
   101  // size returns the current storage size of accumulated preimages.
   102  func (store *preimageStore) size() common.StorageSize {
   103  	store.lock.RLock()
   104  	defer store.lock.RUnlock()
   105  
   106  	return store.preimagesSize
   107  }